Regulatory Guide 8.36: Difference between revisions

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{{#Wiki_filter:U.S. NUCLEAR REGULATORY COMMISSION                                                                    July 1992 REGULATORY (3UIDE
                                    OFFICE OF NUCLEAR REGULATORY RESEARCH
                                                          REGULATORY GUIDE 8.36 (Draft was issued as DG-8011)
                                            RADIATION DOSE TO THE EMBRYO/FETUS


==A. INTRODUCTION==
==A. INTRODUCTION==
Section 20.1208 of 10 CFR Part 20, "Standards for Protection Against Radiation," requires that each licensee ensure that the dose to an embryo/fetus dur ing the entire pregnancy, from occupational exposure of a declared pregnant woman, does not exceed 0.5 rem (5 mSv). Paragraph
20.1208(b)
requires the li censee to make efforts to avoid substantial variation above a uniform monthly exposure rate to a declared pregnant woman that would satisfy the 0.5 rem (5 mSv) limit. The dose to the embryo/fetus is to be the sum of (1) the deep-dose equivalent to the declared pregnant woman (10 CFR 20.1208(c)(1))
and (2) he dose to the embryo/fetus from radionuclides in ne embryo/fetus and radionuclides in the declared pregnant woman (10 CFR 20.1208(c)(2)). 
This guide is being developed to provide guidance on calculating the radiation dose to the embryo/fetus.


Regulatory Guide 8.13, "Instruction Concerning Pre natal Radiation Exposure," provides instructions con cerning the risks associated with prenatal radiation exposure.
==B. DISCUSSION==
Calculating the radiation dose to the embryo/fe Section 20.1208 of 10 CFR Part 20, "Standards tus from internally deposited radionuclides requires for Protection Against Radiation," requires that each quantitative information about maternal radionuclide licensee ensure that the dose to an embryo/fetus dur intake, placental transfer and kinetics, and resulting ing the entire pregnancy, from occupational exposure embryo/fetus radionuclide concentrations. Intakes of of a declared pregnant woman, does not exceed 0.5 radioactive material occurring prior to the pregnancy rem (5 mSv). Paragraph 20.1208(b) requires the li may also be important if these materials remain in the censee to make efforts to avoid substantial variation pregnant woman during all or part of the gestation above a uniform monthly exposure rate to a declared period. Transfer kinetics from the mother to the em pregnant woman that would satisfy the 0.5 rem (5 bryo/fetus are modeled as a function of stage of preg mSv) limit. The dose to the embryo/fetus is to be the nancy, route of intake by the pregnant woman, and sum of (1) the deep-dose equivalent to the declared time after intake. The stage of gestation (or fetal de pregnant woman (10 CFR 20.1208(c)(1)) and (2)
                                                                                velopment) is an important parameter in estimating he dose to the embryo/fetus from radionuclides in radionuclide concentrations in the embryo/fetus. The ne embryo/fetus and radionuclides in the declared geometry of the embryo/fetus (i.e., size and weight)
pregnant woman (10 CFR 20.1208(c)(2)).
                                                                                affects the radionuclide dosimetry.


Any information collection activities mentioned in this regulatory guide are contained as requirements in 10 CFR Part 20, which provides the regulatory ba sis for this guide. The information collection require ments in 10 CFR Part 20 have been cleared under OMB Clearance No. 3150-0014.
This guide is being developed to provide guidance                            It is recognized that calculation of prenatal radia on calculating the radiation dose to the embryo/fetus.                          tion doses from internally deposited radionuclides has Regulatory Guide 8.13, "Instruction Concerning Pre                              many associated difficulties, including a lack of quan natal Radiation Exposure," provides instructions con                            titative information about prenatal radionuclide con cerning the risks associated with prenatal radiation                            centrations and transfer across the placenta. The In exposure.                                                                      ternational Commission on Radiological Protection (ICRP) in Publication 56 (Ref. 1) states that, for most radionuclides, preliminary estimates from dosimetric Any information collection activities mentioned                         and biokinetic models indicate that the dose to the in this regulatory guide are contained as requirements embryo can be approximated by the dose to the in 10 CFR Part 20, which provides the regulatory ba                             uterus. The dose to the fetus is dependent upon the sis for this guide. The information collection require activity present in both fetal and maternal tissues.


USNRC REGULATORY  
ments in 10 CFR Part 20 have been cleared under                                ICRP Publication 56 (Ref. 1) also states that, for most OMB Clearance No. 3150-0014.                                                  radionuclides, the dose to fetal tissue will be similar to USNRC REGULATORY GUIDES                                The guides are issued In the following ten broad divisions:
GUIDES Regulatory Guides are issued to describe and make available to the pub lic methods acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate techniques used by the staff In evaluating specific problems or postulated accidents, or to pro vide guidance to applicants.
Regulatory Guides are issued to describe and make available to the pub lic methods acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate techniques used by the         1.  Power Reactors staff In evaluating specific problems or postulated accidents, or to pro                                          


Regulatory Guides are not substitutes for regulations, and compliance with them is not required.
===6. Products===
                                                                              2.  Research and Test Reactors        7. Transportation vide guidance to applicants. Regulatory Guides are not substitutes for       3.  Fuels and Materials Facilities regulations, and compliance with them is not required. Methods and                                                 


Methods and solutions different from those set out in the guides will be acceptable If they provide a basis for the findings requisite to the issuance or continu ance of a permit or license by the Commission.
===8. Occupational Health===
                                                                              4.  Environmental and Siting          9. Antitrust and Financial Review solutions different from those set out in the guides will be acceptable If   5. Materials and Plant Protection    10. General they provide a basis for the findings requisite to the issuance or continu ance of a permit or license by the Commission.


This guide was issued after consideration of comments received from the public. Comments and suggestions for improvements in these guides are encouraged at all times, and guides will be revised, as ap oropriate, to accommodate comments and to reflect new information or "xperience.
This guide was issued after consideration of comments received from          Copies of Issued guides may be purchased from the Government Printing the public. Comments and suggestions for improvements in these               Office at the current GPO price. Information on current GPO prices may guides are encouraged at all times, and guides will be revised, as ap         be obtained by contacting the Superintendent of Documents, U.S.


Vritten comments may be submitted to the Regulatory Publications Branch, DFIPS, ADM, U.S. Nuclear Regulatory Commission, Washing ton, DC 20555.July 1992 3UIDE
oropriate, to accommodate comments and to reflect new information or          Government Printing Office, Post Office Box 37082, Washington, DC
                                                                              20013-7082, telephone (202)275-2060 or (202)275-2171.


==B. DISCUSSION==
"xperience.
Calculating the radiation dose to the embryo/fe tus from internally deposited radionuclides requires quantitative information about maternal radionuclide intake, placental transfer and kinetics, and resulting embryo/fetus radionuclide concentrations.
 
Vritten comments may be submitted to the Regulatory Publications Branch, DFIPS, ADM, U.S. Nuclear Regulatory Commission, Washing              Issued guides may also be purchased from the National Technical Infor ton, DC 20555.                                                                mation Service on a standing order basis. Details on this service may be obtained by writing NTIS, 5285 Port Royal Road, Springfield, VA 22161.
 
similar to or less than the dose to the corresponding                A graded approach for determining when to maternal tissues.                                              evaluate, with both a simple and more detailed dose assessment methodology, is provided. Both methods The current methods available for assessing the            are acceptable for evaluating the dose to the embryo/
  radiation dose to the human embryo/fetus from inter            fetus. It is recognized that some licensees will only nally deposited radioactive materials in the pregnant          need to demonstrate that the dose to the embryo/fe woman are subject to a number of uncertainties.                tus is not likely to exceed the 0.05 rem (0.5 mSv)
  Revison 1 to NUREG/CR-5631, "Contribution of                  monitoring threshold of 10 CFR 20.1502, while other Maternal Radionuclide Burdens to Prenatal Radiation            licensees may need to determine an embryo/fetus Doses-Interim Recommendations" (Ref. 2), pro                  dose for demonstrating compliance with the dose limit vides recommendations and methods for estimating              of 10 CFR 20.1208 and the recordkeeping require the radiation doses to the embryo/fetus from internal          ments of 10 CFR 20.2106(e).
radionuclides. In Revision 1 to NUREG/CR-5631, a Appendix A provides information on and a table number of radionuclides were evaluated. To expedite of dose equivalent factors for use in approximating efforts, the initial evaluation was directed to those the embryo/fetus dose from radionuclides in maternal radionuclides that were expected to be of greatest sig blood. Appendix B is a table of blood uptake frac nificance for prenatal exposure in the work environ tions for ingested activity. Appendix C contains tables ment. The radionuclides that were identified and in of gestation-time dependent doses to the embryo/fe cluded were 3H, 14C, 57Co, 58Co, 6OCo, 8 9Sr, 90Sr,
106 Ru, 1251, 1311, 1321, 133I, 1341, 1351, 134 CS, 137CS,      tus following introduction of specified radionuclides
2 3 U, M4U, 23U, 238U, 23 8Pu, 239Pu, and 24 1Am. The          and chemical forms into maternal blood. Examples of the use of dose assessment methods are provided in methods of Revision 1 to NUREG/CR-5631 are con Appendix D.
 
sidered interim as efforts continue to further develop the bases and calculational methods for estimating                  The total radiation dose to the embryo/fetus is prenatal radiation doses. Revision 1 to NUREG/                  the sum of the deep-dose equivalent to the declared CR-5631 provides details of the data and bases for              pregnant worker and the dose to the embryo/fetus the dosimetric features that were used for the radi            from intakes of the declared pregnant worker. If mul onuclides listed above.                                        tiple dosimetric devices are used to measure the deep-dose equivalent to the declared pregnant It is expected that the embryo/fetus dose assess          worker, the results of monitoring that are most repre ment methods will evolve over the next several years            sentative of the deep dose to the embryo/fetus may be as more research is conducted in this area. As addi            used. The licensee need not use the deep dose to the tional research is conducted, better estimates of ac          maximally exposed portion of the whole body of the tual embryo/fetus doses resulting from the exposure            mother as the deep dose to the embryo/fetus. The of the declared pregnant woman will be possible. For          licensee may employ temporary or permanent shield internal doses, research that categorizes the degree of        ing to reduce the deep dose to the embryo/fetus. Al placental transfer, the resulting embryo/fetus/placenta        ternatively, deep dose to the embryo/fetus may be concentrations, and the potential radiation exposures          limited by placing more stringent restrictions on the of the embryo/fetus from radionuclides in their more          exposure of the declared pregnant woman than on usual chemical forms should simplify assessment of              other members of the occupational work force.
 
the dose to the embryo/fetus based on the maternal                    As specified in 10 CFR 20.1208(a), the dose to exposure. The ICRP is considering the formulation of            the embryo/fetus from occupational exposure of the dose assessment methods specific for the embryo/                declared pregnant woman during the entire gestation fetus.                                                          period is not to exceed 0.5 rem (5 mSv). In addition, the licensee is required to make efforts to avoid sub This regulatory guide provides acceptable meth            stantial variation in the monthly exposure throughout ods that may be used in determining the dose to the            the period of gestation. If the dose to the embryo/fe embryo/fetus. For internal exposure, a simplified ap            tus is found to have exceeded 0.5 rem (5 mSv) or is proach and a more detailed methodology are pre                  within 0.05 rem (0.5 mSv) of this dose by the time sented for conducting dose evaluations. The regula              the woman declares the pregnancy to the licensee, tory position specified in Section 1 provides guidance          the licensee is required to limit the additional dose to on the threshold criteria for use in determining when          the embryo/fetus to 0.05 rem (0.5 mSv) during the the dose to the embryo/fetus needs to be evaluated.            remainder of the pregnancy.
 
The regulatory position specified in Section 2 presents The tables in the appendices to this guide were a simplified approach for estimating the dose to the          prepared directly from the computer outputs, which embryo/fetus from intakes by the declared pregnant              led to the values generally being expressed to three woman. The regulatory position specified in Section 3          significant figures. This indicates greater accuracy provides an alternative, more detailed methodology than is warranted by the dosimetry model, but the for a limited number of radionuclides, using the gesta          results are presented in this form to avoid roundoff tion-time dependent dosimetric data from Revision 1            errors in calculations. In general, final results should to NUREG/CR-5631 (Ref. 2).                                    be rounded to the nearest thousandth of a rem.


Intakes of radioactive material occurring prior to the pregnancy may also be important if these materials remain in the pregnant woman during all or part of the gestation period. Transfer kinetics from the mother to the em bryo/fetus are modeled as a function of stage of preg nancy, route of intake by the pregnant woman, and time after intake. The stage of gestation (or fetal de velopment)
8.36-2
is an important parameter in estimating radionuclide concentrations in the embryo/fetus.


The geometry of the embryo/fetus (i.e., size and weight) affects the radionuclide dosimetry.
==C. REGULATORY POSITION==
1.3    External Dose to the Embryo/Fetus According to 10 CFR 20.1208(c)(1), the deep CRITERIA FOR DETERMINING DOSE TO
                                                                dose equivalent to the declared pregnant woman will THE EMBRYO/FETUS
                                                                be taken as the external dose component to the em bryo/fetus. The determination of external dose
  1.1    Monitoring                                            should consider all occupational exposures of the de clared pregnant woman since the estimated date of The dose equivalent to the embryo/fetus should        conception. The deep-dose equivalent that should be be determined based on the monitoring of the de                assigned is that dose that would be most representa clared pregnant woman as required by 10 CFR                  tive of the exposure of the embryo/fetus (i.e., in the
20.1502. Specifically, 10 CFR 20.1502(a)(2) re                mother's lower torso region). If multiple measure quires monitoring the exposure of a declared preg            ments have been made, assignment of the highest nant woman when the dose to the embryo/fetus is              deep-dose equivalent for the declared pregnant likely to exceed, in 1 year, a dose from external            woman to the embryo/fetus is not required unless that sources in excess of 10% of the limit of 10 CFR              dose is also the most representative deep-dose equiva
20.1208 (i.e., 0.05 rem). According to 10 CFR                lent for the region of the embryo/fetus.


It is recognized that calculation of prenatal radia tion doses from internally deposited radionuclides has many associated difficulties, including a lack of quan titative information about prenatal radionuclide con centrations and transfer across the placenta.
20.1502(b)(2), the licensee must monitor the occu pational intakes of radioactive material for the de            1.4  Internal Dose to the Embryo/Fetus clared pregnant woman if her intake is likely to ex ceed, in 1 year, a committed effective dose equivalent            The internal dose to the embryo/fetus should in excess of 0.05 rem (0.5 mSv). Based on this 0.05          consider the exposure to the embryo/fetus from radi rem (0.5 mSv) threshold, the dose to the embryo/fe            onuclides in the declared pregnant woman and in the tus should be determined if the intake is likely to ex        embryo/fetus. The dose to the embryo/fetus should ceed 1% of ALI (stochastic) during the entire period          include the contribution from any radionuclides in of gestation.                                                the declared pregnant woman (body burden) from occupational intakes occurring prior to conception.


The In ternational Commission on Radiological Protection (ICRP) in Publication
These monitoring thresholds will ensure that any      The intake for the declared pregnant woman should potentially significant exposures to the embryo/fetus          be determined using air sample data, bioassay data, are evaluated and, as appropriate, doses are deter            or a combination of the tw
56 (Ref. 1) states that, for most radionuclides, preliminary estimates from dosimetric and biokinetic models indicate that the dose to the embryo can be approximated by the dose to the uterus. The dose to the fetus is dependent upon the activity present in both fetal and maternal tissues.


ICRP Publication
====o. Guidance on bioassay====
56 (Ref. 1) also states that, for most radionuclides, the dose to fetal tissue will be similar to The guides are issued In the following ten broad divisions:
  ,ined. The conditions specified in 10 CFR                  measurements used to quantify intake is being devel
1. Power Reactors 2. Research and Test Reactors 3. Fuels and Materials Facilities
    .1502(a) and (b) are based on a 1-yeir period.           oped and has been issued for public comment as n-rior to declaration of pregnancy, the woman may          Draft Regulatory Guide DG-8009, "Interpretation of not have been subject to monitoring based on condi            Bioassay Measurements."        Specific guidance on tions specified in 10 CFR 20.1502(a) (1) and 10 CFR            workplace air sampling is in Revision 1 to Regulatory
4. Environmental and Siting 5. Materials and Plant Protection
20.1502(b)(1). In this case, the licensee should esti          Guide 8.25, "Air Sampling in the Workplace."
6. Products
mate the exposure during the period monitoring was not provided, using any combination of surveys or              1.5   Evaluating Continuous Exposure other available data (for example, air monitoring,                  For continuous or near-continuous exposure to area monitoring, bioassay).                                   radioactive material that may be inhaled or ingested, the cumulative intake should be quantified and the The monitoring criteria contained in 10 CFR            dose determined at least every 30 day


===7. Transportation ===
====s. If significant====
8. Occupational Health 9. Antitrust and Financial Review 10. General Copies of Issued guides may be purchased from the Government Printing Office at the current GPO price. Information on current GPO prices may be obtained by contacting the Superintendent of Documents, U.S.  Government Printing Office, Post Office Box 37082, Washington, DC 20013-7082, telephone
20.1502 do not establish required levels of detection        variation in the exposure levels may have occurred, sensitivity. For some radionuclides it may not be fea        the time interval for quantifying the intake should be sible to actually confirm by bioassay measurements an        reduced. More frequent evaluations should be con intake of 1% of their stochastic ALI. Workplace              sidered as the potential dose to the embryo/fetus ap monitoring, occupancy factors, and access control            proaches the limit.
(202)275-2060
or (202)275-2171.


Issued guides may also be purchased from the National Technical Infor mation Service on a standing order basis. Details on this service may be obtained by writing NTIS, 5285 Port Royal Road, Springfield, VA 22161.U.S. NUCLEAR REGULATORY
should be considered as appropriate in evaluating po tential exposures and monitoring requirements.                1.6  Existing Maternal Body Burdens Maternal body burdens resulting from internal
COMMISSION
1.2      Evaluation of Dose to the Embryo/Fetus occupational exposures prior to conception should be included in determining the embryo/fetus dose. The The appropriate dose to be evaluated for the em      contribution to the embryo/fetus dose from a mater bryo/fetus is the dose equivalent for the duration of        nal burden existing at the time of conception should the pregnancy. An assessment of the 50-year commit            be evaluated if the maternal burden at the time of ted dose is not appropriate. Also, it is not appropriate      pregnancy exceeds 1% of the radionuclide's stochas to use effective dose equivalent or committed effec          tic ALI value for the appropriate mode of intake and
REGULATORY ( OFFICE OF NUCLEAR REGULATORY
"A:e dose equivalent. (Note: the committed dose class (for inhalation intakes). For multiple radio
RESEARCH REGULATORY
    .iivalent to the uterus may be applied to the            nuclide burdens, the dose should be evaluated if the
GUIDE 8.36 (Draft was issued as DG-8011) RADIATION
-. nbryo/fetus under certain conditions as a simplified      sum of the quotients of each burden divided by its approach as described in the regulatory position              stochastic ALI exceeds 0.01. Only body burdens ex specified in Section 2.)                                     isting at the time of conception need to be considered
DOSE TO THE EMBRYO/FETUS
                                                        8.36-3
similar to or less than the dose to the corresponding maternal tissues.


The current methods available for assessing the radiation dose to the human embryo/fetus from inter nally deposited radioactive materials in the pregnant woman are subject to a number of uncertainties.
in evaluating this threshold; radioactive material al              cantly different from a 9-month gestation dose ready eliminated from the body should not be in                      equivalent to the embryo/fetus. Several radionuclides cluded.                                                            of this type have been evaluated in Revision 1 to NUREG/CR-5631 (Ref. 2), and data have been de This threshold of 1% ALl provides a simplified approach for determining when pre-existing body                      veloped for calculating an embryo/fetus gestation burdens should be evaluated. At this threshold, it is                dose instead of using the committed dose equivalent to the uterus.


Revison 1 to NUREG/CR-5631, "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Doses-Interim Recommendations" (Ref. 2), pro vides recommendations and methods for estimating the radiation doses to the embryo/fetus from internal radionuclides.
unlikely that any resultant dose to the embryo/fetus would be significant (i.e., greater than 10% of the 0.5                    For demonstrating compliance with the dose lim rem (5 mSv) limit). As an alternative, the dose as                  its of 10 CFR 20.1208, the dose factors in Appendix sessment methods presented in the regulatory position              *A may be used for approximating the embryo/fetus specified in Section 3 of this guide may be used for                dose equivalent for the entire gestation period.


In Revision 1 to NUREG/CR-5631, a number of radionuclides were evaluated.
determining whether a pre-existing body burden rep resents a potentially significant dose (i.e., greater                      The steps for determining the embryo/fetus dose, than 0.05 rem (0.5 mSv)).                                            using the simplified method, are as follows:
  2.    SIMPLIFIED METHOD FOR                                                2.1 Include all the intakes by the declared preg DETERMINING EMBRYO/FETUS                                      nant woman at any time during the gestation period in DOSE FROM MATERNAL INTAKES                                    the calculation of the embryo/fetus dose.


To expedite efforts, the initial evaluation was directed to those radionuclides that were expected to be of greatest sig nificance for prenatal exposure in the work environ ment. The radionuclides that were identified and in cluded were 3 H, 14C, 5 7 Co, 5 8 Co, 6OCo, 8 9 Sr, 9 0 Sr, 10 6 Ru, 1251, 1311, 1321, 133I, 1341, 1351, 1 3 4 CS, 1 3 7 CS, 2 3 U, M4U, 23U, 2 3 8 U, 2 3 8 Pu, 239Pu, and 2 4 1 Am. The methods of Revision 1 to NUREG/CR-5631 are con sidered interim as efforts continue to further develop the bases and calculational methods for estimating prenatal radiation doses. Revision 1 to NUREG/ CR-5631 provides details of the data and bases for the dosimetric features that were used for the radi onuclides listed above. It is expected that the embryo/fetus dose assess ment methods will evolve over the next several years as more research is conducted in this area. As addi tional research is conducted, better estimates of ac tual embryo/fetus doses resulting from the exposure of the declared pregnant woman will be possible.
The determination of the dose to the embryo/fe                      2.2 For ingested radionuclides, determine the tus from the intake of radioactive material by the                    activity uptake by the first transfer compartment pregnant woman should be based on the best avail                      (blood) by multiplying the intake (1) by the appropri able scientific data. At present, the NRC staff consid                ate uptake factor (fl) from Appendix B (adapted ers Revision 1 to NUREG/CR-5631 (Ref. 2) to pro                      from Federal Guidance Report No. 11, Table 3 (Ref.


For internal doses, research that categorizes the degree of placental transfer, the resulting embryo/fetus/placenta concentrations, and the potential radiation exposures of the embryo/fetus from radionuclides in their more usual chemical forms should simplify assessment of the dose to the embryo/fetus based on the maternal exposure.
vide such data. For most radionuclides, the dose to                  4)). The uptake factor, fl, is the fraction of an in the embryo/fetus will be similar to or less than the                  gested compound of a radionuclide that is transferred dose to the maternal uterus (Ref. 1). However, the                    into the first transfer compartment (i.e., blood uptake data in Revision I to NUREG/CR-5631 indicate that                    fraction).
for some radionuclides the embryo/fetus dose may be significantly different, either greater than or less than                    2.3 For inhaled radionuclides, determining the the dose to the uterus.                                              fraction of initial intake that is transferred to the blood involves an evaluation of the deposition in the Based on these premises (uterus dose similar to              three compartments of the lung and the subsequent fetal dose and the data in Revision 1 to NUREG/                       time-dependent transfer to the body fluids and to the CR-5631 (Ref. 2)), a set of dose factors has been                    GI tract. Unless it is known otherwise, it should be developed for use in calculating an embryo/fetus                     assumed that the transfer from the lung to body fluids dose. Except for those radionuclides addressed in                    and from lung to GI tract to body fluids follows the Revision 1 to NUREG/CR-5631 (Ref. 2), the dose                        ICRP 30 (Ref. 3) modeling (which is the basis for this factors presented in Appendix A to this guide repre                  guide).
sent the committed dose equivalent to the uterus per introduction of unit activity into the first transfer                      2.4 For simplicity and conservatism in the mod compartment (i.e., blood) of the woman.' For the                      eling, the total uptake into the blood from the mater radionuclides in Revision 1 to NUREG/CR-5631, the                    nal intake is assumed to be instantaneous. However, dose factors in Appendix A represent the maximum                      for radionuclides with lung clearance class of W (10
dose equivalent to the embryo/fetus for the gestation                to 100-day half-life clearance) or Y (greater than period from the introduction of unit activity into the                100-day half-life clearance), the actual translocation first transfer compartment of the woman at any time                  from the lung and uptake in the blood may occur during the gestation period.                                          over a time period that exceeds the gestation period.


The ICRP is considering the formulation of dose assessment methods specific for the embryo/ fetus.  This regulatory guide provides acceptable meth ods that may be used in determining the dose to the embryo/fetus.
Clearance from the lung may take up to several years.


For internal exposure, a simplified ap proach and a more detailed methodology are pre sented for conducting dose evaluations.
The dose limit for the embryo/fetus is expressed              All the initially deposited material is not immediately as a 9-month gestation dose equivalent. Particularly                available for uptake by the first transfer compartment for certain radionuclides with both long radiological                (blood). However, an incremental transfer from the half-lives and long-term biological retention, the com              lung to the blood may be assessed based on the lung mitted dose equivalent to the uterus may be signifi                  model as described in ICRP Publications 30 and 19 (Refs. 3 and 5).2
'The committed dose equivalent factors for the uterus pre sented in Appendix A were calculated based on the modeling              Table 1, adapted from the data in Figure 5.2 of employed during the development of the ICRP 30 (Ref. 3)          ICRP 30 (Ref. 3), may be used for determining the data. It is recognized that the metabolism of the pregnant woman may not be adequately represented by the standard          total transfer from the lung to the first transfer metabolic model. However, partly because of the lack of          2As modeled in ICRP Publications 19 and 30, the clearance more definitive data, this modeling has been used for deter        from the different lung compartments is assumed to follow mining the dose commitment factors for the uterus that may          first-order kinetics. This approach is complex, involving in be used for evaluating compliance with the embryo/fetus            terlinking differential equations, and is considered outside the dose limit.                                                        scope of a routine operational health physics program.


The regula tory position specified in Section 1 provides guidance on the threshold criteria for use in determining when the dose to the embryo/fetus needs to be evaluated.
8.36-4


The regulatory position specified in Section 2 presents a simplified approach for estimating the dose to the embryo/fetus from intakes by the declared pregnant woman. The regulatory position specified in Section 3 provides an alternative, more detailed methodology for a limited number of radionuclides, using the gesta tion-time dependent dosimetric data from Revision 1 to NUREG/CR-5631 (Ref. 2).A graded approach for determining when to evaluate, with both a simple and more detailed dose assessment methodology, is provided.
compartment (i.e., blood), where f, is the blood up take fraction from Appendix B.3 The lung clearance                              inhaled activity of radionuclide i that enters class (D, W, or Y) for a particular chemical form of a                          the blood, see Table 1 of this guide)
    )articular radionuclide may be obtained from Appen                        2.6 For pre-existing body burdens, the total bur dix B to 10 CFR 20.1001-20.2401.                                      den determined to exist at time of pregnancy should be assumed to be available for uptake in the blood of Table 1                                  the woman. The dose should be assigned to the em Transfer Fraction of Inhaled Activity                        bryo/fetus as if the maternal blood uptake occurs to First Transfer Compartment                            within the first month of pregnancy. The embryo/fe tus dose is calculated by multiplying the maternal bur Class          Transfer Fraction (TF)                    den of the radionuclide by its dose factor from Ap pendix A using the equation:
                  D                  0.48 + 0.15 f, DE =        AiAxDFi              (Equation 3)
                  W                  0.12 + 0.51 f, where:
                  Y                  0.05 + 0.58 f, DE = dose equivalent to the embryo/fetus Al = maternal burden existing at time of preg
        2.5 Based on the determination of the maternal                            nancy (ACi)
  intake, the dose to the embryo/fetus for the entire                  DFi = dose conversion factor (Appendix A)
  gestation period should be calculated using the follow ing equations:                                                              This method provides a simplified and conserva tive approach for evaluating the significance of pre For ingestion intakes:
                                                                        existing conditions. If the embryo/fetus is likely to re DE =      I1ixf 1 ,ixDFi                              ceive a dose in excess of 25% of the limit from pre (Equation 1)
                                                                        existing burdens (i.e., greater than 0.125 rem (1.25 For inhalation intakes:                                      mSv)),4 more detailed modeling should be consid ered.


Both methods are acceptable for evaluating the dose to the embryo/ fetus. It is recognized that some licensees will only need to demonstrate that the dose to the embryo/fe tus is not likely to exceed the 0.05 rem (0.5 mSv) monitoring threshold of 10 CFR 20.1502, while other licensees may need to determine an embryo/fetus dose for demonstrating compliance with the dose limit of 10 CFR 20.1208 and the recordkeeping require ments of 10 CFR 20.2106(e). 
DE = 2 Ii x TFi x DFj            (Equation 2)
Appendix A provides information on and a table of dose equivalent factors for use in approximating the embryo/fetus dose from radionuclides in maternal blood. Appendix B is a table of blood uptake frac tions for ingested activity.
                                                                              2.7 Doses from multiple nuclides or multiple in here:                                                              takes should be evaluated on a frequency correspond ing to the determination of the intake. Multiple dose DE    =  dose equivalent to the embryo/fetus for the                 determinations should be added to determine the to entire gestation period from the acute intakes            tal dose. Doses may need to be reevaluated if better of all radionuclides during the gestation                  estimates of intakes are provided by followup bioassay period (rem)                                               measurements.


Appendix C contains tables of gestation-time dependent doses to the embryo/fe tus following introduction of specified radionuclides and chemical forms into maternal blood. Examples of the use of dose assessment methods are provided in Appendix D.  The total radiation dose to the embryo/fetus is the sum of the deep-dose equivalent to the declared pregnant worker and the dose to the embryo/fetus from intakes of the declared pregnant worker. If mul tiple dosimetric devices are used to measure the deep-dose equivalent to the declared pregnant worker, the results of monitoring that are most repre sentative of the deep dose to the embryo/fetus may be used. The licensee need not use the deep dose to the maximally exposed portion of the whole body of the mother as the deep dose to the embryo/fetus.
=  intake of radionuclide i by the declared preg              3.    DETERMINING GESTATION-TIME
            nant woman at any time during the gestation                      DEPENDENT DOSE TO THE
            period (gCi)                                                    EMBRYO/FETUS USING REVISION 1 TO
  DFi  =    dose factor for use in approximating the dose                   NUREG/CR-5631 METHODS
            equivalent to the embryo/fetus for the entire gestation period from the introduction of unit                  As an alternative to the simplified methods pre activity (1 jiCi) into the, 'maternal blood at            sented above, a gestation-time dependent dose to the any time during the gestation period, from                embryo/fetus may be calculated for the radionuclides tabular data presented in Appendix A to this              addressed in Revision I to NUREG/CR-5631 (Ref.


The licensee may employ temporary or permanent shield ing to reduce the deep dose to the embryo/fetus.
guide (rem/RCi in maternal blood)                          2). Revision 1 to NUREG/CR-5631 presents dosimetric methods for calculating the dose to the fl,    =    the fraction of radionuclide i reaching the body fluids following ingestion (i.e., the frac            4 This approach for evaluating pre-existing body burdens does tion of ingested activity of radionuclide i that            not specifically address time-dependent releases as could oc enters the blood), from data presented in                    cur for certain radionuclides with both a long biological reten tion and radiological half-life. However, the assumption of Appendix B to this guide                                    blood uptake of the total burden in the first month of the ges tation period provides a simple method with reasonable assur TFi    =  transfer fraction of inhaled activity to the first          ance that any actual dose to the embryo/fetus will not be sig transfer compartment (i.e., the fraction of                  nificantly underestimated. More detailed evaluations may be needed for unusual circumstances in which a pre-existing body burden could present a significant source of exposure to the embryo/fetus. An evaluation of this nature should be con
3 The coefficients for the transfer fraction equations in Table 1        ducted by individuals knowledgeable in the area of internal re applicable to particles with a 1-micrometer activity me          dosimetry. Such a detailed evaluation could consider the ele Jan aerodynamic diameter (AMAD). As a default, these                ment retention functions as presented in ICRP Publications 30
  equations may be used for all particle sizes. However, if the          and 54 (Refs. 3 and 6). Also, the modeling presented in actual particle size distribution is known, transfer fractions        Revision 1 to NUlREG/CR-5631 (Ref. 2) could be applied.


Al ternatively, deep dose to the embryo/fetus may be limited by placing more stringent restrictions on the exposure of the declared pregnant woman than on other members of the occupational work force. As specified in 10 CFR 20.1208(a), the dose to the embryo/fetus from occupational exposure of the declared pregnant woman during the entire gestation period is not to exceed 0.5 rem (5 mSv). In addition, the licensee is required to make efforts to avoid sub stantial variation in the monthly exposure throughout the period of gestation.
for other AMAD particle sizes may be derived from data in              The details of this type of an evaluation are beyond the types Figure 5.2 of ICRP 30 (Ref. 3).                                       of analyses that are considered routinely required and, as such, are outside the scope of this guide.


If the dose to the embryo/fe tus is found to have exceeded 0.5 rem (5 mSv) or is within 0.05 rem (0.5 mSv) of this dose by the time the woman declares the pregnancy to the licensee, the licensee is required to limit the additional dose to the embryo/fetus to 0.05 rem (0.5 mSv) during the remainder of the pregnancy.
8.36-5


The tables in the appendices to this guide were prepared directly from the computer outputs, which led to the values generally being expressed to three significant figures. This indicates greater accuracy than is warranted by the dosimetry model, but the results are presented in this form to avoid roundoff errors in calculations.
embryo/fetus following the instantaneous introduction                the days-to-date in the first gestation month at time of of unit activity into the first transfer compartment                intake divided by 30 days. For example, assuming a (blood) of the pregnant woman at successive stages of                maternal intake of 14 C resulting in a 1-jiCi blood gestation. These method6 include the contribution to the embryo/fetus dose from the resultant body bur dens of the declared pregnant woman and from activ ity in the embryo/fetus resulting from transfer across take on the 20th day of the pregnancy, the embryo/
                                                                        fetus dose should be determined by multiplying the cumulated dose from an intake at day 31 (i.e., Table up
                                                                                                                                        [
                                                                        C3, Cumulated Dose column, 1.89E-04 rads) by the the placenta. Refer to Revision 1 to NUREG/                          ratio of 20 days to 30 days (i.e., 20 divided by 30).
  CR-5631 (Ref. 2) for a detailed description of the modeling.                                                                      3.2.2 For using the tabular dose data in cal culating the embryo/fetus dose, it may be assumed The methods and data of Revision 1 to NUREG/                  that all intakes occurring within any of the 30-day pe CR-5631 (Ref. 2) may be used for determining the                    riods of gestation occur at the beginning of that pe dose to the embryo/fetus from maternal intakes at                    riod.5 The cumulated dose column should be used in successive stages of gestation for the radionuclides                order to determine the total dose for the remainder of
  3 H, 14C, 5 7Co, 58 Co, 6 0C0, 89 Sr, 9 0Sr, 10ORu, 1251, 1311,      the gestation period.


In general, final results should be rounded to the nearest thousandth of a rem.8.36-2 C. REGULATORY
1321,   133I, 134I, 135i, 134Cs,  lSTCS, 233U,  234U,  2"5TU,
POSITION CRITERIA FOR DETERMINING
  238U, 23 8pu, 239 Pu,  and  24 1 Am.                                          3.2.3 For pre-existing body burdens from occupational exposure, the total burden determined The steps for determining the embryo/fetus dose                to exist at time of pregnancy should be assumed to be using the Revision 1 to NUREG/CR-5631 (Ref. 2)                      available for uptake in the blood of the woman. The methods are as follows:                                              dose should be assigned to the embryo/fetus as if the maternal blood uptake occurs within the first month
DOSE TO THE EMBRYO/FETUS
        3.1 The methods presented in the regulatory po                of pregnancy. The embryo/fetus dose is calculated by sition in Sections 2.1 through 2.4 should be used for                multiplying the maternal burden of the radionuclide determining the uptake in the first transfer compart                by its dose factor (Equation 3). The dose factor to be ment (blood) of the declared pregnant woman.                          used from the Appendix C tables is that factor corre sponding to the cumulated dose for a 0-day of gesta
1.1 Monitoring The dose equivalent to the embryo/fetus should be determined based on the monitoring of the de clared pregnant woman as required by 10 CFR 20.1502. Specifically, 10 CFR 20.1502(a)(2)  
        3.2 Equations 1 and 2 of the regulatory position tion at radionuclide introduction (i.e., right-most col specified in Section 2.5 may be used for determining the embryo/fetus dose with the following clarifica                  umn, first data entry). However, for those radi onuclides with an "N" for this 0-day entry, the entry tions:
re quires monitoring the exposure of a declared preg nant woman when the dose to the embryo/fetus is likely to exceed, in 1 year, a dose from external sources in excess of 10% of the limit of 10 CFR 20.1208 (i.e., 0.05 rem). According to 10 CFR 20.1502(b)(2), the licensee must monitor the occu pational intakes of radioactive material for the de clared pregnant woman if her intake is likely to ex ceed, in 1 year, a committed effective dose equivalent in excess of 0.05 rem (0.5 mSv). Based on this 0.05 rem (0.5 mSv) threshold, the dose to the embryo/fe tus should be determined if the intake is likely to ex ceed 1% of ALI (stochastic)
                                                                      for the second gestation month should be used (i.e.,
during the entire period of gestation.
            3.2.1 For Equations I and 2, in place of the            the right-most column, second data entry). Alterna dose factor parameter, DFi, the dose values should                  tively, time-dependent release kinetics may be used be taken from Appendix C to this guide for the time                  for calculating that fraction of the body burden that is period representing the time of intake relative to stage            translocated to the blood through the duration of the of gestation. The data in Appendix C to this guide are              pregnancy. The time-dependent release is described for an absorbed dose (in rads) from the introduction                in ICRP Publications 30 and 54 (Refs. 3 and 6). This of 1 gCi of the radionuclide into the first transfer                approach is complex, involving interlinking differen compartment (blood) of the woman at the beginning                    tial equations, and is considered outside the scope of of the specified month of gestation. To convert from                a routine health physics program.


These monitoring thresholds will ensure that any potentially significant exposures to the embryo/fetus are evaluated and, as appropriate, doses are deter ,ined. The conditions specified in 10 CFR .1502(a) and (b) are based on a 1-yeir period.  n-rior to declaration of pregnancy, the woman may not have been subject to monitoring based on condi tions specified in 10 CFR 20.1502(a)
an absorbed dose (rad) to a dose equivalent (rem),
(1) and 10 CFR 20.1502(b)(1).  
                                                                            3.3 Doses from multiple nuclides and multiple the data in Appendix C should be multiplied by the                  intakes should be evaluated with a frequency corre appropriate quality factor from Table 1004 (b). 1 of 10
In this case, the licensee should esti mate the exposure during the period monitoring was not provided, using any combination of surveys or other available data (for example, air monitoring, area monitoring, bioassay). 
                                                                      sponding to the intake (i.e., at least once every 30
The monitoring criteria contained in 10 CFR 20.1502 do not establish required levels of detection sensitivity.
CFR Part 20. For 3H, 14C, 5 7Co, 5 8 Co, 6 0Co, 89 Sr,              days). Multiple dose determinations should be added
90
    Sr, 10°Ru, 1251, 1311, 1321, 1331, 1341, 135], 13 4 Cs, and
137 Cs, a quality factor of 1 should be applied. For                to determine the total dos


For some radionuclides it may not be fea sible to actually confirm by bioassay measurements an intake of 1% of their stochastic ALI. Workplace monitoring, occupancy factors, and access control should be considered as appropriate in evaluating po tential exposures and monitoring requirements.
====e. Doses may need to be====
233 U, 234 U, 2 35U, 23 8 U, 238 Pu, 23 9pu, and 24lAm, a            reevaluated if better estimates of intakes are provided by followup bioassay measurements.


1.2 Evaluation of Dose to the Embryo/Fetus The appropriate dose to be evaluated for the em bryo/fetus is the dose equivalent for the duration of the pregnancy.
quality factor of 20 should be applied, recognizing that most of the embryo/fetus dose results from alpha                                 


An assessment of the 50-year commit ted dose is not appropriate.
==D. IMPLEMENTATION==
decay.


Also, it is not appropriate to use effective dose equivalent or committed effec"A:e dose equivalent. (Note: the committed dose .iivalent to the uterus may be applied to the -.nbryo/fetus under certain conditions as a simplified approach as described in the regulatory position specified in Section 2.)1.3 External Dose to the Embryo/Fetus According to 10 CFR 20.1208(c)(1), the deep dose equivalent to the declared pregnant woman will be taken as the external dose component to the em bryo/fetus.
The purpose of this section is to provide informa For some radionuclides (e.g., 23 5U), a blood            tion to applicants and licensees regarding the NRC
uptake at the beginning of the gestation period results              staff's plans for using this regulatory guide.


The determination of external dose should consider all occupational exposures of the de clared pregnant woman since the estimated date of conception.
in a negligible dose contribution to the embryo/fetus.


The deep-dose equivalent that should be assigned is that dose that would be most representa tive of the exposure of the embryo/fetus (i.e., in the mother's lower torso region). If multiple measure ments have been made, assignment of the highest deep-dose equivalent for the declared pregnant woman to the embryo/fetus is not required unless that dose is also the most representative deep-dose equiva lent for the region of the embryo/fetus.
These radionuclides are identified in the tables in Ap                      Except in those cases in which an applicant pro pendix C to this guide by an "N" entry in the row for                poses an acceptable alternative method of complying the 0-day of gestation at radionuclide introduction                  with specified portions of the Commission's regula (i.e., the first row of dose factor data). For an intake            tions, the methods described in this guide will be used of these radionuclides within the first month of gesta tion, a time-weighted dose factor using the second                  5 The correlation of intake to actual stage of gestation can only month data (3 1-day row) should be used. The 3 1-day                  be roughly estimated. For this reason, it is believed that the dose factor should be multiplied by the quotient of                    correlation should be limited to the best estimate of the month of gestation.


1.4 Internal Dose to the Embryo/Fetus The internal dose to the embryo/fetus should consider the exposure to the embryo/fetus from radi onuclides in the declared pregnant woman and in the embryo/fetus.
8.36-6


The dose to the embryo/fetus should include the contribution from any radionuclides in the declared pregnant woman (body burden) from occupational intakes occurring prior to conception.
in the evaluation of applications for new licenses, li          including supplements, Annals of the ICRP,
cense renewals, and license amendments and for                  Volume 2, No. 3/4, Pergamon Press Inc., 1979.


The intake for the declared pregnant woman should be determined using air sample data, bioassay data, or a combination of the two. Guidance on bioassay measurements used to quantify intake is being devel oped and has been issued for public comment as Draft Regulatory Guide DG-8009, "Interpretation of Bioassay Measurements." Specific guidance on workplace air sampling is in Revision 1 to Regulatory Guide 8.25, "Air Sampling in the Workplace." 1.5 Evaluating Continuous Exposure For continuous or near-continuous exposure to radioactive material that may be inhaled or ingested, the cumulative intake should be quantified and the dose determined at least every 30 days. If significant variation in the exposure levels may have occurred, the time interval for quantifying the intake should be reduced. More frequent evaluations should be con sidered as the potential dose to the embryo/fetus ap proaches the limit. 1.6 Existing Maternal Body Burdens Maternal body burdens resulting from internal occupational exposures prior to conception should be included in determining the embryo/fetus dose. The contribution to the embryo/fetus dose from a mater nal burden existing at the time of conception should be evaluated if the maternal burden at the time of pregnancy exceeds 1% of the radionuclide's stochas tic ALI value for the appropriate mode of intake and class (for inhalation intakes).
evaluating compliance with 10 CFR 20.1001
For multiple radio nuclide burdens, the dose should be evaluated if the sum of the quotients of each burden divided by its stochastic ALI exceeds 0.01. Only body burdens ex isting at the time of conception need to be considered
  "1.2401.                                                 4. K. F. Eckerman, A. B. Wolbarst, and A. C. B.
8.36-3 in evaluating this threshold;
radioactive material al ready eliminated from the body should not be in cluded.  This threshold of 1% ALl provides a simplified approach for determining when pre-existing body burdens should be evaluated.


At this threshold, it is unlikely that any resultant dose to the embryo/fetus would be significant (i.e., greater than 10% of the 0.5 rem (5 mSv) limit). As an alternative, the dose as sessment methods presented in the regulatory position specified in Section 3 of this guide may be used for determining whether a pre-existing body burden rep resents a potentially significant dose (i.e., greater than 0.05 rem (0.5 mSv)).
Richardson, "Limiting Values of Radionuclide REFERENCES                                Intake and Air Concentration and Dose Conver sion Factors for Inhalation, Submersion, and
1.     International Commission on Radiological Pro            Ingestion," Environmental Protection Agency, tection, "Age-Dependent Doses to Members of             Federal Guidance Report No. 11 (EPA- 520/1 the Public from Intake of Radionuclides: Part            88-020), September 1988.


===2. SIMPLIFIED ===
1," ICRP No. 56, Pergamon Press Inc., 1989.
METHOD FOR DETERMINING
EMBRYO/FETUS
DOSE FROM MATERNAL INTAKES The determination of the dose to the embryo/fe tus from the intake of radioactive material by the pregnant woman should be based on the best avail able scientific data. At present, the NRC staff consid ers Revision 1 to NUREG/CR-5631 (Ref. 2) to pro vide such data. For most radionuclides, the dose to the embryo/fetus will be similar to or less than the dose to the maternal uterus (Ref. 1). However, the data in Revision I to NUREG/CR-5631 indicate that for some radionuclides the embryo/fetus dose may be significantly different, either greater than or less than the dose to the uterus. Based on these premises (uterus dose similar to fetal dose and the data in Revision 1 to NUREG/ CR-5631 (Ref. 2)), a set of dose factors has been developed for use in calculating an embryo/fetus dose. Except for those radionuclides addressed in Revision 1 to NUREG/CR-5631 (Ref. 2), the dose factors presented in Appendix A to this guide repre sent the committed dose equivalent to the uterus per introduction of unit activity into the first transfer compartment (i.e., blood) of the woman.' For the radionuclides in Revision 1 to NUREG/CR-5631, the dose factors in Appendix A represent the maximum dose equivalent to the embryo/fetus for the gestation period from the introduction of unit activity into the first transfer compartment of the woman at any time during the gestation period.  The dose limit for the embryo/fetus is expressed as a 9-month gestation dose equivalent.


Particularly for certain radionuclides with both long radiological half-lives and long-term biological retention, the com mitted dose equivalent to the uterus may be signifi'The committed dose equivalent factors for the uterus pre sented in Appendix A were calculated based on the modeling employed during the development of the ICRP 30 (Ref. 3) data. It is recognized that the metabolism of the pregnant woman may not be adequately represented by the standard metabolic model. However, partly because of the lack of more definitive data, this modeling has been used for deter mining the dose commitment factors for the uterus that may be used for evaluating compliance with the embryo/fetus dose limit.cantly different from a 9-month gestation dose equivalent to the embryo/fetus.
5. International Commission on Radiological Pro
2.    M. R. Sikov et al., "Contribution of Maternal            tection, "The Metabolism of Compounds of Radionuclide Burdens to Prenatal Radiation              Plutonium and Other Actinides," ICRP No. 19, Doses--Interim Recommendations," NUREG/                 Pergamon Press Inc., May 1972.


Several radionuclides of this type have been evaluated in Revision 1 to NUREG/CR-5631 (Ref. 2), and data have been de veloped for calculating an embryo/fetus gestation dose instead of using the committed dose equivalent to the uterus. For demonstrating compliance with the dose lim its of 10 CFR 20.1208, the dose factors in Appendix
CR-5631, Revision 1 (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992.              6. International Commission on Radiological Pro tection, "Individual Monitoring for Intake of Radionuclides by Workers: Design and Interpre
* A may be used for approximating the embryo/fetus dose equivalent for the entire gestation period. The steps for determining the embryo/fetus dose, using the simplified method, are as follows: 2.1 Include all the intakes by the declared preg nant woman at any time during the gestation period in the calculation of the embryo/fetus dose.  2.2 For ingested radionuclides, determine the activity uptake by the first transfer compartment (blood) by multiplying the intake (1) by the appropri ate uptake factor (fl) from Appendix B (adapted from Federal Guidance Report No. 11, Table 3 (Ref.  4)). The uptake factor, fl, is the fraction of an in gested compound of a radionuclide that is transferred into the first transfer compartment (i.e., blood uptake fraction). 
3.     International Commission on Radiological Pro            tation," ICRP No. 54, Annals of the ICRP,
2.3 For inhaled radionuclides, determining the fraction of initial intake that is transferred to the blood involves an evaluation of the deposition in the three compartments of the lung and the subsequent time-dependent transfer to the body fluids and to the GI tract. Unless it is known otherwise, it should be assumed that the transfer from the lung to body fluids and from lung to GI tract to body fluids follows the ICRP 30 (Ref. 3) modeling (which is the basis for this guide).  2.4 For simplicity and conservatism in the mod eling, the total uptake into the blood from the mater nal intake is assumed to be instantaneous.
      tection, "Limits for Intakes of Radionuclides by        Volume 19, No. 1-3, Pergamon Press Inc.,
      Workers," ICRP No. 30, Parts 1 through 4,                 1988.


However, for radionuclides with lung clearance class of W (10 to 100-day half-life clearance)
8.36-7
or Y (greater than 100-day half-life clearance), the actual translocation from the lung and uptake in the blood may occur over a time period that exceeds the gestation period. Clearance from the lung may take up to several years.  All the initially deposited material is not immediately available for uptake by the first transfer compartment (blood). However, an incremental transfer from the lung to the blood may be assessed based on the lung model as described in ICRP Publications
30 and 19 (Refs. 3 and 5).2 Table 1, adapted from the data in Figure 5.2 of ICRP 30 (Ref. 3), may be used for determining the total transfer from the lung to the first transfer 2As modeled in ICRP Publications
19 and 30, the clearance from the different lung compartments is assumed to follow first-order kinetics.


This approach is complex, involving in terlinking differential equations, and is considered outside the scope of a routine operational health physics program.8.36-4 compartment (i.e., blood), where f, is the blood up take fraction from Appendix B.3 The lung clearance class (D, W, or Y) for a particular chemical form of a )articular radionuclide may be obtained from Appen dix B to 10 CFR 20.1001-20.2401.
APPENDIX A
                  DOSE EQUIVALENT FACTORS FOR USE IN APPROXIMATING THE
              EMBRYO/FETUS DOSE FROM RADIONUCLIDES IN MATERNAL BLOOD
      Except as noted, the dose factors (DFi) pre                into the first transfer compartment of the woman at sented in Table A-1 represent the committed dose                  any time during the gestation period. These entries equivalent to the uterus per introduction of unit activ          are based on the modeling of Revision 1 to NUREG/
ity into the first transfer compartment (i.e., blood) of          CR-5631 (Ref. A2) and are derived from the data the woman. These entries were calculated from tabu                tables presented in Appendix C to this guide. The lated values of uterine committed dose equivalent per            maximum calculated embryo/fetus dose (as presented unit intake and fractional absorption (fl) from the              in the Appendix C tables) from intake by the de gastrointestinal tract using ICRP-30 (Ref. Al) meth              clared pregnant woman during the gestation period odology. The DFi dose factors were derived by divid              has been used for inclusion in Table A-1.


Table 1 2.5 Based on the determination of the maternal intake, the dose to the embryo/fetus for the entire gestation period should be calculated using the follow ing equations:
ing the committed dose equivalent per unit intake by the fractional absorption factor (fl). These dose fac                  The dose factor data presented in Revision 1 to tors are based on unit activity in the blood. The most            NUREG/CR-5631 (Ref. A2) are for an absorbed conservative f, (i.e., largest fraction) for each radio          dose expressed in units of rads. To adapt these data nuclide has been used for deriving the data in Table              as presented in Appendix C to this guide for inclusion A-1.                                                             in Table A-i, appropriate quality factors have been applied to convert from rads to dose equivalent, ex For the radionuclides 3H, 14C, 57 Co, 68Co, SOCo,            pressed in units of rem. For beta- and gamma-emit
For ingestion intakes: DE = I 1 ixf 1 ,ixDFi For inhalation intakes: DE = 2 Ii x TFi x DFj (Equation
89Sr, 9°Sr, 106Ru, 125I, 131j, 132j, 133I, 134I, 135j, 134Cs,
1) (Equation
137                                                              ting radionuclides, a quality factor of 1 has been ap Cs, 23U, 23U, 23U, ZaU, MSPu, ZaPu, and                      plied. For 2 wU, 234U, 235U, 238U, 238PU, 239pu, and
2)here: DE = dose equivalent to the embryo/fetus for the entire gestation period from the acute intakes of all radionuclides during the gestation period (rem) = intake of radionuclide i by the declared preg nant woman at any time during the gestation period (gCi) DFi = dose factor for use in approximating the dose equivalent to the embryo/fetus for the entire gestation period from the introduction of unit activity (1 jiCi) into the, 'maternal blood at any time during the gestation period, from tabular data presented in Appendix A to this guide (rem/RCi in maternal blood) fl, = the fraction of radionuclide i reaching the body fluids following ingestion (i.e., the frac tion of ingested activity of radionuclide i that enters the blood), from data presented in Appendix B to this guide TFi = transfer fraction of inhaled activity to the first transfer compartment (i.e., the fraction of 3 The coefficients for the transfer fraction equations in Table 1 re applicable to particles with a 1-micrometer activity me Jan aerodynamic diameter (AMAD). As a default, these equations may be used for all particle sizes. However, if the actual particle size distribution is known, transfer fractions for other AMAD particle sizes may be derived from data in Figure 5.2 of ICRP 30 (Ref. 3).inhaled activity of radionuclide i that enters the blood, see Table 1 of this guide) 2.6 For pre-existing body burdens, the total bur den determined to exist at time of pregnancy should be assumed to be available for uptake in the blood of the woman. The dose should be assigned to the em bryo/fetus as if the maternal blood uptake occurs within the first month of pregnancy.
24
  1Am, the dose factors in Table A-1 represent the               24 1 Am, a quality factor of 20 has been applied, recog maximum dose equivalent to the embryo/fetus for the              nizing that most of the embryo/fetus dose results from gestation period from the introduction of unit activity          the alpha decay.


The embryo/fe tus dose is calculated by multiplying the maternal bur den of the radionuclide by its dose factor from Ap pendix A using the equation: DE = AiAxDFi (Equation
A-I
3)D 0.48 + 0.15 f, W 0.12 + 0.51 f, Y 0.05 + 0.58 f, 8.36-5 Transfer Fraction of Inhaled Activity to First Transfer Compartment Class Transfer Fraction (TF)where: DE = dose equivalent to the embryo/fetus Al = maternal burden existing at time of preg nancy (ACi) DFi = dose conversion factor (Appendix A) This method provides a simplified and conserva tive approach for evaluating the significance of pre existing conditions.


If the embryo/fetus is likely to re ceive a dose in excess of 25% of the limit from pre existing burdens (i.e., greater than 0.125 rem (1.25 mSv)), more detailed modeling should be consid ered.4 2.7 Doses from multiple nuclides or multiple in takes should be evaluated on a frequency correspond ing to the determination of the intake. Multiple dose determinations should be added to determine the to tal dose. Doses may need to be reevaluated if better estimates of intakes are provided by followup bioassay measurements.
L ;
                                                        TABLE A-1 Dose Equivalent Factors for Use in Approximating the Embryo/Fetus Dose from Radionuclides in Maternal Blood DFi                                        DFi Nuclide                                                                                                    DFi (rem/gCi)                Nuclide          (rem/ljCi)            Nuclide            (rem/ACi)
    H-3                5.87E-05"                Cr-51            6.96E-04              Ga-68              5.66E-02 Be-7                1.67E-02                  Mn-51            3.65E-04              Ga-70              8.99E-05 Be-10              1.79E-02                  Mn-52            4.70E-02              Ga-72              1.53E+00
    C-11                1.21E-OS                  Mn-52m            2.80E-04              Ga-73              9.36E-02 C-14                1.29E-03*                Mn-53            5.77E-05              Ge-66                1.42E-04 F-18                1.32E-05                  Mn-54            1.86E-02              Ge-67                1.11E-05 Na-22              1.06E-02                  Mn-56            2.18E-03              Ge-68                8.81E-04 Na-24              1.21E-03                  Fe-52            1.30E-02              Ge-69              3.02E-04 Mg-28              3.83E-03                  Fe-55            3.88E-03              Ge-71              6.99E-06 A1-26              5.33E-01                  Fe-59            4.63E-02              Ge-75                1.61E-05 Si-31              3.85E-05                  Fe-60            1.47E+00              Ge-77              3.40E-04 Si-32              4.33E-02                  Co-55            4.01E-03              Ge-78              1.08E-04 P-32              3.03E-03                  Co-56            3.43E-02              As-69              2.46E-05 P-33              4.33E-04                  Co-57            2.20E-03*              As-70              2.90E-04 S-35              3.53E-04                  Co-58            9.17E-03"              As-71              1.21E-03 CI-36              2.96E-03                  Co-58m            5.17E-05              As-72              2.70E-03 CI-38              3.17E-05                  Co-60            4.18E-02*              As-73              3.02E-04 C1-39              3.89E-05                  Co-60m            4.12E-07              As-74              2.90E-03 K-40                1.84E-02                  Co-61            4.50E-05              As-76              1.11E-03 K-42                7.73E-04                  Co-62m            5.33E-05              As-77              1.88E-04 K-43                7.10E-04                  Ni-56            5.39E-02              As-78              1.85E-04 K-44                1.94E-05                  Ni-57            3.60E-02              Se-70              1.61E-04 K-45                1.21E-05                  Ni-59            2.71E-03              Se-73              3.66E-04 Ca-41              3.2 IE-05                  Ni-63            6.29E-03              Se-73m              3.21E-05 Ca-45              6.6 1E-04                Ni-65            1.43E-03              Se-75              8.79E-03 Ca-47              5.18E-03                  Ni-66            2.81E-03              Se-79              4.19E-03 Sc-43              2.48E+00                  Cu-60            9.32E-05                Se-81              1.OOE-06 Sc-44              4.59E+00                  Cu-61            2.69E-04                Se-81m              1.46E-05 Sc-44m            2.56E+01                  Cu-64            2.09E-04                Se-83              3.62E-05 Sc-46              3.15E+O1                  Cu-67            6.50E-04              Br-74              3.33E-05 Sc-47              1.86E+00                  Zn-62            1.38E-03              Br-74m              6.18E-05 Sc-48              3.52E+01                  Zn-63            5.92E-05              Br-75              6.07E-05 Sc-49              4.18E-04                  Zn-65            3.49E-02              Br-76              1.20E-03 Ti-44              1.36E+00                  Zn-69            3.09E-06              Br-77              3.27E-04 Ti-45              1.54E-02                  Zn-69m          5.54E-04              Br-80              3.01E-06 V-47              2.29E-03                  Zn-71m          5.75E-04              Br-80m              1.46E-04 V-48              4.37E-01                  Zn-72            5.28E-03              Br-82              1. 87E-03 V-49              8.36E-05                  Ga-65            9.18E-03              Br-83              2.72E-05 Cr-48              5.77E-03                  Ga-66            9.95E-01              Br-84              2.56E-05 Cr-49              3.51E-04                  Ga-67            2.50E-01              Rb-79              1. 15E-05
*Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.


===3. DETERMINING ===
A-2
GESTATION-TIME
DEPENDENT
DOSE TO THE EMBRYO/FETUS
USING REVISION 1 TO NUREG/CR-5631 METHODS As an alternative to the simplified methods pre sented above, a gestation-time dependent dose to the embryo/fetus may be calculated for the radionuclides addressed in Revision I to NUREG/CR-5631 (Ref.  2). Revision 1 to NUREG/CR-5631 presents dosimetric methods for calculating the dose to the 4 This approach for evaluating pre-existing body burdens does not specifically address time-dependent releases as could oc cur for certain radionuclides with both a long biological reten tion and radiological half-life.


However, the assumption of blood uptake of the total burden in the first month of the ges tation period provides a simple method with reasonable assur ance that any actual dose to the embryo/fetus will not be sig nificantly underestimated.
TABLE A-1 (continued)
                        DFi                                          DFi -                                      DFi Nuclide          (rem/4Ci)                  Nuclide          (reml/gCi)            Nuclide            (rem/gCi)
    Rb-81              8.18E-05                  Nb-90         
* 2.39E-01              Rh-105              1.93E-03 Rb-8 lm            1.08E-05                  Nb-93m            9.29E-04              Rh-106m              6.86E-03 Rb-82m            3.49E-04                  Nb-94            3.04E-01              Rh-107              8.511E-05 Rb-83              7.07E-03                  Nb-95            1.24E-01              Pd-100              3.94E-01 Rb-84              1.05E-02                  Nb-95m            1.27E-02              Pd-101              3.33E-02 Rb-86              8.14E-03                  Nb-96            2.03E-01              Pd-103              1.39E-03 Rb-87              4.22E-03                  Nb-97            4.11E-03              Pd-107              7.33E-06 Rb-88              1.02E-05                  Nb-98            9.66E-03              Pd-109              1.27E-03 Rb-89              1.20E-05                  Mo-90            7.77E-04              Ag-102              3.76E-04 Sr-80              3.96E-04                  Mo-93            4.36E-04              Ag-103              8.58E-04 Sr-81              1.22E-04                  Mo-93m            4.76E-04              Ag-104              3.05E-03 Sr-82              1.25E-02                  Mo-99            9.39E-04              Ag-104m              1.09E-03 Sr-83              2.31E-03                  Mo-101            1.48E-05              Ag-105              1.94E-02 Sr-85              4.03E-03                  Tc-93            1.33E-04              Ag-106              2.12E-04 Sr-85m              4.8 1E-05                  Tc-93m            4.67E-05              Ag-106m              8.21E-02 Sr-87m              1. 62E-04                  Tc-94            4.566E-04            Ag-108m              6.59E-02 Sr-89              1.84E-02"                  Tc-94m            7.08E-05              Ag-110in            1.04E-01 Sr-90              5.22E-02*                  Tc-95            3.86E-04              Ag-111              1.41E-03 Sr-91              1.49E-03                  Tc-95m            1.23E-03              Ag-i112              2.18E-03 Sr-92              7.79E-04                  Tc-96            2.62E-03              Ag-115              1.98E-04 Y-86                2.18E+01                  Tc-96m          2.29E-05              Cd-104              3.30E-03 Y-86m              1.26E+00                  Tc-97            4.67E-05              Cd-107              1.95E-04 Y-87                1.01E+01                  Tc-97m          2.42E-04              Cd-109              2.12E-02 Y-88                3.96E+01                  Tc-98            2.97E-03              Cd-i113            2.77E-01 Y-90                4.66E-04                  Tc-99            2.79E-04              Cd-113m            2.55E-01 Y-90m              1.21E+00                  Tc-99m          3.32E-05              Cd- 115              9.47E-03 Y-91                6.03E-02                  Tc-101          2.96E-06              Cd-l15m              1.27E-02 Y-9 1m              2.13E-01                  Tc-104          2.07E-05              Cd-117              4.23E-03 Y-92                4.81E-01                  Ru-94            2.32E-03              Cd-117m            9.62E-03 Y-93              4.18E-01                    Ru-97            6.89E-03              In-109              7.95E-03 Y-94                1.10E-01                  Ru-103            1.97E-02              In-1l0              4.01E-02 Y-95                3.56E-02                  Ru-105          4.09E-03              In-110              4.50E-03 Zr-86              8.62E-01                  Ru-106          7.23E-03*              In-Ill              3.05E-02 Zr-88              3.87E-01                  Rh-99            2.19E-02              In-112              9.47E-05 Zr-89              7.31E-01                    Rh-99m          3.5 1E-03              In- 1i3m            1.24E-03 Zr-93              8.79E-05                  Rh--100          3.86E-02              In-i 14m            3.05E-02 Zr-95              6.16E-01                  Rh-101          3.33E-102              In-115              8.99E-01 Zr-97              5.24E-01                    Rh-101m          9.40E-03              In-l 15m            2.16E-03 Nb-88              1.17E-03                  Rh-102            1.93E-01              In-l 16m            4.92E-03 Nb-89              1.83E-02                  Rh-102m          3.48E-02              In-i 17              1.22E-03 Nb-89              1.30E-02                  Rh-103m          1.18E-06              In-I17m            2.61E-03
*Dose equivalent factor based on data presented in Revision I to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.


More detailed evaluations may be needed for unusual circumstances in which a pre-existing body burden could present a significant source of exposure to the embryo/fetus.
A-3


An evaluation of this nature should be con ducted by individuals knowledgeable in the area of internal dosimetry.
TABLE A-1 (continued)
                            DFi                                        DFi Nuclide            (rem/!gCi)                                                                                DFi Nuclide          (rem/gCi)              Nuclide            (rem/gCi)
      In-1 19m            1.39E-05                  Te-127m          1. 82E-03              Ba-131m            1.32E-05 Sn-110              2.1IE-02                  Te-129          2.35E-05              Ba-133              1.27E-02 Sn-ill              8.8 1E-04                  Te-129m          3.39E-03              Ba-133m            8.77E-04 Sn-1l3              2.63E-02                  Te-131            2.18E-04              Ba-135m            7.03E-04 Sn-il7m              1.57E-02                  Te-131m          6.64E-03              Ba-139              4.55E-05 Sn-119m            2.29E-03                  Te-132          8.57E-03                Ba-140              1.54E-02 Sn-121              3.70E-05                  Te-133          3.26E-05                Ba-141              9.47E-05 Sn-121m            5.70E-03                  Te-133mn        5.48E-04                Ba-142              2.74E-04 Sn-123              6.35E-03                  Te-134          3.98E-04                La-131              3.77E-02 Sn-123m            2.48E-04                  i-120            9.36E-05                La-132            5.07E-01 Sn-125              2.37E-02                  l-120m          8.73E-05                La-135            3.43E-02 Sn-126              2.35E-01                  1-121            1.79E-05                La-137            7.55E-02 Sn-127              1.14E-02                  1-123            2.27E-05              La-138              2.84E+00
      Sn-128              7.14E-03                  1-124            2.16E-04              La-140              2.32E+00
    Sb-i 15              2.OOE-04                  1-125            1.38E-03*              La-141              9.43E-03 Sb-I 16              1.59E-04                  1-126            2.23E-04                La-142              1.91E-01 Sb-116m              1.49E-03                  1-128            5.25E-06                La-i43              2.85E-03 Sb-i 17            3.34E-04                  1-129            5.11E-04                Ce-134              3.13E+00
    Sb-1 18m            6.59E-03                  1-130            2.29E-04                Ce-135              4.44E+00
    Sb- 119            2.08E-04                  1-131            3.64E-03"              Ce-137              7.13E-02 Sb-120              3.70E-05                  1-132            1.56E-04*              Ce-137m              3.31E-01 Sb-120              3.42E-02                  1-132m          6.14E-05              Ce-139              I. 15E+00
    Sb-122              5.85E-03                  1-133            9.04E-04*              Ce-14i              5.56E-01 Sb-124              2.98E-02                  1-134            4.83E-05*              Ce-i43              1.05E+00
    Sb-124m              4.88E-05                  1-135            3.72E-04"              Ce-144              3.79E-01 Sb-125              8.5IE-03                  Cs-125            1.33E-05              Pr-136              4.12E-02 Sb-126              4.37E-02                  Cs-127            5.96E-05              Pr-137              1.26E-01 Sb-126m              1.69E-04                  Cs-129            2.13E-04              Pr-138m            9.61E-01 Sb-127              9.66E-03                  Cs-130            6.99E-06              Pr-139              1.16E-01 Sb-128              1.33E-04                  Cs-131          2.27E-04                Pr-142              1.36E-01 Sb-128              8.73E-03                  Cs-132          2. 1OE-03              Pr-142m            1.73E-03 Sb-129              3.36E-03                  Cs-134            1.IiE-01*              Pr-143              4.53E-08 Sb-130              9.40E-04                  Cs-134m          2.66E-05                Pr-144              8.44E-04 Sb-131              3.36E-04                  Cs-135          7.07E-03                Pr-145              1.41E-02 Te-116              1.45E-03                  Cs-135m          2.42E-05                Pr-147              1.95E-02 Te-121              4.87E-03                  Cs-136          1.42E-02                Nd-136            3.59E-01 Te-121m            7.90E-03                  Cs-137          5.94E-02*              Nd-138            8.26E-01 Te-123              3.09E-05                  Cs-138          2.95E-05                Nd-139            4.1IE-02 Te-123m              2.94E-03                  Ba-126          1.14E-03              Nd-139m            1.74E+00
  Te-125m              9.75E-04                  Ba-128          1. 17E-02              Nd-141              4.33E-02 Te-127              6.31E-05                  Ba-131          7.40E-03              Nd-147              8.45E-01
"Dose  equivalent factor based on data presented in Revision
                                                            1 to NUREG/CR-5631 (Ref. A2). All other factors committed dose equivalent to the uterus.                                                                   represent the A-4


Such a detailed evaluation could consider the ele ment retention functions as presented in ICRP Publications
TABLE A-1 (continued)
30 and 54 (Refs. 3 and 6). Also, the modeling presented in Revision 1 to NUlREG/CR-5631 (Ref. 2) could be applied.
          DFi                    DFi                DFi Nuclide (rem/gCi)  Nuclide    (rem/gCi)  Nuclide (rem/!gCi)
Nd-149  1.37E-01    Gd-149      2.47E+00  Tm-166  2.37E+00
Nd-15 1  2.53E-02    Gd-151      4.99E-01  Tm-167  1.03E+00
Pm-141  3.63E-02    Gd-152      0.OOE-01  Tm-170  5.38E-02 Pm-143  1.79E+00  Gd-153      8.92E-01  Tm-171  8.13E-03 Pm-144  8.68E+00  Gd-159      1.52E-01  Tm-172  1.89E+00
Pm-145  2.58E-01  Tb-147      6.76E-01  Tm-173  5.88E-01 Pm-146  4.34E+00  Tb-149      1.27E+00  Tm-175  2.70E-02 Pm-147  3.49E-05  Tb-150      1.01E+00  Yb-162  8.97E-02 Pm-148  2.60E+00  Tb-151      2.33E+00  Yb-166  6.08E+00
Pm-148m  1.08E+01  Tb-153      1.16E+00  Yb- 167  1.23E-02 Pm-149  4.70E-02  Tb-154      5.65E+00  Yb-169  2.47E+00
Pm-150  6.86E-OI  Tb-155      9.52E-01  Yb-175  2.10E-01 Pm--151  I. 1IE+00  Tb-156      8.65E+00  Yb-177  6.98E-02 Sm-141  4.11E-02    Th-156m      9.32E-01  Yb-178  4.11E-02 Sm-141m  1.42E-01  Tb-156m      2.89E-01  Lu-169  3.60E+00
Sm-142  2.11E-01    Tb-157      2.39E-02  Lu-170  8.42E+00
Sm-145  5.56E-01    Tb-158      4.79E+00  Lu-171  3.72E+00
Sm-146  0.OOE-01    Tb-160      6.08E+00  Lu-172  9.20E+00
Sm-147  0.OOE-01    Tb-161      2.64E-01  Lu-173  1.10E+00
Sm-151  1.26E-05  Dy-155      1.08E+00  Lu-174  8.93E-01 Sm-153  3.54E-01    Dy-157      5.8 1E-01 Lu-174m 5.54E-01 Sm-155  5.65E-03    Dy-159      4.19E-01  Lu-176  3.45E+00
Sm-156  3.55E-01    Dy-165      1.3SE-02  Lu-176m  1.53E-0
Eu-145  2.OOE+00    Dy-166      3.56E-01  Lu-177  2.24E-0 1 Eu-146  3.38E+00    Ho-155      1.41E-01  Lu-177m 6.80E+00
Eu-147  8.51E-01    Ho-157      2.57E-02  Lu-178  8.18E-03 Eu-148  3.53E+00    Ho-159      3.47E-02  Lu-178m 5.54E-02 Eu-149  1.40E-01    Ho-161      4.70E-02  Lu-179  3.03E-02 Eu-150  2.92E-02    Ho-162      4.66E-03  Hf-170  4.74E-01 Eu-150  3.02E+00    Ho-162m      1.43E-01  Hf-172  4.63E-01 Eu-152  2.20E+00    Ho-164      3. 1OE-03  Hf-173  2.26E-01 Eu-152m 1.38E-01    Ho-164m      1.32E-02  Hf-175  3.70E-01 Eu-154  2.28E+00    Ho-166      1.04E-01  Hf-177m 5.22E-02 Eu-155  1.60E-01    Ho-166m      1.07E+01  Hf-178m 2.94E+00
Eu-156  1.90E+00    Ho-167      2.38E-01  Hf-179m 8.51E-01 Eu-157  2.01E-01    Er-161      6.29E-01  Hf-180m .71E-01 Eu-158  3.56E-02    Er-165      1. 12E-01 Hf-181  4.96E-01 Gd-145  1.09E-01    Er-169      1.34E-04  Hf-182  1.16E+00
Gd-146  4. 11E+00  Er-171      5.88E-01  Hf-182m 2.61E-02 Gd-i47  4.9 iE+00  Er-172      2.59E+00  Hf-183  2.33E-02 Gd-148  0.OOE-01    Tm-162      6.87E-02  Hf-184  1.94E-01 A-5


The details of this type of an evaluation are beyond the types of analyses that are considered routinely required and, as such, are outside the scope of this guide.
TABLE A-1 (continued)
            DFi                    DFi Nuclide                                                DFi (rem/pCi)  Nuclide      (rem/gCi)  Nuclide  (rem/gCi)
Ta-172    4.07E-02  Os-189m      5.1IE-06  Hg-193m  3.23E-04 Ta-173    1.94E-01  Os-191      1.99E-02 Ta-174                                      Hg-194    1.81E-01
          4.25E-02    Os-191m      1. 12E-03  Hg-195    7.47E-05 Ta-175  4.96E-01    Os-193      8.55E-03  Hg-195m  5.48E-04 Ta-176  8.25E-01    Os-194      8.69E-02  Hg-197    2.38E-04 Ta-177    1.30E-01  Ir-182      2.23E-03  Hg-197m  2.97E-04 Ta-178  1.47E-01    Ir-184      3.24E-02  Hg-199m  7.55E-06 Ta-179  9.40E-02    Ir-185      3.85E-02  Hg-203    5.33E-03 Ta-180  1.16E+00    Ir-186      1.12E-01  T1-194    6.44E-06 Ta-180m  3.47E-02  Ir-187      2.08E-02    Ti-194m  2.16E-05 Ta-182  2.15E+00  Ir-188        1.60E-01  TI-195    3.49E-05 Ta-182m  2.65E-03  Ir-189        1.96E-02  Ti-197    3.85E-05 Ta-183  5.44E-01  Ir-190      2.52E-01    TI-198    1.94E-04 Ta-184  7.40E-01  Ir-190m      1.OIE-03    TI-198m  8.36E-05 Ta-185  9.25E-03  Ir-192      1. 63E-0 1  T1-199  5.55E-05 Ta-186  7.03E-03  Ir-192m      8.99E-02    T1-200  6.55E-04 W-176    6.55E-04  Ir-194      7.55E-03    TI-201  2.48E-04 W-177    3.66E-04  Ir-194m      4.55E-01    TI-202    1.38E-03 W-178    6.43E-04  Ir-195      1.24E-03  Tl-204    2.43E-03 W-179    8.12E-06  Ir-195m      1.03E-02  Pb-195m W-181 W-185 W-187
        2.80E-04
        3.51E-07
          1.04E-03 Pt-186 Pt-188 Pt-.189
                                  2.06E-02
                                  1.21E-01
                                  2.08E-02 Pb-198 Pb-199
                                                      1.65E-04
                                                      3.92E-04
                                                      6.5IE-04 L
                                            Pb-200    3.37E-03 W-188    1.68E-04  Pt-191        4.88E-02  Pb-201    1.78E-03 Re-177  1.49E-05  Pt-193        1.07E-04  Pb-202    6.77E-02 Re-178  8.37E-06  Pt-193m      2.71E-03    Pb-202m  1.91E-03 Re-181  4.61E-04  Pt-195m      1.58E-02  Pb-203  2.02E-03 Re-182  4.56E-04  Pt-197      2.64E-03    Pb-205  3.63E-04 Re-182  1.92E-03  Pt-197m      1.12E-03  Pb-209  9.93E-06 Re-184  1.64E-03  Pt-199      5.40E-04    Pb-2 10  2.31E+00
Re-184m  1.31E-03  Pt-200      2.04E-02    Pb-211  3.63E-04 Re-i86  4.53E-04  Au-193      1.63E-03    Pb-212  3.29E-02 Re-186m  9.43E-04  Au-194      1.10E-02    Pb-214  5.64E-04 Re-187  1.82E-06  Au-195      2.35E-03    Bi-200  1.66E-03 Re-188  3.73E-04  Au-198.      5.66E-03    Bi-201  4.07E-03 Re-188m  8.19E-06  Au-198m      1.05E-02    Bi-202  4.83E-03 Re-189  2.46E-04  Au-199      1.68E-03    Bi-203  2.54E-02 Os-180  1.78E-03  Au-200.      1.01E-04    Bi-205  4.82E-02 Os-181  1.75E-02  Au-200m      1.61E-02    Bi-206  9.03E-02 Os-182  1.07E-01  Au-201      1. 15E-05  Bi-207  4.88E-02 Os-185  1.33E-01  Hg-193      4.88E-05    Bi-210  1.46E-03 A-6


embryo/fetus following the instantaneous introduction of unit activity into the first transfer compartment (blood) of the pregnant woman at successive stages of gestation.
TABLE A-1 (continued)
                        DFi                                        DFi                                        DFi Nuclide          (rem/pCi)                  Nuclide          (rem/gCi)              Nuclide            (rem/gCi)
  Bi-210m            8.66E-02                    U-233            5.84E-01*              Am-245              2.68E-04 Bi-212              1.70E-03                  U-234            5.84E-01"              Am-246m            1.51E-02 Bi-213            4.36E-04                    U-235            5.34E-01*              Am-246              2.03E-02 Bi-214            3.52E-04                    U-236            1.81E-01              Cm-238              1.31E-01 Po-203              1.07E-03                  U-237            5.42E-03              Cm-240              3.50E-02 Po-205              1.64E-03                  U-238            5.10E-01*              Cm-241              8.69E-01 Po-207            4.03E-03                    U-239            5.52E-05              Cm-242              3.30E-02 Po-210            3.05E+00                    U-240            4.17E-03              Cm-243              3.74E-01 At-207            8.32E-04                  Np-232            8.69E-03              Cm-244              3.19E-02 At-211            3.92E-02                    Np-233          2.85E-03              Cm-245              3.11E-01 Fr-222            2.13E-03                    Np-234          1.45E+00              Cm-246              1.27E-01 Fr-223            8.58E-03                  Np-235            2.99E-03              Cm-247              9.51E-01 Ra-223            7.84E-01                    Np-236          4.29E-01              Cm-248              3.49E+01 Ra-224            3.85E-01                  Np-236            5.25E-02              Cm-249              1.07E-03 Ra-225            6.23E-01                    Np-237          3.59E-01              Cm-250              2.76E+02 Ra-226              1.69E+00                  Np-238            6.07E-01              Bk-245              4.11E-01 Ra-227            6.10E-05                    Np-239          2.55E-01              Bk-246              1.04E+00
  Ra-228            2.90E+00                    Np-240          7.07E-02              Bk-247              2.83E-01 Ac-224            9.47E-02                    Pu-234          1.24E-01              Bk-249              8.40E-04 Ac-225            3.68E-01                    Pu-235          1.72E-03              Bk-250              1.54E-01 Ac-226            1.66E-01                    Pu-236          6.81E-02              Cf-244              9.25E-05 Ac-227            2.60E-01                    Pu-237          1.07E-01              Cf-246              2.88E-02 Ac-228            3.12E-0I                    Pu-238          1.11E+00*              Cf-248              4.18E-02 Th-226            3.02E-03                    Pu-239          1.04E+00*              Cf-249              9.80E-01 Th-227            3.52E+00                    Pu-240          2.80E-02              Cf-250              3.30E-01 Th-228            4.40E+O1                    Pu-241          2.96E-04              Cf-251              4.26E-01 Th-229            8.51E+01                    Pu-242          2.81E-02              Cf-252              1.15E+0O1 Th-230              1.26E+01                  Pu-243          9.62E-03              Cf-253              8.55E-04 Th-231            8.97E-02                    Pu-244          1.07E+00              Cf-254              3.70E+02 Th-232            2.26E+01                    Pu-245          2.22E-01              Es-250              4.77E-02 Th-234            2.33E-01                    Pu-246          1.34E+00              Es-251              1.24E-01 Pa-227            2.42E-03                    Am-237          2.60E-02              Es-253              3.58E-02 Pa-228            9.58E-01                    Am-238          7.81E-02              Es-254m            5.22E-01 Pa-230              1.04E+00                  Am-239          1.63E-01              Es-254              1.33E+00
  Pa-231            2.25E-01                    Am-240          1.16E+00              Fm-252              2.61E-02 Pa-232            8.95E-01                    Am-241          2.22E-01"              Fm-253              1.38E-01 Pa-233            3.81E-01                    Am-242m          3.64E-02              Fm-254              6.11E-03 Pa-234            6.77E-01                    Am-242          1.32E-02              Fm-255              2.85E-02 U-230              6.13E-01                  Am-243          4.74E-01              Fm-257              2.60E-01 U-231              2.63E-03                    Am-244m          1.05E-05              Md-257              3.69E-02 U-232              6.02E-01                    Am-244          3.92E-01              Md-258              5.96E-02
*Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.


These method6 include the contribution to the embryo/fetus dose from the resultant body bur dens of the declared pregnant woman and from activ ity in the embryo/fetus resulting from transfer across the placenta.
A-7


Refer to Revision 1 to NUREG/ CR-5631 (Ref. 2) for a detailed description of the modeling.
REFERENCES
Al. International Commission on Radiological Pro tection, "Limits for Intakes of Radionuclides by  A2. M. R. Sikov et al., "Contribution of Maternal Workers," ICRP No. 30, Parts I through 4,            Radionuclide Burdens to Prenatal Radiation including supplements, Annals of the ICRP,            Dose-Interim Recommendations," NUREG/
    Volume 2, No. 3/4, Pergamon Press Inc., 1979.        CR-5631, Revision 1 (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992.


The methods and data of Revision 1 to NUREG/ CR-5631 (Ref. 2) may be used for determining the dose to the embryo/fetus from maternal intakes at successive stages of gestation for the radionuclides
I
3 H, 14C, 5 7 Co, 5 8 Co, 6 0 C0, 8 9 Sr, 9 0 Sr, 1 0ORu, 1251, 1311, 1321, 133I, 134I, 135i, 134Cs, lSTCS, 233U, 234U, 2"5TU, 238U, 2 3 8pu, 23 9 Pu, and 2 4 1 Am.  The steps for determining the embryo/fetus dose using the Revision 1 to NUREG/CR-5631 (Ref. 2) methods are as follows: 3.1 The methods presented in the regulatory po sition in Sections 2.1 through 2.4 should be used for determining the uptake in the first transfer compart ment (blood) of the declared pregnant woman.  3.2 Equations
                                                  A-8
1 and 2 of the regulatory position specified in Section 2.5 may be used for determining the embryo/fetus dose with the following clarifica tions: 3.2.1 For Equations I and 2, in place of the dose factor parameter, DFi, the dose values should be taken from Appendix C to this guide for the time period representing the time of intake relative to stage of gestation.


The data in Appendix C to this guide are for an absorbed dose (in rads) from the introduction of 1 gCi of the radionuclide into the first transfer compartment (blood) of the woman at the beginning of the specified month of gestation.
APPENDIX B
            BLOOD UPTAKE FRACTIONS FOR INGESTED ACTIVTY
Element            fi                    Element        fl Actinium          IE-3                  Einsteinium    1E-3 (Ac)                                    (Es)
Aluminum          IE-2                  Erbium        3E-4 (Al)                                    (Er)
Americium        1E-3                  Europium      1E-3 (Am)                                      (Eu)
Antimony          1E-1                  Fermium        1E-3 (Sb)                                      (Fm)
Arsenic          5E-1                  Fluorine      1E0
(As)                                      (F)
Astatine          1E0                    Francium      1E0
(At)                                      (Fr)
Barium            IE-l                  Gadolinium    3E-4 (Ba)                                      (Gd)
Berkelium        1E-3.                  Gallium        1E-3 (Bk)                                      (Ga)
Beryllium        5E-3                  Germanium      1E0
(Be)                                      (Ge)
Bismuth          5E-2                  Gold          1E-1 (Bi)                                      (Au)
Bromine          1E0                    Hafnium        2E-3 (Br)                                      (Hf)
Cadmium          5E-2                  Holmium        3E-4 (Cd)                                    (Ho)
Calcium          3E-1                  Hydrogen      lEO
(Ca)                                      (H)
Californium      1E-3                  Indium        2E-2 (Co                                      (In)
Carbon            1E0                    Iodine        1E0
(C)                                      .(I)
Cerium            3E-4                  Iridium        1E-2 (Ce)                                      (Ir)
Cesium            1E0                    Iron          1E-1 (Cs)                                      (Fe)
Chlorine          1E0                    Lanthanum      lE-3 (Cl)                                      (La)
Chromium          iE-I                  Lead          2E-1 (Cr)                                      (Pb)
Cobalt            3E-1                    Lutetium      3E-4 (Co)                                      (Lu)
Copper            5E-1                    Magnesium    5E-1 (Cu)                                      (Mg)
Curium            1E-3                    Manganese    IE-1 (Cm)                                      (Mn)
Dysprosium        3E-4                    Mendelevium  lE-3 (Dy)                                      (Md)
                                B-1


To convert from an absorbed dose (rad) to a dose equivalent (rem), the data in Appendix C should be multiplied by the appropriate quality factor from Table 1004 (b). 1 of 10 CFR Part 20. For 3H, 14C, 5 7 Co, 5 8 Co, 6 0 Co, 8 9 Sr, 9 0 Sr, 1 0°Ru, 1251, 1311, 1321, 1331, 1341, 135], 1 3 4 Cs, and 1 3 7 Cs, a quality factor of 1 should be applied. For 2 3 3 U, 2 3 4 U, 2 3 5 U, 2 3 8 U, 2 3 8 Pu, 2 3 9pu, and 2 4 lAm, a quality factor of 20 should be applied, recognizing that most of the embryo/fetus dose results from alpha decay.  For some radionuclides (e.g., 2 3 5 U), a blood uptake at the beginning of the gestation period results in a negligible dose contribution to the embryo/fetus.
APPENDIX B (continued)
  Element      fl                      Element    fi Mercury      1EO                      Selenium  8E-1 (Hg)                                 (Se)
  Molybdenum  8E-1                     Silicon    1E-2 (Mo)                                  (Si)
  Neodymium    3E-4                    Silver    5E-2 (Nd)
                                        (Ag)
Neptunium    1E-3 (Np)                                  Sodium    lEO
                                        (Na)
Nickel      5E-2 (Ni)                                  Strontium  3E-I
                                        (Sr)
Niobium      1E-2 (Nb)                                  Sulfur    8E-i (s)
Osmium      1E-2 (Os)                                Tantalum    1E-3 (Ta)
Palladium    5E-3 (Pd)                                  Technetium  8E-1 (Tc)
Phosphorus  8E-1 (P)                                  Tellurium  2E-1 Platinum                              (Te)
              1E-2 (Pt)                                  Terbium    3E-4 Plutonium    1E-3                     (Tb)
(Pu)                                  Thallium    1EO
Polonium      1E-1                     (T)
(Po)
                                      Thorium    2E-4 Potassium    1EO                      (Th)
(K)
                                      Thulium    3E-4 Praseodymium 3E-4                      (Tm)
(Pr)
                                      Tin        2E-2 Promethium  3E-4                     (Sn)
(Pm)
                                      Titanium    1E-2 Protactinium  1E-3 (Pa)                                  (Ti)
Radium                                Tungsten    3E-1
            2E-1 (Ra)                                  (W)
Rhenium                              Uranium    5E-2
            8E-1 (Re)                                  (U)
Rhodium      5E-2                     Vanadium    1E-2 (Rh)                                  (V)
Rubidium    1EO                      Ytterbium  3E-4 (Rb)                                  (Yb)
Ruthenium    5E-2                     Yttrium    1E-4 (Ru)                                  (Y)
Samarium    3E-4                     Zinc        5E-1 (Sm)                                  (Zn)
Scandium    1E-4                    Zirconium  2E-3 (Sc)                                  (Zr)
                          B-2


These radionuclides are identified in the tables in Ap pendix C to this guide by an "N" entry in the row for the 0-day of gestation at radionuclide introduction (i.e., the first row of dose factor data). For an intake of these radionuclides within the first month of gesta tion, a time-weighted dose factor using the second month data (3 1-day row) should be used. The 3 1-day dose factor should be multiplied by the quotient of the days-to-date in the first gestation month at time of intake divided by 30 days. For example, assuming a maternal intake of 1 4 C resulting in a 1-jiCi blood up take on the 20th day of the pregnancy, the embryo/ fetus dose should be determined by multiplying the cumulated dose from an intake at day 31 (i.e., Table C3, Cumulated Dose column, 1.89E-04 rads) by the ratio of 20 days to 30 days (i.e., 20 divided by 30).  3.2.2 For using the tabular dose data in cal culating the embryo/fetus dose, it may be assumed that all intakes occurring within any of the 30-day pe riods of gestation occur at the beginning of that pe riod.5 The cumulated dose column should be used in order to determine the total dose for the remainder of the gestation period.  3.2.3 For pre-existing body burdens from occupational exposure, the total burden determined to exist at time of pregnancy should be assumed to be available for uptake in the blood of the woman. The dose should be assigned to the embryo/fetus as if the maternal blood uptake occurs within the first month of pregnancy.
APPENDIX C
                          RADIATION ABSORBED DOSE TO THE EMBRYO/FETUS
                  FOLLOWIN


The embryo/fetus dose is calculated by multiplying the maternal burden of the radionuclide by its dose factor (Equation
==G. INTRODUCTION==
3). The dose factor to be used from the Appendix C tables is that factor corre sponding to the cumulated dose for a 0-day of gesta tion at radionuclide introduction (i.e., right-most col umn, first data entry). However, for those radi onuclides with an "N" for this 0-day entry, the entry for the second gestation month should be used (i.e., the right-most column, second data entry). Alterna tively, time-dependent release kinetics may be used for calculating that fraction of the body burden that is translocated to the blood through the duration of the pregnancy.
OF SPECIFIED RADIONUCLIDES AND
          CHEMICAL FORMS INTO THE MATERNAL TRANSFER COMPARTMENT (BLOOD)
      The entries for selected radionuclides and chemi              As noted in Revision 1 to NUREG/CR-5631 cal forms in the tables in this appendix have been            (Ref. Cl), ICRP Publication 30 (Ref. C2) employs a calculated from the modeling presented in Revision I          metabolic model in which a fraction of activity in the to NUREG/CR-5631 (Ref. Cl). It has been assumed              first transfer compartment (blood) often is assumed that 1 jiCi of activity is introduced into the maternal      to go immediately to excretion. Because of the minus transfer compartment (blood). Pregnancy is assumed            cule mass of the embryo/fetus immediately following to begin at the time of fertilization, roughly 2 weeks        fertilization, for some materials the biokinetic model after menses, and gestation is considered to consist of      thus predicts that there would be negligible initial ac nine 30-day months.                                          tivity in the embryo after administration at that time, and that there would be minimal activity at later times. As a consequence, the dose rate and doses Radiation dose rates were calculated from the in        also would be negligible, which is indicated by N in itial fraction that was present after a single administra    the table. For these nuclides, an approximation of the tion at the start of each of these months or on the           cumulative dose for an intake occurring during the assumed final day (day 270) of gestation. Monthly            first 30 days should be made based on a time doses were determined by integrating under the curve          weighted average of the 31-day intake data. The cu relating the fraction of the activity in the embryo/fetus    mulative dose from an intake in the first 30 days of at the start of each month after administration and          pregnancy may be estimated by multiplying the
                                                              31-day cumulated dose value by the ratio of the days the fraction at the beginning of the subsequent month to-date in the first month to a 30-day period. For ex of gestation. Monthly doses are shown for the inclu ample, assuming a maternal intake of 14C resulting in sive periods, expressed in days. Doses to the embryo/        a I-RCi blood uptake on the 20th day of the preg fetus from radionuclides in maternal organs were cal          nancy, the gestation dose should be determined by culated; when appropriate, these are included to pro          multiplying the cumulated dose from an intake at day vide total radiation absorbed doses. The tabulated            31 (i.e., Table C3, Cumulated Dose column, ialues of cumulated doses were determined as the            1.89E-04 rads) by the ratio of 20 days to 30 days sum of the monthly doses.                                    (i.e., 20 divided by 30).
                                                          C-1


The time-dependent release is described in ICRP Publications
Table C1 Radiation Doses to the Embryo/Fetus from 1 gCi of 3H, as Tritiated Water, Introduced into the Maternal Transfer Compartment (Blood)
30 and 54 (Refs. 3 and 6). This approach is complex, involving interlinking differen tial equations, and is considered outside the scope of a routine health physics program.
        Days of Gestation at                                Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                                          Cumulated Introduction        0-30            31-60                                                                                                                      Dose
                                                          61-90        91-120        121-150        151-180        181-210        211-240        241-270          0-270
          0              9.03E-06      3.96E-11        7.*71*.-1 14  2.OOE-15      5.31E-17      2.63E-18      1.72E-19        1.34E-20        1.18E-21      9.03E-06
        31                            1.77E-05        2.64E-0 )8    7.50E-10        1.94E-11      9.70E-13      6.30E-14        4.94E-15      4.33E-16        1.77E-05
        ,61                                            3.93E-0 '5    8.96E-07        2.47E-08      1.21E-09      7.91E-11        6.17E-12      5.41E-13        4.02E-05
        91                                                          3.82E-05        1.06E-06      5.19E-08      3.39E-09      2.64E-10        2.32E-11        3.93E-05
        121                                                                          4.50E-05      2.14E-06      1.41E-07        1.10E-08      9.63E-10        4.73E-05
      151                                                                                          4.98E-05      3.22E-06      2.53E-07        2.21E-08        5.33E-05
      181
                                                                                                                    5.28E-05      4.08E-06        3.57E-07        5.72E-05
      211
      241
                                                                                                                                  5.40E-05        4.70E-06        5.87E-05
                                                                                                                                                  5.28E-05        5.28E-05 Table C2 C.)                                       Radiation Doses to the Embryo/Fetus from 1 pCi of 3H, as a Hexose or Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)
        Days of Gestation at                                Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                                          Cumulated Introduction        A
                        Nj*u'A
                                        31-60            61-90                                                                                                    Dose
                                                                    91-120          121-150        151-180        181-210        211-240        241-270          0-270
          0                          -N              N            N .            N              N              N              N              N              N
        31                            2.21E-05 2.14E-07 4.68E-08 1.04E-08                          4.37E-09      2.35E-09        1.50E-09        1.06E-09      2.24E-05
        61                                            6.OOE-05      7.27E-06        1.67E-06      6.81E-07 3.68E-07            2.34E-07        1.66E-07      7.04E-05
        91                                                          5.82E-05        9.25E-06      3.69E-06      1.97E-06        1.26E-06      8.92E-07        7.53E-05
      121                                                                            7.24E-05      1.97E-05 1.03E-05            6.50E-06        4.62E-06        1. 14E-04
      151                                                                                          8.29E-05 3.05E-05            1.89E-05        1.33E-05        1.46E-04
      181
                                                                                                                  8.96E-05      3.93E-05        2.72E-05        1.56E-04
    211
                                                                                                                                  9.31E-05        4.58E-05        1.39E-04
    241
                                                                                                                                                  1.05E-04        1.OSE-04 N indicates that the metabolid pattern is such that the dose rates and doses would be negligible fertilization. Approximations of doses resulting from administration during the                  throughout gestation when activity is administered immediately after first month are described on page C-1.


3.3 Doses from multiple nuclides and multiple intakes should be evaluated with a frequency corre sponding to the intake (i.e., at least once every 30 days). Multiple dose determinations should be added to determine the total dose. Doses may need to be reevaluated if better estimates of intakes are provided by followup bioassay measurements.
Table C3 Radiation Doses to the Embryo/Fetus from 1 jiCi of 14C, as a Bicarbonate, Hexose, Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)
    Days of Gestation at                                Dose (rad) to Embryo/Fetus During Indicated Gestatio )n Periods (days)                                        Cumulated
                    0-30            31-60                                                                                                                      Dose Introduction        0-30            31-60          61-90        91-120        121-150        151-180        181-210        21i-240        241-270          0-270
      0            N*            N              N              N              N              N            N              N              N              N
    31                            1.87E-04      1.72E-06      4.12E-07      9.18E-08        3.88E-08      2.09E-08        1.34E-08        9.56E-09        1.89E-04
    61                                            4.96E-04      5.83E-05      1.46E-05        6.02E-06      3,26E-06        2.09E-06        1.49E-06        5.82E-04
    91                                                          4.8 1E-04      7.48E-05      3.24E-05        1.74E-05      1.IIE-05        7.95E-06        6.25E-04
  121                                                                          5.96E-04        1.59E-04      9.09E-05        5.74E-05        4.1IE-05        9.44E-04
  151                                                                                          6.80E-04      2.47E-04        1.66E-04        1. 17E-04      1.21E-03
  181                                                                                                        7.33E-04        3.19E-04        2.39E-04        1.29E-03
  211
                                                                                                                              7.61E-04        3.70E-04        1.13E-03
  241
                                                                                                                                              8.88E-04      8.88E-04 Table C4 Radiation Doses to the Embryo/Fetus from 1 gCi of 5 7Co Introduced into the Maternal Transfer Compartment (Blood)
    Days of Gestation at                               Dose (rad) to Embryo/Fetus During Indic*ated Gestation Periods (days)                                         Cumulated Introduction      0-30                                                                        151-180        181-210        211-240        241-270          Dose
                                                                                                                                                              0-270
                                    31-60          61-90        91-120        121-150
      0            7.30E-04      2.76E-04        2.36E-04      1.97E-04      1.75E-04        1.56E-04      1.39E-04      1.23E-04        1.09E-04        2.14E-03
    31                            8.66E-04        2.74E-04      2.45E-04      2.07E-04        1.82E-04      1.60E-04      1.41E-04        1.24E-04        2.20E-03
    61                                            8.71E-04      2.82E-04      2.56E-04      2.15E-04      1.88E-04        1.63E-04        1.42E-04      2.12E-03
    91                                                          8.96E-04      2.96E-04      2.67E-04      2.22E-04        1.91E-04        1.64E-04      2.04E-03
  121                                                                          9.37E-04      3.08E-04      2.75E-04        2.25E-04        1.92E-04        1.94E-03
  151                                                                                          9.78E-04      3.18E-04        2.79E-04        2.27E-04      1.80E-03
  181                                                                                                        1.01E-03        3.22E-04        2.83E-04      1.61E-03
211
                                                                                                                              1.03E-03        3.19E-04      1.35E-03
241
                                                                                                                                              1.04E-03      1.04E-03
*N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.


==D. IMPLEMENTATION==
Table C5 Radiation Doses to the Embryo/Fetus from 1 gCi of 68Co, Introduced into the Maternal Transfer Compartment (Blood)
The purpose of this section is to provide informa tion to applicants and licensees regarding the NRC staff's plans for using this regulatory guide.  Except in those cases in which an applicant pro poses an acceptable alternative method of complying with specified portions of the Commission's regula tions, the methods described in this guide will be used 5 The correlation of intake to actual stage of gestation can only be roughly estimated.
    Days of Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestatio 9n Periods (days)                    Cumulated Dose Introduction  0-30        31-60        61-90    91-120    121-150    151-180        181-210        211-240  241-270    0-270
      0        4.81E-03  1.27E-03    9.03E-04  6.03E-04  4.25E-04    3.OOE-04      2.13E-04        1.52E-04  1.09E-04  8.79E-03
    31                  5.12E-03    1.30E-03  9.30E-04  6.24E-04    4.37E-04      3.06E-04        2.15E-04  1.53E-04  9.08E-03
    61                                5.26E-03  1.34E-03  9.62E-04    6.41E-04      4.45E-04        3.09E-04  2.17E-04  9.17E-03
    91                                          5.39E-03  1.38E-03    9.88E-04      6.54E-04        4.49E-04  3.11E-04  9.17E-03
  121                                                      5.59E-03    1.42E-03      1.01E-03        6.59E-04  4.53E-04  9.13E-03
  151                                                                  5.75E-03      1.45E-03        1.02E-03  6.64E-04  8.88E-03
  181                                                                                  5.87E-03        1.46E-03  1.03E-03  8.36E-03
  211
  241                                                                                                  5.95E-03  1.45E-03  7.40E-03
                                                                                                                  6.OOE-03  6.00E-03 Table C6 Radiation Doses to the Embryo/Fetus from 1 jiCi of 6oCo, Introduced into the Maternal Transfer Compartment (Blood)
  Days of Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day                        Cumulated ys)                      Dose Introduction  0-30        31-60        61-90    91-120    121-150    151-180      181-210        211-240    241-270    0-270
      0        1.28E-02  4.73E-03    4.37E-03  3.79E-03    3.60E-03    3.40E-03    3.22E-03        3.05E-03  2.88E-03  4.18E-02
    31                  1.38E-02    4.73E-03  4.40E-03    3.98E-03    3.73E-03    3.48E-03        3.26E-03  3.06E-03  4.04E-02
  61                                1.39E-02  4.76E-03    4.62E-03    4.12E-03      3.8 1E-03      3.52E-03  3.27E-03  3.80E-02
  91                                            1.40E-02  4.99E-03    4.79E-03      4.22E-03        3.86E-03  3.54E-03  3.54E-02
  121                                                      1.46E-02    5.17F-03      4.90E-03        4.27E-03  3.88E-03  3.28E-02
  151                                                                    1.52E-02    5.29E-03        4.96E-03  4.29E-03  2.97E-02
  181                                                                                1.56E-02        5.35E-03  5.01E-03  2.60E-02
211
                                                                                                      1.59E-02  5.29E-03  2.12E-02
241
                                                                                                                1.60E-02  1.60E-02


For this reason, it is believed that the correlation should be limited to the best estimate of the month of gestation.
Table C7 Radiation Doses to the Embryo/Fetus from 1          gCi  of 57Co, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)
    Days of                                                                                                            Cumulated Gestation at                  Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)
                                                                                                                          Dose Introduction 0-30        31-60        61-90    91-120      121-150      151-180      181-210        211-240  241-270      0-270
      0        1.47E-03  1.11E-03    7.18E-04  4.88E-04    3.34E-04    2.28E-04    1.54E-04      1.02E-04  6,74E-05  4.67E-03
    31                  1.67E-03    1.10E-03  7.44E-04    5.1OE-04    3.48E-04    2.35E-04      1.56E-04  1.03E-04  4.87E-03
    61                              1,68E-03  1.14E-03    7.80E-04    5.31E-04    3.59E-04      2.38E-04  1.57E-04  4.89E-03
    91                                          1.74E-03    1.19E-03    8.13E-04    5.49E-04      3.64E-04  2.40E-04  4.90E-03
  121                                                      1.82E-03    1.24E-03    8.38E-04      5.56E-04  3.67E-04  4.82E-03
  151                                                                    1.89E-03    1.28E-03      8.48E-04  5.60E-04  4.58E-03
  181                                                                                1.95E-03      1.30E-03  8.55E-04  4.1OE-03
  211                                                                                                1.98E-03  1.31E-03  3.29E-03
  241                                                                                                          1.99E-03  1.99E-03 Table C8 Radiation Doses to the Embryo/Fetus from 1 gCi of 6oCo, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)
  Days of                                                                                                             Cumulated Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da~ys)                      Dose Introduction  0-30        31-60      61-90    91-120      121-150    151-180      .181-210      211-240  241-270    0-270
    0        2.54E-02  1.90E-02    1.33E-02  9.38E-03    6.88E-03    4.98E-03    3.56E-03      2.52E-03  1.77E-03  8.68E-02
    31                  2.71E-02    1.90E-02  1.34E-02    9.82E-03    7. 1OE-03    5.09E-03      3.61E-03  2.53E-03    8.76E-02
    61                              2.70E-02  1.91E-02    1.40E-02    1.02E-02    7.28E-03      5.16E-03  3.62E-03  8.64E-02
  91                                          2.74E-02    2.OOE-02    1.45E-02    1.04E-02      7,38E-03  5.18E-03  8.49E-02
  121                                                      2.86E-02    2.08E-02    1.49E-02      1.05E-02  7.4 1E-03  8.22E-02
  151                                                                    2.97E-02    2.13E-02      1.5 1E-02 1.06E-02  7.67E-02
  181                                                                                3.04E-02      2.15E-02  1.51E-02  6.70E-02
  211                                                                                              3.08E-02  2.16E-02  5.24E-02
  241                                                                                                        3. 1OE-02  3. 1OE-02


8.36-6[
Table C9 Radiation Doses to the Embryo/Fetus from 1 jiCi of 89Sr Introduced into the Maternal Transfer Compartment (Blood)
in the evaluation of applications for new licenses, li cense renewals, and license amendments and for evaluating compliance with 10 CFR 20.1001"1.2401.
      Days of Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                    Cumulated Introduction  0-30        31-60      61-90    91-120      121-150      151-180                                          Dose
                                                                                        181-210      211-240    241-270      0-270
        0        4.09E-03  5.66E-04    2.92E-04  1.37E-04    6.64E-05    3.59E-05    2.10E-05    1.23E-05  7.01E-06    5.23E-03
      31                  5.35E-03    5.74E-04  2,95E-04    1.36E-04    6.57E-05    3.53E-05    2.05E-05  1.20E-05    6.49E-03
      61                                9.01E-03  1.20E-03    3.84E-04    1.63E-04    7.45E-05    3.86E-05  2.18E-05    1.09E-02
      91                                          9.09E-03    1.36E-03    5.06E-04    2.12E-04    9.67E-05  4.93E-05    1.13E-02
    121                                                      1.07E-02    2.24E-03    8.99E-04    3.90E-04  1.84E-04    1.44E-02
    151
                                                                            1.19E-02    3.15E-03    1.40E-03  6.55E-04    1.71E-02
    181
                                                                                        1.26E-02    3.87E-03  1.89E-03    1.84E-02
    211
                                                                                                      1.29E-02  4.38E-03    1.73E-02
    241
                                                                                                                1.31E-02    1.31E-02
0
                                                                Table C10
                        Radiation Doses to the Embryo/Fetus from 1 jiCi of 90Sr (in Equilibrium with 90Y)
                                    Introduced into the Maternal Transfer Compartment (Blood)
    Days of Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da: s)                  Cumulated Introduction  0-30        31-60      61-90                                                                                Dose
                                                  91-120      121-150    151-180      .181-210      211-240    241-270    0-270
      0        9.07E-03  2.01E-03    1.57E-03  1.1OE-03    8.07E-04    6.58E-04    5.81E-04    5.15E-04  4.43E-04    1.68E-02
    31                    1.13E-02    2.04E-03  1.57E-03    1.09E-03    7.99E-04    6.49E-04    5.69E-04  5.00E-04    1.85E-02
    61                                2.03E-02  3.60E-03    1.72E-03    1.33E-03    8.94E-04    7.10E-04  6.04E-04  2.92E-02
    91                                          1.50E-02    3.31E-03    2.80E-03      1.67E-03    1.17E-03  8.98E-04  2.48E-02
    121                                                      1.90E-02    7.93E-03    4.71E-03      3.11E-03  2.22E-03  3.70E-02
  151
                                                                          2.69E-02      1.1OE-02    7.41E-03  5.23E-03  5.05E-02
  181
                                                                                      2.86E-02      1.36E-02  1.00E-02  5.22E-02
  211
  241                                                                                              2.95E-02    1.54E-02  4.49E-02
                                                                                                                2.93E-02  2.93E-02


REFERENCES
Table Cl1 Radiation Doses to the Embryo/Fetus from 1 giCi of 106Ru (in Equilibrium with
1. International Commission on Radiological Pro tection, "Age-Dependent Doses to Members of the Public from Intake of Radionuclides:
                                106Rh) Introduced into the Maternal Transfer Compartment (Blood)
Part 1," ICRP No. 56, Pergamon Press Inc., 1989.  2. M. R. Sikov et al., "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Doses--Interim Recommendations," NUREG/ CR-5631, Revision 1 (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992.  3. International Commission on Radiological Pro tection, "Limits for Intakes of Radionuclides by Workers," ICRP No. 30, Parts 1 through 4, including supplements, Annals of the ICRP, Volume 2, No. 3/4, Pergamon Press Inc., 1979. 4. K. F. Eckerman, A. B. Wolbarst, and A. C. B.  Richardson, "Limiting Values of Radionuclide Intake and Air Concentration and Dose Conver sion Factors for Inhalation, Submersion, and Ingestion," Environmental Protection Agency, Federal Guidance Report No. 11 (EPA- 520/1 88-020), September
    Days of                                                                                                             Cumulated Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da3ys)                    Dose Introduction 0-30        31-60      61-90    91-120      121-150      151-180    181-210        211-240  241-270    0-270
1988.  5. International Commission on Radiological Pro tection, "The Metabolism of Compounds of Plutonium and Other Actinides," ICRP No. 19, Pergamon Press Inc., May 1972.  6. International Commission on Radiological Pro tection, "Individual Monitoring for Intake of Radionuclides by Workers: Design and Interpre tation," ICRP No. 54, Annals of the ICRP, Volume 19, No. 1-3, Pergamon Press Inc., 1988.8.36-7 APPENDIX A DOSE EQUIVALENT
      0        1.56E-03 1.OOE-03    9.36E-04  7.68E-04    6.67E-04    5.94E-04    5.35E-04      4.85E-04  4.41E-04  6.99E-03
FACTORS FOR USE IN APPROXIMATING
    31                    2.02E-03    1.21E-03  9.48E-04    7.77E-04    6.72E-04    5.94E-04      5.32E-04 4.80E-04  7.23E-03
THE EMBRYO/FETUS
    61                                2.42E-03  1.23E-03    9.56E-04    7.80E-04    6.70E-04      5.90E-04  5.27E-04 7.17E-03
DOSE FROM RADIONUCLIDES
    91                                            2.50E-03    1.24E-03    9.68E-04    7.84E-04      6.68E-04  5.85E-04  6.74E-03
IN MATERNAL BLOOD Except as noted, the dose factors (DFi) pre sented in Table A-1 represent the committed dose equivalent to the uterus per introduction of unit activ ity into the first transfer compartment (i.e., blood) of the woman. These entries were calculated from tabu lated values of uterine committed dose equivalent per unit intake and fractional absorption (fl) from the gastrointestinal tract using ICRP-30 (Ref. Al) meth odology. The DFi dose factors were derived by divid ing the committed dose equivalent per unit intake by the fractional absorption factor (fl). These dose fac tors are based on unit activity in the blood. The most conservative f, (i.e., largest fraction)
    121                                                        2.53E-03    1.25E-03    9.63E-04      7.77E-04  6.62E-04  6.18E-03
for each radio nuclide has been used for deriving the data in Table A-1. For the radionuclides
    151                                                                    2.551E-03  1.26E-03      9.59E-04  7.69E-04  5.54E-03
3 H, 14C, 5 7 Co, 68Co, SOCo, 89Sr, 9°Sr, 106Ru, 125I, 131j, 132j, 133I, 134I, 135j, 134Cs, 1 3 7 Cs, 23U, 23U, 23U, ZaU, MSPu, ZaPu, and 2 4 1Am, the dose factors in Table A-1 represent the maximum dose equivalent to the embryo/fetus for the gestation period from the introduction of unit activity into the first transfer compartment of the woman at any time during the gestation period. These entries are based on the modeling of Revision 1 to NUREG/ CR-5631 (Ref. A2) and are derived from the data tables presented in Appendix C to this guide. The maximum calculated embryo/fetus dose (as presented in the Appendix C tables) from intake by the de clared pregnant woman during the gestation period has been used for inclusion in Table A-1.  The dose factor data presented in Revision 1 to NUREG/CR-5631 (Ref. A2) are for an absorbed dose expressed in units of rads. To adapt these data as presented in Appendix C to this guide for inclusion in Table A-i, appropriate quality factors have been applied to convert from rads to dose equivalent, ex pressed in units of rem. For beta- and gamma-emit ting radionuclides, a quality factor of 1 has been ap plied. For 2 wU, 234U, 235U, 238U, 238PU, 239pu, and 2 4 1 Am, a quality factor of 20 has been applied, recog nizing that most of the embryo/fetus dose results from the alpha decay.A-I
    181                                                                                2.55E-03      1.25E-03  9.55E-04  4.75E-03
TABLE A-1 Dose Equivalent Factors for Use in Approximating the Embryo/Fetus Dose from Radionuclides in Maternal Blood DFi DFi DFi Nuclide (rem/gCi)
    211                                                                                                2.54E-03  1.23E-03  3.77E-03
Nuclide (rem/ljCi)
    241                                                                                                          2.53E-03  2.53E-03
Nuclide (rem/ACi)H-3 Be-7 Be-10 C-11 C-14 F-18 Na-22 Na-24 Mg-28 A1-26 Si-31 Si-32 P-32 P-33 S-35 CI-36 CI-38 C1-39 K-40 K-42 K-43 K-44 K-45 Ca-41 Ca-45 Ca-47 Sc-43 Sc-44 Sc-44m Sc-46 Sc-47 Sc-48 Sc-49 Ti-44 Ti-45 V-47 V-48 V-49 Cr-48 Cr-49 5.87E-05" 1.67E-02 1.79E-02 1.21E-OS 1.29E-03*
0                                                                Table C12 Radiation Doses to the Embryo/Fetus from 1 giCi of 1251 Introduced into the Maternal Transfer Compartment (Blood)
1.32E-05 1.06E-02 1.21E-03 3.83E-03 5.33E-01 3.85E-05 4.33E-02 3.03E-03 4.33E-04 3.53E-04 2.96E-03 3.17E-05 3.89E-05 1.84E-02 7.73E-04 7.10E-04 1.94E-05 1.21E-05 3.2 IE-05 6.6 1E-04 5.18E-03 2.48E+00 4.59E+00 2.56E+01 3.15E+O1 1.86E+00 3.52E+01 4.18E-04 1.36E+00 1.54E-02 2.29E-03 4.37E-01 8.36E-05 5.77E-03 3.51E-04 Cr-51 Mn-51 Mn-52 Mn-52m Mn-53 Mn-54 Mn-56 Fe-52 Fe-55 Fe-59 Fe-60 Co-55 Co-56 Co-57 Co-58 Co-58m Co-60 Co-60m Co-61 Co-62m Ni-56 Ni-57 Ni-59 Ni-63 Ni-65 Ni-66 Cu-60 Cu-61 Cu-64 Cu-67 Zn-62 Zn-63 Zn-65 Zn-69 Zn-69m Zn-71m Zn-72 Ga-65 Ga-66 Ga-67 6.96E-04 3.65E-04 4.70E-02 2.80E-04 5.77E-05 1.86E-02 2.18E-03 1.30E-02 3.88E-03 4.63E-02 1.47E+00 4.01E-03 3.43E-02 2.20E-03*
    Days of                                                                                                              Cumulated Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)
9.17E-03" 5.17E-05 4.18E-02*
                                                                                                                            Dose Introduction  0-30        31-60        61-90    91-120      121-150      151-180    181-210        211-2 )40 241-270    0-270
4.12E-07 4.50E-05 5.33E-05 5.39E-02 3.60E-02 2.71E-03 6.29E-03 1.43E-03 2.81E-03 9.32E-05 2.69E-04 2.09E-04 6.50E-04 1.38E-03 5.92E-05 3.49E-02 3.09E-06 5.54E-04 5.75E-04 5.28E-03 9.18E-03 9.95E-01 2.50E-01 Ga-68 Ga-70 Ga-72 Ga-73 Ge-66 Ge-67 Ge-68 Ge-69 Ge-71 Ge-75 Ge-77 Ge-78 As-69 As-70 As-71 As-72 As-73 As-74 As-76 As-77 As-78 Se-70 Se-73 Se-73m Se-75 Se-79 Se-81 Se-81m Se-83 Br-74 Br-74m Br-75 Br-76 Br-77 Br-80 Br-80m Br-82 Br-83 Br-84 Rb-79 5.66E-02 8.99E-05 1.53E+00 9.36E-02 1.42E-04 1.11E-05 8.81E-04 3.02E-04 6.99E-06 1.61E-05 3.40E-04 1.08E-04 2.46E-05 2.90E-04 1.21E-03 2.70E-03 3.02E-04 2.90E-03 1.11E-03 1.88E-04 1.85E-04 1.61E-04 3.66E-04 3.21E-05 8.79E-03 4.19E-03 1.OOE-06 1.46E-05 3.62E-05 3.33E-05 6.18E-05 6.07E-05 1.20E-03 3.27E-04 3.01E-06 1.46E-04 1. 87E-03 2.72E-05 2.56E-05 1. 15E-05*Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.A-2 L ;
      0        2.081E-05 1.12E-05    7.34E-06    1.34E-05    1.46E-05     6.07E-06    4.65E-06      3.01E-06  2.07E-06  8.31E-05
TABLE A-1 (continued)
    31                    2.72E-05    1.05E-05    1.27E-05    1.40E-05    1.04E-05    7.27E-06      4.83E-06  3.31E-06  9.02E-05
DFi DFi -DFi Nuclide (rem/4Ci)
    61                                2.74E-05    1.70E-05   2.23E-05     1.63E-05    1. 15E-05     7.66E-06  5.28E-06  1.07E-04
Nuclide (reml/gCi)
    91                                            1.64E-04   5.21E-05    3.23E-05    2.05E-05      1.31E-05  8.84E-06  2.91E-04
Nuclide (rem/gCi)Rb-81 Rb-8 lm Rb-82m Rb-83 Rb-84 Rb-86 Rb-87 Rb-88 Rb-89 Sr-80 Sr-81 Sr-82 Sr-83 Sr-85 Sr-85m Sr-87m Sr-89 Sr-90 Sr-91 Sr-92 Y-86 Y-86m Y-87 Y-88 Y-90 Y-90m Y-91 Y-9 1m Y-92 Y-93 Y-94 Y-95 Zr-86 Zr-88 Zr-89 Zr-93 Zr-95 Zr-97 Nb-88 Nb-89 Nb-89 8.18E-05 1.08E-05 3.49E-04 7.07E-03 1.05E-02 8.14E-03 4.22E-03 1.02E-05 1.20E-05 3.96E-04 1.22E-04 1.25E-02 2.31E-03 4.03E-03 4.8 1E-05 1. 62E-04 1.84E-02" 5.22E-02*
    121                                                        8.79E-04     2.88E-04    1.22E-04      5.70E-05  3.05E-05  1.38E-03
1.49E-03 7.79E-04 2.18E+01 1.26E+00 1.01E+01 3.96E+01 4.66E-04 1.21E+00 6.03E-02 2.13E-01 4.81E-01 4.18E-01 1.10E-01 3.56E-02 8.62E-01 3.87E-01 7.31E-01 8.79E-05 6.16E-01 5.24E-01 1.17E-03 1.83E-02 1.30E-02 Nb-90 Nb-93m Nb-94 Nb-95 Nb-95m Nb-96 Nb-97 Nb-98 Mo-90 Mo-93 Mo-93m Mo-99 Mo-101 Tc-93 Tc-93m Tc-94 Tc-94m Tc-95 Tc-95m Tc-96 Tc-96m Tc-97 Tc-97m Tc-98 Tc-99 Tc-99m Tc-101 Tc-104 Ru-94 Ru-97 Ru-103 Ru-105 Ru-106 Rh-99 Rh-99m Rh--100 Rh-101 Rh-101m Rh-102 Rh-102m Rh-103m* 2.39E-01 9.29E-04 3.04E-01 1.24E-01 1.27E-02 2.03E-01 4.11E-03 9.66E-03 7.77E-04 4.36E-04 4.76E-04 9.39E-04 1.48E-05 1.33E-04 4.67E-05 4.566E-04
    151                                                                    7.81E-04    3.12E-04      1.40E-04  7.08E-05  1.30E-03
7.08E-05 3.86E-04 1.23E-03 2.62E-03 2.29E-05 4.67E-05 2.42E-04 2.97E-03 2.79E-04 3.32E-05 2.96E-06 2.07E-05 2.32E-03 6.89E-03 1.97E-02 4.09E-03 7.23E-03*
    181                                                                                6.78E-04      2.99E-04  1.48E-04  1. 12E-03
2.19E-02 3.5 1E-03 3.86E-02 3.33E-102
    211                                                                                              5.97E-04  2.98E-04  8.95E-04
9.40E-03 1.93E-01 3.48E-02 1.18E-06*Dose equivalent factor based on data presented in Revision I to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.A-3 Rh-105 Rh-106m Rh-107 Pd-100 Pd-101 Pd-103 Pd-107 Pd-109 Ag-102 Ag-103 Ag-104 Ag-104m Ag-105 Ag-106 Ag-106m Ag-108m Ag-110in Ag-111 Ag-i112 Ag-115 Cd-104 Cd-107 Cd-109 Cd-i113 Cd-113m Cd- 115 Cd-l15m Cd-117 Cd-117m In-109 In-1l0 In-110 In-Ill In-112 In- 1i3m In-i 14m In-115 In-l 15m In-l 16m In-i 17 In-I17m 1.93E-03 6.86E-03 8.511E-05
    241                                                                                                          5.33E-04  5.33E-04
3.94E-01 3.33E-02 1.39E-03 7.33E-06 1.27E-03 3.76E-04 8.58E-04 3.05E-03 1.09E-03 1.94E-02 2.12E-04 8.21E-02 6.59E-02 1.04E-01 1.41E-03 2.18E-03 1.98E-04 3.30E-03 1.95E-04 2.12E-02 2.77E-01 2.55E-01 9.47E-03 1.27E-02 4.23E-03 9.62E-03 7.95E-03 4.01E-02 4.50E-03 3.05E-02 9.47E-05 1.24E-03 3.05E-02 8.99E-01 2.16E-03 4.92E-03 1.22E-03 2.61E-03 TABLE A-1 (continued)
DFi DFi DFi Nuclide (rem/!gCi)
Nuclide (rem/gCi)
Nuclide (rem/gCi)In-1 19m Sn-110 Sn-ill Sn-1l3 Sn-il7m Sn-119m Sn-121 Sn-121m Sn-123 Sn-123m Sn-125 Sn-126 Sn-127 Sn-128 Sb-i 15 Sb-I 16 Sb-116m Sb-i 17 Sb-1 18m Sb- 119 Sb-120 Sb-120 Sb-122 Sb-124 Sb-124m Sb-125 Sb-126 Sb-126m Sb-127 Sb-128 Sb-128 Sb-129 Sb-130 Sb-131 Te-116 Te-121 Te-121m Te-123 Te-123m Te-125m Te-127 1.39E-05 2.1IE-02 8.8 1E-04 2.63E-02 1.57E-02 2.29E-03 3.70E-05 5.70E-03 6.35E-03 2.48E-04 2.37E-02 2.35E-01 1.14E-02 7.14E-03 2.OOE-04 1.59E-04 1.49E-03 3.34E-04 6.59E-03 2.08E-04 3.70E-05 3.42E-02 5.85E-03 2.98E-02 4.88E-05 8.5IE-03 4.37E-02 1.69E-04 9.66E-03 1.33E-04 8.73E-03 3.36E-03 9.40E-04 3.36E-04 1.45E-03 4.87E-03 7.90E-03 3.09E-05 2.94E-03 9.75E-04 6.31E-05 Te-127m Te-129 Te-129m Te-131 Te-131m Te-132 Te-133 Te-133mn Te-134 i-120 l-120m 1-121 1-123 1-124 1-125 1-126 1-128 1-129 1-130 1-131 1-132 1-132m 1-133 1-134 1-135 Cs-125 Cs-127 Cs-129 Cs-130 Cs-131 Cs-132 Cs-134 Cs-134m Cs-135 Cs-135m Cs-136 Cs-137 Cs-138 Ba-126 Ba-128 Ba-131 1. 82E-03 2.35E-05 3.39E-03 2.18E-04 6.64E-03 8.57E-03 3.26E-05 5.48E-04 3.98E-04 9.36E-05 8.73E-05 1.79E-05 2.27E-05 2.16E-04 1.38E-03*
2.23E-04 5.25E-06 5.11E-04 2.29E-04 3.64E-03" 1.56E-04*
6.14E-05 9.04E-04*
4.83E-05*
3.72E-04" 1.33E-05 5.96E-05 2.13E-04 6.99E-06 2.27E-04 2. 1OE-03 1.IiE-01*
2.66E-05 7.07E-03 2.42E-05 1.42E-02 5.94E-02*
2.95E-05 1.14E-03 1. 17E-02 7.40E-03 Ba-131m Ba-133 Ba-133m Ba-135m Ba-139 Ba-140 Ba-141 Ba-142 La-131 La-132 La-135 La-137 La-138 La-140 La-141 La-142 La-i43 Ce-134 Ce-135 Ce-137 Ce-137m Ce-139 Ce-14i Ce-i43 Ce-144 Pr-136 Pr-137 Pr-138m Pr-139 Pr-142 Pr-142m Pr-143 Pr-144 Pr-145 Pr-147 Nd-136 Nd-138 Nd-139 Nd-139m Nd-141 Nd-147 1.32E-05 1.27E-02 8.77E-04 7.03E-04 4.55E-05 1.54E-02 9.47E-05 2.74E-04 3.77E-02 5.07E-01 3.43E-02 7.55E-02 2.84E+00 2.32E+00 9.43E-03 1.91E-01 2.85E-03 3.13E+00 4.44E+00 7.13E-02 3.31E-01 I. 15E+00 5.56E-01 1.05E+00 3.79E-01 4.12E-02 1.26E-01 9.61E-01 1.16E-01 1.36E-01 1.73E-03 4.53E-08 8.44E-04 1.41E-02 1.95E-02 3.59E-01 8.26E-01 4.1IE-02 1.74E+00 4.33E-02 8.45E-01"Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.A-4 TABLE A-1 (continued)
DFi DFi DFi Nuclide (rem/gCi)
Nuclide (rem/gCi)
Nuclide (rem/!gCi)
Nd-149 Nd-15 1 Pm-141 Pm-143 Pm-144 Pm-145 Pm-146 Pm-147 Pm-148 Pm-148m Pm-149 Pm-150 Pm--151 Sm-141 Sm-141m Sm-142 Sm-145 Sm-146 Sm-147 Sm-151 Sm-153 Sm-155 Sm-156 Eu-145 Eu-146 Eu-147 Eu-148 Eu-149 Eu-150 Eu-150 Eu-152 Eu-152m Eu-154 Eu-155 Eu-156 Eu-157 Eu-158 Gd-145 Gd-146 Gd-i47 Gd-148 1.37E-01 2.53E-02 3.63E-02 1.79E+00 8.68E+00 2.58E-01 4.34E+00 3.49E-05 2.60E+00 1.08E+01 4.70E-02 6.86E-OI I. 1IE+00 4.11E-02 1.42E-01 2.11E-01 5.56E-01 0.OOE-01 0.OOE-01 1.26E-05 3.54E-01 5.65E-03 3.55E-01 2.OOE+00 3.38E+00 8.51E-01 3.53E+00 1.40E-01 2.92E-02 3.02E+00 2.20E+00 1.38E-01 2.28E+00 1.60E-01 1.90E+00 2.01E-01 3.56E-02 1.09E-01 4. 11E+00 4.9 iE+00 0.OOE-01 Gd-149 Gd-151 Gd-152 Gd-153 Gd-159 Tb-147 Tb-149 Tb-150 Tb-151 Tb-153 Tb-154 Tb-155 Tb-156 Th-156m Tb-156m Tb-157 Tb-158 Tb-160 Tb-161 Dy-155 Dy-157 Dy-159 Dy-165 Dy-166 Ho-155 Ho-157 Ho-159 Ho-161 Ho-162 Ho-162m Ho-164 Ho-164m Ho-166 Ho-166m Ho-167 Er-161 Er-165 Er-169 Er-171 Er-172 Tm-162 2.47E+00 4.99E-01 0.OOE-01 8.92E-01 1.52E-01 6.76E-01 1.27E+00 1.01E+00 2.33E+00 1.16E+00 5.65E+00 9.52E-01 8.65E+00 9.32E-01 2.89E-01 2.39E-02 4.79E+00 6.08E+00 2.64E-01 1.08E+00 5.8 1E-01 4.19E-01 1.3SE-02 3.56E-01 1.41E-01 2.57E-02 3.47E-02 4.70E-02 4.66E-03 1.43E-01 3. 1OE-03 1.32E-02 1.04E-01 1.07E+01 2.38E-01 6.29E-01 1. 12E-01 1.34E-04 5.88E-01 2.59E+00 6.87E-02 Tm-166 Tm-167 Tm-170 Tm-171 Tm-172 Tm-173 Tm-175 Yb-162 Yb-166 Yb- 167 Yb-169 Yb-175 Yb-177 Yb-178 Lu-169 Lu-170 Lu-171 Lu-172 Lu-173 Lu-174 Lu-174m Lu-176 Lu-176m Lu-177 Lu-177m Lu-178 Lu-178m Lu-179 Hf-170 Hf-172 Hf-173 Hf-175 Hf-177m Hf-178m Hf-179m Hf-180m Hf-181 Hf-182 Hf-182m Hf-183 Hf-184 2.37E+00 1.03E+00 5.38E-02 8.13E-03 1.89E+00 5.88E-01 2.70E-02 8.97E-02 6.08E+00 1.23E-02 2.47E+00 2.10E-01 6.98E-02 4.11E-02 3.60E+00 8.42E+00 3.72E+00 9.20E+00 1.10E+00 8.93E-01 5.54E-01 3.45E+00 1.53E-0 2.24E-0 1 6.80E+00 8.18E-03 5.54E-02 3.03E-02 4.74E-01 4.63E-01 2.26E-01 3.70E-01 5.22E-02 2.94E+00 8.51E-01 .71E-01 4.96E-01 1.16E+00 2.61E-02 2.33E-02 1.94E-01 A-5 TABLE A-1 (continued)
DFi DFi DFi Nuclide (rem/pCi)
Nuclide (rem/gCi)
Nuclide (rem/gCi)Ta-172 Ta-173 Ta-174 Ta-175 Ta-176 Ta-177 Ta-178 Ta-179 Ta-180 Ta-180m Ta-182 Ta-182m Ta-183 Ta-184 Ta-185 Ta-186 W-176 W-177 W-178 W-179 W-181 W-185 W-187 W-188 Re-177 Re-178 Re-181 Re-182 Re-182 Re-184 Re-184m Re-i86 Re-186m Re-187 Re-188 Re-188m Re-189 Os-180 Os-181 Os-182 Os-185 4.07E-02 1.94E-01 4.25E-02 4.96E-01 8.25E-01 1.30E-01 1.47E-01 9.40E-02 1.16E+00 3.47E-02 2.15E+00 2.65E-03 5.44E-01 7.40E-01 9.25E-03 7.03E-03 6.55E-04 3.66E-04 6.43E-04 8.12E-06 2.80E-04 3.51E-07 1.04E-03 1.68E-04 1.49E-05 8.37E-06 4.61E-04 4.56E-04 1.92E-03 1.64E-03 1.31E-03 4.53E-04 9.43E-04 1.82E-06 3.73E-04 8.19E-06 2.46E-04 1.78E-03 1.75E-02 1.07E-01 1.33E-01 Os-189m Os-191 Os-191m Os-193 Os-194 Ir-182 Ir-184 Ir-185 Ir-186 Ir-187 Ir-188 Ir-189 Ir-190 Ir-190m Ir-192 Ir-192m Ir-194 Ir-194m Ir-195 Ir-195m Pt-186 Pt-188 Pt-.189 Pt-191 Pt-193 Pt-193m Pt-195m Pt-197 Pt-197m Pt-199 Pt-200 Au-193 Au-194 Au-195 Au-198.  Au-198m Au-199 Au-200.  Au-200m Au-201 Hg-193 5.1IE-06 1.99E-02 1. 12E-03 8.55E-03 8.69E-02 2.23E-03 3.24E-02 3.85E-02 1.12E-01 2.08E-02 1.60E-01 1.96E-02 2.52E-01 1.OIE-03 1. 63E-0 1 8.99E-02 7.55E-03 4.55E-01 1.24E-03 1.03E-02 2.06E-02 1.21E-01 2.08E-02 4.88E-02 1.07E-04 2.71E-03 1.58E-02 2.64E-03 1.12E-03 5.40E-04 2.04E-02 1.63E-03 1.10E-02 2.35E-03 5.66E-03 1.05E-02 1.68E-03 1.01E-04 1.61E-02 1. 15E-05 4.88E-05 Hg-193m Hg-194 Hg-195 Hg-195m Hg-197 Hg-197m Hg-199m Hg-203 T1-194 Ti-194m TI-195 Ti-197 TI-198 TI-198m T1-199 T1-200 TI-201 TI-202 Tl-204 Pb-195m Pb-198 Pb-199 Pb-200 Pb-201 Pb-202 Pb-202m Pb-203 Pb-205 Pb-209 Pb-2 10 Pb-211 Pb-212 Pb-214 Bi-200 Bi-201 Bi-202 Bi-203 Bi-205 Bi-206 Bi-207 Bi-210 3.23E-04 1.81E-01 7.47E-05 5.48E-04 2.38E-04 2.97E-04 7.55E-06 5.33E-03 6.44E-06 2.16E-05 3.49E-05 3.85E-05 1.94E-04 8.36E-05 5.55E-05 6.55E-04 2.48E-04 1.38E-03 2.43E-03 1.65E-04 3.92E-04 6.5IE-04 3.37E-03 1.78E-03 6.77E-02 1.91E-03 2.02E-03 3.63E-04 9.93E-06 2.31E+00 3.63E-04 3.29E-02 5.64E-04 1.66E-03 4.07E-03 4.83E-03 2.54E-02 4.82E-02 9.03E-02 4.88E-02 1.46E-03 A-6 L
TABLE A-1 (continued)
DFi DFi DFi Nuclide (rem/pCi)
Nuclide (rem/gCi)
Nuclide (rem/gCi)
Bi-210m 8.66E-02 U-233 5.84E-01*
Am-245 2.68E-04 Bi-212 1.70E-03 U-234 5.84E-01" Am-246m 1.51E-02 Bi-213 4.36E-04 U-235 5.34E-01*
Am-246 2.03E-02 Bi-214 3.52E-04 U-236 1.81E-01 Cm-238 1.31E-01 Po-203 1.07E-03 U-237 5.42E-03 Cm-240 3.50E-02 Po-205 1.64E-03 U-238 5.10E-01*
Cm-241 8.69E-01 Po-207 4.03E-03 U-239 5.52E-05 Cm-242 3.30E-02 Po-210 3.05E+00 U-240 4.17E-03 Cm-243 3.74E-01 At-207 8.32E-04 Np-232 8.69E-03 Cm-244 3.19E-02 At-211 3.92E-02 Np-233 2.85E-03 Cm-245 3.11E-01 Fr-222 2.13E-03 Np-234 1.45E+00 Cm-246 1.27E-01 Fr-223 8.58E-03 Np-235 2.99E-03 Cm-247 9.51E-01 Ra-223 7.84E-01 Np-236 4.29E-01 Cm-248 3.49E+01 Ra-224 3.85E-01 Np-236 5.25E-02 Cm-249 1.07E-03 Ra-225 6.23E-01 Np-237 3.59E-01 Cm-250 2.76E+02 Ra-226 1.69E+00 Np-238 6.07E-01 Bk-245 4.11E-01 Ra-227 6.10E-05 Np-239 2.55E-01 Bk-246 1.04E+00 Ra-228 2.90E+00 Np-240 7.07E-02 Bk-247 2.83E-01 Ac-224 9.47E-02 Pu-234 1.24E-01 Bk-249 8.40E-04 Ac-225 3.68E-01 Pu-235 1.72E-03 Bk-250 1.54E-01 Ac-226 1.66E-01 Pu-236 6.81E-02 Cf-244 9.25E-05 Ac-227 2.60E-01 Pu-237 1.07E-01 Cf-246 2.88E-02 Ac-228 3.12E-0I Pu-238 1.11E+00*
Cf-248 4.18E-02 Th-226 3.02E-03 Pu-239 1.04E+00*
Cf-249 9.80E-01 Th-227 3.52E+00 Pu-240 2.80E-02 Cf-250 3.30E-01 Th-228 4.40E+O1 Pu-241 2.96E-04 Cf-251 4.26E-01 Th-229 8.51E+01 Pu-242 2.81E-02 Cf-252 1.15E+0O1 Th-230 1.26E+01 Pu-243 9.62E-03 Cf-253 8.55E-04 Th-231 8.97E-02 Pu-244 1.07E+00 Cf-254 3.70E+02 Th-232 2.26E+01 Pu-245 2.22E-01 Es-250 4.77E-02 Th-234 2.33E-01 Pu-246 1.34E+00 Es-251 1.24E-01 Pa-227 2.42E-03 Am-237 2.60E-02 Es-253 3.58E-02 Pa-228 9.58E-01 Am-238 7.81E-02 Es-254m 5.22E-01 Pa-230 1.04E+00 Am-239 1.63E-01 Es-254 1.33E+00 Pa-231 2.25E-01 Am-240 1.16E+00 Fm-252 2.61E-02 Pa-232 8.95E-01 Am-241 2.22E-01" Fm-253 1.38E-01 Pa-233 3.81E-01 Am-242m 3.64E-02 Fm-254 6.11E-03 Pa-234 6.77E-01 Am-242 1.32E-02 Fm-255 2.85E-02 U-230 6.13E-01 Am-243 4.74E-01 Fm-257 2.60E-01 U-231 2.63E-03 Am-244m 1.05E-05 Md-257 3.69E-02 U-232 6.02E-01 Am-244 3.92E-01 Md-258 5.96E-02 *Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.A-7 REFERENCES
Al. International Commission on Radiological Pro tection, "Limits for Intakes of Radionuclides by Workers," ICRP No. 30, Parts I through 4, including supplements, Annals of the ICRP, Volume 2, No. 3/4, Pergamon Press Inc., 1979.A2. M. R. Sikov et al., "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Dose-Interim Recommendations," NUREG/ CR-5631, Revision 1 (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992.I A-8 Element Actinium (Ac) Aluminum (Al) Americium (Am) Antimony (Sb) Arsenic (As) Astatine (At) Barium (Ba) Berkelium (Bk) Beryllium (Be) Bismuth (Bi) Bromine (Br) Cadmium (Cd) Calcium (Ca) Californium (Co Carbon (C) Cerium (Ce) Cesium (Cs) Chlorine (Cl) Chromium (Cr) Cobalt (Co) Copper (Cu) Curium (Cm) Dysprosium (Dy)APPENDIX B FRACTIONS
FOR B-1 BLOOD UPTAKE fi IE-3 IE-2 1E-3 1E-1 5E-1 1E0 IE-l 1E-3.  5E-3 5E-2 1E0 5E-2 3E-1 1E-3 1E0 3E-4 1E0 1E0 iE-I 3E-1 5E-1 1E-3 3E-4 INGESTED ACTIVTY Element Einsteinium (Es) Erbium (Er) Europium (Eu) Fermium (Fm) Fluorine (F) Francium (Fr) Gadolinium (Gd) Gallium (Ga) Germanium (Ge) Gold (Au) Hafnium (Hf) Holmium (Ho) Hydrogen (H) Indium (In) Iodine .(I) Iridium (Ir) Iron (Fe) Lanthanum (La) Lead (Pb) Lutetium (Lu) Magnesium (Mg) Manganese (Mn) Mendelevium (Md)fl 1E-3 3E-4 1E-3 1E-3 1E0 1E0 3E-4 1E-3 1E0 1E-1 2E-3 3E-4 lEO 2E-2 1E0 1E-2 1E-1 lE-3 2E-1 3E-4 5E-1 IE-1 lE-3 Element Mercury (Hg) Molybdenum (Mo) Neodymium (Nd) Neptunium (Np) Nickel (Ni) Niobium (Nb) Osmium (Os) Palladium (Pd) Phosphorus (P) Platinum (Pt) Plutonium (Pu) Polonium (Po) Potassium (K) Praseodymium (Pr) Promethium (Pm) Protactinium (Pa) Radium (Ra) Rhenium (Re) Rhodium (Rh) Rubidium (Rb) Ruthenium (Ru) Samarium (Sm) Scandium (Sc)B-2 fl 1EO 8E-1 3E-4 1E-3 5E-2 1E-2 1E-2 5E-3 8E-1 1E-2 1E-3 1E-1 1EO 3E-4 3E-4 1E-3 2E-1 8E-1 5E-2 1EO 5E-2 3E-4 1E-4 APPENDIX B (continued)
Element Selenium (Se) Silicon (Si) Silver (Ag) Sodium (Na) Strontium (Sr) Sulfur (s) Tantalum (Ta) Technetium (Tc) Tellurium (Te) Terbium (Tb) Thallium (T) Thorium (Th) Thulium (Tm) Tin (Sn) Titanium (Ti) Tungsten (W) Uranium (U) Vanadium (V) Ytterbium (Yb) Yttrium (Y) Zinc (Zn) Zirconium (Zr)fi 8E-1 1E-2 5E-2 lEO 3E-I 8E-i 1E-3 8E-1 2E-1 3E-4 1EO 2E-4 3E-4 2E-2 1E-2 3E-1 5E-2 1E-2 3E-4 1E-4 5E-1 2E-3 APPENDIX C RADIATION
ABSORBED DOSE TO THE EMBRYO/FETUS
FOLLOWING
INTRODUCTION
OF SPECIFIED
RADIONUCLIDES
AND CHEMICAL FORMS INTO THE MATERNAL TRANSFER COMPARTMENT (BLOOD)The entries for selected radionuclides and chemi cal forms in the tables in this appendix have been calculated from the modeling presented in Revision I to NUREG/CR-5631 (Ref. Cl). It has been assumed that 1 jiCi of activity is introduced into the maternal transfer compartment (blood). Pregnancy is assumed to begin at the time of fertilization, roughly 2 weeks after menses, and gestation is considered to consist of nine 30-day months.  Radiation dose rates were calculated from the in itial fraction that was present after a single administra tion at the start of each of these months or on the assumed final day (day 270) of gestation.


Monthly doses were determined by integrating under the curve relating the fraction of the activity in the embryo/fetus at the start of each month after administration and the fraction at the beginning of the subsequent month of gestation.
Table C13 Radiation Doses to the Embryo/Fetus from 1          giCi  of 1311 Introduced into the Maternal Transfer Compartment (Blood)
      Days of Gestation at                   Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                        Cumulated Introduction  0-30                                                                                                            Dose
                              31-60        61-90    91-120    121-150    151-180      181-210          211-240  241-270      0-270
        0        5.93E-05  2.58E-06      1.88E-07  2.20E-08  3.39E-09    2.1OE-10    2.29E-1 1        1.32E-12  6.35E-14    6.21E-05
      31                    9.73E-05    2.31E-06    3.38E-07  5.05E-08    3.22E-09    3.47E-10        2.01E-11  9.66E-13    1.00E-04
      61                                9.44E-05  4.14E-06  7.60E-07    4.75E-08    5.23E-09        3.02E-10  1.46E-11    9.94E-05
      91                                            6.52E-04  2. 11E-05    9.30E-07    9.12E-08        5.01E-09  2.33E-10    6.74E-04
      121                                                      3.54E-03    8.90E-05    6.03E-06        2.33E-07  7.82E-09    3.64E-03
      151                                                                    2.35E-03    1.49E-04        5.56E-06  1.75E-07    2.50E-03
      181
                                                                                        2.88E-03          1.15E-04  3.48E-06    3.OOE-03
    211
    241                                                                                                  1.98E-03  6.80E-05    2.05E-03
                                                                                                                      1.00E-03    1.OOE-03 (I
                                                                  Table C14 Radiation Doses to the Embryo/Fetus from 1          4Ci  of 1321 Introduced into the Maternal Transfer Compartment (Blood)
      Days of Gestation at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day                          Cumulated Introduction  0-30        31-60                                                                    ys)                        Dose
                                          61-90    91-120    121-150    151-180      181-210          211-240    241-270      0-270
        0        8.43E-05  .0            0          0          0            0          0                0          0            8.43E-05
      31                    1.06E-04    0          0          0            0          0                0          0            1.06E-04
      61                                1.27E-04  0          0            0          0                0          0            1.27E-04
      91                                            1.30E-04  0          0
                                                                                        0                0          0            1.30E-04
    121                                                      1,51E-04    0            0                0          0            1.51E-04
    151                                                                    1.53E-04    0                0          0          1.53E-04
    181
                                                                                        1.56E-04        0          0          1.56E-04
    211
                                                                                                        1.56E-04  0          1.56E-04
    241
                                                                                                                    1.56E-04    1.56E-04


Monthly doses are shown for the inclu sive periods, expressed in days. Doses to the embryo/ fetus from radionuclides in maternal organs were cal culated; when appropriate, these are included to pro vide total radiation absorbed doses. The tabulated ialues of cumulated doses were determined as the sum of the monthly doses.As noted in Revision 1 to NUREG/CR-5631 (Ref. Cl), ICRP Publication
Table C15 Radiation Doses to the Embryo/Fetus from 1 pCi of 1331 Introduced into the Maternal Transfer Compartment (Blood)
30 (Ref. C2) employs a metabolic model in which a fraction of activity in the first transfer compartment (blood) often is assumed to go immediately to excretion.
      Days of Gestation  at                    Dose (rad) to Embryo/Fetus During Indicated Gestation Periods                            Cumulated (days)
    Introduction                                                                                                                  Dose
                  0-30         31-60        61-90    91-120      121-150    151-180      181-210        211-240  241-270        0-270
          0        2.81E-04  0            0          0          0            0          0            0          0            2.81E-04
        31                  5.32E-04      0          0          0            0          0            0          0            5.32E-04
        61                                6.85E-04  0          0          0            0            0          0            6.85E-04
        91                                            7.04E-04    0          0            0            0          0            7.04E-04
      121                                                        9.04E-04    0            0            0          0            9.04E-04
      151                                                                    8.59E-04    0            0          0            8.59E-04
      181                                                                                  8.49E-04      0          0            8.49E-04
    211                                                                                                8. 27E-04  0            8.27E-04
    241                                                                                                            8.11E-04    8.11E-04 C)
                                                                    Table. C16 Radiation Doses to the Embryo/Fetus from 1 gCi of 1341 Introduced into the Maternal Transfer Compartment (Blood)
      Days of                                                                                                             
* Cumulated Gestation at                      Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)
                                                                                                                                Dose Introduction  0-30        31-60        61-90    91-120      121-150    151-180      181-210        211-2 40  241-270      0-270
        0        2.22E-05  0            0          0          0            0          0              0        0            2.22E-05
      31                  2.79E-05      0          0          0            0          0              0        0            2.79E-05
      61                                3.44E-0S  0          0            0          0              0        0            3.44E-05
      91                                            3.50E-05    0            0          0            0          0            3.50E-05
    121                                                            81E-05    0          0            0          0            3.8 IE-05
    151                                                                      3.91E-05    0            0          0            3.91E-05
    181                                                                                  4.03E-05      0          0            4.03E-05
    211                                                                                                4.83E-05  0            4.83E-05
    241                                                                                                          4.06E-05    4.06E-05


Because of the minus cule mass of the embryo/fetus immediately following fertilization, for some materials the biokinetic model thus predicts that there would be negligible initial ac tivity in the embryo after administration at that time, and that there would be minimal activity at later times. As a consequence, the dose rate and doses also would be negligible, which is indicated by N in the table. For these nuclides, an approximation of the cumulative dose for an intake occurring during the first 30 days should be made based on a time weighted average of the 31-day intake data. The cu mulative dose from an intake in the first 30 days of pregnancy may be estimated by multiplying the 31-day cumulated dose value by the ratio of the days to-date in the first month to a 30-day period. For ex ample, assuming a maternal intake of 1 4 C resulting in a I-RCi blood uptake on the 20th day of the preg nancy, the gestation dose should be determined by multiplying the cumulated dose from an intake at day 31 (i.e., Table C3, Cumulated Dose column, 1.89E-04 rads) by the ratio of 20 days to 30 days (i.e., 20 divided by 30).C-1 Table C1 Radiation Doses to the Embryo/Fetus from 1 gCi of 3H, as Tritiated Water, Introduced into the Maternal Transfer Compartment (Blood)D Introduction
Table C17 Radiation Doses to the Embryo/Fetus from 1 gCi of lms Introduced into the Maternal Transfer Compartment (Blood)
0-30 31-60 0 9.03E-06 3.96E-11 ose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)61-90 91-120 121-150 151-180 1.77E-05 2.64E-0 3.93E-0 14 2.OOE-15 )8 7.50E-10 '5 8.96E-07 3.82E-05 5.31E-17 1.94E-11 2.47E-08 1.06E-06 4.50E-05 2.63E-18 9.70E-13 1.21E-09 5.19E-08 2.14E-06 4.98E-05 181-210 1.72E-19 6.30E-14 7.91E-11 3.39E-09 1.41E-07 3.22E-06 5.28E-05 211-240 241-270 1.34E-20 4.94E-15 6.17E-12 2.64E-10 1.10E-08 2.53E-07 4.08E-06 5.40E-05 1.18E-21 4.33E-16 5.41E-13 2.32E-11 9.63E-10 2.21E-08 3.57E-07 4.70E-06 5.28E-05 Table C2 Radiation Doses to the Embryo/Fetus from 1 pCi of 3H, as a Hexose or Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)Days of Gestation at Introduction
      Days of Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (dayys)                     Cumulated Gestation at                                                                                                                Dose Introduction 0-30        31-60        61-90   91-120     121-150     151-180       181-210        211-240  241-270      0-270
0 31 61 91 121 151 181 211 241 Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)A Nj*u 31-60 61-90 -N N 2.21E-05 2.14E-07 6.OOE-05 91-120 121-150 151-180 181-210 N .  4.68E-08 7.27E-06 5.82E-05 N 1.04E-08 1.67E-06 9.25E-06 7.24E-05 N 4.37E-09 6.81E-07 3.69E-06 1.97E-05 8.29E-05 N 2.35E-09 3.68E-07 1.97E-06 1.03E-05 3.05E-05 8.96E-05 211-240 241-270 N 1.50E-09 2.34E-07 1.26E-06 6.50E-06 1.89E-05 3.93E-05 9.31E-05 N 1.06E-09 1.66E-07 8.92E-07 4.62E-06 1.33E-05 2.72E-05 4.58E-05 1.05E-04 N indicates that the metabolid pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization.
        0       1.95E-04  0            0          0          0          0            0              0          0          1.95E-04
        31                  2.63E-04      0        0            0          0            0              0          0          2.63E-04
        61                              3.07E-04  0            0          0            0              0          0          3.07E-04
        91                                          3.04E-04    0          0            0              0          0          3.04E-04
      121                                                        3.65E-04    03.66E-04    00              00        0          3.65E-04
      151                                                                                                            0          3.66E-04
      181                                                                                  3.72E-04        0        0          3.72E-04
    211                                                                                                  3.69E-04  0          3.69E-04
    241                                                                                                             3.70E-04  3.70E-04 C>
                                                                  Table C18 Radiation Doses to the Embryo/Fetus from 1 giCi of 134Cs Introduced into the Maternal Transfer Compartment (Blood)
      Days of                                                                                                                 Cumulated Gestation at                     Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (dayys)
                                                                                                                                Dose Introduction 0-30      31-60         61-90   91-120     121-150     151-180     181-210       211-240    241-270    0-270
        0      2.55E-02 2.15E-02      1.69E-02  1.33E-02    1.05E-02    8.29E-03    6.35E-03      4.37E-03    2.81E-03  1.10E-01
      31                  2.82E-02      2.23E-02  1.75E-02    1.38E-02    1.09E-02    8.38E-03      5.75E-03    3.71E-03  1.11E-01
      61                                2.92E-02  2.30E-02    1.82E-02    1.44E-02    1.10E-02      7.59E-03    4.88E-03  1.08E-01
      91                                          3.03E-02   2.40E-02    1.89E-02    1.45E-02      9.98E-03    6.43E-03  1.04E-01
    121                                                        3.16E-02    2.49E-02    1.91E-02      1.31E-02    8.46E-03  9.72E-02
    151                                                                    3.28E-02    2.5 1E-02      1.73E-02    1. 12E-02  8.64E-02
    181                                                                                3.30E-02      2.28E-02    1.46E-02  7.04E-02
    211                                                                                                3.14E-02    2.03E-02  5.17E-02
    241                                                                                                            3.24E-02  3.24E-02


Approximations of doses resulting from administration during the first month are described on page C-1.Days of Gestation at 31 ,61 91 121 151 181 211 241 C.)Cumulated Dose 0-270 9.03E-06 1.77E-05 4.02E-05 3.93E-05 4.73E-05 5.33E-05 5.72E-05 5.87E-05 5.28E-05 Cumulated Dose 0-270 N 2.24E-05 7.04E-05 7.53E-05 1. 14E-04 1.46E-04 1.56E-04 1.39E-04 1.OSE-04 Days of Gestation at Introduction
Table C19 Radiation Doses to the Embryo/Fetus from 1 gCi of 137Cs Introduced into the Maternal Transfer Compartment (Blood)
0 31 61 91 121 151 181 211 241 Table C3 Radiation Doses to the Embryo/Fetus from 1 jiCi of 14C, as a Bicarbonate, Hexose, Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus During Indicated Gestatio 0-30 31-60 N*61-90 91-120 121-150 151-180 N N 1.87E-04 1.72E-06 4.96E-04 N 4.12E-07 5.83E-05 4.8 1E-04 N 9.18E-08 1.46E-05 7.48E-05 5.96E-04 N 3.88E-08 6.02E-06 3.24E-05 1.59E-04 6.80E-04)n Periods (days) Cumulated Dose 181-210 21i-240 241-270 0-270 N 2.09E-08 3,26E-06 1.74E-05 9.09E-05 2.47E-04 7.33E-04 N 1.34E-08 2.09E-06 1.IIE-05 5.74E-05 1.66E-04 3.19E-04 7.61E-04 N 9.56E-09 1.49E-06 7.95E-06 4.1IE-05 1. 17E-04 2.39E-04 3.70E-04 8.88E-04 N 1.89E-04 5.82E-04 6.25E-04 9.44E-04 1.21E-03 1.29E-03 1.13E-03 8.88E-04 Days of Gestation at Introduction
        Days of                                                                                                                                                Cumulated Gestation at                              Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)
0-30 Table C4 Radiation Doses to the Embryo/Fetus from 1 gCi of 5 7Co Introduced into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus During 31-60 61-90 91-120 121-150 ated Gestation Periods (days) Cumulated Dose 151-180 181-210 211-240 241-270 0-270 7.30E-04 2.76E-04 2.36E-04 8.66E-04 2.74E-04 8.71E-04 1.97E-04 2.45E-04 2.82E-04 8.96E-04 1.75E-04 2.07E-04 2.56E-04 2.96E-04 9.37E-04 1.56E-04 1.82E-04 2.15E-04 2.67E-04 3.08E-04 9.78E-04 1.39E-04 1.60E-04 1.88E-04 2.22E-04 2.75E-04 3.18E-04 1.01E-03 1.23E-04 1.41E-04 1.63E-04 1.91E-04 2.25E-04 2.79E-04 3.22E-04 1.03E-03 1.09E-04 1.24E-04 1.42E-04 1.64E-04 1.92E-04 2.27E-04 2.83E-04 3.19E-04 1.04E-03 2.14E-03 2.20E-03 2.12E-03 2.04E-03 1.94E-03 1.80E-03 1.61E-03 1.35E-03 1.04E-03*N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization.
                                                                                                                                                                    Dose Introduction      0-30           31-60           61-90       91-120         121-150       151-180       181-210        211-240        241-270          0-270
          0            1.18E-02      1.13E-02        9.13E-03      7.36E-03        5.91E-03      4.74E-03      3.70E-03        2.60E-03        1.71E-03      5.83E-02
        31                            1.43E-02        1.17E-02      9.43E-03        7.59E-03      6.08E-03      4.74E-03        3.33E-03        2.19E-03      5.94E-02
        61                                            1.501E-02      1.21E-02      9.72E-03      7.80E-03      6.09E-03        4.27E-03        2.81E-03      5.78E-02
        91                                                          1.55E-02        1.25E-02      1.OOE-02      7.79E-03        5.48E-03        3.60E-03      5.49E-02
      121                                                                          1.60E-02      1.29E-02      1.00E-02        7.02E-03        4.63E-03      5.05E-02
      151                                                                                          1.65E-02      1.29E-02        9.05E-03        5.96E-03      4.44E-02
      181                                                                                                        1.65E-02        1.16E-02      7.60E-03        3.57E-02
      211                                                                                                                          1.56E-02        1.03E-02      2.59E-02
      241                                                                                                                                          1. 60E-02      1.60E-02 Table C20
CT3                                                  Radiation Doses to the Embryo/Fetus from 1 gCi of 2MU
                                                  Introduced into the Maternal Transfer Compartment (Blood)
      Days of                                                                                                                                                Cumulated Gestation at                                Dose (rad) to Embryo/Fetus During Indicated Gestatiorn Periods (days)                                              Dose Introduction      0-30            31-60           61-90       91-120         121-150       151-180       181-210         211-240         241-270         0-270
          0            N*            N              N            N              N              N              N              N              N              N
        31                            1.41E-03        2.31E-05      5.30E-06      1.19E-06      5.01E-07      2.71E-07        1.74E-07        1.24E-07        1.44E-03
        61                                            4.30E-03      7.86E-04       1.89E-04       7.84E-05      4.25E-05        2.72E-05        1.94E-05      5.44E-03
        91                                                          6.29E-03      1.52E-03      6.29E-04       3.42E-04       2.19E-04       1.566E-04     9.16E-03
      121                                                                          8.1OE-03      3.25E-03      1.78E-03        1.13E-03       8.09E-04       1.51E-02
      151                                                                                          9.51E-03      5.11E-03        3.28E-03        2.34E-03      2.02E-02
      181                                                                                                        1.40E-02        8.88E-03       6.36E-03       2.92E-02
      211                                                                                                                        1.49E-02        1.06E-02      2.55E-02
      241                                                                                                                                        2.38E-02      2.38E-02
    *N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.


Approximations of doses resulting from administration during the first month are described on page C-1.0 31 61 91 121 151 181 211 241 0-30 31-60
Table C21 Radiation Doses to the Embryo/Fetus from 1 4Ci of 234U
Days of Gestation at Introduction
                                                    Introduced into the Maternal Transfer Compartment (Blood)
0 31 61 91 121 151 181 211 241 Table C5 Radiation Doses to the Embryo/Fetus from 1 gCi of 68Co, Introduced into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus During Indicated Gestatio 0-30 31-60 61-90 91-120 4.81E-03 1.27E-03 9.03E-04 5.12E-03 1.30E-03 5.26E-03 6.03E-04 9.30E-04 1.34E-03 5.39E-03 121-150 151-180 4.25E-04 6.24E-04 9.62E-04 1.38E-03 5.59E-03 3.OOE-04 4.37E-04 6.41E-04 9.88E-04 1.42E-03 5.75E-03 9n Periods (days) Cumulated Dose 181-210 211-240 241-270 0-270 2.13E-04 3.06E-04 4.45E-04 6.54E-04 1.01E-03 1.45E-03 5.87E-03 1.52E-04 2.15E-04 3.09E-04 4.49E-04 6.59E-04 1.02E-03 1.46E-03 5.95E-03 1.09E-04 1.53E-04 2.17E-04 3.11E-04 4.53E-04 6.64E-04 1.03E-03 1.45E-03 6.OOE-03 8.79E-03 9.08E-03 9.17E-03 9.17E-03 9.13E-03 8.88E-03 8.36E-03 7.40E-03 6.00E-03 Days of Gestation at Introduction
        Days of Gestation at                               Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                                           Cumulated Introduction        0-30           31-60           61-90       91-120         121-150        151-180                                                        Dose
0 31 61 91 121 151 181 211 241 Table C6 Radiation Doses to the Embryo/Fetus from 1 jiCi of 6oCo, Introduced into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day 0-30 31-60 61-90 1.28E-02 4.73E-03 4.37E-03 1.38E-02 4.73E-03 1.39E-02 91-120 121-150 151-180 3.79E-03 4.40E-03 4.76E-03 1.40E-02 3.60E-03 3.98E-03 4.62E-03 4.99E-03 1.46E-02 3.40E-03 3.73E-03 4.12E-03 4.79E-03 5.17F-03 1.52E-02 181-210 3.22E-03 3.48E-03 3.8 1E-03 4.22E-03 4.90E-03 5.29E-03 1.56E-02 Cumulated ys) Dose 211-240 241-270 0-270 3.05E-03 3.26E-03 3.52E-03 3.86E-03 4.27E-03 4.96E-03 5.35E-03 1.59E-02 2.88E-03 3.06E-03 3.27E-03 3.54E-03 3.88E-03 4.29E-03 5.01E-03 5.29E-03 1.60E-02 4.18E-02 4.04E-02 3.80E-02 3.54E-02 3.28E-02 2.97E-02 2.60E-02 2.12E-02 1.60E-02 Days of Gestation at Introduction
                                                                                                                  181-210        211-240        241-270        0-270
0-30 0 31 61 91 121 151 181 211 241 31-60 61-90 91-120 121-150 151-180 181-210 1.47E-03 1.11E-03 7.18E-04 1.67E-03 1.10E-03 1,68E-03 4.88E-04 7.44E-04 1.14E-03 1.74E-03 3.34E-04 5.1OE-04 7.80E-04 1.19E-03 1.82E-03 2.28E-04 3.48E-04 5.31E-04 8.13E-04 1.24E-03 1.89E-03 1.54E-04 2.35E-04 3.59E-04 5.49E-04 8.38E-04 1.28E-03 1.95E-03 211-240 241-270 1.02E-04 1.56E-04 2.38E-04 3.64E-04 5.56E-04 8.48E-04 1.30E-03 1.98E-03 6,74E-05 1.03E-04 1.57E-04 2.40E-04 3.67E-04 5.60E-04 8.55E-04 1.31E-03 1.99E-03 Table C8 Radiation Doses to the Embryo/Fetus from 1 gCi of 6oCo, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)Days of Gestation at Introduction Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da~0-30 31-60 61-90 91-120 121-150 151-180 .181-210 Cumulated ys) Dose 211-240 241-270 0-270 2.54E-02 1.90E-02 1.33E-02 2.71E-02 1.90E-02 2.70E-02 0 31 61 91 121 151 181 211 241 Table C7 Radiation Doses to the Embryo/Fetus from 1 gCi of 57Co, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)Cumulated Dose 0-270 4.67E-03 4.87E-03 4.89E-03 4.90E-03 4.82E-03 4.58E-03 4.1OE-03 3.29E-03 1.99E-03 9.38E-03 1.34E-02 1.91E-02 2.74E-02 6.88E-03 9.82E-03 1.40E-02 2.OOE-02 2.86E-02 4.98E-03 7. 1OE-03 1.02E-02 1.45E-02 2.08E-02 2.97E-02 3.56E-03 5.09E-03 7.28E-03 1.04E-02 1.49E-02 2.13E-02 3.04E-02 2.52E-03 3.61E-03 5.16E-03 7,38E-03 1.05E-02 1.5 1E-02 2.15E-02 3.08E-02 1.77E-03 2.53E-03 3.62E-03 5.18E-03 7.4 1E-03 1.06E-02 1.51E-02 2.16E-02 3. 1OE-02 8.68E-02 8.76E-02 8.64E-02 8.49E-02 8.22E-02 7.67E-02 6.70E-02 5.24E-02 3. 1OE-02 Days of Gestation at Introduction
          0            N*            N                N            N              N              N              N              N              N
0 31 61 91 121 151 181 211 241 Table C9 Radiation Doses to the Embryo/Fetus from 1 jiCi of 89Sr Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 4.09E-03 5.66E-04 5.35E-03 Table C10 Radiation Doses to the Embryo/Fetus from 1 jiCi of 90Sr (in Equilibrium with 90Y) Introduced into the Maternal Transfer Compartment (Blood)Days of Gestation at Introduction
        31                                                                                                                                                        N
0 31 61 91 121 151 181 211 241 Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da: 0-30 31-60 61-90 9.07E-03 2.01E-03 1.57E-03 1.13E-02 2.04E-03 2.03E-02 91-120 121-150 151-180 1.1OE-03 1.57E-03 3.60E-03 1.50E-02 8.07E-04 1.09E-03 1.72E-03 3.31E-03 1.90E-02 6.58E-04 7.99E-04 1.33E-03 2.80E-03 7.93E-03 2.69E-02.181-210 5.81E-04 6.49E-04 8.94E-04 1.67E-03 4.71E-03 1.1OE-02 2.86E-02 s) Cumulated Dose 211-240 241-270 0-270 5.15E-04 5.69E-04 7.10E-04 1.17E-03 3.11E-03 7.41E-03 1.36E-02 2.95E-02 4.43E-04 5.00E-04 6.04E-04 8.98E-04 2.22E-03 5.23E-03 1.00E-02 1.54E-02 2.93E-02 1.68E-02 1.85E-02 2.92E-02 2.48E-02 3.70E-02 5.05E-02 5.22E-02 4.49E-02 2.93E-02 2.92E-04 5.74E-04 9.01E-03 1.37E-04 2,95E-04 1.20E-03 9.09E-03 6.64E-05 1.36E-04 3.84E-04 1.36E-03 1.07E-02 3.59E-05 6.57E-05 1.63E-04 5.06E-04 2.24E-03 1.19E-02 0 2.10E-05 3.53E-05 7.45E-05 2.12E-04 8.99E-04 3.15E-03 1.26E-02 1.23E-05 2.05E-05 3.86E-05 9.67E-05 3.90E-04 1.40E-03 3.87E-03 1.29E-02 Cumulated Dose 0-270 5.23E-03 6.49E-03 1.09E-02 1.13E-02 1.44E-02 1.71E-02 1.84E-02 1.73E-02 1.31E-02 7.01E-06 1.20E-05 2.18E-05 4.93E-05 1.84E-04 6.55E-04 1.89E-03 4.38E-03 1.31E-02 Table Cl1 Radiation Doses to the Embryo/Fetus from 1 giCi of 106Ru (in Equilibrium with 106Rh) Introduced into the Maternal Transfer Compartment (Blood)Days of Gestation at Introduction
                                      1.40E-03        2.30E-05      5.26E-06        1. 18E-06      5.OOE-07      2.70E-07        1.73E-07
0-30 0 31 61 91 121 151 181 211 241 Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da3 31-60 61-90 1.56E-03 1.OOE-03 9.36E-04 2.02E-03 1.21E-03 2.42E-03 0 Days of Gestation at Introduction
        61                                                                                                                                        1.23E-07      1.43E-03
0-30 91-120 121-150 151-180 7.68E-04 9.48E-04 1.23E-03 2.50E-03 6.67E-04 7.77E-04 9.56E-04 1.24E-03 2.53E-03 5.94E-04 6.72E-04 7.80E-04 9.68E-04 1.25E-03 2.551E-03 181-210 5.35E-04 5.94E-04 6.70E-04 7.84E-04 9.63E-04 1.26E-03 2.55E-03 Cumulated ys) Dose 211-240 241-270 0-270 4.85E-04 5.32E-04 5.90E-04 6.68E-04 7.77E-04 9.59E-04 1.25E-03 2.54E-03 Table C12 Radiation Doses to the Embryo/Fetus from 1 giCi of 1251 Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)31-60 61-90 91-120 121-150 151-180 181-210 211-2 4.41E-04 4.80E-04 5.27E-04 5.85E-04 6.62E-04 7.69E-04 9.55E-04 1.23E-03 2.53E-03 6.99E-03 7.23E-03 7.17E-03 6.74E-03 6.18E-03 5.54E-03 4.75E-03 3.77E-03 2.53E-03 Cumulated Dose )40 241-270 0-270 1.12E-05 7.34E-06 2.72E-05 1.05E-05 2.74E-05 2.081E-05 0 31 61 91 121 151 181 211 241 1.34E-05 1.27E-05 1.70E-05 1.64E-04 1.46E-05 1.40E-05 2.23E-05 5.21E-05 8.79E-04 6.07E-06 1.04E-05 1.63E-05 3.23E-05 2.88E-04 7.81E-04 4.65E-06 7.27E-06 1. 15E-05 2.05E-05 1.22E-04 3.12E-04 6.78E-04 3.01E-06 4.83E-06 7.66E-06 1.31E-05 5.70E-05 1.40E-04 2.99E-04 5.97E-04 2.07E-06 3.31E-06 5.28E-06 8.84E-06 3.05E-05 7.08E-05 1.48E-04 2.98E-04 5.33E-04 8.31E-05 9.02E-05 1.07E-04 2.91E-04 1.38E-03 1.30E-03 1. 12E-03 8.95E-04 5.33E-04 Days of Gestation at Introduction
                                                      4.27E-03     7.82E-04       1.87E-04       7.79E-05      4.22E-05        2.70E-05        1.93E-05      5.41E-03
0-30 0 31 61 91 121 151 181 211 241 Table C13 Radiation Doses to the Embryo/Fetus from 1 giCi of 1311 Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)31-60 61-90 91-120 121-150 151-180 181-210 5.93E-05 2.58E-06 1.88E-07 9.73E-05 2.31E-06 9.44E-05 2.20E-08 3.38E-07 4.14E-06 6.52E-04 3.39E-09 5.05E-08 7.60E-07 2. 11E-05 3.54E-03 2.1OE-10 3.22E-09 4.75E-08 9.30E-07 8.90E-05 2.35E-03 2.29E-1 1 3.47E-10 5.23E-09 9.12E-08 6.03E-06 1.49E-04 2.88E-03 211-240 241-270 1.32E-12 6.35E-14 2.01E-11 9.66E-13 3.02E-10 1.46E-11 5.01E-09 2.33E-10 2.33E-07 7.82E-09 5.56E-06 1.75E-07 1.15E-04 3.48E-06 1.98E-03 6.80E-05 1.00E-03 Days of Gestation at Introduction
        91                                                          6.25E-03        1.51E-03      6.28E-04     3.39E-04       2.17E-04         1.55E-04       9.1OE-03
0 31 61 91 121 151 181 211 241 Table C14 Radiation Doses to the Embryo/Fetus from 1 4Ci of 1321 Introduced into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day 0-30 31-60 8.43E-05 .0 1.06E-04 61-90 91-120 121-150 151-180 181-210 0 0 0 0 1.27E-04 0 0 0 0 1.30E-04 0 0 0 0 0 1,51E-04 0 1.53E-04 0 0 0 0 0 0 1.56E-04 Cumulated ys) Dose 211-240 241-270 0-270 0 0 8.43E-05 0 0 1.06E-04 0 0 1.27E-04 0 0 1.30E-04 0 0 1.51E-04 0 0 1.53E-04 0 0 1.56E-04 1.56E-04 0 1.56E-04 1.56E-04 1.56E-04 (I Cumulated Dose 0-270 6.21E-05 1.00E-04 9.94E-05 6.74E-04 3.64E-03 2.50E-03 3.OOE-03 2.05E-03 1.OOE-03 Table C15 Radiation Doses to the Embryo/Fetus from 1 pCi of 1331 Introduced into the Maternal Transfer Compartment (Blood) Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Introduction
      121                                                                          8.05E-03       3.23E-03       1.77E-03        1.13E-03        8.07E-04       1.50E-02
0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 2.81E-04 0 5.32E-04 0 0 0 0 6.85E-04 0 7.04E-04 0 0 0 0 0 0 0 0 9.04E-04 0 0 0 0 0 0 0 0 0 0 0 8.59E-04 0 0 8.49E-04 0 8.27E-04 0 2.81E-04 0 5.32E-04 0 6.85E-04 0 7.04E-04 0 9.04E-04 0 8.59E-04 0 8.49E-04 0 8.27E-04 8.11E-04 8.11E-04 C)Days of Gestation at Introduction
      151
0-30 Table. C16 Radiation Doses to the Embryo/Fetus from 1 gCi of 1341 Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)31-60 61-90 91-120 121-150 151-180 181-210 211-2* Cumulated Dose 40 241-270 0-270 2.22E-05 0 0 2.79E-05 0 0 0 3.44E-0S 0 0 3.50E-05 0 0 0 0 0 81E-05 0 0 0 0 0 0 3.91E-05 0 4.03E-05 0 0 4.83E-05 0 4.06E-05 0 31 61 91 121 151 181 211 241 Cumulated Dose 0-270 0 31 61 91 121 151 181 211 241 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.22E-05 2.79E-05 3.44E-05 3.50E-05 3.8 IE-05 3.91E-05 4.03E-05 4.83E-05 4.06E-05 Table C17 Radiation Doses to the Embryo/Fetus from 1 gCi of lms Introduced into the Maternal Transfer Compartment (Blood)Days of Gestation at Introduction
                                                                                                    9.46E-03      5.07E-03       3.26E-03         2.32E-03       2.01E-02
0-30 0 1.95E-04 31 61 91 121 151 181 211 241 Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day 31-60 61-90 0 0 2.63E-04 0 91-120 121-150 151-180 181-210 0 0 3.07E-04 0 0 0 0 3.04E-04 0 0 0 0 0 0 0 0 0 3.65E-04 0 0 0 3.66E-04 0 0 3.72E-04 0 3.Cumulated ys) Dose 211-240 241-270 0-270 0 0 0 0 69E-04 0 1.95E-04 0 2.63E-04 0 3.07E-04 0 3.04E-04 0 3.65E-04 0 3.66E-04 0 3.72E-04 0 3.69E-04 3.70E-04 3.70E-04 C>Days of Gestation at Introduction
      181
0-30 0 31 61 91 121 151 181 211 241 Table C18 Radiation Doses to the Embryo/Fetus from 1 giCi of 134Cs Introduced into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day 31-60 61-90 2.55E-02 2.15E-02 1.69E-02 2.82E-02 2.23E-02 2.92E-02 91-120 121-150 151-180 1.33E-02 1.75E-02 2.30E-02 3.03E-02 1.05E-02 1.38E-02 1.82E-02 2.40E-02 3.16E-02 8.29E-03 1.09E-02 1.44E-02 1.89E-02 2.49E-02 3.28E-02 181-210 6.35E-03 8.38E-03 1.10E-02 1.45E-02 1.91E-02 2.5 1E-02 3.30E-02 Cumulated ys) Dose 211-240 241-270 0-270 4.37E-03 5.75E-03 7.59E-03 9.98E-03 1.31E-02 1.73E-02 2.28E-02 3.14E-02 2.81E-03 3.71E-03 4.88E-03 6.43E-03 8.46E-03 1. 12E-02 1.46E-02 2.03E-02 3.24E-02 1.10E-01 1.11E-01 1.08E-01 1.04E-01 9.72E-02 8.64E-02 7.04E-02 5.17E-02 3.24E-02 Days of Gestation at Introduction
                                                                                                                  1.40E-02        8.88E-03        6.34E-03      2.92E-02
0-30 0 31 61 91 121 151 181 211 241 31-60 61-90 1.18E-02 1.13E-02 9.13E-03 1.43E-02 1.17E-02 1.501E-02 91-120 121-150 151-180 7.36E-03 9.43E-03 1.21E-02 1.55E-02 5.91E-03 7.59E-03 9.72E-03 1.25E-02 1.60E-02 4.74E-03 6.08E-03 7.80E-03 1.OOE-02 1.29E-02 1.65E-02 181-210 211-240 241-270 3.70E-03 2.60E-03 1.71E-03 4.74E-03 3.33E-03 2.19E-03 6.09E-03 4.27E-03 2.81E-03 7.79E-03 5.48E-03 3.60E-03 1.00E-02 7.02E-03 4.63E-03 1.29E-02 9.05E-03 5.96E-03 1.65E-02 1.16E-02 7.60E-03 1.56E-02 1.03E-02 1. 60E-02 Table C20 Radiation Doses to the Embryo/Fetus from 1 gCi of 2MU Introduced into the Maternal Transfer Compartment (Blood)Days of Gestation at Introduction
      211
0-30 Dose (rad) to Embryo/Fetus During Indicated Gestatior 31-60 61-90 91-120 121-150 151-180 Cumulated n Periods (days) Dose 181-210 211-240 241-270 0-270 N N N 1.41E-03 2.31E-05 5.30E-06 4.30E-03 7.86E-04 6.29E-03 N 1.19E-06 1.89E-04 1.52E-03 8.1OE-03 N 5.01E-07 7.84E-05 6.29E-04 3.25E-03 9.51E-03 N 2.71E-07 4.25E-05 3.42E-04 1.78E-03 5.11E-03 1.40E-02 N 1.74E-07 2.72E-05 2.19E-04 1.13E-03 3.28E-03 8.88E-03 1.49E-02 N 1.24E-07 1.94E-05 1.566E-04
                                                                                                                                  1.48E-02        1.05E-02      2.53E-02
8.09E-04 2.34E-03 6.36E-03 1.06E-02 2.38E-02 N 1.44E-03 5.44E-03 9.16E-03 1.51E-02 2.02E-02 2.92E-02 2.55E-02 2.38E-02*N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization.
      241
                                                                                                                                                  2.36E-02        2.36E-02 Table C22 I-
                                                    Radiation Doses to the Embryo/Fetus from 1 gCi of 235U
                                                  Introduced into the Maternal Transfer Compartment (Blood)
      Days of Gestation at                               Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                                          Cumulated Introduction        0-30                                                                                                                                       Dose
                                      31-60           61-90       91-120         121-150       151-180         181-210        211-240        241-270          0-270
        0            N*            N                              N
                                                    N                            N              N            N              N
      31                                                                                                                                        N              N
                                      1.29E-03       2.11E-05      4.84E-06        1.09E-06      4.60E-07      2.48E-07        1.59E-07        1.13E-07      1.32E-03
      61                                            3.93E-03       7.19E-04        1.73E-04      7.18E-05      3.88E-05        2.49E-05        1.77E-05      4.98E-03
      91                                                          5.75E-03       1.39E-03       5.78E-04      3.12E-04        2.OOE-04        1.43E-04      8.37E-03
    121                                                                          7.40E-03       2.97E-03       1.62E-03       1.04E-03       7.41E-04        1.38E-02
    151                                                                                          8.70E-03       4.67E-03       3.OOE-03       2.14E-03       1.85E-02
    181
                                                                                                                1.28E-02        8.12E-03       5.82E-03       2.67E-02
    211
                                                                                                                                1.36E-02       9.69E-03        2.33E-02
    241
                                                                                                                                                2.17E-02       2.17E-02
  *N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.


Approximations of doses resulting from administration during the first month are described on page C-1.Table C19 Radiation Doses to the Embryo/Fetus from 1 gCi of 1 3 7 Cs Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)CT3 Cumulated Dose 0-270 5.83E-02 5.94E-02 5.78E-02 5.49E-02 5.05E-02 4.44E-02 3.57E-02 2.59E-02 1.60E-02 N*0 31 61 91 121 151 181 211 241 Days of Gestation at Introduction
r-
0 31 61 91 121 151 181 211 241 Table C21 Radiation Doses to the Embryo/Fetus from 1 4Ci of 234U Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 N* N N N N N N N N 1.40E-03 2.30E-05 5.26E-06 4.27E-03 7.82E-04 6.25E-03 1. 18E-06 1.87E-04 1.51E-03 8.05E-03 5.OOE-07 7.79E-05 6.28E-04 3.23E-03 9.46E-03 2.70E-07 4.22E-05 3.39E-04 1.77E-03 5.07E-03 1.40E-02 1.73E-07 2.70E-05 2.17E-04 1.13E-03 3.26E-03 8.88E-03 1.48E-02 1.23E-07 1.93E-05 1.55E-04 8.07E-04 2.32E-03 6.34E-03 1.05E-02 2.36E-02 Table C22 Radiation Doses to the Embryo/Fetus from 1 gCi of 235U Introduced into the Maternal Transfer Compartment (Blood)I-Days of Gestation at Introduction
0 31 61 91 121 151 181 211 241 Dose (rad) to Embryo/Fetus
0-30 N*31-60 61-90 N N 91-120 N 1.29E-03 2.11E-05 4.84E-06 3.93E-03 7.19E-04 5.75E-03 During Indicated Gestation Periods (days) 121-150 151-180 181-210 211-240 241-270 N 1.09E-06 1.73E-04 1.39E-03 7.40E-03 N 4.60E-07 7.18E-05 5.78E-04 2.97E-03 8.70E-03 N 2.48E-07 3.88E-05 3.12E-04 1.62E-03 4.67E-03 1.28E-02 N 1.59E-07 2.49E-05 2.OOE-04 1.04E-03 3.OOE-03 8.12E-03 1.36E-02 N 1.13E-07 1.77E-05 1.43E-04 7.41E-04 2.14E-03 5.82E-03 9.69E-03 2.17E-02*N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization.


Approximations of doses resulting from administration during the first month are described on page C-1.Cumulated Dose 0-270 N 1.43E-03 5.41E-03 9.1OE-03 1.50E-02 2.01E-02 2.92E-02 2.53E-02 2.36E-02 Cumulated Dose 0-270 N 1.32E-03 4.98E-03 8.37E-03 1.38E-02 1.85E-02 2.67E-02 2.33E-02 2.17E-02 r- Days of Gestation at Introduction
Table C23 Radiation Doses to the Embryo/Fetus from 1 pCi of 238U
0-30 0 N* 31 61 91 121 151 181 211 241 C-Days of Gestation at Introduction
                                                  Introduced into the Maternal Transfer Compartment (Blood)
0-30 0 31 61 91 121 151 181 211 241 N*Table C23 Radiation Doses to the Embryo/Fetus from 1 pCi of 238U Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)31-60 61-90 91-120 121-150 151-180 181-210 N N N 1.23E-03 2.01E-05 4.59E-06 3.75E-03 6,86E-04 5.49E-03 N 1.04E-06 1.64E-04 1.32E-03 7.06E-03 N 4.38E-07 6.83E-05 5.49E-04 2.83E-03 8.30E-03 N 2.36E-07 3.70E-05 2.98E-04 1.55E-03 4.45E-03 1.22E-02 211-1 Cumulated Dose 240 241-270 0-270 N 1.51E-07 2.37E-05 1.90E-04 9.9 1E-04 2.86E-03 7.76E-03 1.30E-02 Table C24 Radiation Doses to the Embryo/Fetus from 1 gCi of 238Pu. Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)31-60 61-90 N N 2.68E-03 4.38E-05 8.19E-03 91-120 121-150 151-180 N 1.00E-05 1.50E-03 1.20E-02 N 2.26E-06 3.58E-04 2.89E-03 1.54E-02 N 9.55E-07 1.49E-04 1.20E-03 6.18E-03 1.81E-02 181-210 N 5.14E-07 8.05E-05 6.50E-04 3.37E-03 9.70E-03 2.66E-02 211-2 N 1.08E-07 1.69E-05 1.36E-04 7.08E-04 2.04E-03 5.54E-03 9.23E-03 2.07E-02 N 1.26E-03 4.75E-03 7.98E-03 1.31E-02 1.77E-02 2.55E-02 2.22E-02 2.07E-02 Cumulated Dose 40 241-270 0-270 N 3.30E-07 5.16E-05 4.15E-04 2.15E-03 6.24E-03 1.69E-02 2.84E-02 N 2.35E-07 3.67E-05 2.96E-04 1.54E-03 4.43E-03 1.21E-02 2.01E-02 4.51E-02 N 2.74E-03 1.04E-02 1.75E-02 2.86E-02 3.85E-02 5.56E-02 4.85E-02 4.51E-02*N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization.
      Days of                                                                                                                                                Cumulated Gestation at                              Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)
                                                                                                                                                                  Dose Introduction      0-30            31-60           61-90       91-120         121-150       151-180       181-210         211-1 240      241-270        0-270
        0            N*            N              N              N              N              N              N              N               N             N
      31                            1.23E-03       2.01E-05       4.59E-06       1.04E-06       4.38E-07     2.36E-07       1.51E-07        1.08E-07       1.26E-03
      61                                            3.75E-03       6,86E-04      1.64E-04        6.83E-05      3.70E-05       2.37E-05        1.69E-05       4.75E-03
      91                                                          5.49E-03       1.32E-03       5.49E-04       2.98E-04        1.90E-04        1.36E-04       7.98E-03
    121                                                                          7.06E-03       2.83E-03       1.55E-03       9.9 1E-04      7.08E-04        1.31E-02
    151                                                                                          8.30E-03      4.45E-03        2.86E-03       2.04E-03       1.77E-02
    181                                                                                                          1.22E-02       7.76E-03        5.54E-03       2.55E-02
    211                                                                                                                        1.30E-02       9.23E-03       2.22E-02
    241                                                                                                                                        2.07E-02       2.07E-02 Table C24 C-                                                 Radiation Doses to the Embryo/Fetus from 1 gCi of 238Pu.


Approximations of doses resulting from administration during the first month are described on page C-1.
Introduced into the Maternal Transfer Compartment (Blood)
      Days of                                                                                                                                                Cumulated Gestation at                              Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)
                                                                                                                                                                Dose Introduction      0-30            31-60          61-90        91-120          121-150        151-180        181-210        211-2 40      241-270          0-270
        0            N*            N              N            N              N              N              N              N              N              N
      31                            2.68E-03        4.38E-05      1.00E-05      2.26E-06      9.55E-07      5.14E-07        3.30E-07        2.35E-07      2.74E-03
      61                                            8.19E-03      1.50E-03        3.58E-04      1.49E-04      8.05E-05        5.16E-05        3.67E-05      1.04E-02
      91                                                          1.20E-02        2.89E-03      1.20E-03      6.50E-04        4.15E-04        2.96E-04      1.75E-02
    121                                                                          1.54E-02      6.18E-03      3.37E-03        2.15E-03        1.54E-03      2.86E-02
    151                                                                                          1.81E-02      9.70E-03        6.24E-03        4.43E-03      3.85E-02
    181                                                                                                        2.66E-02        1.69E-02        1.21E-02      5.56E-02
    211                                                                                                                        2.84E-02        2.01E-02        4.85E-02
    241                                                                                                                                        4.51E-02      4.51E-02
    *N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.


Days of Gestation at Introduction
Table C25 Radiation Doses to the Embryo/Fetus from 1 piCi of 239Pu Introduced into the Maternal Transfer Compartment (Blood)
0 31 61 91 121 151 181 211 241 Table C25 Radiation Doses to the Embryo/Fetus from 1 piCi of 239Pu Introduced into the Maternal Transfer Compartment (Blood) Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) 0-30 31-60 61-90 91-120 121-150 151-180 1.81-210 211-240 241-270 N 2.52E-03 4.12E-05 9.40E-06 7.68E-03 1.40E-03 1. 12E-02 N 2.12E-06 3.36E-04 2.71E-03 1.45E-02 N 8.97E-07 1.40E-04 1.12E-03 5.80E-03 1.70E-02 N 4.83E-07 7.56E-05 6.07E-04 3.17E-03 9.09E-03 2.50E-02 N 3. 1OE-07 4.85E-05 3.90E-04 2.02E-03 5.85E-03 1.59E-02 2.66E-02 N 2.21E-07 3.46E-05 2.78E-04 1.44E-03 4.17E-03 1.13E-02 1.88E-02 4.23E-02 Cumulated Dose 0-270 N 2.57E-03 9.71E-03 1.63E-02 2.69E-02 3.61E-02 5.22E-02 4.54E-02 4.23E-02 Days of Gestation at Introduction
        Days of Gestation at                              Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)                                             Cumulated Introduction        0-30           31-60           61-90         91-120       121-150         151-180                                                         Dose
0 31 61 91 121 151 181 211 241 Radiation Introduced Table C26 Doses to the Embryo/Fetus from 1 jiCi of 2 41Am into the Maternal Transfer Compartment (Blood)Dose (rad) to Embryo/Fetus
                                                                                                                  1.81-210         211-240       241-270         0-270
0-30 31-60 61-90 N N 5.36E-04 8.76E-06 1.64E-03 91-120 N 2.OOE-06 2.99E-04 2.39E-03 Indicated Gestation Periods (days) 50 151-180 181-210 211-240 241-270 N 4.52E-07 7.16E-05 5.76E-04 3.08E-03 N 1.91E-07 2.97E-05 2.39E-04 1.23E-03 3.61E-03 N 1.03E-07 1.61E-05 1.30E-04 6.75E-04 1.94E-03 5.32E-03 N 6.60E-08 1.03E-05 8.30E-05 4.31E-04 1.24E-03 3.38E-03 5.67E-03 N 4.71E-08 7.35E-06 5.92E-05 3.08E-04 8.89E-04 2.41E-03 4.02E-03 9.04E-03*N indicates that the metabolic pattern Is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization.
          0                          N              N              N              N              N              N               N              N              N
        31                            2.52E-03       4.12E-05       9.40E-06       2.12E-06        8.97E-07
        61                                                                                                        4.83E-07        3. 1OE-07      2.21E-07      2.57E-03
                                                      7.68E-03        1.40E-03     3.36E-04        1.40E-04      7.56E-05         4.85E-05
        91                                                                                                                                          3.46E-05      9.71E-03
                                                                      1. 12E-02    2.71E-03        1.12E-03      6.07E-04        3.90E-04       2.78E-04
      121                                                                                                                                                        1.63E-02
                                                                                    1.45E-02       5.80E-03      3.17E-03        2.02E-03        1.44E-03       2.69E-02
      151
                                                                                                    1.70E-02       9.09E-03        5.85E-03        4.17E-03        3.61E-02
      181
                                                                                                                  2.50E-02        1.59E-02      1.13E-02        5.22E-02
      211
      241                                                                                                                          2.66E-02       1.88E-02       4.54E-02
                                                                                                                                                  4.23E-02       4.23E-02
03 Table C26 Radiation Doses to the Embryo/Fetus from 1 jiCi of 241Am Introduced into the Maternal Transfer Compartment (Blood)
      Days of Gestation at                                Dose (rad) to Embryo/Fetus                   Indicated Gestation Periods (days)                                Cumulated Introduction        0-30           31-60           61-90                                                                                                       Dose
                                                                    91-120                50      151-180        181-210          211-240        241-270          0-270
        0            N*            N               N             N              N              N              N              N              N              N
      31                            5.36E-04       8.76E-06       2.OOE-06       4.52E-07        1.91E-07      1.03E-07        6.60E-08        4.71E-08        5.48E-04
      61                                            1.64E-03       2.99E-04      7.16E-05        2.97E-05       1.61E-05        1.03E-05        7.35E-06        2.07E-03
      91                                                          2.39E-03       5.76E-04        2.39E-04      1.30E-04       8.30E-05        5.92E-05        3.48E-03
    121                                                                          3.08E-03        1.23E-03      6.75E-04        4.31E-04       3.08E-04        5.72E-03
    151                                                                                          3.61E-03        1.94E-03       1.24E-03       8.89E-04        7.68E-03
    181
                                                                                                                  5.32E-03        3.38E-03        2.41E-03        1.11E-02
    211
    241                                                                                                                          5.67E-03       4.02E-03       9.69E-03
                                                                                                                                                  9.04E-03       9.04E-03
    *N indicates that the metabolic pattern Is such that the dose rates and doses would be negligible fertilization. Approximations o doses resulting                                                  throughout gestation when activity is administered immediately after from administration during the first month are described on page C-1.


Approximations o doses resulting from administration during the first month are described on page C-1.03 Cumulated Dose 0-270 N 5.48E-04 2.07E-03 3.48E-03 5.72E-03 7.68E-03 1.11E-02 9.69E-03 9.04E-03 N N N*
REFERENCES
REFERENCES
C1. M. R. Sikov et al., "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Dose-Interim Recommendations," NUREG/ CR-5631, Revision I (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992.C2. International Commission on Radiological Pro tection, "Limits for Intakes of Radionuclides by Workers," ICRP No. 30, Parts 1 through 4, including supplements, Annals of the ICRP, Volume 2, No. 3/4, Pergamon Press Inc., 1979.C-15 APPENDIX D EXAMPLES OF EMBRYO/FETUS
C1. M. R. Sikov et al., "Contribution of Maternal   C2. International Commission on Radiological Pro Radionuclide Burdens to Prenatal Radiation           tection, "Limits for Intakes of Radionuclides by Dose-Interim Recommendations,"       NUREG/         Workers," ICRP No. 30, Parts 1 through 4, CR-5631, Revision I (PNL-7445), U.S. Nu             including supplements, Annals of the ICRP,
DOSE CALCULATIONS
    clear Regulatory Commission, March 1992.            Volume 2, No. 3/4, Pergamon Press Inc., 1979.
The purpose of this appendix is to present exam ples of the methods of the guide for calculating the dose equivalent to the embryo/fetus.
 
The examples have been developed to demonstrate the calculational methods; the methods for evaluating and determining maternal exposures, body burdens, and intakes are not included.


These examples are not intended to de scribe all the measures that would be required for de termining the maternal exposure.
C-15


Instead, the exam ples are presented to concisely demonstrate the cal culational methods once data on maternal exposure have been obtained.
APPENDIX D
                        EXAMPLES OF EMBRYO/FETUS DOSE CALCULATIONS
    The purpose of this appendix is to present exam       appropriate transfer fraction. The second step in ples of the methods of the guide for calculating the        volves the determination of the embryo/fetus dose dose equivalent to the embryo/fetus. The examples          based on the maternal radionuclide blood content.


It is important to keep in mind that an evaluation is no better than the quality of the data. In applying the methods of this guide, a primary concern has to be the reliability of the maternal expo sure data. The calculation of the embryo/fetus dose consists of a two-step process. First, the content of a radionuclide in maternal blood has to be determined.
have been developed to demonstrate the calculational methods; the methods for evaluating and determining              Six example calculations are provide


This is accomplished by multiplying the intake by the appropriate transfer fraction.
====d. Cases I====
maternal exposures, body burdens, and intakes are          and 2 address ingestion intakes by the declared preg not included. These examples are not intended to de        nant woman. Cases 3 and 4 address inhalation in scribe all the measures that would be required for de      takes. Case 5 evaluates a pre-existing body burden termining the maternal exposure. Instead, the exam          and determines the embryo/fetus dose equivalent ples are presented to concisely demonstrate the cal        based on the maternal burden existing at time of pregnancy. Case 6 presents an example of summing culational methods once data on maternal exposure external and internal doses and instituting worker have been obtained. It is important to keep in mind that an evaluation is no better than the quality of the     controls to ensure the dose limit is not exceeded.


The second step in volves the determination of the embryo/fetus dose based on the maternal radionuclide blood content.
data. In applying the methods of this guide, a primary          The two methods in the guide for calculating the concern has to be the reliability of the maternal expo      embryo/fetus dose equivalent are presented: the sim sure data. The calculation of the embryo/fetus dose        plified method as presented in the regulatory position consists of a two-step process. First, the content of a    in Section 2 of this guide and the Revision 1 to radionuclide in maternal blood has to be determined.        NUREG/CR-5631 gestation-time dependent method This is accomplished by multiplying the intake by the      as presented in the regulatory position in Section 3.


Six example calculations are provided.
D-1


Cases I and 2 address ingestion intakes by the declared preg nant woman. Cases 3 and 4 address inhalation in takes. Case 5 evaluates a pre-existing body burden and determines the embryo/fetus dose equivalent based on the maternal burden existing at time of pregnancy.
CASE 1 EMBRYO/FETUS DOSE FOLLOWING ACUTE INGESTION
                                  INTAKE BY DECLARED PREGNANT WOMAN
  1.1  Exposure Scenario
                                                                      1.3.1  Simplified Method A declared pregnant woman unknowingly ingests a substance that contains trace amounts of 58Co. The              The regulatory position in Section 2 of the guide licensee determines that the woman ingested 22 gCi            presents the Simplified Method for calculating the of S8Co over a 4-day period.* The intake is confined          embryo/fetus dose equivalent. From Appendix A to to a short time period (relative to the effective bio          the guide, the 58 Co dose equivalent factor is logical retention half-life of 5 8Co) within the first        9.17E-03 rem/gCi (in blood). The dose equivalent is month of the pregnancy. Because the intake is as              calculated using Equation 1 from the regulatory posi sumed to have occurred within a single 30-day gesta            tion in Section 2.5 of the guide. Substituting the val tion period interval (i.e., a 30-day period as used for        ues for intake, the gut-to-blood transfer factor (fl)
  calculating intakes and doses), the ingestion may be          and dose factor into this equation yields the following dose equivalent calculation:
  treated as a single, acute intake.


Case 6 presents an example of summing external and internal doses and instituting worker controls to ensure the dose limit is not exceeded.
1.2    Determining Blood Uptake                                Dose Equivalent = Intake x f, x Dose Factor
                                                                                  = 22 p-Ci x 0.3 x 9.17E-03 The calculation of the dose to the embryo/fetus is                          rem/p.Ci based on the amount of the intake that is available for                          = 0.061 rem uptake within the first transfer compartment (i.e.,
blood). Applying the guidance of the regulatory posi                1.3.2    Method Using Revision 1 to tion in Section 2.2 of the guide, the blood uptake for                        NUREG/CR-5631 an ingestion intake may be calculated by multiplying the intake by the gut-to-blood transfer factor (fl):                The regulatory position specified in Section 3 of the guide presents the method for calculating the em Blood Uptake = f, x Ingestion Intake                      bryo/fetus dose using the gestation-time dependent methodology of Revision 1 to NUREG/CR-5631. Ta For cobalt, the f, value from Appendix B to the          ble C5 of Appendix C to the guide presents the gesta guide is 0.3. For this example, the predetermined in          tion-time dependent dose factors for 5 8Co. From this gestion intake is 22 p.Ci. Inserting these values into        table, the column under the heading "Cumulated the above equation results in the following calculation        Dose" presents the dose to the embryo/fetus for the of the maternal blood content:                                remainder of the gestation period resulting from the introduction of unit activity (i.e., 1 gCi) into the Blood Uptake = 0.3 x 22 pCi = 6.6 gCi                    blood of the woman at the beginning of the specified monthly gestation period interva


The two methods in the guide for calculating the embryo/fetus dose equivalent are presented:
====l. The cumulated====
the sim plified method as presented in the regulatory position in Section 2 of this guide and the Revision 1 to NUREG/CR-5631 gestation-time dependent method as presented in the regulatory position in Section 3.D-1 CASE 1 EMBRYO/FETUS
1.3    Calculating the Embryo/Fetus Dose                      dose factor for a SSCo intake during the first month of gestation is 8.79E-03 rads per microcurie in maternal Equivalent blood. The regulatory position specified in Section The calculation of the embryo/fetus dose equiva        3.2.2 of the guide states that it should be assumed lent is based on the activity uptake into the first trans      that all intakes occurring within any of the 30-day fer compartment (i.e., maternal blood). First, the            time periods of gestation occur at the beginning of dose will be calculated using the Simplified Method as         that period. As discussed in the regulatory position in presented in the regulatory position specified in Sec          Section 3.2.1, a radiation quality factor of 1.0 should tion 2 of the guide. Next, the gestation-time depend          be used for -SCo in converting from an absorbed dose ent method for calculating the dose equivalent will be        in rads to an equivalent dose expressed as rems.
DOSE FOLLOWING
ACUTE INGESTION
INTAKE BY DECLARED PREGNANT WOMAN 1.1 Exposure Scenario A declared pregnant woman unknowingly ingests a substance that contains trace amounts of 5 8 Co. The licensee determines that the woman ingested 22 gCi of S 8 Co over a 4-day period.* The intake is confined to a short time period (relative to the effective bio logical retention half-life of 5 8 Co) within the first month of the pregnancy.


Because the intake is as sumed to have occurred within a single 30-day gesta tion period interval (i.e., a 30-day period as used for calculating intakes and doses), the ingestion may be treated as a single, acute intake.  1.2 Determining Blood Uptake The calculation of the dose to the embryo/fetus is based on the amount of the intake that is available for uptake within the first transfer compartment (i.e., blood). Applying the guidance of the regulatory posi tion in Section 2.2 of the guide, the blood uptake for an ingestion intake may be calculated by multiplying the intake by the gut-to-blood transfer factor (fl): Blood Uptake = f, x Ingestion Intake For cobalt, the f, value from Appendix B to the guide is 0.3. For this example, the predetermined in gestion intake is 22 p.Ci. Inserting these values into the above equation results in the following calculation of the maternal blood content: Blood Uptake = 0.3 x 22 pCi = 6.6 gCi 1.3 Calculating the Embryo/Fetus Dose Equivalent The calculation of the embryo/fetus dose equiva lent is based on the activity uptake into the first trans fer compartment (i.e., maternal blood). First, the dose will be calculated using the Simplified Method as presented in the regulatory position specified in Sec tion 2 of the guide. Next, the gestation-time depend ent method for calculating the dose equivalent will be presented.
presented.                                                     Applying the method of the regulatory position speci fied in Section 3.2, the dose equivalent to the em bryo/fetus is calculated as follows:
                                                                    Dose Equivalent = Intake x f, x Dose Factor x
*Acceptable methods for determining intake using bioassay                              1.0 rem/rad measurements are presented in Proposed Revision 1 to Regu latory Guide 8.9 (DG-8009), "Interpretation of Bioassay                            = 22 ItCi x 0.3 x 8.79E-03 rad/
Measurements."                                                                        jiCi x 1.0 rem/rad
                                                                                    = 0.058 rem D-2


*Acceptable methods for determining intake using bioassay measurements are presented in Proposed Revision 1 to Regu latory Guide 8.9 (DG-8009), "Interpretation of Bioassay Measurements." 1.3.1 Simplified Method The regulatory position in Section 2 of the guide presents the Simplified Method for calculating the embryo/fetus dose equivalent.
CASE 2 EMBRYO/FETUS DOSE FOLLOWING CHRONIC INGESTION
                                  INTAKE BY DECLARED PREGNANT WOMAN
  2.1 Exposure Scenario                                        from Appendix A is 5.87E-05 rem per microcurie in Over an extended period of time, a declared              maternal blood. The dose contribution to the em pregnant woman unknowingly consumes water that                bryo/fetus for each monthly intake may be calculated contains low levels of tritium contamination. The li          as follows:
censee discovers the tritium contaminated water in the third month of the woman's pregnancy. A thor                  Dose Equivalent = Intake x f, x Dose Factor ough evaluation of the situation and associated per            First-month intake sonnel exposures is conducted, including bioassay measurements and contaminated water sample analy                156 jiCi x 1.0 x 5.87E-05 rem/liCi = 0.009 rem sis. It is determined that the source did not exist prior Second-month intake to the woman's pregnancy. In keeping with the regu latory positions specified in Sections 2.7 and 3.3 of          248 jiCi x 1.0 x 5.87E-05 rem/ltCi = 0.015 rem the guide, multiple intakes should be evaluated on at least a 30-day frequency. The licensee determines            Third-month intake that the declared pregnant woman ingested the fol              185 j+/-Ci x 1.0 x 5.87E-05 rem/gCi = 0.011 rem lowing amounts of tritium over the 3-month period:
                                                                                TOTAL = 0.035 rem
                                                                    2.3.2    Method Using Revision 1 to Stage of Gestation at          Intake                                NUREG/CR-5631 Time of Intake              (ACi)
                (days)                                            Using the methods of Revision 1 to NUREG/
                                                              CR-5631, the dose to the embryo/fetus is calculated
                0 - 30                    156                in a manner similar to that of the Simplified Method,
              31 - 60                                        as presented above. However, as discussed in the
                                          248 regulatory position specified in Section 3.2.1, the
              61 - 90                    185                dose factor should be taken from Appendix C for the time period representing the time of intake relative to stage of gestation. Table C1 in Appendix C presents the 3H dose factors. The first column of Table C1
2.2 Determining Blood Uptake                                  presents the gestation time (e.g., 0, 30, 60 days), and The amount of tritium that is available for uptake      the last column presents the cumulated dose to the by the blood is calculated by multiplying the intake by        embryo/fetus for the remainder of the gestation pe the f, value for the radionuclide. For tritium, the            riod following the introduction of unit activity into value of f, is 1.0 (refer to the hydrogen entry in Ap          maternal blood at the specified gestation time. As pendix B to this guide). Therefore, the amount of              specified in the regulatory position in Section 3.2.2 of tritium that is absorbed into the blood (as evaluated        the guide, an intake at any time within a specific for calculating the embryo/fetus dose) is the same as        monthly gestation period (i.e., a 30-day period) may the intake quantities presented above.                        be assumed to have occurred at the beginning of the monthly period for the purpose of determining the
2.3    Calculating Embryo/Fetus Dose Equivalent              appropriate dose factor to be used. For example, for intakes occurring during the first month of pregnancy,
      2.3.1      Simplified Method                            the dose factor under the "Cumulated Dose" column corresponding to 0 days of gestation (as designated in Equation 1 from the regulatory position specified      the left-most column of the table) should be used.


From Appendix A to the guide, the 5 8 Co dose equivalent factor is 9.17E-03 rem/gCi (in blood). The dose equivalent is calculated using Equation 1 from the regulatory posi tion in Section 2.5 of the guide. Substituting the val ues for intake, the gut-to-blood transfer factor (fl) and dose factor into this equation yields the following dose equivalent calculation:  
in Section 2.5 of the guide may be used for calculat          Cumulated dose factors taken from Table C1 for in ing the dose equivalent for the entire gestation period      takes in the respective months of gestation are pre from each monthly intake. The tritium dose factor             sented below:
Dose Equivalent
                          Stage of Gestation at              Cumulated Dose Factor for Time of Intake               Remainder of Gestation Period (rad/gCi, blood)
= Intake x f, x Dose Factor = 22 p-Ci x 0.3 x 9.17E-03 rem/p.Ci = 0.061 rem 1.3.2 Method Using Revision 1 to NUREG/CR-5631 The regulatory position specified in Section 3 of the guide presents the method for calculating the em bryo/fetus dose using the gestation-time dependent methodology of Revision 1 to NUREG/CR-5631.
                        1st Month    (0 - 30 days)                      9.03E-06
                        2nd Month (31 - 60 days)                        1.77E-05
                        3rd Month (61 - 90 days)                        4.02E-05 D-3


Ta ble C5 of Appendix C to the guide presents the gesta tion-time dependent dose factors for 5 8 Co. From this table, the column under the heading "Cumulated Dose" presents the dose to the embryo/fetus for the remainder of the gestation period resulting from the introduction of unit activity (i.e., 1 gCi) into the blood of the woman at the beginning of the specified monthly gestation period interval.
Using these gestation-time dependent dose fac          Second-month intake tors, the dose equivalent to the embryo/fetus is calcu lated using the regulatory position specified in Section        248 gCi x 1.0 x 1.77E-05 rad/4Ci x
3.2 of the guide. The radiation quality factor for 3H is              1.0 rem/rad = 0.004 rem
1.0. The dose to the embryo/fetus for the remainder Third-month intake of the gestation period resulting from intakes occur ring within each month is calculated as follows:                185 gCi x 1.0 x 4.02E-05 rad/gCi x
                                                                      1.0 rem/rad = 0.007 rem Dose Equivalent = Intake x f, x DFi                    TOTAL = 0.013 remi*
First-month intake                                          *The difference between the sum of the monthly doses and the total (i.e., 0.012 rem versus 0.013 rem) is caused by round
    156 gCi x 1.0 x 9.03E-06 rad/gCi x                      ing. In keeping with the recommendation contained in the Discussion section of this guide, final results should be
        1.0 remlrad = 0.001 rem                            rounded to the nearest thousandth of a rem.


The cumulated dose factor for a SSCo intake during the first month of gestation is 8.79E-03 rads per microcurie in maternal blood. The regulatory position specified in Section 3.2.2 of the guide states that it should be assumed that all intakes occurring within any of the 30-day time periods of gestation occur at the beginning of that period. As discussed in the regulatory position in Section 3.2.1, a radiation quality factor of 1.0 should be used for -SCo in converting from an absorbed dose in rads to an equivalent dose expressed as rems.  Applying the method of the regulatory position speci fied in Section 3.2, the dose equivalent to the em bryo/fetus is calculated as follows: Dose Equivalent
D-4
= Intake x f, x Dose Factor x 1.0 rem/rad = 22 ItCi x 0.3 x 8.79E-03 rad/ jiCi x 1.0 rem/rad = 0.058 rem D-2 CASE 2 EMBRYO/FETUS
DOSE FOLLOWING
CHRONIC INGESTION
INTAKE BY DECLARED PREGNANT WOMAN 2.1 Exposure Scenario Over an extended period of time, a declared pregnant woman unknowingly consumes water that contains low levels of tritium contamination.


The li censee discovers the tritium contaminated water in the third month of the woman's pregnancy.
CASE 3 EMBRYO/FETUS DOSE FOLLOWING ACUTE INHALATION INTAKE
                                      BY DECLARED PREGNANT WOMAN
  3.1  Exposure Scenario Blood Uptake      = TFi x Inhalation Intake During the performance of a medical administra                                = 0.63 x 100 gCi tion, a woman worker accidentally receives a single, acute inhalation intake of 100 gCi of 1311. At the time                            = 63 gxCi of the exposure, the woman was in the third month of
                                                                3.3  Calculating Embryo/Fetus Dose Equivalent pregnancy but had not declared her pregnancy to her employer (the licensee). Shortly thereafter, she de                3.3.1    Simplified Method clares her pregnancy in writing.


A thor ough evaluation of the situation and associated per sonnel exposures is conducted, including bioassay measurements and contaminated water sample analy sis. It is determined that the source did not exist prior to the woman's pregnancy.
For this example, the predetermined inhalation
3.2    Determining Blood Uptake                                intake is 100 gzCi. From Appendix A to the guide, the dose factor for 1311 is 3.64E-03 rem/gCi (in blood).
      The calculation of the dose to the embryo/fetus is      The dose equivalent to the embryo/fetus may be cal based on the amount of the intake that is available for        culated using Equation 2 from the regulatory position uptake within the first transfer compartment (i.e.,            specified in Section 2.5 of the guide:
blood). Also, the transfer to the blood is a function of the lung clearance class. The lung clearance class for            Dose Equivalent = Ii x TFi x DFi all chemical compounds of iodine is Class D, denoting                                  = 100 gCi x 0.63 x 3.64E-03 a 0- to 10-day lung clearance half-life. (Appendix B                                    rem/! Ci to 10 CFR 20.1001-20.2401 provides the lung clear                                      = 0.229 rem ance classes for the different chemical compounds of the specified radionuclides.) Applying the guidance of              3.3.2    Method Using Revision 1 to the regulatory positions specified in Sections 2.3 and                       NUREG/CR-5631
2.4 of the guide, the transfer fraction of inhaled activ ity to the blood for a Class D radionuclide may be                The regulatory position specified in Section 3 of calculated as follows:                                        the guide presents the method for calculating the em bryo/fetus dose using the methodology of Revision 1 to NUREG/CR-5631. The inhalation intake is deter TFi (Class D) = 0.48 + 0.15 x flj                        mined to have occurred during the third month of the gestation period. Table C13 of Appendix C to the where:                                                        guide presents the gestation-time dependent dose fac tors for 1311. In this table, the left-most column speci fies the beginning time for each monthly gestation TFi    = transfer fraction of inhaled activity to the        period (e.g., 0 for 0-30 days, 31 for 31-60 days).
            first transfer compartment (blood)                The right-most column presents the corresponding cumulated dose to the embryo/fetus for the remain der of the gestation period for unit activity introduced fl,i        gut-to-blood transfer factor forradionuclide i (from Appendix B to the guide)                  into the maternal blood. From this table, the cumu lated dose factor for an 1311 intake during the third
0.48    =  fraction of inhalation intake that is cleared    month of gestation is 9.94E-05 rad/p.Ci uptake into directly from the lung to the blood for Class    blood. As discussed in the regulatory position speci D compounds                                      fied in Section 3.2.1, a radiation quality factor of 1.0
                                                              should be used for 1311. Applying the methods of the
0.15    =  fraction of inhaled radionuclide that is          regulatory position specified in Section 3.2, the dose cleared from the lung to the GI tract for        equivalent to the embryo/fetus may be calculated.


In keeping with the regu latory positions specified in Sections 2.7 and 3.3 of the guide, multiple intakes should be evaluated on at least a 30-day frequency.
Class D compounds                                The value for the transfer fraction (TFi) is the same as calculated above (i.e., 0.63). Using these parame For iodine, the f, value from Appendix B to the        ter values along with Equation 2 from the guide, the guide is 1.0. Inserting these values into the above          embryo/fetus dose is calculated as follows:
equation results in the following calculation of the transfer fraction:
                                                                  Dose Equivalent      = Ii x TFi x DFi x 1.0
                                                                                          rem/rad
                                                                                        = 100 Ci x 0.63 x 9.94E-05 TFi  = 0.48 + 0.15 x 1.0                                                              rad/p.Ci x 1.0 rem/rad
          = 0.63                                                                        = 0.006 rem The resultant blood uptake may be calculated by multiplying the transfer fraction by the total intake:              This example illustrates the difference that can occur by using the gestation-time dependent dose D-5


The licensee determines that the declared pregnant woman ingested the fol lowing amounts of tritium over the 3-month period: Stage of Gestation at Intake Time of Intake (ACi) (days) 0 -30 156 31 -60 248 61 -90 185 2.2 Determining Blood Uptake The amount of tritium that is available for uptake by the blood is calculated by multiplying the intake by the f, value for the radionuclide.
factors for the calculation of the embryo/fetus dose equivalent. The Simplified Method, as presented            of iodine by the embryo; the thyroid has not yet de above, for this example yields an embryo/fetus dose      veloped. It is not until approximately the beginning of of 0.229 rem; using the gestation-time dependent          the fourth month of the gestation period that the fetal dose factors results in a calculated embryo/fetus dose    thyroid develops to a point that thyroid iodine uptake equivalent of 0.006 rem-a factor of almost 40 less.      is thought to occur. Therefore, any maternal intakes This difference reflects the fact that during early em    during the second and third trimesters will result in a bryonic development there is no preferential uptake       significantly larger dose to the embryo/fetus than will result from the same intake during the first trimester.


For tritium, the value of f, is 1.0 (refer to the hydrogen entry in Ap pendix B to this guide). Therefore, the amount of tritium that is absorbed into the blood (as evaluated for calculating the embryo/fetus dose) is the same as the intake quantities presented above.  2.3 Calculating Embryo/Fetus Dose Equivalent
D-6
2.3.1 Simplified Method Equation 1 from the regulatory position specified in Section 2.5 of the guide may be used for calculat ing the dose equivalent for the entire gestation period from each monthly intake. The tritium dose factor from Appendix A is 5.87E-05 rem per microcurie in maternal blood. The dose contribution to the em bryo/fetus for each monthly intake may be calculated as follows: Dose Equivalent
= Intake x f, x Dose Factor First-month intake 156 jiCi x 1.0 x 5.87E-05 rem/liCi = 0.009 rem Second-month intake 248 jiCi x 1.0 x 5.87E-05 rem/ltCi = 0.015 rem Third-month intake 185 j+/-Ci x 1.0 x 5.87E-05 rem/gCi = 0.011 rem TOTAL = 0.035 rem 2.3.2 Method Using Revision 1 to NUREG/CR-5631 Using the methods of Revision 1 to NUREG/ CR-5631, the dose to the embryo/fetus is calculated in a manner similar to that of the Simplified Method, as presented above. However, as discussed in the regulatory position specified in Section 3.2.1, the dose factor should be taken from Appendix C for the time period representing the time of intake relative to stage of gestation.


Table C1 in Appendix C presents the 3 H dose factors. The first column of Table C1 presents the gestation time (e.g., 0, 30, 60 days), and the last column presents the cumulated dose to the embryo/fetus for the remainder of the gestation pe riod following the introduction of unit activity into maternal blood at the specified gestation time. As specified in the regulatory position in Section 3.2.2 of the guide, an intake at any time within a specific monthly gestation period (i.e., a 30-day period) may be assumed to have occurred at the beginning of the monthly period for the purpose of determining the appropriate dose factor to be used. For example, for intakes occurring during the first month of pregnancy, the dose factor under the "Cumulated Dose" column corresponding to 0 days of gestation (as designated in the left-most column of the table) should be used.  Cumulated dose factors taken from Table C1 for in takes in the respective months of gestation are pre sented below: Stage of Gestation at Cumulated Dose Factor for Time of Intake Remainder of Gestation Period (rad/gCi, blood) 1st Month (0 -30 days) 9.03E-06 2nd Month (31 -60 days) 1.77E-05 3rd Month (61 -90 days) 4.02E-05 D-3 Using these gestation-time dependent dose fac tors, the dose equivalent to the embryo/fetus is calcu lated using the regulatory position specified in Section 3.2 of the guide. The radiation quality factor for 3H is 1.0. The dose to the embryo/fetus for the remainder of the gestation period resulting from intakes occur ring within each month is calculated as follows: Dose Equivalent
CASE 4 EMBRYO/FETUS DOSE FOR CHRONIC INHALATION INTAKE
= Intake x f, x DFi First-month intake 156 gCi x 1.0 x 9.03E-06 rad/gCi x 1.0 remlrad = 0.001 rem Second-month intake 248 gCi x 1.0 x 1.77E-05 rad/4Ci x 1.0 rem/rad = 0.004 rem Third-month intake 185 gCi x 1.0 x 4.02E-05 rad/gCi x 1.0 rem/rad = 0.007 rem TOTAL = 0.013 remi* *The difference between the sum of the monthly doses and the total (i.e., 0.012 rem versus 0.013 rem) is caused by round ing. In keeping with the recommendation contained in the Discussion section of this guide, final results should be rounded to the nearest thousandth of a rem.D-4 CASE 3 EMBRYO/FETUS
                                      BY DECLARED PREGNANT WOMAN
DOSE FOLLOWING
4.1    Exposure Scenario                                      of a mixture of 30% Class D and 70% Class Y com During the third through fifth month of her preg          pounds. In keeping with the regulatory positions nancy, a declared pregnant woman is exposed to air            specified in Sections 2.7 and 3.3 of the guide, intakes borne levels 9 f 23U. Extensive air sampling and fol          over an extended time should be evaluated on at least lowup bioassay measurements are conducted to                  a 30-day frequency. The licensee determines that the closely monitor the woman's intake. From these                woman inhaled the following amounts of 238 U over measurements, it is determined that the mU consists            the 3-month period:
ACUTE INHALATION
                            Stage of Gestation at         Class D Intake        Class Y Intake Time of Intake                   (p.Ci)               (.Ci)
INTAKE BY DECLARED PREGNANT WOMAN 3.1 Exposure Scenario During the performance of a medical administra tion, a woman worker accidentally receives a single, acute inhalation intake of 100 gCi of 1311. At the time of the exposure, the woman was in the third month of pregnancy but had not declared her pregnancy to her employer (the licensee).
                                  (days)
Shortly thereafter, she de clares her pregnancy in writing.
                                  61 -   90                     0.038                0.089
                                  91 - 120                      0.061                0.14
                                121 - 150                      0.15                  0.35
4.2    Determining Blood Uptake                                The resultant total blood uptake is calculated. by multiplying the TFi value by the inhalation intake:
      The calculation of the dose to the embryo/fetus is based on the amount of intake that is available for uptake within the first transfer compartment (i.e.,                Blood Uptake = TFi x Inhalation Intake blood). Also, the transfer to the blood is a function of
"he lung clearance class. Applying the guidance of the               For a Class Y compound, the transfer fraction is egulatory positions specified in Sections 2.3 and 2.4        calculated as follows:
of the guide, the transfer fraction (TFi) of inhaled activity to the first transfer compartment for a Class D
compound may be calculated as follows:
                                                                    TFi (Class Y) = 0.05 + 0.58 x fjj where:
    TFi  (Class D) = 0.48 + 0.15 x fli where:                                                          0.05 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class Y compounds TFi    =   transfer fraction of inhaled activity to the      0.58 =     fraction of inhaled radionuclide that is first transfer compartment cleared from the lung to the GI tract for Class Y compounds f1 i        gut-to-blood transfer factor for radionuclide i (from Appendix B to the guide).                       The total blood uptake can be calculated in the same manner as discussed above for the Class D com
0.48  =    fraction of inhalation intake that is cleared      pound.


3.2 Determining Blood Uptake The calculation of the dose to the embryo/fetus is based on the amount of the intake that is available for uptake within the first transfer compartment (i.e., blood). Also, the transfer to the blood is a function of the lung clearance class. The lung clearance class for all chemical compounds of iodine is Class D, denoting a 0- to 10-day lung clearance half-life. (Appendix B to 10 CFR 20.1001-20.2401 provides the lung clear ance classes for the different chemical compounds of the specified radionuclides.)
directly from the lung to the blood for Class D compounds                                             For uranium, the f, value from Appendix B to the guide is 0.05. Applying the above equations, the
Applying the guidance of the regulatory positions specified in Sections 2.3 and 2.4 of the guide, the transfer fraction of inhaled activ ity to the blood for a Class D radionuclide may be calculated as follows: TFi (Class D) = 0.48 + 0.15 x flj where: TFi = transfer fraction of inhaled activity to the first transfer compartment (blood) fl,i gut-to-blood transfer factor forradionuclide i (from Appendix B to the guide) 0.48 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class D compounds
0.15   =   fraction of inhaled radionuclide that is           amounts of m2U transferred to the blood as a func cleared from the lung to the GI tract for         tion of gestation period are presented in the following Class D compounds                                 table:
0.15 = fraction of inhaled radionuclide that is cleared from the lung to the GI tract for Class D compounds For iodine, the f, value from Appendix B to the guide is 1.0. Inserting these values into the above equation results in the following calculation of the transfer fraction:  
                                                          D-7
TFi = 0.48 + 0.15 x 1.0 = 0.63 The resultant blood uptake may be calculated by multiplying the transfer fraction by the total intake: Blood Uptake = TFi x Inhalation Intake = 0.63 x 100 gCi = 63 gxCi 3.3 Calculating Embryo/Fetus Dose Equivalent
3.3.1 Simplified Method For this example, the predetermined inhalation intake is 100 gzCi. From Appendix A to the guide, the dose factor for 1311 is 3.64E-03 rem/gCi (in blood).  The dose equivalent to the embryo/fetus may be cal culated using Equation 2 from the regulatory position specified in Section 2.5 of the guide: Dose Equivalent
= Ii x TFi x DFi = 100 gCi x 0.63 x 3.64E-03 rem/! Ci = 0.229 rem 3.3.2 Method Using Revision 1 to NUREG/CR-5631 The regulatory position specified in Section 3 of the guide presents the method for calculating the em bryo/fetus dose using the methodology of Revision 1 to NUREG/CR-5631.


The inhalation intake is deter mined to have occurred during the third month of the gestation period. Table C13 of Appendix C to the guide presents the gestation-time dependent dose fac tors for 1311. In this table, the left-most column speci fies the beginning time for each monthly gestation period (e.g., 0 for 0-30 days, 31 for 31-60 days). The right-most column presents the corresponding cumulated dose to the embryo/fetus for the remain der of the gestation period for unit activity introduced into the maternal blood. From this table, the cumu lated dose factor for an 1311 intake during the third month of gestation is 9.94E-05 rad/p.Ci uptake into blood. As discussed in the regulatory position speci fied in Section 3.2.1, a radiation quality factor of 1.0 should be used for 1311. Applying the methods of the regulatory position specified in Section 3.2, the dose equivalent to the embryo/fetus may be calculated.
Transfer Fraction and        Transfer Fraction and Blood Uptake                  Blood Uptake Stage of Gestation at            (Class D)                    (Class Y)
                        Time of Intake          Transfer      Blood        Transfer      Blood (days)            Fraction      Uptake        Fraction      Uptake (TFi)        (AiCi)        (TFi)        (xCi)
                              61 -   90          0.49        0.0186        0.079      0.00703
                              91 - 120            0.49        0.0299        0.079        0.0111
                            121 - 150            0.49        0.0735        0.079        0.0276
4.3  Calculating Embryo/Fetus Dose Equivalent              Class Y Inhalation Intake
      4.3.1    Simplified Method The dose to the embryo/fetus is calculated by us            Dose Equivalent = Intake x TF1 x DFi ing Equation 2 from the regulatory position in Section
2.5 of the guide. From Appendix A, the dose factor         Third-month intake for 238U is 5.10E-01 rem/4Ci (in blood). Applying this dose factor along with the monthly transfer frac tions (as calculated above) results in the following            0.089 pCi x 0.079 x 5.10E-01 rem/giCi dose calculations:                                                  = 0.004 rem Class D Inhalation Intake                                  Fourth-month intake Dose Equivalent  =  Intake x TFi x DFi                      0.14 jiCi x 0.079 x 5.10E-01 rem/4Ci
                                                                      = 0.006 rem Third-month intake
    0.038 gCi x 0.49 x 5.10E-01 rem/4Ci                      Fifth-month intake
        = 0.009 rem Fourth-month intake                                            0.35 j+/-Ci x 0.079 x 5.10E-01 rem/liCi
                                                                      = 0.014 rem
    0.061 p.Ci x 0.49 x 5.10E-01 rem/p.Ci
        = 0.015 rem                                                          TOTAL = 0.024 rem Fifth-month intake The dose to the embryo/fetus resulting from each
    0.15 gCi x 0.49 x 5.10E-05 rem/jiCi                    single-month intake should be determined by adding
        = 0.037 rem                                        the Class D component with the Class Y component.


The value for the transfer fraction (TFi) is the same as calculated above (i.e., 0.63). Using these parame ter values along with Equation 2 from the guide, the embryo/fetus dose is calculated as follows: Dose Equivalent
The total gestation period dose is the sum of the TOTAL = 0.061 rem                                 cumulated dose resulting from each monthly intake.
= Ii x TFi x DFi x 1.0 rem/rad = 100 Ci x 0.63 x 9.94E-05 rad/p.Ci x 1.0 rem/rad = 0.006 rem This example illustrates the difference that can occur by using the gestation-time dependent dose D-5 factors for the calculation of the embryo/fetus dose equivalent.


The Simplified Method, as presented above, for this example yields an embryo/fetus dose of 0.229 rem; using the gestation-time dependent dose factors results in a calculated embryo/fetus dose equivalent of 0.006 rem-a factor of almost 40 less. This difference reflects the fact that during early em bryonic development there is no preferential uptake of iodine by the embryo; the thyroid has not yet de veloped. It is not until approximately the beginning of the fourth month of the gestation period that the fetal thyroid develops to a point that thyroid iodine uptake is thought to occur. Therefore, any maternal intakes during the second and third trimesters will result in a significantly larger dose to the embryo/fetus than will result from the same intake during the first trimester.
Class D Dose      Class Y Dose      Total Dose Gestation Month                (rem)              (rem)          (rem)
                3rd Month (61 - 90 days)              0.009              0.004            0.013
                4th Month    (91 -120  days)          0.015              0.006           0.021
                5th Month (121 -150    days)          0.037              0.014          0.051 TOTAL                                        0.085 rem
    4.3.2    Method Using Revision 1 to                   in a manner similar to the Simplified Method above.


D-6 CASE 4 EMBRYO/FETUS
NUREG/CR-5631                                However, as discussed in the regulatory position Using the methods of Revision 1 to NUREG/              specified in Section 3.2, the dose factor should be CR-5631, the dose to the embryo/fetus is calculated        taken from Appendix C for the period representing D-8
DOSE FOR CHRONIC INHALATION
INTAKE BY DECLARED PREGNANT WOMAN 4.1 Exposure Scenario During the third through fifth month of her preg nancy, a declared pregnant woman is exposed to air borne levels 9 f 23U. Extensive air sampling and fol lowup bioassay measurements are conducted to closely monitor the woman's intake. From these measurements, it is determined that the mU consists of a mixture of 30% Class D and 70% Class Y com pounds. In keeping with the regulatory positions specified in Sections 2.7 and 3.3 of the guide, intakes over an extended time should be evaluated on at least a 30-day frequency.


The licensee determines that the woman inhaled the following amounts of 2 3 8 U over the 3-month period: Stage of Gestation at Class D Intake Class Y Intake Time of Intake (p.Ci) (.Ci) (days) 61 -90 0.038 0.089 91 -120 0.061 0.14 121 -150 0.15 0.35 4.2 Determining Blood Uptake The calculation of the dose to the embryo/fetus is based on the amount of intake that is available for uptake within the first transfer compartment (i.e., blood). Also, the transfer to the blood is a function of "he lung clearance class. Applying the guidance of the egulatory positions specified in Sections 2.3 and 2.4 of the guide, the transfer fraction (TFi) of inhaled activity to the first transfer compartment for a Class D compound may be calculated as follows: TFi (Class D) = 0.48 + 0.15 x fli where: TFi = transfer fraction of inhaled activity to the first transfer compartment f 1 i gut-to-blood transfer factor for radionuclide i (from Appendix B to the guide). 0.48 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class D compounds
the time of intake relative to stage of gestation. Table      corresponding cumulated dose to the embryo/fetus C23 of Appendix C presents the gestation-time de              for the remainder of the gestation period per unit ac pendent dose factors for 238U. In this table, the left        tivity introduced into the maternal blood. From Table most column specifies the beginning time for each              C23, the 238U cumulated dose factors for intakes in monthly gestation period (e.g., 0 for 0-30 days, 31          the respective month of gestation are presented be for 31-60 days). The right-most column presents the          low:
0.15 = fraction of inhaled radionuclide that is cleared from the lung to the GI tract for Class D compounds The resultant total blood uptake is calculated.
                        Stage of Gestation at           Cumulated Dose Factor for Remainder Time                               of Gestation Period of Intake                               (rad/gCi, blood)
                    3rd Month (61 - 90 days)                              4.75E-03
                    4th Month    (91 -120   days)                        7.98E-03
                    5th Month (121 -150     days)                        1.31E-02 Using these gestation-time dependent dose fac            Class Y Inhalation Intake tors, the dose equivalent to the embryo/fetus is calcu lated using the regulatory position specified in Section          Dose Equivalent = Intake x TF1 x DFi
3.2 of the guide. A radiation quality factor of 20                      x 20 rem/rad should be used for MU as specified in the regulatory position in Section 3.2.1. The dose equivalent is cal        Third-month intake culated on a monthly basis as follows:
Class D Inhalation Intake                                          0.089 RCi x 0.079 x 4.75E-03 rad/gCi x 20 rem/rad = 0.001 rem Dose Equivalent = Intake x TF1 x DFi Fourth-month intake x 20 rem/rad Third-month intake                                                0.14 gCi x 0.079 x 7.98E-03 rad/gCi x 20 rem/rad = 0.002 rem
    0.038 gCi x 0.49 x 4.75E-03 rad/ixCi x 20 rem/rad = 0.002 rem                            Fifth-month intake Fourth-month intake                                              0.35 ACi x 0.079 x 1.31E-02 rad/;iCi x 20 rem/rad = 0.007 rem
    0.061 jtCi x 0.49 x 7.98E-03 rad/LCi x 20 rem/rad = 0.005 rem                                              TOTAL = 0.010 rem Fifth-month intake The dose to the embryo/fetus resulting from each
    0.15 gCi x 0.49 x 1.31E-02 rad/tCi                        single-month intake should be determined by adding x 20 rem/rad = 0.019 rem                            the Class D component with the Class Y component.


by multiplying the TFi value by the inhalation intake: Blood Uptake = TFi x Inhalation Intake For a Class Y compound, the transfer fraction is calculated as follows: TFi (Class Y) = 0.05 + 0.58 x fjj where: 0.05 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class Y compounds
The total gestation period dose is the sum of the TOTAL = 0.026 rem                             cumulated dose resulting from each monthly intake.
0.58 = fraction of inhaled radionuclide that is cleared from the lung to the GI tract for Class Y compounds The total blood uptake can be calculated in the same manner as discussed above for the Class D com pound.  For uranium, the f, value from Appendix B to the guide is 0.05. Applying the above equations, the amounts of m2U transferred to the blood as a func tion of gestation period are presented in the following table: D-7
4.3 Calculating Embryo/Fetus Dose Equivalent
4.3.1 Simplified Method The dose to the embryo/fetus is calculated by us ing Equation 2 from the regulatory position in Section 2.5 of the guide. From Appendix A, the dose factor for 238U is 5.10E-01 rem/4Ci (in blood). Applying this dose factor along with the monthly transfer frac tions (as calculated above) results in the following dose calculations:
Class D Inhalation Intake Dose Equivalent
= Intake x TFi x DFi Third-month intake 0.038 gCi x 0.49 x 5.10E-01 rem/4Ci = 0.009 rem Fourth-month intake 0.061 p.Ci x 0.49 x 5.10E-01 rem/p.Ci = 0.015 rem Fifth-month intake 0.15 gCi x 0.49 x 5.10E-05 rem/jiCi = 0.037 rem TOTAL = 0.061 rem Class Y Inhalation Intake Dose Equivalent
= Intake x TF 1 x DFi Third-month intake 0.089 pCi x 0.079 x 5.10E-01 rem/giCi = 0.004 rem Fourth-month intake 0.14 jiCi x 0.079 x 5.10E-01 rem/4Ci = 0.006 rem Fifth-month intake 0.35 j+/-Ci x 0.079 x 5.10E-01 rem/liCi = 0.014 rem TOTAL = 0.024 rem The dose to the embryo/fetus resulting from each single-month intake should be determined by adding the Class D component with the Class Y component.


The total gestation period dose is the sum of the cumulated dose resulting from each monthly intake.Class D Dose Class Y Dose Total Dose Gestation Month (rem) (rem) (rem) 3rd Month (61 -90 days) 0.009 0.004 0.013 4th Month (91 -120 days) 0.015 0.006 0.021 5th Month (121 -150 days) 0.037 0.014 0.051 TOTAL 0.085 rem 4.3.2 Method Using Revision 1 to NUREG/CR-5631 Using the methods of Revision 1 to NUREG/ CR-5631, the dose to the embryo/fetus is calculated in a manner similar to the Simplified Method above.  However, as discussed in the regulatory position specified in Section 3.2, the dose factor should be taken from Appendix C for the period representing D-8 Transfer Fraction and Transfer Fraction and Blood Uptake Blood Uptake Stage of Gestation at (Class D) (Class Y) Time of Intake Transfer Blood Transfer Blood (days) Fraction Uptake Fraction Uptake (TFi) (AiCi) (TFi) (xCi) 61 -90 0.49 0.0186 0.079 0.00703 91 -120 0.49 0.0299 0.079 0.0111 121 -150 0.49 0.0735 0.079 0.0276 the time of intake relative to stage of gestation.
Class D Dose       Class Y Dose   Total Dose Gestation Month                   (rem)             (rem)         (rem)
                3rd Month (61 - 90 days)                 0.002              0.001          0.003
                4th Month   (91 -120   days)           0.005              0.002          0.007
                5th Month (121 -150     days)           0.019              0.007          0.026 TOTAL                                           0.036 rem D-9


Table C23 of Appendix C presents the gestation-time de pendent dose factors for 238U. In this table, the left most column specifies the beginning time for each monthly gestation period (e.g., 0 for 0-30 days, 31 for 31-60 days). The right-most column presents the Using these gestation-time dependent dose fac tors, the dose equivalent to the embryo/fetus is calcu lated using the regulatory position specified in Section 3.2 of the guide. A radiation quality factor of 20 should be used for MU as specified in the regulatory position in Section 3.2.1. The dose equivalent is cal culated on a monthly basis as follows: Class D Inhalation Intake Dose Equivalent
CASE 5 PRE-EXISTING MATERNAL BODY BURDEN AT TIME OF PREGNANCY
= Intake x TF 1 x DFi x 20 rem/rad Third-month intake 0.038 gCi x 0.49 x 4.75E-03 rad/ixCi x 20 rem/rad = 0.002 rem Fourth-month intake 0.061 jtCi x 0.49 x 7.98E-03 rad/LCi x 20 rem/rad = 0.005 rem Fifth-month intake 0.15 gCi x 0.49 x 1.31E-02 rad/tCi x 20 rem/rad = 0.019 rem TOTAL = 0.026 rem corresponding cumulated dose to the embryo/fetus for the remainder of the gestation period per unit ac tivity introduced into the maternal blood. From Table C23, the 238U cumulated dose factors for intakes in the respective month of gestation are presented be low: Class Y Inhalation Intake Dose Equivalent
  5.1 Exposure Scenario                                              r      ,..   I          A.
= Intake x TF 1 x DFi x 20 rem/rad Third-month intake 0.089 RCi x 0.079 x 4.75E-03 rad/gCi x 20 rem/rad = 0.001 rem Fourth-month intake 0.14 gCi x 0.079 x 7.98E-03 rad/gCi x 20 rem/rad = 0.002 rem Fifth-month intake 0.35 ACi x 0.079 x 1.31E-02 rad/;iCi x 20 rem/rad = 0.007 rem TOTAL = 0.010 rem The dose to the embryo/fetus resulting from each single-month intake should be determined by adding the Class D component with the Class Y component.


The total gestation period dose is the sum of the cumulated dose resulting from each monthly intake.Class D Dose Class Y Dose Total Dose Gestation Month (rem) (rem) (rem) 3rd Month (61 -90 days) 0.002 0.001 0.003 4th Month (91 -120 days) 0.005 0.002 0.007 5th Month (121 -150 days) 0.019 0.007 0.026 TOTAL 0.036 rem D-9 Stage of Gestation at Cumulated Dose Factor for Remainder Time of Gestation Period of Intake (rad/gCi, blood) 3rd Month (61 -90 days) 4.75E-03 4th Month (91 -120 days) 7.98E-03 5th Month (121 -150 days) 1.31E-02 CASE 5 PRE-EXISTING
va~-u      pi W-existung  rjurclefl)
MATERNAL BODY BURDEN AT TIME OF PREGNANCY
                                                                                                x DFi A declared pregnant woman is determined to have an existing body burden of 137Cs at the time of                                     =    2.8 jxCi x 5.94E-02 pregnancy. The burden is a result of an acute inhala                                          rem/gCi tion intake that occurred around 2 months prior to                                      =    0.166 rem the pregnancy. Extrapolating from bioassay measure ments, the body burden at the time of pregnancy is              5.4.2 Method Using Revision 1 to estimated to be 2.8 gCi.                                                   NUREG/CR-5631 Similar to the calculation above, the dose to the
5.1 Exposure Scenario r ,.. I A.A declared pregnant woman is determined to have an existing body burden of 1 3 7 Cs at the time of pregnancy.
  5.2 Evaluating the 1% ALI Threshold                        embryo/fetus is calculated by multiplying the body burden existing at time of pregnancy by the appropri ate gestation-time dependent dose factor. Table C19 The regulatory position specified in Section 1.6      of Appendix C to this guide presents the gestation of the guide states that if a body burden existing at     time dependent dose factors for ' 37Cs. In this table, time of pregnancy exceeds 1% of the stochastic ALI        the left-most column specifies the beginning time for for the appropriate mode of intake (ingestion or inha      each monthly gestation period (e.g., 0 for 0-30 days, lation), the dose to the embryo/fetus from this burden      31 for 31-60 days). The right-most column presents should be evaluated. From Appendix B to 10 CFR            the corresponding cumulated dose to the embryo/fe
20.1001-20.2401, the inhalation* stochastic ALI            tus for the remainder of the gestation period for unit value for 137Cs is 200 p.Ci (Column 2 entry under Ta      activity introduced into the maternal blood. As stated ble 1 of the appendix). Since the existing burden of       in the regulatory position specified in Section 3.2.3 of
2.8 jiCi is larger than 1% of this ALI value, the dose    the guide, the uptake in the blood for burdens exist to the embryo/fetus should be evaluated.                  ing at time of pregnancy should be assumed to occur during the first month of pregnancy.


The burden is a result of an acute inhala tion intake that occurred around 2 months prior to the pregnancy.
* From this table,
5.3 Determining Blood Uptake                              the cumulated dose factor for a 137 Cs intake during the first month of gestation is 5.83E-02 rad/4Ci up take into blood. As discussed in Section 3.2.1 of the
      .The regulatory position specified in Section 2.6    guide, a radiation quality factor of 1.0 should be used of the guide states that the total burden determined to    for 13 7Cs. The dose equivalent to the embryo/fetus is exist at the time of pregnancy should be assumed to        calculated as follows:
be available for uptake in the blood of the woman.


Extrapolating from bioassay measure ments, the body burden at the time of pregnancy is estimated to be 2.8 gCi. 5.2 Evaluating the 1% ALI Threshold The regulatory position specified in Section 1.6 of the guide states that if a body burden existing at time of pregnancy exceeds 1% of the stochastic ALI for the appropriate mode of intake (ingestion or inha lation), the dose to the embryo/fetus from this burden should be evaluated.
Therefore, for this example, blood uptake should be assumed to be the same as the existing body burden                 Dose Equivalent      =  Ai (pre-existing burden)
of 2.8 p.Ci.                                                                                x DFi x 1.0 rem/rad
                                                                                          =  2.8 gCi x 5.83E-02
5.4    Calculating the Embryo/Fetus                                                          rad/p.Ci x 1.0 rem/rad
                                                                                          =  0.163 rem Dose Equivalent
      5.4.1 Simplified Method
                                                            *The regulatory position specified in Section 3.2.3 of the guide allows the use of time-dependent release kinetics for estimat With the assumption that the blood uptake              ing the uptake in the maternal blood. This in-depth evaluation equates to the body burden existing at the time of           may be warranted for unusual exposure situations; however, for this example, the simplifying assumption of total uptake pregnancy, the dose to the embryo/fetus is calculated        during the first month will be used. Also, note that for certain simply by multiplying the burden by the radionuclide        radionuclides a blood uptake at the beginning of the gestation period results in a negligible dose contribution to the embryo/
dose factor. From Appendix A to the guide, the dose          fetus. For these radionuclides, per guidance of the regulatory factor for 137CS is 5.94E-02 rem/ACi (in blood);            position specified in Section 3.2.3 and Appendix C, the cumu therefore, the dose is calculated as follows:                lated dose value for the second month of the gestation period (i.e., the 31-day gestation time) should be used.


From Appendix B to 10 CFR 20.1001-20.2401, the inhalation*
L
stochastic ALI value for 1 3 7 Cs is 200 p.Ci (Column 2 entry under Ta ble 1 of the appendix).
                                                      D-10
Since the existing burden of 2.8 jiCi is larger than 1% of this ALI value, the dose to the embryo/fetus should be evaluated.


5.3 Determining Blood Uptake .The regulatory position specified in Section 2.6 of the guide states that the total burden determined to exist at the time of pregnancy should be assumed to be available for uptake in the blood of the woman.  Therefore, for this example, blood uptake should be assumed to be the same as the existing body burden of 2.8 p.Ci.  5.4 Calculating the Embryo/Fetus Dose Equivalent
CASE 6 MATERNAL CHRONIC EXTERNAL EXPOSURE AND INHALATION INTAKE
5.4.1 Simplified Method With the assumption that the blood uptake equates to the body burden existing at the time of pregnancy, the dose to the embryo/fetus is calculated simply by multiplying the burden by the radionuclide dose factor. From Appendix A to the guide, the dose factor for 137CS is 5.94E-02 rem/ACi (in blood); therefore, the dose is calculated as follows:-u va~ pi W-existung rjurclefl)
  .1   Exposure Scenario                                    embryo/fetus become applicable. Once declared, past exposures incurred during the gestation period and During the processing of byproduct material any burdens existing at time of pregnancy should be specimens, a woman receives periodic exposure to             evaluated.
x DFi = 2.8 jxCi x 5.94E-02 rem/gCi = 0.166 rem 5.4.2 Method Using Revision 1 to NUREG/CR-5631 Similar to the calculation above, the dose to the embryo/fetus is calculated by multiplying the body burden existing at time of pregnancy by the appropri ate gestation-time dependent dose factor. Table C19 of Appendix C to this guide presents the gestation time dependent dose factors for '3 7 Cs. In this table, the left-most column specifies the beginning time for each monthly gestation period (e.g., 0 for 0-30 days, 31 for 31-60 days). The right-most column presents the corresponding cumulated dose to the embryo/fe tus for the remainder of the gestation period for unit activity introduced into the maternal blood. As stated in the regulatory position specified in Section 3.2.3 of the guide, the uptake in the blood for burdens exist ing at time of pregnancy should be assumed to occur during the first month of pregnancy.


* From this table, the cumulated dose factor for a 1 3 7 Cs intake during the first month of gestation is 5.83E-02 rad/4Ci up take into blood. As discussed in Section 3.2.1 of the guide, a radiation quality factor of 1.0 should be used for 1 3 7 Cs. The dose equivalent to the embryo/fetus is calculated as follows: Dose Equivalent
airborne levels of 137Cs and 144Ce. The lung clearance class for all compounds of cesium is Class D; and for              The licensee evaluates the dosimetry records for cerium the chemical compound is determined to be            the declared pregnant woman, including air sample an oxide, thereby representing a "Y" lung clearance          data and bioassay measurements. It is determined class. The woman becomes pregnant. However, she              that at the time of pregnancy the woman had an exist does not inform her employer (the licensee) until the        ing body burden of 1.14      gCi of 1
= Ai (pre-existing burden) x DFi x 1.0 rem/rad = 2.8 gCi x 5.83E-02 rad/p.Ci x 1.0 rem/rad = 0.163 rem *The regulatory position specified in Section 3.2.3 of the guide allows the use of time-dependent release kinetics for estimat ing the uptake in the maternal blood. This in-depth evaluation may be warranted for unusual exposure situations;
                                                                                                    37 Cs and 0.12 p.Ci of third month of the gestation period. At this time, she        144Ce. Intakes during the first, second, and third becomes a declared pregnant woman and the more                months of the gestation period are determined and restrictive dose limits of 10 CFR 20.1208 for the             are presented in the following table:
however, for this example, the simplifying assumption of total uptake during the first month will be used. Also, note that for certain radionuclides a blood uptake at the beginning of the gestation period results in a negligible dose contribution to the embryo/ fetus. For these radionuclides, per guidance of the regulatory position specified in Section 3.2.3 and Appendix C, the cumu lated dose value for the second month of the gestation period (i.e., the 31-day gestation time) should be used.L D-10
                                                                        Total Intake Stage of Gestation at                      (ACi)
CASE 6 MATERNAL CHRONIC EXTERNAL EXPOSURE AND INHALATION
                                                                    37              1 Time of Intake                  1 CS              "Ce (days)                  (Class D)        (Class Y)
INTAKE.1 Exposure Scenario During the processing of byproduct material specimens, a woman receives periodic exposure to airborne levels of 1 3 7 Cs and 144Ce. The lung clearance class for all compounds of cesium is Class D; and for cerium the chemical compound is determined to be an oxide, thereby representing a "Y" lung clearance class. The woman becomes pregnant.
                                      Pre-Existing                    1.14          0.12
                                        0 - 30                      0.48          0.078
                                        31 - 60                      0.76          0.14
                                        61 - 90                      0.23          0.093 The declared pregnant woman's external expo                  6.2.2    Determining Blood Uptake sure is evaluated and is determined to be 0.285 rem from the time of pregnancy to the time of declaration.             The regulatory position specified in Section 2.6 After declaration, the licensee imposes radiological        of the guide states that the total burden determined to controls to ensure that additional exposures are kept        exist at the time of pregnancy should be assumed to to a minimum, pending a thorough evaluation of the          be available for uptake in the blood of the woman.


However, she does not inform her employer (the licensee)
woman's exposures and the resultant embryo/fetus            Therefore, for this example, blood uptake should be dose equivalent.                                            assumed to be the same as the existing body burdens of 1.14 iCi of 137 Cs and 0.12 giCi of 144Ce.
until the third month of the gestation period. At this time, she becomes a declared pregnant woman and the more restrictive dose limits of 10 CFR 20.1208 for the The declared pregnant woman's external expo sure is evaluated and is determined to be 0.285 rem from the time of pregnancy to the time of declaration.


After declaration, the licensee imposes radiological controls to ensure that additional exposures are kept to a minimum, pending a thorough evaluation of the woman's exposures and the resultant embryo/fetus dose equivalent.
6.2    Evaluating Embryo/Fetus Dose Equivalent
                                                                    6.2.3    Calculating the Embryo/Fetus Dose from Pre-Existing Body Burden                                          Equivalent from Pre-Existing Burden
      6.2.1    Evaluating the 1% ALI Threshold Only the Simplified Method will be used in this example      for calculating the embryo/fetus doses. For The regulatory position specified in Section 1.6      ' 37 Cs, the approach for using the gestation-time of the guide states that if a body burden existing at        dependent method (Revision 1 to NUREG/CR-5631 time of pregnancy exceeds 1% of the stochastic ALI          method) would be similar to the calculations pre for the appropriate mode of intake (ingestion or inha        sented in Case 5, Section 5.4.2. For '44Ce, gekiation lation), the dose to the embryo/fetus from this burden      time dependent dose factors have not been devel should be evaluated. From Appendix B to 10 CFR              oped.


6.2 Evaluating Embryo/Fetus Dose Equivalent from Pre-Existing Body Burden 6.2.1 Evaluating the 1% ALI Threshold The regulatory position specified in Section 1.6 of the guide states that if a body burden existing at time of pregnancy exceeds 1% of the stochastic ALI for the appropriate mode of intake (ingestion or inha lation), the dose to the embryo/fetus from this burden should be evaluated.
20.1001-20.2401, the inhalation stochastic ALI
value for 13 7Cs is 200 gtCi, and for Class Y 144Ce is 10          With the assumption that the blood uptake ptCi (Column 2 entry under Table 1 of the appendix).         equates to the body burden existing at the time of Since the sum of the existing burdens of 1.14 p.Ci of       pregnancy, the dose to the embryo/fetus is calculated
"-17Cs and 0.12 ptCi of 1'4Ce divided by their respec        simply by multiplying the burden by the radionuclide e ALI values is larger than 0.01 (i.e., Y (bur          dose factor. From Appendix A to the guide, the dose
,.eni -- ALIi ) > 0.01), the dose to the embryo/fetus       factor for 13 7 Cs is 5.94E-02 rem/p.Ci (in blood) and resulting from the maternal pre-existing burden             for 144Ce is 3.79E-0 1 rem/pLCi (in blood). The dose is should be evaluated.                                         calculated as follows:
                                                        D-11


From Appendix B to 10 CFR 20.1001-20.2401, the inhalation stochastic ALI value for 1 3 7 Cs is 200 gtCi, and for Class Y 1 44Ce is 10 ptCi (Column 2 entry under Table 1 of the appendix).
TFi    (Class D) = 0.48 + 0.15 x fl,i Dose Equivalent = 7 Ai (pre-existing burden x DFi                            where:
Since the sum of the existing burdens of 1.14 p.Ci of "-1 7 Cs and 0.12 ptCi of 1'4Ce divided by their respec e ALI values is larger than 0.01 (i.e., Y (bur ,.eni -- ALIi ) > 0.01), the dose to the embryo/fetus resulting from the maternal pre-existing burden should be evaluated.
                          = (1.14 gCi x 5.94E-02 rem/ACi)              TFi    = transfer fraction of inhaled activity to the
                              + (0.12 gCi                                first transfer compartment x 3.79E-01 rem/gCi)
                          = 0.068 + 0.045 rem                  fij    = gut-to-blood transfer factor for radionuclide
                          = 0.113 rem                                    i (from Appendix B to this guide)
                                                              0.48  =  fraction of inhalation intake that is cleared
6.3    Calculating the Embryo/Fetus Dose Equiv                          directly from the lung to the blood for Class alent from Intakes During Pregnancy                              D compounds
                                                              0.15 =    fraction of inhaled radionuclide that is
      6.3.1   Evaluating 1% ALI Threshold                              cleared from the lung to the GI tract for Class D compounds Based on the requirements of 10 CFR
                                                              The resultant total blood uptake is calculated by
20.1502(b) (2) and the regulatory position specified in Section 1.1 of this guide, the dose to the embryo/         multiplying the TFi value by the inhalation intake:
fetus is to be evaluated if intakes during the year by the declared pregnant woman are likely to exceed 1%                  Blood Uptake = TFi x Inhalation Intake of the stochastic ALIs. Without having to consider For a Class Y compound, the transfer fraction is other intakes by the woman during the year, the 1%
threshold is exceeded based on the intakes by the de          calculated as follows:
clared pregnant woman during the first 3 months of the pregnancy. Therefore, an evaluation of the em                    TFi    (Class Y) = 0.05 + 0.58 x flj bryo/fetus dose is required.


embryo/fetus become applicable.
where:
      With multiple intakes occurring during a single          0.05  =  fraction of inhalation intake that is cleared monthly period, the intakes may be modeled as cu mulative intakes within each specified gestational monthly period.


Once declared, past exposures incurred during the gestation period and any burdens existing at time of pregnancy should be evaluated.
directly from the lung to the blood for Class Y compounds
                                                              0.58 = fraction of inhaled radionuclide that is L
                                                                        cleared from the lung to the GI tract for
      6.3.2    Determining Blood Uptake                                  Class Y compounds The calculation of the dose to the embryo/fetus is          The total blood uptake can be Calculated in the based on the amount of the intake that is available for      same manner as discussed above for the Class D com uptake within the first transfer compartment (i.e.,          pound.


The licensee evaluates the dosimetry records for the declared pregnant woman, including air sample data and bioassay measurements.
blood). Also, the transfer to the blood is a function of the lung clearance class. Applying the guidance of the            For cesium, the f, value from Appendix B to this regulatory positions specified in Sections 2.3 and 2.4, guide is 1.0; for cerium, the value is 3E-04. Applying the transfer fraction (TFi) of inhaled activity to the        the above equations, the amounts of 137Cs and 144Ce first transfer compartment for a Class D compound            that are transferred to the blood as a function of ges may be calculated as follows:                                tation period are presented in the following table:
                                              Transfer Fraction and          Transfer Fraction and Blood Uptake of 137Cs        Blood Uptake of 144Ce Stage of Gestation at              (Class D)                    (Class Y)
                      Time of Intake          Transfer        Blood        Transfer      Blood (days)            Fraction      Uptake        Fraction      Uptake (TFi0)        (3Aci)          (TFi)        (00Ci)
                              0 -  30            0.63          0.30          0.050        0.0039
                            31 -    60            0.63          0.48          0.050        0.0070
                            61 -    90      1    0.63          0.14          0.050        0.0046 I
                                                        D-12


It is determined that at the time of pregnancy the woman had an exist ing body burden of 1.14 gCi of 1 3 7 Cs and 0.12 p.Ci of 144Ce. Intakes during the first, second, and third months of the gestation period are determined and are presented in the following table: 6.2.2 Determining Blood Uptake The regulatory position specified in Section 2.6 of the guide states that the total burden determined to exist at the time of pregnancy should be assumed to be available for uptake in the blood of the woman.  Therefore, for this example, blood uptake should be assumed to be the same as the existing body burdens of 1.14 iCi of 1 3 7 Cs and 0.12 giCi of 144Ce.  6.2.3 Calculating the Embryo/Fetus Dose Equivalent from Pre-Existing Burden Only the Simplified Method will be used in this example for calculating the embryo/fetus doses. For '3 7 Cs, the approach for using the gestation-time dependent method (Revision  
6.3.3   Calculating Embryo/Fetus Dose               Third-month intake Equivalent from Maternal Intakes
1 to NUREG/CR-5631 method) would be similar to the calculations pre sented in Case 5, Section 5.4.2. For '44Ce, gekiation time dependent dose factors have not been devel oped.  With the assumption that the blood uptake equates to the body burden existing at the time of pregnancy, the dose to the embryo/fetus is calculated simply by multiplying the burden by the radionuclide dose factor. From Appendix A to the guide, the dose factor for 1 3 7 Cs is 5.94E-02 rem/p.Ci (in blood) and for 144Ce is 3.79E-0 1 rem/pLCi (in blood). The dose is calculated as follows: D-11 Total Intake Stage of Gestation at (ACi) Time of Intake 1 3 7 CS 1"Ce (days) (Class D) (Class Y) Pre-Existing
                                                                    0.23 gCi x 0.63 x 5.94E-02 rem/gCi Only the Simplified Method will be used in this             = 0.009 rem
1.14 0.12 0 -30 0.48 0.078 31 -60 0.76 0.14 61 -90 0.23 0.093 Dose Equivalent
  .xample
= 7 Ai (pre-existing burden x DFi = (1.14 gCi x 5.94E-02 rem/ACi) + (0.12 gCi x 3.79E-01 rem/gCi) = 0.068 + 0.045 rem = 0.113 rem 6.3 Calculating the Embryo/Fetus Dose Equiv alent from Intakes During Pregnancy
  13 7        for calculating the embryo/fetus doses. For
6.3.1 Evaluating
-      Cs, the approach of the gestation-time dependent                     TOTAL = 0.055 rem method (the method in Revision 1 to NUREG/
1% ALI Threshold Based on the requirements of 10 CFR 20.1502(b)
  CR-5631) would be similar to the calculations pre           Class Y Inhalation Intake--144Ce sented in Case 4, Section 4.3.2, of this Appendix D.
(2) and the regulatory position specified in Section 1.1 of this guide, the dose to the embryo/ fetus is to be evaluated if intakes during the year by the declared pregnant woman are likely to exceed 1% of the stochastic ALIs. Without having to consider other intakes by the woman during the year, the 1% threshold is exceeded based on the intakes by the de clared pregnant woman during the first 3 months of the pregnancy.


Therefore, an evaluation of the em bryo/fetus dose is required.
For 144Ce, gestation-time dependent dose factors                  Dose Equivalent = Intake x TF 1 x DFi have not been developed. The dose to the embryo/fe          First-month intake tus is calculated by using Equation 2 from the regula tory position specified in Section 2.5 of this guide.              0.078 gCi x 0.050 x 3.79E-01 rem/RCi From Appendix A, the dose factor for 137Cs is                      = 0.001 rem
  5.94E-02 rem/;Ci (in blood) and for 144Ce is
  3.79E-01 rem/jCi (in blood). Applying these dose            Second-month intake factors along with the monthly transfer fractions (as              0.14 gCi x 0.050 x 3.79E-01 rem/jxCi calculated above) results in the following dose calcu              = 0.003 rem lations:
                                                              Third-month intake Class D Inhalation Intake- 137Cs
                                                                    0.093 pCi x 0.050 x 3.79E-01 rem/gCi Dose Equivalent = Intake x TF1 x DFi                      - 0.002 rem First-month intake                                                        TOTAL = 0.006 rem
          0.48 gCi x 0.63 x 5.94E-02 rem/pgCi
          = 0.018 rem                                        6.4  Summing Internal and External Doses Second-month intake                                            The doses to the embryo/fetus for the existing maternal burden, the maternal inhalation intakes,
          0.76 jCi x 0.63 x 5.94E-02 rem/gCi                and the deep-dose equivalent to the declared preg
          = 0.028 rem                                        nant woman are summarized in the following table:
                      Exposure Pathway and              Embryo/Fetus Dose Equivalent Stage of Gestation                          (rem)
                                                      137 Cs          1
                                                                        44Cs          Total Pre-Existing Body Burden      0.068            0.045          0.113 Inhalation Intakes        0.018            0.001          0.019
                              (0 - 30 days)
                            Inhalation Intakes        0.028            0.003            0.031
                              (31 - 60 days)
                            Inhalation Intakes        0.009            0.002          0.011
                              (61 - 90 days)
                          Deep-Dose Equivalent                        0.285
                              (0 - 90 days)
                                  Total                              0.459 The sum of the deep-dose equivalent to the de        ternal exposures). This total of 0.459 rem is within clared pregnant woman and the embryo/fetus dose            0.05 rem of the 0.5 rem limit for the embryo/fetus.


With multiple intakes occurring during a single monthly period, the intakes may be modeled as cu mulative intakes within each specified gestational monthly period.  6.3.2 Determining Blood Uptake The calculation of the dose to the embryo/fetus is based on the amount of the intake that is available for uptake within the first transfer compartment (i.e., blood). Also, the transfer to the blood is a function of the lung clearance class. Applying the guidance of the regulatory positions specified in Sections 2.3 and 2.4, the transfer fraction (TFi) of inhaled activity to the first transfer compartment for a Class D compound may be calculated as follows: TFi (Class D) = 0.48 + 0.15 x fl,i where: TFi = transfer fraction of inhaled activity to the first transfer compartment fij = gut-to-blood transfer factor for radionuclide i (from Appendix B to this guide) 0.48 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class D compounds
resulting from the inhalation intakes of the declared      Therefore, the dose limit for the embryo/fetus for the pregnant woman represents the total dose equivalent        remainder of the gestation period is an additional to the embryo/fetus (i.e., 0.285 rem deep-dose              dose of 0.05 rem from the date of the declared preg equivalent, plus 0.174 rem dose equivalent from in-         nancy (refer to 10 CFR 20.1208(d)).
0.15 = fraction of inhaled radionuclide that is cleared from the lung to the GI tract for Class D compounds The resultant total blood uptake is calculated by multiplying the TFi value by the inhalation intake: Blood Uptake = TFi x Inhalation Intake For a Class Y compound, the transfer fraction is calculated as follows: TFi (Class Y) = 0.05 + 0.58 x flj where: 0.05 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class Y compounds
                                                          D-13
0.58 = fraction of inhaled radionuclide that is cleared from the lung to the GI tract for Class Y compounds The total blood uptake can be Calculated in the same manner as discussed above for the Class D com pound.  For cesium, the f, value from Appendix B to this guide is 1.0; for cerium, the value is 3E-04. Applying the above equations, the amounts of 1 3 7 Cs and 144Ce that are transferred to the blood as a function of ges tation period are presented in the following table: D-12 L Transfer Fraction and Transfer Fraction and Blood Uptake of 1 3 7 Cs Blood Uptake of 144Ce Stage of Gestation at (Class D) (Class Y) Time of Intake Transfer Blood Transfer Blood (days) Fraction Uptake Fraction Uptake (TFi0) (3Aci) (TFi) (00Ci) 0 -30 0.63 0.30 0.050 0.0039 31 -60 0.63 0.48 0.050 0.0070 61 -90 1 0.63 0.14 0.050 0.0046 I
6.3.3 Calculating Embryo/Fetus Dose Equivalent from Maternal Intakes Only the Simplified Method will be used in this .xample for calculating the embryo/fetus doses. For -1 3 7 Cs, the approach of the gestation-time dependent method (the method in Revision 1 to NUREG/ CR-5631) would be similar to the calculations pre sented in Case 4, Section 4.3.2, of this Appendix D.  For 1 44Ce, gestation-time dependent dose factors have not been developed.


The dose to the embryo/fe tus is calculated by using Equation 2 from the regula tory position specified in Section 2.5 of this guide. From Appendix A, the dose factor for 1 3 7 Cs is 5.94E-02 rem/;Ci (in blood) and for 1 44Ce is 3.79E-01 rem/jCi (in blood). Applying these dose factors along with the monthly transfer fractions (as calculated above) results in the following dose calcu lations: Class D Inhalation Intake-1 3 7 Cs Dose Equivalent
REGULATORY ANALYSIS
= Intake x TF 1 x DFi First-month intake 0.48 gCi x 0.63 x 5.94E-02 rem/pgCi = 0.018 rem Second-month intake 0.76 jCi x 0.63 x 5.94E-02 rem/gCi = 0.028 rem The sum of the deep-dose equivalent to the de clared pregnant woman and the embryo/fetus dose resulting from the inhalation intakes of the declared pregnant woman represents the total dose equivalent to the embryo/fetus (i.e., 0.285 rem deep-dose equivalent, plus 0.174 rem dose equivalent from in-Third-month intake 0.23 gCi x 0.63 x 5.94E-02 rem/gCi = 0.009 rem TOTAL = 0.055 rem Class Y Inhalation Intake--144Ce Dose Equivalent
    A separate regulatory analysis was not prepared      copy of the "Regulatory Analysis for the Revision of for this regulatory guide. The regulatory analysis pre    10 CFR Part 20" (PNL-6712, November 1988) is pared for 10 CFR Part 20, "Standards for Protection        available for inspection and copying for a fee at the Against Radiation" (56 FR 23360), provides the regu        NRC Public Document Room, 2120 L Street NW.,
= Intake x TF 1 x DFi First-month intake 0.078 gCi x 0.050 x 3.79E-01 rem/RCi = 0.001 rem Second-month intake 0.14 gCi x 0.050 x 3.79E-01 rem/jxCi = 0.003 rem Third-month intake 0.093 pCi x 0.050 x 3.79E-01 rem/gCi -0.002 rem TOTAL = 0.006 rem 6.4 Summing Internal and External Doses The doses to the embryo/fetus for the existing maternal burden, the maternal inhalation intakes, and the deep-dose equivalent to the declared preg nant woman are summarized in the following table: ternal exposures).  
latory basis for this guide and examines the costs and    Washington, DC, as an enclosure to Part 20 (56 FR
This total of 0.459 rem is within 0.05 rem of the 0.5 rem limit for the embryo/fetus.
benefits of the rule as implemented by the guide. A        23360).
                                                      RA-1


Therefore, the dose limit for the embryo/fetus for the remainder of the gestation period is an additional dose of 0.05 rem from the date of the declared preg nancy (refer to 10 CFR 20.1208(d)).
THIS DOCUMENT WAS PRINTED USING RECYCLED PAPER
D-13 Exposure Pathway and Embryo/Fetus Dose Equivalent Stage of Gestation (rem) 1 3 7 Cs 1 44Cs Total Pre-Existing Body Burden 0.068 0.045 0.113 Inhalation Intakes 0.018 0.001 0.019 (0 -30 days) Inhalation Intakes 0.028 0.003 0.031 (31 -60 days) Inhalation Intakes 0.009 0.002 0.011 (61 -90 days) Deep-Dose Equivalent
                                                  1 UNITED STATES
0.285 (0 -90 days) Total 0.459 REGULATORY
NUCLEAR REGULATORY COMMISSION       FIRST CLASS MAIL
ANALYSIS A separate regulatory analysis was not prepared for this regulatory guide. The regulatory analysis pre pared for 10 CFR Part 20, "Standards for Protection Against Radiation" (56 FR 23360), provides the regu latory basis for this guide and examines the costs and benefits of the rule as implemented by the guide. A copy of the "Regulatory Analysis for the Revision of 10 CFR Part 20" (PNL-6712, November 1988) is available for inspection and copying for a fee at the NRC Public Document Room, 2120 L Street NW., Washington, DC, as an enclosure to Part 20 (56 FR 23360).RA-1 THIS DOCUMENT WAS PRINTED USING RECYCLED PAPER  
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(Draft Issued as DG-8011) Radiation Dose to Embryo/Fetus
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Issue date: 07/31/1992
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U.S. NUCLEAR REGULATORY COMMISSION July 1992 REGULATORY (3UIDE

OFFICE OF NUCLEAR REGULATORY RESEARCH

REGULATORY GUIDE 8.36 (Draft was issued as DG-8011)

RADIATION DOSE TO THE EMBRYO/FETUS

A. INTRODUCTION

B. DISCUSSION

Calculating the radiation dose to the embryo/fe Section 20.1208 of 10 CFR Part 20, "Standards tus from internally deposited radionuclides requires for Protection Against Radiation," requires that each quantitative information about maternal radionuclide licensee ensure that the dose to an embryo/fetus dur intake, placental transfer and kinetics, and resulting ing the entire pregnancy, from occupational exposure embryo/fetus radionuclide concentrations. Intakes of of a declared pregnant woman, does not exceed 0.5 radioactive material occurring prior to the pregnancy rem (5 mSv). Paragraph 20.1208(b) requires the li may also be important if these materials remain in the censee to make efforts to avoid substantial variation pregnant woman during all or part of the gestation above a uniform monthly exposure rate to a declared period. Transfer kinetics from the mother to the em pregnant woman that would satisfy the 0.5 rem (5 bryo/fetus are modeled as a function of stage of preg mSv) limit. The dose to the embryo/fetus is to be the nancy, route of intake by the pregnant woman, and sum of (1) the deep-dose equivalent to the declared time after intake. The stage of gestation (or fetal de pregnant woman (10 CFR 20.1208(c)(1)) and (2)

velopment) is an important parameter in estimating he dose to the embryo/fetus from radionuclides in radionuclide concentrations in the embryo/fetus. The ne embryo/fetus and radionuclides in the declared geometry of the embryo/fetus (i.e., size and weight)

pregnant woman (10 CFR 20.1208(c)(2)).

affects the radionuclide dosimetry.

This guide is being developed to provide guidance It is recognized that calculation of prenatal radia on calculating the radiation dose to the embryo/fetus. tion doses from internally deposited radionuclides has Regulatory Guide 8.13, "Instruction Concerning Pre many associated difficulties, including a lack of quan natal Radiation Exposure," provides instructions con titative information about prenatal radionuclide con cerning the risks associated with prenatal radiation centrations and transfer across the placenta. The In exposure. ternational Commission on Radiological Protection (ICRP) in Publication 56 (Ref. 1) states that, for most radionuclides, preliminary estimates from dosimetric Any information collection activities mentioned and biokinetic models indicate that the dose to the in this regulatory guide are contained as requirements embryo can be approximated by the dose to the in 10 CFR Part 20, which provides the regulatory ba uterus. The dose to the fetus is dependent upon the sis for this guide. The information collection require activity present in both fetal and maternal tissues.

ments in 10 CFR Part 20 have been cleared under ICRP Publication 56 (Ref. 1) also states that, for most OMB Clearance No. 3150-0014. radionuclides, the dose to fetal tissue will be similar to USNRC REGULATORY GUIDES The guides are issued In the following ten broad divisions:

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similar to or less than the dose to the corresponding A graded approach for determining when to maternal tissues. evaluate, with both a simple and more detailed dose assessment methodology, is provided. Both methods The current methods available for assessing the are acceptable for evaluating the dose to the embryo/

radiation dose to the human embryo/fetus from inter fetus. It is recognized that some licensees will only nally deposited radioactive materials in the pregnant need to demonstrate that the dose to the embryo/fe woman are subject to a number of uncertainties. tus is not likely to exceed the 0.05 rem (0.5 mSv)

Revison 1 to NUREG/CR-5631, "Contribution of monitoring threshold of 10 CFR 20.1502, while other Maternal Radionuclide Burdens to Prenatal Radiation licensees may need to determine an embryo/fetus Doses-Interim Recommendations" (Ref. 2), pro dose for demonstrating compliance with the dose limit vides recommendations and methods for estimating of 10 CFR 20.1208 and the recordkeeping require the radiation doses to the embryo/fetus from internal ments of 10 CFR 20.2106(e).

radionuclides. In Revision 1 to NUREG/CR-5631, a Appendix A provides information on and a table number of radionuclides were evaluated. To expedite of dose equivalent factors for use in approximating efforts, the initial evaluation was directed to those the embryo/fetus dose from radionuclides in maternal radionuclides that were expected to be of greatest sig blood. Appendix B is a table of blood uptake frac nificance for prenatal exposure in the work environ tions for ingested activity. Appendix C contains tables ment. The radionuclides that were identified and in of gestation-time dependent doses to the embryo/fe cluded were 3H, 14C, 57Co, 58Co, 6OCo, 8 9Sr, 90Sr,

106 Ru, 1251, 1311, 1321, 133I, 1341, 1351, 134 CS, 137CS, tus following introduction of specified radionuclides

2 3 U, M4U, 23U, 238U, 23 8Pu, 239Pu, and 24 1Am. The and chemical forms into maternal blood. Examples of the use of dose assessment methods are provided in methods of Revision 1 to NUREG/CR-5631 are con Appendix D.

sidered interim as efforts continue to further develop the bases and calculational methods for estimating The total radiation dose to the embryo/fetus is prenatal radiation doses. Revision 1 to NUREG/ the sum of the deep-dose equivalent to the declared CR-5631 provides details of the data and bases for pregnant worker and the dose to the embryo/fetus the dosimetric features that were used for the radi from intakes of the declared pregnant worker. If mul onuclides listed above. tiple dosimetric devices are used to measure the deep-dose equivalent to the declared pregnant It is expected that the embryo/fetus dose assess worker, the results of monitoring that are most repre ment methods will evolve over the next several years sentative of the deep dose to the embryo/fetus may be as more research is conducted in this area. As addi used. The licensee need not use the deep dose to the tional research is conducted, better estimates of ac maximally exposed portion of the whole body of the tual embryo/fetus doses resulting from the exposure mother as the deep dose to the embryo/fetus. The of the declared pregnant woman will be possible. For licensee may employ temporary or permanent shield internal doses, research that categorizes the degree of ing to reduce the deep dose to the embryo/fetus. Al placental transfer, the resulting embryo/fetus/placenta ternatively, deep dose to the embryo/fetus may be concentrations, and the potential radiation exposures limited by placing more stringent restrictions on the of the embryo/fetus from radionuclides in their more exposure of the declared pregnant woman than on usual chemical forms should simplify assessment of other members of the occupational work force.

the dose to the embryo/fetus based on the maternal As specified in 10 CFR 20.1208(a), the dose to exposure. The ICRP is considering the formulation of the embryo/fetus from occupational exposure of the dose assessment methods specific for the embryo/ declared pregnant woman during the entire gestation fetus. period is not to exceed 0.5 rem (5 mSv). In addition, the licensee is required to make efforts to avoid sub This regulatory guide provides acceptable meth stantial variation in the monthly exposure throughout ods that may be used in determining the dose to the the period of gestation. If the dose to the embryo/fe embryo/fetus. For internal exposure, a simplified ap tus is found to have exceeded 0.5 rem (5 mSv) or is proach and a more detailed methodology are pre within 0.05 rem (0.5 mSv) of this dose by the time sented for conducting dose evaluations. The regula the woman declares the pregnancy to the licensee, tory position specified in Section 1 provides guidance the licensee is required to limit the additional dose to on the threshold criteria for use in determining when the embryo/fetus to 0.05 rem (0.5 mSv) during the the dose to the embryo/fetus needs to be evaluated. remainder of the pregnancy.

The regulatory position specified in Section 2 presents The tables in the appendices to this guide were a simplified approach for estimating the dose to the prepared directly from the computer outputs, which embryo/fetus from intakes by the declared pregnant led to the values generally being expressed to three woman. The regulatory position specified in Section 3 significant figures. This indicates greater accuracy provides an alternative, more detailed methodology than is warranted by the dosimetry model, but the for a limited number of radionuclides, using the gesta results are presented in this form to avoid roundoff tion-time dependent dosimetric data from Revision 1 errors in calculations. In general, final results should to NUREG/CR-5631 (Ref. 2). be rounded to the nearest thousandth of a rem.

8.36-2

C. REGULATORY POSITION

1.3 External Dose to the Embryo/Fetus According to 10 CFR 20.1208(c)(1), the deep CRITERIA FOR DETERMINING DOSE TO

dose equivalent to the declared pregnant woman will THE EMBRYO/FETUS

be taken as the external dose component to the em bryo/fetus. The determination of external dose

1.1 Monitoring should consider all occupational exposures of the de clared pregnant woman since the estimated date of The dose equivalent to the embryo/fetus should conception. The deep-dose equivalent that should be be determined based on the monitoring of the de assigned is that dose that would be most representa clared pregnant woman as required by 10 CFR tive of the exposure of the embryo/fetus (i.e., in the

20.1502. Specifically, 10 CFR 20.1502(a)(2) re mother's lower torso region). If multiple measure quires monitoring the exposure of a declared preg ments have been made, assignment of the highest nant woman when the dose to the embryo/fetus is deep-dose equivalent for the declared pregnant likely to exceed, in 1 year, a dose from external woman to the embryo/fetus is not required unless that sources in excess of 10% of the limit of 10 CFR dose is also the most representative deep-dose equiva

20.1208 (i.e., 0.05 rem). According to 10 CFR lent for the region of the embryo/fetus.

20.1502(b)(2), the licensee must monitor the occu pational intakes of radioactive material for the de 1.4 Internal Dose to the Embryo/Fetus clared pregnant woman if her intake is likely to ex ceed, in 1 year, a committed effective dose equivalent The internal dose to the embryo/fetus should in excess of 0.05 rem (0.5 mSv). Based on this 0.05 consider the exposure to the embryo/fetus from radi rem (0.5 mSv) threshold, the dose to the embryo/fe onuclides in the declared pregnant woman and in the tus should be determined if the intake is likely to ex embryo/fetus. The dose to the embryo/fetus should ceed 1% of ALI (stochastic) during the entire period include the contribution from any radionuclides in of gestation. the declared pregnant woman (body burden) from occupational intakes occurring prior to conception.

These monitoring thresholds will ensure that any The intake for the declared pregnant woman should potentially significant exposures to the embryo/fetus be determined using air sample data, bioassay data, are evaluated and, as appropriate, doses are deter or a combination of the tw

o. Guidance on bioassay

,ined. The conditions specified in 10 CFR measurements used to quantify intake is being devel

.1502(a) and (b) are based on a 1-yeir period. oped and has been issued for public comment as n-rior to declaration of pregnancy, the woman may Draft Regulatory Guide DG-8009, "Interpretation of not have been subject to monitoring based on condi Bioassay Measurements." Specific guidance on tions specified in 10 CFR 20.1502(a) (1) and 10 CFR workplace air sampling is in Revision 1 to Regulatory

20.1502(b)(1). In this case, the licensee should esti Guide 8.25, "Air Sampling in the Workplace."

mate the exposure during the period monitoring was not provided, using any combination of surveys or 1.5 Evaluating Continuous Exposure other available data (for example, air monitoring, For continuous or near-continuous exposure to area monitoring, bioassay). radioactive material that may be inhaled or ingested, the cumulative intake should be quantified and the The monitoring criteria contained in 10 CFR dose determined at least every 30 day

s. If significant

20.1502 do not establish required levels of detection variation in the exposure levels may have occurred, sensitivity. For some radionuclides it may not be fea the time interval for quantifying the intake should be sible to actually confirm by bioassay measurements an reduced. More frequent evaluations should be con intake of 1% of their stochastic ALI. Workplace sidered as the potential dose to the embryo/fetus ap monitoring, occupancy factors, and access control proaches the limit.

should be considered as appropriate in evaluating po tential exposures and monitoring requirements. 1.6 Existing Maternal Body Burdens Maternal body burdens resulting from internal

1.2 Evaluation of Dose to the Embryo/Fetus occupational exposures prior to conception should be included in determining the embryo/fetus dose. The The appropriate dose to be evaluated for the em contribution to the embryo/fetus dose from a mater bryo/fetus is the dose equivalent for the duration of nal burden existing at the time of conception should the pregnancy. An assessment of the 50-year commit be evaluated if the maternal burden at the time of ted dose is not appropriate. Also, it is not appropriate pregnancy exceeds 1% of the radionuclide's stochas to use effective dose equivalent or committed effec tic ALI value for the appropriate mode of intake and

"A:e dose equivalent. (Note: the committed dose class (for inhalation intakes). For multiple radio

.iivalent to the uterus may be applied to the nuclide burdens, the dose should be evaluated if the

-. nbryo/fetus under certain conditions as a simplified sum of the quotients of each burden divided by its approach as described in the regulatory position stochastic ALI exceeds 0.01. Only body burdens ex specified in Section 2.) isting at the time of conception need to be considered

8.36-3

in evaluating this threshold; radioactive material al cantly different from a 9-month gestation dose ready eliminated from the body should not be in equivalent to the embryo/fetus. Several radionuclides cluded. of this type have been evaluated in Revision 1 to NUREG/CR-5631 (Ref. 2), and data have been de This threshold of 1% ALl provides a simplified approach for determining when pre-existing body veloped for calculating an embryo/fetus gestation burdens should be evaluated. At this threshold, it is dose instead of using the committed dose equivalent to the uterus.

unlikely that any resultant dose to the embryo/fetus would be significant (i.e., greater than 10% of the 0.5 For demonstrating compliance with the dose lim rem (5 mSv) limit). As an alternative, the dose as its of 10 CFR 20.1208, the dose factors in Appendix sessment methods presented in the regulatory position *A may be used for approximating the embryo/fetus specified in Section 3 of this guide may be used for dose equivalent for the entire gestation period.

determining whether a pre-existing body burden rep resents a potentially significant dose (i.e., greater The steps for determining the embryo/fetus dose, than 0.05 rem (0.5 mSv)). using the simplified method, are as follows:

2. SIMPLIFIED METHOD FOR 2.1 Include all the intakes by the declared preg DETERMINING EMBRYO/FETUS nant woman at any time during the gestation period in DOSE FROM MATERNAL INTAKES the calculation of the embryo/fetus dose.

The determination of the dose to the embryo/fe 2.2 For ingested radionuclides, determine the tus from the intake of radioactive material by the activity uptake by the first transfer compartment pregnant woman should be based on the best avail (blood) by multiplying the intake (1) by the appropri able scientific data. At present, the NRC staff consid ate uptake factor (fl) from Appendix B (adapted ers Revision 1 to NUREG/CR-5631 (Ref. 2) to pro from Federal Guidance Report No. 11, Table 3 (Ref.

vide such data. For most radionuclides, the dose to 4)). The uptake factor, fl, is the fraction of an in the embryo/fetus will be similar to or less than the gested compound of a radionuclide that is transferred dose to the maternal uterus (Ref. 1). However, the into the first transfer compartment (i.e., blood uptake data in Revision I to NUREG/CR-5631 indicate that fraction).

for some radionuclides the embryo/fetus dose may be significantly different, either greater than or less than 2.3 For inhaled radionuclides, determining the the dose to the uterus. fraction of initial intake that is transferred to the blood involves an evaluation of the deposition in the Based on these premises (uterus dose similar to three compartments of the lung and the subsequent fetal dose and the data in Revision 1 to NUREG/ time-dependent transfer to the body fluids and to the CR-5631 (Ref. 2)), a set of dose factors has been GI tract. Unless it is known otherwise, it should be developed for use in calculating an embryo/fetus assumed that the transfer from the lung to body fluids dose. Except for those radionuclides addressed in and from lung to GI tract to body fluids follows the Revision 1 to NUREG/CR-5631 (Ref. 2), the dose ICRP 30 (Ref. 3) modeling (which is the basis for this factors presented in Appendix A to this guide repre guide).

sent the committed dose equivalent to the uterus per introduction of unit activity into the first transfer 2.4 For simplicity and conservatism in the mod compartment (i.e., blood) of the woman.' For the eling, the total uptake into the blood from the mater radionuclides in Revision 1 to NUREG/CR-5631, the nal intake is assumed to be instantaneous. However, dose factors in Appendix A represent the maximum for radionuclides with lung clearance class of W (10

dose equivalent to the embryo/fetus for the gestation to 100-day half-life clearance) or Y (greater than period from the introduction of unit activity into the 100-day half-life clearance), the actual translocation first transfer compartment of the woman at any time from the lung and uptake in the blood may occur during the gestation period. over a time period that exceeds the gestation period.

Clearance from the lung may take up to several years.

The dose limit for the embryo/fetus is expressed All the initially deposited material is not immediately as a 9-month gestation dose equivalent. Particularly available for uptake by the first transfer compartment for certain radionuclides with both long radiological (blood). However, an incremental transfer from the half-lives and long-term biological retention, the com lung to the blood may be assessed based on the lung mitted dose equivalent to the uterus may be signifi model as described in ICRP Publications 30 and 19 (Refs. 3 and 5).2

'The committed dose equivalent factors for the uterus pre sented in Appendix A were calculated based on the modeling Table 1, adapted from the data in Figure 5.2 of employed during the development of the ICRP 30 (Ref. 3) ICRP 30 (Ref. 3), may be used for determining the data. It is recognized that the metabolism of the pregnant woman may not be adequately represented by the standard total transfer from the lung to the first transfer metabolic model. However, partly because of the lack of 2As modeled in ICRP Publications 19 and 30, the clearance more definitive data, this modeling has been used for deter from the different lung compartments is assumed to follow mining the dose commitment factors for the uterus that may first-order kinetics. This approach is complex, involving in be used for evaluating compliance with the embryo/fetus terlinking differential equations, and is considered outside the dose limit. scope of a routine operational health physics program.

8.36-4

compartment (i.e., blood), where f, is the blood up take fraction from Appendix B.3 The lung clearance inhaled activity of radionuclide i that enters class (D, W, or Y) for a particular chemical form of a the blood, see Table 1 of this guide)

)articular radionuclide may be obtained from Appen 2.6 For pre-existing body burdens, the total bur dix B to 10 CFR 20.1001-20.2401. den determined to exist at time of pregnancy should be assumed to be available for uptake in the blood of Table 1 the woman. The dose should be assigned to the em Transfer Fraction of Inhaled Activity bryo/fetus as if the maternal blood uptake occurs to First Transfer Compartment within the first month of pregnancy. The embryo/fe tus dose is calculated by multiplying the maternal bur Class Transfer Fraction (TF) den of the radionuclide by its dose factor from Ap pendix A using the equation:

D 0.48 + 0.15 f, DE = AiAxDFi (Equation 3)

W 0.12 + 0.51 f, where:

Y 0.05 + 0.58 f, DE = dose equivalent to the embryo/fetus Al = maternal burden existing at time of preg

2.5 Based on the determination of the maternal nancy (ACi)

intake, the dose to the embryo/fetus for the entire DFi = dose conversion factor (Appendix A)

gestation period should be calculated using the follow ing equations: This method provides a simplified and conserva tive approach for evaluating the significance of pre For ingestion intakes:

existing conditions. If the embryo/fetus is likely to re DE = I1ixf 1 ,ixDFi ceive a dose in excess of 25% of the limit from pre (Equation 1)

existing burdens (i.e., greater than 0.125 rem (1.25 For inhalation intakes: mSv)),4 more detailed modeling should be consid ered.

DE = 2 Ii x TFi x DFj (Equation 2)

2.7 Doses from multiple nuclides or multiple in here: takes should be evaluated on a frequency correspond ing to the determination of the intake. Multiple dose DE = dose equivalent to the embryo/fetus for the determinations should be added to determine the to entire gestation period from the acute intakes tal dose. Doses may need to be reevaluated if better of all radionuclides during the gestation estimates of intakes are provided by followup bioassay period (rem) measurements.

= intake of radionuclide i by the declared preg 3. DETERMINING GESTATION-TIME

nant woman at any time during the gestation DEPENDENT DOSE TO THE

period (gCi) EMBRYO/FETUS USING REVISION 1 TO

DFi = dose factor for use in approximating the dose NUREG/CR-5631 METHODS

equivalent to the embryo/fetus for the entire gestation period from the introduction of unit As an alternative to the simplified methods pre activity (1 jiCi) into the, 'maternal blood at sented above, a gestation-time dependent dose to the any time during the gestation period, from embryo/fetus may be calculated for the radionuclides tabular data presented in Appendix A to this addressed in Revision I to NUREG/CR-5631 (Ref.

guide (rem/RCi in maternal blood) 2). Revision 1 to NUREG/CR-5631 presents dosimetric methods for calculating the dose to the fl, = the fraction of radionuclide i reaching the body fluids following ingestion (i.e., the frac 4 This approach for evaluating pre-existing body burdens does tion of ingested activity of radionuclide i that not specifically address time-dependent releases as could oc enters the blood), from data presented in cur for certain radionuclides with both a long biological reten tion and radiological half-life. However, the assumption of Appendix B to this guide blood uptake of the total burden in the first month of the ges tation period provides a simple method with reasonable assur TFi = transfer fraction of inhaled activity to the first ance that any actual dose to the embryo/fetus will not be sig transfer compartment (i.e., the fraction of nificantly underestimated. More detailed evaluations may be needed for unusual circumstances in which a pre-existing body burden could present a significant source of exposure to the embryo/fetus. An evaluation of this nature should be con

3 The coefficients for the transfer fraction equations in Table 1 ducted by individuals knowledgeable in the area of internal re applicable to particles with a 1-micrometer activity me dosimetry. Such a detailed evaluation could consider the ele Jan aerodynamic diameter (AMAD). As a default, these ment retention functions as presented in ICRP Publications 30

equations may be used for all particle sizes. However, if the and 54 (Refs. 3 and 6). Also, the modeling presented in actual particle size distribution is known, transfer fractions Revision 1 to NUlREG/CR-5631 (Ref. 2) could be applied.

for other AMAD particle sizes may be derived from data in The details of this type of an evaluation are beyond the types Figure 5.2 of ICRP 30 (Ref. 3). of analyses that are considered routinely required and, as such, are outside the scope of this guide.

8.36-5

embryo/fetus following the instantaneous introduction the days-to-date in the first gestation month at time of of unit activity into the first transfer compartment intake divided by 30 days. For example, assuming a (blood) of the pregnant woman at successive stages of maternal intake of 14 C resulting in a 1-jiCi blood gestation. These method6 include the contribution to the embryo/fetus dose from the resultant body bur dens of the declared pregnant woman and from activ ity in the embryo/fetus resulting from transfer across take on the 20th day of the pregnancy, the embryo/

fetus dose should be determined by multiplying the cumulated dose from an intake at day 31 (i.e., Table up

[

C3, Cumulated Dose column, 1.89E-04 rads) by the the placenta. Refer to Revision 1 to NUREG/ ratio of 20 days to 30 days (i.e., 20 divided by 30).

CR-5631 (Ref. 2) for a detailed description of the modeling. 3.2.2 For using the tabular dose data in cal culating the embryo/fetus dose, it may be assumed The methods and data of Revision 1 to NUREG/ that all intakes occurring within any of the 30-day pe CR-5631 (Ref. 2) may be used for determining the riods of gestation occur at the beginning of that pe dose to the embryo/fetus from maternal intakes at riod.5 The cumulated dose column should be used in successive stages of gestation for the radionuclides order to determine the total dose for the remainder of

3 H, 14C, 5 7Co, 58 Co, 6 0C0, 89 Sr, 9 0Sr, 10ORu, 1251, 1311, the gestation period.

1321, 133I, 134I, 135i, 134Cs, lSTCS, 233U, 234U, 2"5TU,

238U, 23 8pu, 239 Pu, and 24 1 Am. 3.2.3 For pre-existing body burdens from occupational exposure, the total burden determined The steps for determining the embryo/fetus dose to exist at time of pregnancy should be assumed to be using the Revision 1 to NUREG/CR-5631 (Ref. 2) available for uptake in the blood of the woman. The methods are as follows: dose should be assigned to the embryo/fetus as if the maternal blood uptake occurs within the first month

3.1 The methods presented in the regulatory po of pregnancy. The embryo/fetus dose is calculated by sition in Sections 2.1 through 2.4 should be used for multiplying the maternal burden of the radionuclide determining the uptake in the first transfer compart by its dose factor (Equation 3). The dose factor to be ment (blood) of the declared pregnant woman. used from the Appendix C tables is that factor corre sponding to the cumulated dose for a 0-day of gesta

3.2 Equations 1 and 2 of the regulatory position tion at radionuclide introduction (i.e., right-most col specified in Section 2.5 may be used for determining the embryo/fetus dose with the following clarifica umn, first data entry). However, for those radi onuclides with an "N" for this 0-day entry, the entry tions:

for the second gestation month should be used (i.e.,

3.2.1 For Equations I and 2, in place of the the right-most column, second data entry). Alterna dose factor parameter, DFi, the dose values should tively, time-dependent release kinetics may be used be taken from Appendix C to this guide for the time for calculating that fraction of the body burden that is period representing the time of intake relative to stage translocated to the blood through the duration of the of gestation. The data in Appendix C to this guide are pregnancy. The time-dependent release is described for an absorbed dose (in rads) from the introduction in ICRP Publications 30 and 54 (Refs. 3 and 6). This of 1 gCi of the radionuclide into the first transfer approach is complex, involving interlinking differen compartment (blood) of the woman at the beginning tial equations, and is considered outside the scope of of the specified month of gestation. To convert from a routine health physics program.

an absorbed dose (rad) to a dose equivalent (rem),

3.3 Doses from multiple nuclides and multiple the data in Appendix C should be multiplied by the intakes should be evaluated with a frequency corre appropriate quality factor from Table 1004 (b). 1 of 10

sponding to the intake (i.e., at least once every 30

CFR Part 20. For 3H, 14C, 5 7Co, 5 8 Co, 6 0Co, 89 Sr, days). Multiple dose determinations should be added

90

Sr, 10°Ru, 1251, 1311, 1321, 1331, 1341, 135], 13 4 Cs, and

137 Cs, a quality factor of 1 should be applied. For to determine the total dos

e. Doses may need to be

233 U, 234 U, 2 35U, 23 8 U, 238 Pu, 23 9pu, and 24lAm, a reevaluated if better estimates of intakes are provided by followup bioassay measurements.

quality factor of 20 should be applied, recognizing that most of the embryo/fetus dose results from alpha

D. IMPLEMENTATION

decay.

The purpose of this section is to provide informa For some radionuclides (e.g., 23 5U), a blood tion to applicants and licensees regarding the NRC

uptake at the beginning of the gestation period results staff's plans for using this regulatory guide.

in a negligible dose contribution to the embryo/fetus.

These radionuclides are identified in the tables in Ap Except in those cases in which an applicant pro pendix C to this guide by an "N" entry in the row for poses an acceptable alternative method of complying the 0-day of gestation at radionuclide introduction with specified portions of the Commission's regula (i.e., the first row of dose factor data). For an intake tions, the methods described in this guide will be used of these radionuclides within the first month of gesta tion, a time-weighted dose factor using the second 5 The correlation of intake to actual stage of gestation can only month data (3 1-day row) should be used. The 3 1-day be roughly estimated. For this reason, it is believed that the dose factor should be multiplied by the quotient of correlation should be limited to the best estimate of the month of gestation.

8.36-6

in the evaluation of applications for new licenses, li including supplements, Annals of the ICRP,

cense renewals, and license amendments and for Volume 2, No. 3/4, Pergamon Press Inc., 1979.

evaluating compliance with 10 CFR 20.1001

"1.2401. 4. K. F. Eckerman, A. B. Wolbarst, and A. C. B.

Richardson, "Limiting Values of Radionuclide REFERENCES Intake and Air Concentration and Dose Conver sion Factors for Inhalation, Submersion, and

1. International Commission on Radiological Pro Ingestion," Environmental Protection Agency, tection, "Age-Dependent Doses to Members of Federal Guidance Report No. 11 (EPA- 520/1 the Public from Intake of Radionuclides: Part 88-020), September 1988.

1," ICRP No. 56, Pergamon Press Inc., 1989.

5. International Commission on Radiological Pro

2. M. R. Sikov et al., "Contribution of Maternal tection, "The Metabolism of Compounds of Radionuclide Burdens to Prenatal Radiation Plutonium and Other Actinides," ICRP No. 19, Doses--Interim Recommendations," NUREG/ Pergamon Press Inc., May 1972.

CR-5631, Revision 1 (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992. 6. International Commission on Radiological Pro tection, "Individual Monitoring for Intake of Radionuclides by Workers: Design and Interpre

3. International Commission on Radiological Pro tation," ICRP No. 54, Annals of the ICRP,

tection, "Limits for Intakes of Radionuclides by Volume 19, No. 1-3, Pergamon Press Inc.,

Workers," ICRP No. 30, Parts 1 through 4, 1988.

8.36-7

APPENDIX A

DOSE EQUIVALENT FACTORS FOR USE IN APPROXIMATING THE

EMBRYO/FETUS DOSE FROM RADIONUCLIDES IN MATERNAL BLOOD

Except as noted, the dose factors (DFi) pre into the first transfer compartment of the woman at sented in Table A-1 represent the committed dose any time during the gestation period. These entries equivalent to the uterus per introduction of unit activ are based on the modeling of Revision 1 to NUREG/

ity into the first transfer compartment (i.e., blood) of CR-5631 (Ref. A2) and are derived from the data the woman. These entries were calculated from tabu tables presented in Appendix C to this guide. The lated values of uterine committed dose equivalent per maximum calculated embryo/fetus dose (as presented unit intake and fractional absorption (fl) from the in the Appendix C tables) from intake by the de gastrointestinal tract using ICRP-30 (Ref. Al) meth clared pregnant woman during the gestation period odology. The DFi dose factors were derived by divid has been used for inclusion in Table A-1.

ing the committed dose equivalent per unit intake by the fractional absorption factor (fl). These dose fac The dose factor data presented in Revision 1 to tors are based on unit activity in the blood. The most NUREG/CR-5631 (Ref. A2) are for an absorbed conservative f, (i.e., largest fraction) for each radio dose expressed in units of rads. To adapt these data nuclide has been used for deriving the data in Table as presented in Appendix C to this guide for inclusion A-1. in Table A-i, appropriate quality factors have been applied to convert from rads to dose equivalent, ex For the radionuclides 3H, 14C, 57 Co, 68Co, SOCo, pressed in units of rem. For beta- and gamma-emit

89Sr, 9°Sr, 106Ru, 125I, 131j, 132j, 133I, 134I, 135j, 134Cs,

137 ting radionuclides, a quality factor of 1 has been ap Cs, 23U, 23U, 23U, ZaU, MSPu, ZaPu, and plied. For 2 wU, 234U, 235U, 238U, 238PU, 239pu, and

24

1Am, the dose factors in Table A-1 represent the 24 1 Am, a quality factor of 20 has been applied, recog maximum dose equivalent to the embryo/fetus for the nizing that most of the embryo/fetus dose results from gestation period from the introduction of unit activity the alpha decay.

A-I

L ;

TABLE A-1 Dose Equivalent Factors for Use in Approximating the Embryo/Fetus Dose from Radionuclides in Maternal Blood DFi DFi Nuclide DFi (rem/gCi) Nuclide (rem/ljCi) Nuclide (rem/ACi)

H-3 5.87E-05" Cr-51 6.96E-04 Ga-68 5.66E-02 Be-7 1.67E-02 Mn-51 3.65E-04 Ga-70 8.99E-05 Be-10 1.79E-02 Mn-52 4.70E-02 Ga-72 1.53E+00

C-11 1.21E-OS Mn-52m 2.80E-04 Ga-73 9.36E-02 C-14 1.29E-03* Mn-53 5.77E-05 Ge-66 1.42E-04 F-18 1.32E-05 Mn-54 1.86E-02 Ge-67 1.11E-05 Na-22 1.06E-02 Mn-56 2.18E-03 Ge-68 8.81E-04 Na-24 1.21E-03 Fe-52 1.30E-02 Ge-69 3.02E-04 Mg-28 3.83E-03 Fe-55 3.88E-03 Ge-71 6.99E-06 A1-26 5.33E-01 Fe-59 4.63E-02 Ge-75 1.61E-05 Si-31 3.85E-05 Fe-60 1.47E+00 Ge-77 3.40E-04 Si-32 4.33E-02 Co-55 4.01E-03 Ge-78 1.08E-04 P-32 3.03E-03 Co-56 3.43E-02 As-69 2.46E-05 P-33 4.33E-04 Co-57 2.20E-03* As-70 2.90E-04 S-35 3.53E-04 Co-58 9.17E-03" As-71 1.21E-03 CI-36 2.96E-03 Co-58m 5.17E-05 As-72 2.70E-03 CI-38 3.17E-05 Co-60 4.18E-02* As-73 3.02E-04 C1-39 3.89E-05 Co-60m 4.12E-07 As-74 2.90E-03 K-40 1.84E-02 Co-61 4.50E-05 As-76 1.11E-03 K-42 7.73E-04 Co-62m 5.33E-05 As-77 1.88E-04 K-43 7.10E-04 Ni-56 5.39E-02 As-78 1.85E-04 K-44 1.94E-05 Ni-57 3.60E-02 Se-70 1.61E-04 K-45 1.21E-05 Ni-59 2.71E-03 Se-73 3.66E-04 Ca-41 3.2 IE-05 Ni-63 6.29E-03 Se-73m 3.21E-05 Ca-45 6.6 1E-04 Ni-65 1.43E-03 Se-75 8.79E-03 Ca-47 5.18E-03 Ni-66 2.81E-03 Se-79 4.19E-03 Sc-43 2.48E+00 Cu-60 9.32E-05 Se-81 1.OOE-06 Sc-44 4.59E+00 Cu-61 2.69E-04 Se-81m 1.46E-05 Sc-44m 2.56E+01 Cu-64 2.09E-04 Se-83 3.62E-05 Sc-46 3.15E+O1 Cu-67 6.50E-04 Br-74 3.33E-05 Sc-47 1.86E+00 Zn-62 1.38E-03 Br-74m 6.18E-05 Sc-48 3.52E+01 Zn-63 5.92E-05 Br-75 6.07E-05 Sc-49 4.18E-04 Zn-65 3.49E-02 Br-76 1.20E-03 Ti-44 1.36E+00 Zn-69 3.09E-06 Br-77 3.27E-04 Ti-45 1.54E-02 Zn-69m 5.54E-04 Br-80 3.01E-06 V-47 2.29E-03 Zn-71m 5.75E-04 Br-80m 1.46E-04 V-48 4.37E-01 Zn-72 5.28E-03 Br-82 1. 87E-03 V-49 8.36E-05 Ga-65 9.18E-03 Br-83 2.72E-05 Cr-48 5.77E-03 Ga-66 9.95E-01 Br-84 2.56E-05 Cr-49 3.51E-04 Ga-67 2.50E-01 Rb-79 1. 15E-05

  • Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-2

TABLE A-1 (continued)

DFi DFi - DFi Nuclide (rem/4Ci) Nuclide (reml/gCi) Nuclide (rem/gCi)

Rb-81 8.18E-05 Nb-90

  • 2.39E-01 Rh-105 1.93E-03 Rb-8 lm 1.08E-05 Nb-93m 9.29E-04 Rh-106m 6.86E-03 Rb-82m 3.49E-04 Nb-94 3.04E-01 Rh-107 8.511E-05 Rb-83 7.07E-03 Nb-95 1.24E-01 Pd-100 3.94E-01 Rb-84 1.05E-02 Nb-95m 1.27E-02 Pd-101 3.33E-02 Rb-86 8.14E-03 Nb-96 2.03E-01 Pd-103 1.39E-03 Rb-87 4.22E-03 Nb-97 4.11E-03 Pd-107 7.33E-06 Rb-88 1.02E-05 Nb-98 9.66E-03 Pd-109 1.27E-03 Rb-89 1.20E-05 Mo-90 7.77E-04 Ag-102 3.76E-04 Sr-80 3.96E-04 Mo-93 4.36E-04 Ag-103 8.58E-04 Sr-81 1.22E-04 Mo-93m 4.76E-04 Ag-104 3.05E-03 Sr-82 1.25E-02 Mo-99 9.39E-04 Ag-104m 1.09E-03 Sr-83 2.31E-03 Mo-101 1.48E-05 Ag-105 1.94E-02 Sr-85 4.03E-03 Tc-93 1.33E-04 Ag-106 2.12E-04 Sr-85m 4.8 1E-05 Tc-93m 4.67E-05 Ag-106m 8.21E-02 Sr-87m 1. 62E-04 Tc-94 4.566E-04 Ag-108m 6.59E-02 Sr-89 1.84E-02" Tc-94m 7.08E-05 Ag-110in 1.04E-01 Sr-90 5.22E-02* Tc-95 3.86E-04 Ag-111 1.41E-03 Sr-91 1.49E-03 Tc-95m 1.23E-03 Ag-i112 2.18E-03 Sr-92 7.79E-04 Tc-96 2.62E-03 Ag-115 1.98E-04 Y-86 2.18E+01 Tc-96m 2.29E-05 Cd-104 3.30E-03 Y-86m 1.26E+00 Tc-97 4.67E-05 Cd-107 1.95E-04 Y-87 1.01E+01 Tc-97m 2.42E-04 Cd-109 2.12E-02 Y-88 3.96E+01 Tc-98 2.97E-03 Cd-i113 2.77E-01 Y-90 4.66E-04 Tc-99 2.79E-04 Cd-113m 2.55E-01 Y-90m 1.21E+00 Tc-99m 3.32E-05 Cd- 115 9.47E-03 Y-91 6.03E-02 Tc-101 2.96E-06 Cd-l15m 1.27E-02 Y-9 1m 2.13E-01 Tc-104 2.07E-05 Cd-117 4.23E-03 Y-92 4.81E-01 Ru-94 2.32E-03 Cd-117m 9.62E-03 Y-93 4.18E-01 Ru-97 6.89E-03 In-109 7.95E-03 Y-94 1.10E-01 Ru-103 1.97E-02 In-1l0 4.01E-02 Y-95 3.56E-02 Ru-105 4.09E-03 In-110 4.50E-03 Zr-86 8.62E-01 Ru-106 7.23E-03* In-Ill 3.05E-02 Zr-88 3.87E-01 Rh-99 2.19E-02 In-112 9.47E-05 Zr-89 7.31E-01 Rh-99m 3.5 1E-03 In- 1i3m 1.24E-03 Zr-93 8.79E-05 Rh--100 3.86E-02 In-i 14m 3.05E-02 Zr-95 6.16E-01 Rh-101 3.33E-102 In-115 8.99E-01 Zr-97 5.24E-01 Rh-101m 9.40E-03 In-l 15m 2.16E-03 Nb-88 1.17E-03 Rh-102 1.93E-01 In-l 16m 4.92E-03 Nb-89 1.83E-02 Rh-102m 3.48E-02 In-i 17 1.22E-03 Nb-89 1.30E-02 Rh-103m 1.18E-06 In-I17m 2.61E-03
  • Dose equivalent factor based on data presented in Revision I to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-3

TABLE A-1 (continued)

DFi DFi Nuclide (rem/!gCi) DFi Nuclide (rem/gCi) Nuclide (rem/gCi)

In-1 19m 1.39E-05 Te-127m 1. 82E-03 Ba-131m 1.32E-05 Sn-110 2.1IE-02 Te-129 2.35E-05 Ba-133 1.27E-02 Sn-ill 8.8 1E-04 Te-129m 3.39E-03 Ba-133m 8.77E-04 Sn-1l3 2.63E-02 Te-131 2.18E-04 Ba-135m 7.03E-04 Sn-il7m 1.57E-02 Te-131m 6.64E-03 Ba-139 4.55E-05 Sn-119m 2.29E-03 Te-132 8.57E-03 Ba-140 1.54E-02 Sn-121 3.70E-05 Te-133 3.26E-05 Ba-141 9.47E-05 Sn-121m 5.70E-03 Te-133mn 5.48E-04 Ba-142 2.74E-04 Sn-123 6.35E-03 Te-134 3.98E-04 La-131 3.77E-02 Sn-123m 2.48E-04 i-120 9.36E-05 La-132 5.07E-01 Sn-125 2.37E-02 l-120m 8.73E-05 La-135 3.43E-02 Sn-126 2.35E-01 1-121 1.79E-05 La-137 7.55E-02 Sn-127 1.14E-02 1-123 2.27E-05 La-138 2.84E+00

Sn-128 7.14E-03 1-124 2.16E-04 La-140 2.32E+00

Sb-i 15 2.OOE-04 1-125 1.38E-03* La-141 9.43E-03 Sb-I 16 1.59E-04 1-126 2.23E-04 La-142 1.91E-01 Sb-116m 1.49E-03 1-128 5.25E-06 La-i43 2.85E-03 Sb-i 17 3.34E-04 1-129 5.11E-04 Ce-134 3.13E+00

Sb-1 18m 6.59E-03 1-130 2.29E-04 Ce-135 4.44E+00

Sb- 119 2.08E-04 1-131 3.64E-03" Ce-137 7.13E-02 Sb-120 3.70E-05 1-132 1.56E-04* Ce-137m 3.31E-01 Sb-120 3.42E-02 1-132m 6.14E-05 Ce-139 I. 15E+00

Sb-122 5.85E-03 1-133 9.04E-04* Ce-14i 5.56E-01 Sb-124 2.98E-02 1-134 4.83E-05* Ce-i43 1.05E+00

Sb-124m 4.88E-05 1-135 3.72E-04" Ce-144 3.79E-01 Sb-125 8.5IE-03 Cs-125 1.33E-05 Pr-136 4.12E-02 Sb-126 4.37E-02 Cs-127 5.96E-05 Pr-137 1.26E-01 Sb-126m 1.69E-04 Cs-129 2.13E-04 Pr-138m 9.61E-01 Sb-127 9.66E-03 Cs-130 6.99E-06 Pr-139 1.16E-01 Sb-128 1.33E-04 Cs-131 2.27E-04 Pr-142 1.36E-01 Sb-128 8.73E-03 Cs-132 2. 1OE-03 Pr-142m 1.73E-03 Sb-129 3.36E-03 Cs-134 1.IiE-01* Pr-143 4.53E-08 Sb-130 9.40E-04 Cs-134m 2.66E-05 Pr-144 8.44E-04 Sb-131 3.36E-04 Cs-135 7.07E-03 Pr-145 1.41E-02 Te-116 1.45E-03 Cs-135m 2.42E-05 Pr-147 1.95E-02 Te-121 4.87E-03 Cs-136 1.42E-02 Nd-136 3.59E-01 Te-121m 7.90E-03 Cs-137 5.94E-02* Nd-138 8.26E-01 Te-123 3.09E-05 Cs-138 2.95E-05 Nd-139 4.1IE-02 Te-123m 2.94E-03 Ba-126 1.14E-03 Nd-139m 1.74E+00

Te-125m 9.75E-04 Ba-128 1. 17E-02 Nd-141 4.33E-02 Te-127 6.31E-05 Ba-131 7.40E-03 Nd-147 8.45E-01

"Dose equivalent factor based on data presented in Revision

1 to NUREG/CR-5631 (Ref. A2). All other factors committed dose equivalent to the uterus. represent the A-4

TABLE A-1 (continued)

DFi DFi DFi Nuclide (rem/gCi) Nuclide (rem/gCi) Nuclide (rem/!gCi)

Nd-149 1.37E-01 Gd-149 2.47E+00 Tm-166 2.37E+00

Nd-15 1 2.53E-02 Gd-151 4.99E-01 Tm-167 1.03E+00

Pm-141 3.63E-02 Gd-152 0.OOE-01 Tm-170 5.38E-02 Pm-143 1.79E+00 Gd-153 8.92E-01 Tm-171 8.13E-03 Pm-144 8.68E+00 Gd-159 1.52E-01 Tm-172 1.89E+00

Pm-145 2.58E-01 Tb-147 6.76E-01 Tm-173 5.88E-01 Pm-146 4.34E+00 Tb-149 1.27E+00 Tm-175 2.70E-02 Pm-147 3.49E-05 Tb-150 1.01E+00 Yb-162 8.97E-02 Pm-148 2.60E+00 Tb-151 2.33E+00 Yb-166 6.08E+00

Pm-148m 1.08E+01 Tb-153 1.16E+00 Yb- 167 1.23E-02 Pm-149 4.70E-02 Tb-154 5.65E+00 Yb-169 2.47E+00

Pm-150 6.86E-OI Tb-155 9.52E-01 Yb-175 2.10E-01 Pm--151 I. 1IE+00 Tb-156 8.65E+00 Yb-177 6.98E-02 Sm-141 4.11E-02 Th-156m 9.32E-01 Yb-178 4.11E-02 Sm-141m 1.42E-01 Tb-156m 2.89E-01 Lu-169 3.60E+00

Sm-142 2.11E-01 Tb-157 2.39E-02 Lu-170 8.42E+00

Sm-145 5.56E-01 Tb-158 4.79E+00 Lu-171 3.72E+00

Sm-146 0.OOE-01 Tb-160 6.08E+00 Lu-172 9.20E+00

Sm-147 0.OOE-01 Tb-161 2.64E-01 Lu-173 1.10E+00

Sm-151 1.26E-05 Dy-155 1.08E+00 Lu-174 8.93E-01 Sm-153 3.54E-01 Dy-157 5.8 1E-01 Lu-174m 5.54E-01 Sm-155 5.65E-03 Dy-159 4.19E-01 Lu-176 3.45E+00

Sm-156 3.55E-01 Dy-165 1.3SE-02 Lu-176m 1.53E-0

Eu-145 2.OOE+00 Dy-166 3.56E-01 Lu-177 2.24E-0 1 Eu-146 3.38E+00 Ho-155 1.41E-01 Lu-177m 6.80E+00

Eu-147 8.51E-01 Ho-157 2.57E-02 Lu-178 8.18E-03 Eu-148 3.53E+00 Ho-159 3.47E-02 Lu-178m 5.54E-02 Eu-149 1.40E-01 Ho-161 4.70E-02 Lu-179 3.03E-02 Eu-150 2.92E-02 Ho-162 4.66E-03 Hf-170 4.74E-01 Eu-150 3.02E+00 Ho-162m 1.43E-01 Hf-172 4.63E-01 Eu-152 2.20E+00 Ho-164 3. 1OE-03 Hf-173 2.26E-01 Eu-152m 1.38E-01 Ho-164m 1.32E-02 Hf-175 3.70E-01 Eu-154 2.28E+00 Ho-166 1.04E-01 Hf-177m 5.22E-02 Eu-155 1.60E-01 Ho-166m 1.07E+01 Hf-178m 2.94E+00

Eu-156 1.90E+00 Ho-167 2.38E-01 Hf-179m 8.51E-01 Eu-157 2.01E-01 Er-161 6.29E-01 Hf-180m .71E-01 Eu-158 3.56E-02 Er-165 1. 12E-01 Hf-181 4.96E-01 Gd-145 1.09E-01 Er-169 1.34E-04 Hf-182 1.16E+00

Gd-146 4. 11E+00 Er-171 5.88E-01 Hf-182m 2.61E-02 Gd-i47 4.9 iE+00 Er-172 2.59E+00 Hf-183 2.33E-02 Gd-148 0.OOE-01 Tm-162 6.87E-02 Hf-184 1.94E-01 A-5

TABLE A-1 (continued)

DFi DFi Nuclide DFi (rem/pCi) Nuclide (rem/gCi) Nuclide (rem/gCi)

Ta-172 4.07E-02 Os-189m 5.1IE-06 Hg-193m 3.23E-04 Ta-173 1.94E-01 Os-191 1.99E-02 Ta-174 Hg-194 1.81E-01

4.25E-02 Os-191m 1. 12E-03 Hg-195 7.47E-05 Ta-175 4.96E-01 Os-193 8.55E-03 Hg-195m 5.48E-04 Ta-176 8.25E-01 Os-194 8.69E-02 Hg-197 2.38E-04 Ta-177 1.30E-01 Ir-182 2.23E-03 Hg-197m 2.97E-04 Ta-178 1.47E-01 Ir-184 3.24E-02 Hg-199m 7.55E-06 Ta-179 9.40E-02 Ir-185 3.85E-02 Hg-203 5.33E-03 Ta-180 1.16E+00 Ir-186 1.12E-01 T1-194 6.44E-06 Ta-180m 3.47E-02 Ir-187 2.08E-02 Ti-194m 2.16E-05 Ta-182 2.15E+00 Ir-188 1.60E-01 TI-195 3.49E-05 Ta-182m 2.65E-03 Ir-189 1.96E-02 Ti-197 3.85E-05 Ta-183 5.44E-01 Ir-190 2.52E-01 TI-198 1.94E-04 Ta-184 7.40E-01 Ir-190m 1.OIE-03 TI-198m 8.36E-05 Ta-185 9.25E-03 Ir-192 1. 63E-0 1 T1-199 5.55E-05 Ta-186 7.03E-03 Ir-192m 8.99E-02 T1-200 6.55E-04 W-176 6.55E-04 Ir-194 7.55E-03 TI-201 2.48E-04 W-177 3.66E-04 Ir-194m 4.55E-01 TI-202 1.38E-03 W-178 6.43E-04 Ir-195 1.24E-03 Tl-204 2.43E-03 W-179 8.12E-06 Ir-195m 1.03E-02 Pb-195m W-181 W-185 W-187

2.80E-04

3.51E-07

1.04E-03 Pt-186 Pt-188 Pt-.189

2.06E-02

1.21E-01

2.08E-02 Pb-198 Pb-199

1.65E-04

3.92E-04

6.5IE-04 L

Pb-200 3.37E-03 W-188 1.68E-04 Pt-191 4.88E-02 Pb-201 1.78E-03 Re-177 1.49E-05 Pt-193 1.07E-04 Pb-202 6.77E-02 Re-178 8.37E-06 Pt-193m 2.71E-03 Pb-202m 1.91E-03 Re-181 4.61E-04 Pt-195m 1.58E-02 Pb-203 2.02E-03 Re-182 4.56E-04 Pt-197 2.64E-03 Pb-205 3.63E-04 Re-182 1.92E-03 Pt-197m 1.12E-03 Pb-209 9.93E-06 Re-184 1.64E-03 Pt-199 5.40E-04 Pb-2 10 2.31E+00

Re-184m 1.31E-03 Pt-200 2.04E-02 Pb-211 3.63E-04 Re-i86 4.53E-04 Au-193 1.63E-03 Pb-212 3.29E-02 Re-186m 9.43E-04 Au-194 1.10E-02 Pb-214 5.64E-04 Re-187 1.82E-06 Au-195 2.35E-03 Bi-200 1.66E-03 Re-188 3.73E-04 Au-198. 5.66E-03 Bi-201 4.07E-03 Re-188m 8.19E-06 Au-198m 1.05E-02 Bi-202 4.83E-03 Re-189 2.46E-04 Au-199 1.68E-03 Bi-203 2.54E-02 Os-180 1.78E-03 Au-200. 1.01E-04 Bi-205 4.82E-02 Os-181 1.75E-02 Au-200m 1.61E-02 Bi-206 9.03E-02 Os-182 1.07E-01 Au-201 1. 15E-05 Bi-207 4.88E-02 Os-185 1.33E-01 Hg-193 4.88E-05 Bi-210 1.46E-03 A-6

TABLE A-1 (continued)

DFi DFi DFi Nuclide (rem/pCi) Nuclide (rem/gCi) Nuclide (rem/gCi)

Bi-210m 8.66E-02 U-233 5.84E-01* Am-245 2.68E-04 Bi-212 1.70E-03 U-234 5.84E-01" Am-246m 1.51E-02 Bi-213 4.36E-04 U-235 5.34E-01* Am-246 2.03E-02 Bi-214 3.52E-04 U-236 1.81E-01 Cm-238 1.31E-01 Po-203 1.07E-03 U-237 5.42E-03 Cm-240 3.50E-02 Po-205 1.64E-03 U-238 5.10E-01* Cm-241 8.69E-01 Po-207 4.03E-03 U-239 5.52E-05 Cm-242 3.30E-02 Po-210 3.05E+00 U-240 4.17E-03 Cm-243 3.74E-01 At-207 8.32E-04 Np-232 8.69E-03 Cm-244 3.19E-02 At-211 3.92E-02 Np-233 2.85E-03 Cm-245 3.11E-01 Fr-222 2.13E-03 Np-234 1.45E+00 Cm-246 1.27E-01 Fr-223 8.58E-03 Np-235 2.99E-03 Cm-247 9.51E-01 Ra-223 7.84E-01 Np-236 4.29E-01 Cm-248 3.49E+01 Ra-224 3.85E-01 Np-236 5.25E-02 Cm-249 1.07E-03 Ra-225 6.23E-01 Np-237 3.59E-01 Cm-250 2.76E+02 Ra-226 1.69E+00 Np-238 6.07E-01 Bk-245 4.11E-01 Ra-227 6.10E-05 Np-239 2.55E-01 Bk-246 1.04E+00

Ra-228 2.90E+00 Np-240 7.07E-02 Bk-247 2.83E-01 Ac-224 9.47E-02 Pu-234 1.24E-01 Bk-249 8.40E-04 Ac-225 3.68E-01 Pu-235 1.72E-03 Bk-250 1.54E-01 Ac-226 1.66E-01 Pu-236 6.81E-02 Cf-244 9.25E-05 Ac-227 2.60E-01 Pu-237 1.07E-01 Cf-246 2.88E-02 Ac-228 3.12E-0I Pu-238 1.11E+00* Cf-248 4.18E-02 Th-226 3.02E-03 Pu-239 1.04E+00* Cf-249 9.80E-01 Th-227 3.52E+00 Pu-240 2.80E-02 Cf-250 3.30E-01 Th-228 4.40E+O1 Pu-241 2.96E-04 Cf-251 4.26E-01 Th-229 8.51E+01 Pu-242 2.81E-02 Cf-252 1.15E+0O1 Th-230 1.26E+01 Pu-243 9.62E-03 Cf-253 8.55E-04 Th-231 8.97E-02 Pu-244 1.07E+00 Cf-254 3.70E+02 Th-232 2.26E+01 Pu-245 2.22E-01 Es-250 4.77E-02 Th-234 2.33E-01 Pu-246 1.34E+00 Es-251 1.24E-01 Pa-227 2.42E-03 Am-237 2.60E-02 Es-253 3.58E-02 Pa-228 9.58E-01 Am-238 7.81E-02 Es-254m 5.22E-01 Pa-230 1.04E+00 Am-239 1.63E-01 Es-254 1.33E+00

Pa-231 2.25E-01 Am-240 1.16E+00 Fm-252 2.61E-02 Pa-232 8.95E-01 Am-241 2.22E-01" Fm-253 1.38E-01 Pa-233 3.81E-01 Am-242m 3.64E-02 Fm-254 6.11E-03 Pa-234 6.77E-01 Am-242 1.32E-02 Fm-255 2.85E-02 U-230 6.13E-01 Am-243 4.74E-01 Fm-257 2.60E-01 U-231 2.63E-03 Am-244m 1.05E-05 Md-257 3.69E-02 U-232 6.02E-01 Am-244 3.92E-01 Md-258 5.96E-02

  • Dose equivalent factor based on data presented in Revision 1 to NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-7

REFERENCES

Al. International Commission on Radiological Pro tection, "Limits for Intakes of Radionuclides by A2. M. R. Sikov et al., "Contribution of Maternal Workers," ICRP No. 30, Parts I through 4, Radionuclide Burdens to Prenatal Radiation including supplements, Annals of the ICRP, Dose-Interim Recommendations," NUREG/

Volume 2, No. 3/4, Pergamon Press Inc., 1979. CR-5631, Revision 1 (PNL-7445), U.S. Nu clear Regulatory Commission, March 1992.

I

A-8

APPENDIX B

BLOOD UPTAKE FRACTIONS FOR INGESTED ACTIVTY

Element fi Element fl Actinium IE-3 Einsteinium 1E-3 (Ac) (Es)

Aluminum IE-2 Erbium 3E-4 (Al) (Er)

Americium 1E-3 Europium 1E-3 (Am) (Eu)

Antimony 1E-1 Fermium 1E-3 (Sb) (Fm)

Arsenic 5E-1 Fluorine 1E0

(As) (F)

Astatine 1E0 Francium 1E0

(At) (Fr)

Barium IE-l Gadolinium 3E-4 (Ba) (Gd)

Berkelium 1E-3. Gallium 1E-3 (Bk) (Ga)

Beryllium 5E-3 Germanium 1E0

(Be) (Ge)

Bismuth 5E-2 Gold 1E-1 (Bi) (Au)

Bromine 1E0 Hafnium 2E-3 (Br) (Hf)

Cadmium 5E-2 Holmium 3E-4 (Cd) (Ho)

Calcium 3E-1 Hydrogen lEO

(Ca) (H)

Californium 1E-3 Indium 2E-2 (Co (In)

Carbon 1E0 Iodine 1E0

(C) .(I)

Cerium 3E-4 Iridium 1E-2 (Ce) (Ir)

Cesium 1E0 Iron 1E-1 (Cs) (Fe)

Chlorine 1E0 Lanthanum lE-3 (Cl) (La)

Chromium iE-I Lead 2E-1 (Cr) (Pb)

Cobalt 3E-1 Lutetium 3E-4 (Co) (Lu)

Copper 5E-1 Magnesium 5E-1 (Cu) (Mg)

Curium 1E-3 Manganese IE-1 (Cm) (Mn)

Dysprosium 3E-4 Mendelevium lE-3 (Dy) (Md)

B-1

APPENDIX B (continued)

Element fl Element fi Mercury 1EO Selenium 8E-1 (Hg) (Se)

Molybdenum 8E-1 Silicon 1E-2 (Mo) (Si)

Neodymium 3E-4 Silver 5E-2 (Nd)

(Ag)

Neptunium 1E-3 (Np) Sodium lEO

(Na)

Nickel 5E-2 (Ni) Strontium 3E-I

(Sr)

Niobium 1E-2 (Nb) Sulfur 8E-i (s)

Osmium 1E-2 (Os) Tantalum 1E-3 (Ta)

Palladium 5E-3 (Pd) Technetium 8E-1 (Tc)

Phosphorus 8E-1 (P) Tellurium 2E-1 Platinum (Te)

1E-2 (Pt) Terbium 3E-4 Plutonium 1E-3 (Tb)

(Pu) Thallium 1EO

Polonium 1E-1 (T)

(Po)

Thorium 2E-4 Potassium 1EO (Th)

(K)

Thulium 3E-4 Praseodymium 3E-4 (Tm)

(Pr)

Tin 2E-2 Promethium 3E-4 (Sn)

(Pm)

Titanium 1E-2 Protactinium 1E-3 (Pa) (Ti)

Radium Tungsten 3E-1

2E-1 (Ra) (W)

Rhenium Uranium 5E-2

8E-1 (Re) (U)

Rhodium 5E-2 Vanadium 1E-2 (Rh) (V)

Rubidium 1EO Ytterbium 3E-4 (Rb) (Yb)

Ruthenium 5E-2 Yttrium 1E-4 (Ru) (Y)

Samarium 3E-4 Zinc 5E-1 (Sm) (Zn)

Scandium 1E-4 Zirconium 2E-3 (Sc) (Zr)

B-2

APPENDIX C

RADIATION ABSORBED DOSE TO THE EMBRYO/FETUS

FOLLOWIN

G. INTRODUCTION

OF SPECIFIED RADIONUCLIDES AND

CHEMICAL FORMS INTO THE MATERNAL TRANSFER COMPARTMENT (BLOOD)

The entries for selected radionuclides and chemi As noted in Revision 1 to NUREG/CR-5631 cal forms in the tables in this appendix have been (Ref. Cl), ICRP Publication 30 (Ref. C2) employs a calculated from the modeling presented in Revision I metabolic model in which a fraction of activity in the to NUREG/CR-5631 (Ref. Cl). It has been assumed first transfer compartment (blood) often is assumed that 1 jiCi of activity is introduced into the maternal to go immediately to excretion. Because of the minus transfer compartment (blood). Pregnancy is assumed cule mass of the embryo/fetus immediately following to begin at the time of fertilization, roughly 2 weeks fertilization, for some materials the biokinetic model after menses, and gestation is considered to consist of thus predicts that there would be negligible initial ac nine 30-day months. tivity in the embryo after administration at that time, and that there would be minimal activity at later times. As a consequence, the dose rate and doses Radiation dose rates were calculated from the in also would be negligible, which is indicated by N in itial fraction that was present after a single administra the table. For these nuclides, an approximation of the tion at the start of each of these months or on the cumulative dose for an intake occurring during the assumed final day (day 270) of gestation. Monthly first 30 days should be made based on a time doses were determined by integrating under the curve weighted average of the 31-day intake data. The cu relating the fraction of the activity in the embryo/fetus mulative dose from an intake in the first 30 days of at the start of each month after administration and pregnancy may be estimated by multiplying the

31-day cumulated dose value by the ratio of the days the fraction at the beginning of the subsequent month to-date in the first month to a 30-day period. For ex of gestation. Monthly doses are shown for the inclu ample, assuming a maternal intake of 14C resulting in sive periods, expressed in days. Doses to the embryo/ a I-RCi blood uptake on the 20th day of the preg fetus from radionuclides in maternal organs were cal nancy, the gestation dose should be determined by culated; when appropriate, these are included to pro multiplying the cumulated dose from an intake at day vide total radiation absorbed doses. The tabulated 31 (i.e., Table C3, Cumulated Dose column, ialues of cumulated doses were determined as the 1.89E-04 rads) by the ratio of 20 days to 30 days sum of the monthly doses. (i.e., 20 divided by 30).

C-1

Table C1 Radiation Doses to the Embryo/Fetus from 1 gCi of 3H, as Tritiated Water, Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction 0-30 31-60 Dose

61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 9.03E-06 3.96E-11 7.*71*.-1 14 2.OOE-15 5.31E-17 2.63E-18 1.72E-19 1.34E-20 1.18E-21 9.03E-06

31 1.77E-05 2.64E-0 )8 7.50E-10 1.94E-11 9.70E-13 6.30E-14 4.94E-15 4.33E-16 1.77E-05

,61 3.93E-0 '5 8.96E-07 2.47E-08 1.21E-09 7.91E-11 6.17E-12 5.41E-13 4.02E-05

91 3.82E-05 1.06E-06 5.19E-08 3.39E-09 2.64E-10 2.32E-11 3.93E-05

121 4.50E-05 2.14E-06 1.41E-07 1.10E-08 9.63E-10 4.73E-05

151 4.98E-05 3.22E-06 2.53E-07 2.21E-08 5.33E-05

181

5.28E-05 4.08E-06 3.57E-07 5.72E-05

211

241

5.40E-05 4.70E-06 5.87E-05

5.28E-05 5.28E-05 Table C2 C.) Radiation Doses to the Embryo/Fetus from 1 pCi of 3H, as a Hexose or Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction A

Nj*u'A

31-60 61-90 Dose

91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 -N N N . N N N N N N

31 2.21E-05 2.14E-07 4.68E-08 1.04E-08 4.37E-09 2.35E-09 1.50E-09 1.06E-09 2.24E-05

61 6.OOE-05 7.27E-06 1.67E-06 6.81E-07 3.68E-07 2.34E-07 1.66E-07 7.04E-05

91 5.82E-05 9.25E-06 3.69E-06 1.97E-06 1.26E-06 8.92E-07 7.53E-05

121 7.24E-05 1.97E-05 1.03E-05 6.50E-06 4.62E-06 1. 14E-04

151 8.29E-05 3.05E-05 1.89E-05 1.33E-05 1.46E-04

181

8.96E-05 3.93E-05 2.72E-05 1.56E-04

211

9.31E-05 4.58E-05 1.39E-04

241

1.05E-04 1.OSE-04 N indicates that the metabolid pattern is such that the dose rates and doses would be negligible fertilization. Approximations of doses resulting from administration during the throughout gestation when activity is administered immediately after first month are described on page C-1.

Table C3 Radiation Doses to the Embryo/Fetus from 1 jiCi of 14C, as a Bicarbonate, Hexose, Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestatio )n Periods (days) Cumulated

0-30 31-60 Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 21i-240 241-270 0-270

0 N* N N N N N N N N N

31 1.87E-04 1.72E-06 4.12E-07 9.18E-08 3.88E-08 2.09E-08 1.34E-08 9.56E-09 1.89E-04

61 4.96E-04 5.83E-05 1.46E-05 6.02E-06 3,26E-06 2.09E-06 1.49E-06 5.82E-04

91 4.8 1E-04 7.48E-05 3.24E-05 1.74E-05 1.IIE-05 7.95E-06 6.25E-04

121 5.96E-04 1.59E-04 9.09E-05 5.74E-05 4.1IE-05 9.44E-04

151 6.80E-04 2.47E-04 1.66E-04 1. 17E-04 1.21E-03

181 7.33E-04 3.19E-04 2.39E-04 1.29E-03

211

7.61E-04 3.70E-04 1.13E-03

241

8.88E-04 8.88E-04 Table C4 Radiation Doses to the Embryo/Fetus from 1 gCi of 5 7Co Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indic*ated Gestation Periods (days) Cumulated Introduction 0-30 151-180 181-210 211-240 241-270 Dose

0-270

31-60 61-90 91-120 121-150

0 7.30E-04 2.76E-04 2.36E-04 1.97E-04 1.75E-04 1.56E-04 1.39E-04 1.23E-04 1.09E-04 2.14E-03

31 8.66E-04 2.74E-04 2.45E-04 2.07E-04 1.82E-04 1.60E-04 1.41E-04 1.24E-04 2.20E-03

61 8.71E-04 2.82E-04 2.56E-04 2.15E-04 1.88E-04 1.63E-04 1.42E-04 2.12E-03

91 8.96E-04 2.96E-04 2.67E-04 2.22E-04 1.91E-04 1.64E-04 2.04E-03

121 9.37E-04 3.08E-04 2.75E-04 2.25E-04 1.92E-04 1.94E-03

151 9.78E-04 3.18E-04 2.79E-04 2.27E-04 1.80E-03

181 1.01E-03 3.22E-04 2.83E-04 1.61E-03

211

1.03E-03 3.19E-04 1.35E-03

241

1.04E-03 1.04E-03

  • N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.

Table C5 Radiation Doses to the Embryo/Fetus from 1 gCi of 68Co, Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestatio 9n Periods (days) Cumulated Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 4.81E-03 1.27E-03 9.03E-04 6.03E-04 4.25E-04 3.OOE-04 2.13E-04 1.52E-04 1.09E-04 8.79E-03

31 5.12E-03 1.30E-03 9.30E-04 6.24E-04 4.37E-04 3.06E-04 2.15E-04 1.53E-04 9.08E-03

61 5.26E-03 1.34E-03 9.62E-04 6.41E-04 4.45E-04 3.09E-04 2.17E-04 9.17E-03

91 5.39E-03 1.38E-03 9.88E-04 6.54E-04 4.49E-04 3.11E-04 9.17E-03

121 5.59E-03 1.42E-03 1.01E-03 6.59E-04 4.53E-04 9.13E-03

151 5.75E-03 1.45E-03 1.02E-03 6.64E-04 8.88E-03

181 5.87E-03 1.46E-03 1.03E-03 8.36E-03

211

241 5.95E-03 1.45E-03 7.40E-03

6.OOE-03 6.00E-03 Table C6 Radiation Doses to the Embryo/Fetus from 1 jiCi of 6oCo, Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day Cumulated ys) Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 1.28E-02 4.73E-03 4.37E-03 3.79E-03 3.60E-03 3.40E-03 3.22E-03 3.05E-03 2.88E-03 4.18E-02

31 1.38E-02 4.73E-03 4.40E-03 3.98E-03 3.73E-03 3.48E-03 3.26E-03 3.06E-03 4.04E-02

61 1.39E-02 4.76E-03 4.62E-03 4.12E-03 3.8 1E-03 3.52E-03 3.27E-03 3.80E-02

91 1.40E-02 4.99E-03 4.79E-03 4.22E-03 3.86E-03 3.54E-03 3.54E-02

121 1.46E-02 5.17F-03 4.90E-03 4.27E-03 3.88E-03 3.28E-02

151 1.52E-02 5.29E-03 4.96E-03 4.29E-03 2.97E-02

181 1.56E-02 5.35E-03 5.01E-03 2.60E-02

211

1.59E-02 5.29E-03 2.12E-02

241

1.60E-02 1.60E-02

Table C7 Radiation Doses to the Embryo/Fetus from 1 gCi of 57Co, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 1.47E-03 1.11E-03 7.18E-04 4.88E-04 3.34E-04 2.28E-04 1.54E-04 1.02E-04 6,74E-05 4.67E-03

31 1.67E-03 1.10E-03 7.44E-04 5.1OE-04 3.48E-04 2.35E-04 1.56E-04 1.03E-04 4.87E-03

61 1,68E-03 1.14E-03 7.80E-04 5.31E-04 3.59E-04 2.38E-04 1.57E-04 4.89E-03

91 1.74E-03 1.19E-03 8.13E-04 5.49E-04 3.64E-04 2.40E-04 4.90E-03

121 1.82E-03 1.24E-03 8.38E-04 5.56E-04 3.67E-04 4.82E-03

151 1.89E-03 1.28E-03 8.48E-04 5.60E-04 4.58E-03

181 1.95E-03 1.30E-03 8.55E-04 4.1OE-03

211 1.98E-03 1.31E-03 3.29E-03

241 1.99E-03 1.99E-03 Table C8 Radiation Doses to the Embryo/Fetus from 1 gCi of 6oCo, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da~ys) Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 .181-210 211-240 241-270 0-270

0 2.54E-02 1.90E-02 1.33E-02 9.38E-03 6.88E-03 4.98E-03 3.56E-03 2.52E-03 1.77E-03 8.68E-02

31 2.71E-02 1.90E-02 1.34E-02 9.82E-03 7. 1OE-03 5.09E-03 3.61E-03 2.53E-03 8.76E-02

61 2.70E-02 1.91E-02 1.40E-02 1.02E-02 7.28E-03 5.16E-03 3.62E-03 8.64E-02

91 2.74E-02 2.OOE-02 1.45E-02 1.04E-02 7,38E-03 5.18E-03 8.49E-02

121 2.86E-02 2.08E-02 1.49E-02 1.05E-02 7.4 1E-03 8.22E-02

151 2.97E-02 2.13E-02 1.5 1E-02 1.06E-02 7.67E-02

181 3.04E-02 2.15E-02 1.51E-02 6.70E-02

211 3.08E-02 2.16E-02 5.24E-02

241 3. 1OE-02 3. 1OE-02

Table C9 Radiation Doses to the Embryo/Fetus from 1 jiCi of 89Sr Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction 0-30 31-60 61-90 91-120 121-150 151-180 Dose

181-210 211-240 241-270 0-270

0 4.09E-03 5.66E-04 2.92E-04 1.37E-04 6.64E-05 3.59E-05 2.10E-05 1.23E-05 7.01E-06 5.23E-03

31 5.35E-03 5.74E-04 2,95E-04 1.36E-04 6.57E-05 3.53E-05 2.05E-05 1.20E-05 6.49E-03

61 9.01E-03 1.20E-03 3.84E-04 1.63E-04 7.45E-05 3.86E-05 2.18E-05 1.09E-02

91 9.09E-03 1.36E-03 5.06E-04 2.12E-04 9.67E-05 4.93E-05 1.13E-02

121 1.07E-02 2.24E-03 8.99E-04 3.90E-04 1.84E-04 1.44E-02

151

1.19E-02 3.15E-03 1.40E-03 6.55E-04 1.71E-02

181

1.26E-02 3.87E-03 1.89E-03 1.84E-02

211

1.29E-02 4.38E-03 1.73E-02

241

1.31E-02 1.31E-02

0

Table C10

Radiation Doses to the Embryo/Fetus from 1 jiCi of 90Sr (in Equilibrium with 90Y)

Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da: s) Cumulated Introduction 0-30 31-60 61-90 Dose

91-120 121-150 151-180 .181-210 211-240 241-270 0-270

0 9.07E-03 2.01E-03 1.57E-03 1.1OE-03 8.07E-04 6.58E-04 5.81E-04 5.15E-04 4.43E-04 1.68E-02

31 1.13E-02 2.04E-03 1.57E-03 1.09E-03 7.99E-04 6.49E-04 5.69E-04 5.00E-04 1.85E-02

61 2.03E-02 3.60E-03 1.72E-03 1.33E-03 8.94E-04 7.10E-04 6.04E-04 2.92E-02

91 1.50E-02 3.31E-03 2.80E-03 1.67E-03 1.17E-03 8.98E-04 2.48E-02

121 1.90E-02 7.93E-03 4.71E-03 3.11E-03 2.22E-03 3.70E-02

151

2.69E-02 1.1OE-02 7.41E-03 5.23E-03 5.05E-02

181

2.86E-02 1.36E-02 1.00E-02 5.22E-02

211

241 2.95E-02 1.54E-02 4.49E-02

2.93E-02 2.93E-02

Table Cl1 Radiation Doses to the Embryo/Fetus from 1 giCi of 106Ru (in Equilibrium with

106Rh) Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (da3ys) Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 1.56E-03 1.OOE-03 9.36E-04 7.68E-04 6.67E-04 5.94E-04 5.35E-04 4.85E-04 4.41E-04 6.99E-03

31 2.02E-03 1.21E-03 9.48E-04 7.77E-04 6.72E-04 5.94E-04 5.32E-04 4.80E-04 7.23E-03

61 2.42E-03 1.23E-03 9.56E-04 7.80E-04 6.70E-04 5.90E-04 5.27E-04 7.17E-03

91 2.50E-03 1.24E-03 9.68E-04 7.84E-04 6.68E-04 5.85E-04 6.74E-03

121 2.53E-03 1.25E-03 9.63E-04 7.77E-04 6.62E-04 6.18E-03

151 2.551E-03 1.26E-03 9.59E-04 7.69E-04 5.54E-03

181 2.55E-03 1.25E-03 9.55E-04 4.75E-03

211 2.54E-03 1.23E-03 3.77E-03

241 2.53E-03 2.53E-03

0 Table C12 Radiation Doses to the Embryo/Fetus from 1 giCi of 1251 Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-2 )40 241-270 0-270

0 2.081E-05 1.12E-05 7.34E-06 1.34E-05 1.46E-05 6.07E-06 4.65E-06 3.01E-06 2.07E-06 8.31E-05

31 2.72E-05 1.05E-05 1.27E-05 1.40E-05 1.04E-05 7.27E-06 4.83E-06 3.31E-06 9.02E-05

61 2.74E-05 1.70E-05 2.23E-05 1.63E-05 1. 15E-05 7.66E-06 5.28E-06 1.07E-04

91 1.64E-04 5.21E-05 3.23E-05 2.05E-05 1.31E-05 8.84E-06 2.91E-04

121 8.79E-04 2.88E-04 1.22E-04 5.70E-05 3.05E-05 1.38E-03

151 7.81E-04 3.12E-04 1.40E-04 7.08E-05 1.30E-03

181 6.78E-04 2.99E-04 1.48E-04 1. 12E-03

211 5.97E-04 2.98E-04 8.95E-04

241 5.33E-04 5.33E-04

Table C13 Radiation Doses to the Embryo/Fetus from 1 giCi of 1311 Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction 0-30 Dose

31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 5.93E-05 2.58E-06 1.88E-07 2.20E-08 3.39E-09 2.1OE-10 2.29E-1 1 1.32E-12 6.35E-14 6.21E-05

31 9.73E-05 2.31E-06 3.38E-07 5.05E-08 3.22E-09 3.47E-10 2.01E-11 9.66E-13 1.00E-04

61 9.44E-05 4.14E-06 7.60E-07 4.75E-08 5.23E-09 3.02E-10 1.46E-11 9.94E-05

91 6.52E-04 2. 11E-05 9.30E-07 9.12E-08 5.01E-09 2.33E-10 6.74E-04

121 3.54E-03 8.90E-05 6.03E-06 2.33E-07 7.82E-09 3.64E-03

151 2.35E-03 1.49E-04 5.56E-06 1.75E-07 2.50E-03

181

2.88E-03 1.15E-04 3.48E-06 3.OOE-03

211

241 1.98E-03 6.80E-05 2.05E-03

1.00E-03 1.OOE-03 (I

Table C14 Radiation Doses to the Embryo/Fetus from 1 4Ci of 1321 Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (day Cumulated Introduction 0-30 31-60 ys) Dose

61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 8.43E-05 .0 0 0 0 0 0 0 0 8.43E-05

31 1.06E-04 0 0 0 0 0 0 0 1.06E-04

61 1.27E-04 0 0 0 0 0 0 1.27E-04

91 1.30E-04 0 0

0 0 0 1.30E-04

121 1,51E-04 0 0 0 0 1.51E-04

151 1.53E-04 0 0 0 1.53E-04

181

1.56E-04 0 0 1.56E-04

211

1.56E-04 0 1.56E-04

241

1.56E-04 1.56E-04

Table C15 Radiation Doses to the Embryo/Fetus from 1 pCi of 1331 Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods Cumulated (days)

Introduction Dose

0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 2.81E-04 0 0 0 0 0 0 0 0 2.81E-04

31 5.32E-04 0 0 0 0 0 0 0 5.32E-04

61 6.85E-04 0 0 0 0 0 0 6.85E-04

91 7.04E-04 0 0 0 0 0 7.04E-04

121 9.04E-04 0 0 0 0 9.04E-04

151 8.59E-04 0 0 0 8.59E-04

181 8.49E-04 0 0 8.49E-04

211 8. 27E-04 0 8.27E-04

241 8.11E-04 8.11E-04 C)

Table. C16 Radiation Doses to the Embryo/Fetus from 1 gCi of 1341 Introduced into the Maternal Transfer Compartment (Blood)

Days of

  • Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-2 40 241-270 0-270

0 2.22E-05 0 0 0 0 0 0 0 0 2.22E-05

31 2.79E-05 0 0 0 0 0 0 0 2.79E-05

61 3.44E-0S 0 0 0 0 0 0 3.44E-05

91 3.50E-05 0 0 0 0 0 3.50E-05

121 81E-05 0 0 0 0 3.8 IE-05

151 3.91E-05 0 0 0 3.91E-05

181 4.03E-05 0 0 4.03E-05

211 4.83E-05 0 4.83E-05

241 4.06E-05 4.06E-05

Table C17 Radiation Doses to the Embryo/Fetus from 1 gCi of lms Introduced into the Maternal Transfer Compartment (Blood)

Days of Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (dayys) Cumulated Gestation at Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 1.95E-04 0 0 0 0 0 0 0 0 1.95E-04

31 2.63E-04 0 0 0 0 0 0 0 2.63E-04

61 3.07E-04 0 0 0 0 0 0 3.07E-04

91 3.04E-04 0 0 0 0 0 3.04E-04

121 3.65E-04 03.66E-04 00 00 0 3.65E-04

151 0 3.66E-04

181 3.72E-04 0 0 3.72E-04

211 3.69E-04 0 3.69E-04

241 3.70E-04 3.70E-04 C>

Table C18 Radiation Doses to the Embryo/Fetus from 1 giCi of 134Cs Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (dayys)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 2.55E-02 2.15E-02 1.69E-02 1.33E-02 1.05E-02 8.29E-03 6.35E-03 4.37E-03 2.81E-03 1.10E-01

31 2.82E-02 2.23E-02 1.75E-02 1.38E-02 1.09E-02 8.38E-03 5.75E-03 3.71E-03 1.11E-01

61 2.92E-02 2.30E-02 1.82E-02 1.44E-02 1.10E-02 7.59E-03 4.88E-03 1.08E-01

91 3.03E-02 2.40E-02 1.89E-02 1.45E-02 9.98E-03 6.43E-03 1.04E-01

121 3.16E-02 2.49E-02 1.91E-02 1.31E-02 8.46E-03 9.72E-02

151 3.28E-02 2.5 1E-02 1.73E-02 1. 12E-02 8.64E-02

181 3.30E-02 2.28E-02 1.46E-02 7.04E-02

211 3.14E-02 2.03E-02 5.17E-02

241 3.24E-02 3.24E-02

Table C19 Radiation Doses to the Embryo/Fetus from 1 gCi of 137Cs Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 1.18E-02 1.13E-02 9.13E-03 7.36E-03 5.91E-03 4.74E-03 3.70E-03 2.60E-03 1.71E-03 5.83E-02

31 1.43E-02 1.17E-02 9.43E-03 7.59E-03 6.08E-03 4.74E-03 3.33E-03 2.19E-03 5.94E-02

61 1.501E-02 1.21E-02 9.72E-03 7.80E-03 6.09E-03 4.27E-03 2.81E-03 5.78E-02

91 1.55E-02 1.25E-02 1.OOE-02 7.79E-03 5.48E-03 3.60E-03 5.49E-02

121 1.60E-02 1.29E-02 1.00E-02 7.02E-03 4.63E-03 5.05E-02

151 1.65E-02 1.29E-02 9.05E-03 5.96E-03 4.44E-02

181 1.65E-02 1.16E-02 7.60E-03 3.57E-02

211 1.56E-02 1.03E-02 2.59E-02

241 1. 60E-02 1.60E-02 Table C20

CT3 Radiation Doses to the Embryo/Fetus from 1 gCi of 2MU

Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestatiorn Periods (days) Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 N* N N N N N N N N N

31 1.41E-03 2.31E-05 5.30E-06 1.19E-06 5.01E-07 2.71E-07 1.74E-07 1.24E-07 1.44E-03

61 4.30E-03 7.86E-04 1.89E-04 7.84E-05 4.25E-05 2.72E-05 1.94E-05 5.44E-03

91 6.29E-03 1.52E-03 6.29E-04 3.42E-04 2.19E-04 1.566E-04 9.16E-03

121 8.1OE-03 3.25E-03 1.78E-03 1.13E-03 8.09E-04 1.51E-02

151 9.51E-03 5.11E-03 3.28E-03 2.34E-03 2.02E-02

181 1.40E-02 8.88E-03 6.36E-03 2.92E-02

211 1.49E-02 1.06E-02 2.55E-02

241 2.38E-02 2.38E-02

  • N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.

Table C21 Radiation Doses to the Embryo/Fetus from 1 4Ci of 234U

Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction 0-30 31-60 61-90 91-120 121-150 151-180 Dose

181-210 211-240 241-270 0-270

0 N* N N N N N N N N

31 N

1.40E-03 2.30E-05 5.26E-06 1. 18E-06 5.OOE-07 2.70E-07 1.73E-07

61 1.23E-07 1.43E-03

4.27E-03 7.82E-04 1.87E-04 7.79E-05 4.22E-05 2.70E-05 1.93E-05 5.41E-03

91 6.25E-03 1.51E-03 6.28E-04 3.39E-04 2.17E-04 1.55E-04 9.1OE-03

121 8.05E-03 3.23E-03 1.77E-03 1.13E-03 8.07E-04 1.50E-02

151

9.46E-03 5.07E-03 3.26E-03 2.32E-03 2.01E-02

181

1.40E-02 8.88E-03 6.34E-03 2.92E-02

211

1.48E-02 1.05E-02 2.53E-02

241

2.36E-02 2.36E-02 Table C22 I-

Radiation Doses to the Embryo/Fetus from 1 gCi of 235U

Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction 0-30 Dose

31-60 61-90 91-120 121-150 151-180 181-210 211-240 241-270 0-270

0 N* N N

N N N N N

31 N N

1.29E-03 2.11E-05 4.84E-06 1.09E-06 4.60E-07 2.48E-07 1.59E-07 1.13E-07 1.32E-03

61 3.93E-03 7.19E-04 1.73E-04 7.18E-05 3.88E-05 2.49E-05 1.77E-05 4.98E-03

91 5.75E-03 1.39E-03 5.78E-04 3.12E-04 2.OOE-04 1.43E-04 8.37E-03

121 7.40E-03 2.97E-03 1.62E-03 1.04E-03 7.41E-04 1.38E-02

151 8.70E-03 4.67E-03 3.OOE-03 2.14E-03 1.85E-02

181

1.28E-02 8.12E-03 5.82E-03 2.67E-02

211

1.36E-02 9.69E-03 2.33E-02

241

2.17E-02 2.17E-02

  • N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.

r-

Table C23 Radiation Doses to the Embryo/Fetus from 1 pCi of 238U

Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-1 240 241-270 0-270

0 N* N N N N N N N N N

31 1.23E-03 2.01E-05 4.59E-06 1.04E-06 4.38E-07 2.36E-07 1.51E-07 1.08E-07 1.26E-03

61 3.75E-03 6,86E-04 1.64E-04 6.83E-05 3.70E-05 2.37E-05 1.69E-05 4.75E-03

91 5.49E-03 1.32E-03 5.49E-04 2.98E-04 1.90E-04 1.36E-04 7.98E-03

121 7.06E-03 2.83E-03 1.55E-03 9.9 1E-04 7.08E-04 1.31E-02

151 8.30E-03 4.45E-03 2.86E-03 2.04E-03 1.77E-02

181 1.22E-02 7.76E-03 5.54E-03 2.55E-02

211 1.30E-02 9.23E-03 2.22E-02

241 2.07E-02 2.07E-02 Table C24 C- Radiation Doses to the Embryo/Fetus from 1 gCi of 238Pu.

Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days)

Dose Introduction 0-30 31-60 61-90 91-120 121-150 151-180 181-210 211-2 40 241-270 0-270

0 N* N N N N N N N N N

31 2.68E-03 4.38E-05 1.00E-05 2.26E-06 9.55E-07 5.14E-07 3.30E-07 2.35E-07 2.74E-03

61 8.19E-03 1.50E-03 3.58E-04 1.49E-04 8.05E-05 5.16E-05 3.67E-05 1.04E-02

91 1.20E-02 2.89E-03 1.20E-03 6.50E-04 4.15E-04 2.96E-04 1.75E-02

121 1.54E-02 6.18E-03 3.37E-03 2.15E-03 1.54E-03 2.86E-02

151 1.81E-02 9.70E-03 6.24E-03 4.43E-03 3.85E-02

181 2.66E-02 1.69E-02 1.21E-02 5.56E-02

211 2.84E-02 2.01E-02 4.85E-02

241 4.51E-02 4.51E-02

  • N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.

Table C25 Radiation Doses to the Embryo/Fetus from 1 piCi of 239Pu Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Cumulated Introduction 0-30 31-60 61-90 91-120 121-150 151-180 Dose

1.81-210 211-240 241-270 0-270

0 N N N N N N N N N

31 2.52E-03 4.12E-05 9.40E-06 2.12E-06 8.97E-07

61 4.83E-07 3. 1OE-07 2.21E-07 2.57E-03

7.68E-03 1.40E-03 3.36E-04 1.40E-04 7.56E-05 4.85E-05

91 3.46E-05 9.71E-03

1. 12E-02 2.71E-03 1.12E-03 6.07E-04 3.90E-04 2.78E-04

121 1.63E-02

1.45E-02 5.80E-03 3.17E-03 2.02E-03 1.44E-03 2.69E-02

151

1.70E-02 9.09E-03 5.85E-03 4.17E-03 3.61E-02

181

2.50E-02 1.59E-02 1.13E-02 5.22E-02

211

241 2.66E-02 1.88E-02 4.54E-02

4.23E-02 4.23E-02

03 Table C26 Radiation Doses to the Embryo/Fetus from 1 jiCi of 241Am Introduced into the Maternal Transfer Compartment (Blood)

Days of Gestation at Dose (rad) to Embryo/Fetus Indicated Gestation Periods (days) Cumulated Introduction 0-30 31-60 61-90 Dose

91-120 50 151-180 181-210 211-240 241-270 0-270

0 N* N N N N N N N N N

31 5.36E-04 8.76E-06 2.OOE-06 4.52E-07 1.91E-07 1.03E-07 6.60E-08 4.71E-08 5.48E-04

61 1.64E-03 2.99E-04 7.16E-05 2.97E-05 1.61E-05 1.03E-05 7.35E-06 2.07E-03

91 2.39E-03 5.76E-04 2.39E-04 1.30E-04 8.30E-05 5.92E-05 3.48E-03

121 3.08E-03 1.23E-03 6.75E-04 4.31E-04 3.08E-04 5.72E-03

151 3.61E-03 1.94E-03 1.24E-03 8.89E-04 7.68E-03

181

5.32E-03 3.38E-03 2.41E-03 1.11E-02

211

241 5.67E-03 4.02E-03 9.69E-03

9.04E-03 9.04E-03

  • N indicates that the metabolic pattern Is such that the dose rates and doses would be negligible fertilization. Approximations o doses resulting throughout gestation when activity is administered immediately after from administration during the first month are described on page C-1.

REFERENCES

C1. M. R. Sikov et al., "Contribution of Maternal C2. International Commission on Radiological Pro Radionuclide Burdens to Prenatal Radiation tection, "Limits for Intakes of Radionuclides by Dose-Interim Recommendations," NUREG/ Workers," ICRP No. 30, Parts 1 through 4, CR-5631, Revision I (PNL-7445), U.S. Nu including supplements, Annals of the ICRP,

clear Regulatory Commission, March 1992. Volume 2, No. 3/4, Pergamon Press Inc., 1979.

C-15

APPENDIX D

EXAMPLES OF EMBRYO/FETUS DOSE CALCULATIONS

The purpose of this appendix is to present exam appropriate transfer fraction. The second step in ples of the methods of the guide for calculating the volves the determination of the embryo/fetus dose dose equivalent to the embryo/fetus. The examples based on the maternal radionuclide blood content.

have been developed to demonstrate the calculational methods; the methods for evaluating and determining Six example calculations are provide

d. Cases I

maternal exposures, body burdens, and intakes are and 2 address ingestion intakes by the declared preg not included. These examples are not intended to de nant woman. Cases 3 and 4 address inhalation in scribe all the measures that would be required for de takes. Case 5 evaluates a pre-existing body burden termining the maternal exposure. Instead, the exam and determines the embryo/fetus dose equivalent ples are presented to concisely demonstrate the cal based on the maternal burden existing at time of pregnancy. Case 6 presents an example of summing culational methods once data on maternal exposure external and internal doses and instituting worker have been obtained. It is important to keep in mind that an evaluation is no better than the quality of the controls to ensure the dose limit is not exceeded.

data. In applying the methods of this guide, a primary The two methods in the guide for calculating the concern has to be the reliability of the maternal expo embryo/fetus dose equivalent are presented: the sim sure data. The calculation of the embryo/fetus dose plified method as presented in the regulatory position consists of a two-step process. First, the content of a in Section 2 of this guide and the Revision 1 to radionuclide in maternal blood has to be determined. NUREG/CR-5631 gestation-time dependent method This is accomplished by multiplying the intake by the as presented in the regulatory position in Section 3.

D-1

CASE 1 EMBRYO/FETUS DOSE FOLLOWING ACUTE INGESTION

INTAKE BY DECLARED PREGNANT WOMAN

1.1 Exposure Scenario

1.3.1 Simplified Method A declared pregnant woman unknowingly ingests a substance that contains trace amounts of 58Co. The The regulatory position in Section 2 of the guide licensee determines that the woman ingested 22 gCi presents the Simplified Method for calculating the of S8Co over a 4-day period.* The intake is confined embryo/fetus dose equivalent. From Appendix A to to a short time period (relative to the effective bio the guide, the 58 Co dose equivalent factor is logical retention half-life of 5 8Co) within the first 9.17E-03 rem/gCi (in blood). The dose equivalent is month of the pregnancy. Because the intake is as calculated using Equation 1 from the regulatory posi sumed to have occurred within a single 30-day gesta tion in Section 2.5 of the guide. Substituting the val tion period interval (i.e., a 30-day period as used for ues for intake, the gut-to-blood transfer factor (fl)

calculating intakes and doses), the ingestion may be and dose factor into this equation yields the following dose equivalent calculation:

treated as a single, acute intake.

1.2 Determining Blood Uptake Dose Equivalent = Intake x f, x Dose Factor

= 22 p-Ci x 0.3 x 9.17E-03 The calculation of the dose to the embryo/fetus is rem/p.Ci based on the amount of the intake that is available for = 0.061 rem uptake within the first transfer compartment (i.e.,

blood). Applying the guidance of the regulatory posi 1.3.2 Method Using Revision 1 to tion in Section 2.2 of the guide, the blood uptake for NUREG/CR-5631 an ingestion intake may be calculated by multiplying the intake by the gut-to-blood transfer factor (fl): The regulatory position specified in Section 3 of the guide presents the method for calculating the em Blood Uptake = f, x Ingestion Intake bryo/fetus dose using the gestation-time dependent methodology of Revision 1 to NUREG/CR-5631. Ta For cobalt, the f, value from Appendix B to the ble C5 of Appendix C to the guide presents the gesta guide is 0.3. For this example, the predetermined in tion-time dependent dose factors for 5 8Co. From this gestion intake is 22 p.Ci. Inserting these values into table, the column under the heading "Cumulated the above equation results in the following calculation Dose" presents the dose to the embryo/fetus for the of the maternal blood content: remainder of the gestation period resulting from the introduction of unit activity (i.e., 1 gCi) into the Blood Uptake = 0.3 x 22 pCi = 6.6 gCi blood of the woman at the beginning of the specified monthly gestation period interva

l. The cumulated

1.3 Calculating the Embryo/Fetus Dose dose factor for a SSCo intake during the first month of gestation is 8.79E-03 rads per microcurie in maternal Equivalent blood. The regulatory position specified in Section The calculation of the embryo/fetus dose equiva 3.2.2 of the guide states that it should be assumed lent is based on the activity uptake into the first trans that all intakes occurring within any of the 30-day fer compartment (i.e., maternal blood). First, the time periods of gestation occur at the beginning of dose will be calculated using the Simplified Method as that period. As discussed in the regulatory position in presented in the regulatory position specified in Sec Section 3.2.1, a radiation quality factor of 1.0 should tion 2 of the guide. Next, the gestation-time depend be used for -SCo in converting from an absorbed dose ent method for calculating the dose equivalent will be in rads to an equivalent dose expressed as rems.

presented. Applying the method of the regulatory position speci fied in Section 3.2, the dose equivalent to the em bryo/fetus is calculated as follows:

Dose Equivalent = Intake x f, x Dose Factor x

  • Acceptable methods for determining intake using bioassay 1.0 rem/rad measurements are presented in Proposed Revision 1 to Regu latory Guide 8.9 (DG-8009), "Interpretation of Bioassay = 22 ItCi x 0.3 x 8.79E-03 rad/

Measurements." jiCi x 1.0 rem/rad

= 0.058 rem D-2

CASE 2 EMBRYO/FETUS DOSE FOLLOWING CHRONIC INGESTION

INTAKE BY DECLARED PREGNANT WOMAN

2.1 Exposure Scenario from Appendix A is 5.87E-05 rem per microcurie in Over an extended period of time, a declared maternal blood. The dose contribution to the em pregnant woman unknowingly consumes water that bryo/fetus for each monthly intake may be calculated contains low levels of tritium contamination. The li as follows:

censee discovers the tritium contaminated water in the third month of the woman's pregnancy. A thor Dose Equivalent = Intake x f, x Dose Factor ough evaluation of the situation and associated per First-month intake sonnel exposures is conducted, including bioassay measurements and contaminated water sample analy 156 jiCi x 1.0 x 5.87E-05 rem/liCi = 0.009 rem sis. It is determined that the source did not exist prior Second-month intake to the woman's pregnancy. In keeping with the regu latory positions specified in Sections 2.7 and 3.3 of 248 jiCi x 1.0 x 5.87E-05 rem/ltCi = 0.015 rem the guide, multiple intakes should be evaluated on at least a 30-day frequency. The licensee determines Third-month intake that the declared pregnant woman ingested the fol 185 j+/-Ci x 1.0 x 5.87E-05 rem/gCi = 0.011 rem lowing amounts of tritium over the 3-month period:

TOTAL = 0.035 rem

2.3.2 Method Using Revision 1 to Stage of Gestation at Intake NUREG/CR-5631 Time of Intake (ACi)

(days) Using the methods of Revision 1 to NUREG/

CR-5631, the dose to the embryo/fetus is calculated

0 - 30 156 in a manner similar to that of the Simplified Method,

31 - 60 as presented above. However, as discussed in the

248 regulatory position specified in Section 3.2.1, the

61 - 90 185 dose factor should be taken from Appendix C for the time period representing the time of intake relative to stage of gestation. Table C1 in Appendix C presents the 3H dose factors. The first column of Table C1

2.2 Determining Blood Uptake presents the gestation time (e.g., 0, 30, 60 days), and The amount of tritium that is available for uptake the last column presents the cumulated dose to the by the blood is calculated by multiplying the intake by embryo/fetus for the remainder of the gestation pe the f, value for the radionuclide. For tritium, the riod following the introduction of unit activity into value of f, is 1.0 (refer to the hydrogen entry in Ap maternal blood at the specified gestation time. As pendix B to this guide). Therefore, the amount of specified in the regulatory position in Section 3.2.2 of tritium that is absorbed into the blood (as evaluated the guide, an intake at any time within a specific for calculating the embryo/fetus dose) is the same as monthly gestation period (i.e., a 30-day period) may the intake quantities presented above. be assumed to have occurred at the beginning of the monthly period for the purpose of determining the

2.3 Calculating Embryo/Fetus Dose Equivalent appropriate dose factor to be used. For example, for intakes occurring during the first month of pregnancy,

2.3.1 Simplified Method the dose factor under the "Cumulated Dose" column corresponding to 0 days of gestation (as designated in Equation 1 from the regulatory position specified the left-most column of the table) should be used.

in Section 2.5 of the guide may be used for calculat Cumulated dose factors taken from Table C1 for in ing the dose equivalent for the entire gestation period takes in the respective months of gestation are pre from each monthly intake. The tritium dose factor sented below:

Stage of Gestation at Cumulated Dose Factor for Time of Intake Remainder of Gestation Period (rad/gCi, blood)

1st Month (0 - 30 days) 9.03E-06

2nd Month (31 - 60 days) 1.77E-05

3rd Month (61 - 90 days) 4.02E-05 D-3

Using these gestation-time dependent dose fac Second-month intake tors, the dose equivalent to the embryo/fetus is calcu lated using the regulatory position specified in Section 248 gCi x 1.0 x 1.77E-05 rad/4Ci x

3.2 of the guide. The radiation quality factor for 3H is 1.0 rem/rad = 0.004 rem

1.0. The dose to the embryo/fetus for the remainder Third-month intake of the gestation period resulting from intakes occur ring within each month is calculated as follows: 185 gCi x 1.0 x 4.02E-05 rad/gCi x

1.0 rem/rad = 0.007 rem Dose Equivalent = Intake x f, x DFi TOTAL = 0.013 remi*

First-month intake *The difference between the sum of the monthly doses and the total (i.e., 0.012 rem versus 0.013 rem) is caused by round

156 gCi x 1.0 x 9.03E-06 rad/gCi x ing. In keeping with the recommendation contained in the Discussion section of this guide, final results should be

1.0 remlrad = 0.001 rem rounded to the nearest thousandth of a rem.

D-4

CASE 3 EMBRYO/FETUS DOSE FOLLOWING ACUTE INHALATION INTAKE

BY DECLARED PREGNANT WOMAN

3.1 Exposure Scenario Blood Uptake = TFi x Inhalation Intake During the performance of a medical administra = 0.63 x 100 gCi tion, a woman worker accidentally receives a single, acute inhalation intake of 100 gCi of 1311. At the time = 63 gxCi of the exposure, the woman was in the third month of

3.3 Calculating Embryo/Fetus Dose Equivalent pregnancy but had not declared her pregnancy to her employer (the licensee). Shortly thereafter, she de 3.3.1 Simplified Method clares her pregnancy in writing.

For this example, the predetermined inhalation

3.2 Determining Blood Uptake intake is 100 gzCi. From Appendix A to the guide, the dose factor for 1311 is 3.64E-03 rem/gCi (in blood).

The calculation of the dose to the embryo/fetus is The dose equivalent to the embryo/fetus may be cal based on the amount of the intake that is available for culated using Equation 2 from the regulatory position uptake within the first transfer compartment (i.e., specified in Section 2.5 of the guide:

blood). Also, the transfer to the blood is a function of the lung clearance class. The lung clearance class for Dose Equivalent = Ii x TFi x DFi all chemical compounds of iodine is Class D, denoting = 100 gCi x 0.63 x 3.64E-03 a 0- to 10-day lung clearance half-life. (Appendix B rem/! Ci to 10 CFR 20.1001-20.2401 provides the lung clear = 0.229 rem ance classes for the different chemical compounds of the specified radionuclides.) Applying the guidance of 3.3.2 Method Using Revision 1 to the regulatory positions specified in Sections 2.3 and NUREG/CR-5631

2.4 of the guide, the transfer fraction of inhaled activ ity to the blood for a Class D radionuclide may be The regulatory position specified in Section 3 of calculated as follows: the guide presents the method for calculating the em bryo/fetus dose using the methodology of Revision 1 to NUREG/CR-5631. The inhalation intake is deter TFi (Class D) = 0.48 + 0.15 x flj mined to have occurred during the third month of the gestation period. Table C13 of Appendix C to the where: guide presents the gestation-time dependent dose fac tors for 1311. In this table, the left-most column speci fies the beginning time for each monthly gestation TFi = transfer fraction of inhaled activity to the period (e.g., 0 for 0-30 days, 31 for 31-60 days).

first transfer compartment (blood) The right-most column presents the corresponding cumulated dose to the embryo/fetus for the remain der of the gestation period for unit activity introduced fl,i gut-to-blood transfer factor forradionuclide i (from Appendix B to the guide) into the maternal blood. From this table, the cumu lated dose factor for an 1311 intake during the third

0.48 = fraction of inhalation intake that is cleared month of gestation is 9.94E-05 rad/p.Ci uptake into directly from the lung to the blood for Class blood. As discussed in the regulatory position speci D compounds fied in Section 3.2.1, a radiation quality factor of 1.0

should be used for 1311. Applying the methods of the

0.15 = fraction of inhaled radionuclide that is regulatory position specified in Section 3.2, the dose cleared from the lung to the GI tract for equivalent to the embryo/fetus may be calculated.

Class D compounds The value for the transfer fraction (TFi) is the same as calculated above (i.e., 0.63). Using these parame For iodine, the f, value from Appendix B to the ter values along with Equation 2 from the guide, the guide is 1.0. Inserting these values into the above embryo/fetus dose is calculated as follows:

equation results in the following calculation of the transfer fraction:

Dose Equivalent = Ii x TFi x DFi x 1.0

rem/rad

= 100 Ci x 0.63 x 9.94E-05 TFi = 0.48 + 0.15 x 1.0 rad/p.Ci x 1.0 rem/rad

= 0.63 = 0.006 rem The resultant blood uptake may be calculated by multiplying the transfer fraction by the total intake: This example illustrates the difference that can occur by using the gestation-time dependent dose D-5

factors for the calculation of the embryo/fetus dose equivalent. The Simplified Method, as presented of iodine by the embryo; the thyroid has not yet de above, for this example yields an embryo/fetus dose veloped. It is not until approximately the beginning of of 0.229 rem; using the gestation-time dependent the fourth month of the gestation period that the fetal dose factors results in a calculated embryo/fetus dose thyroid develops to a point that thyroid iodine uptake equivalent of 0.006 rem-a factor of almost 40 less. is thought to occur. Therefore, any maternal intakes This difference reflects the fact that during early em during the second and third trimesters will result in a bryonic development there is no preferential uptake significantly larger dose to the embryo/fetus than will result from the same intake during the first trimester.

D-6

CASE 4 EMBRYO/FETUS DOSE FOR CHRONIC INHALATION INTAKE

BY DECLARED PREGNANT WOMAN

4.1 Exposure Scenario of a mixture of 30% Class D and 70% Class Y com During the third through fifth month of her preg pounds. In keeping with the regulatory positions nancy, a declared pregnant woman is exposed to air specified in Sections 2.7 and 3.3 of the guide, intakes borne levels 9 f 23U. Extensive air sampling and fol over an extended time should be evaluated on at least lowup bioassay measurements are conducted to a 30-day frequency. The licensee determines that the closely monitor the woman's intake. From these woman inhaled the following amounts of 238 U over measurements, it is determined that the mU consists the 3-month period:

Stage of Gestation at Class D Intake Class Y Intake Time of Intake (p.Ci) (.Ci)

(days)

61 - 90 0.038 0.089

91 - 120 0.061 0.14

121 - 150 0.15 0.35

4.2 Determining Blood Uptake The resultant total blood uptake is calculated. by multiplying the TFi value by the inhalation intake:

The calculation of the dose to the embryo/fetus is based on the amount of intake that is available for uptake within the first transfer compartment (i.e., Blood Uptake = TFi x Inhalation Intake blood). Also, the transfer to the blood is a function of

"he lung clearance class. Applying the guidance of the For a Class Y compound, the transfer fraction is egulatory positions specified in Sections 2.3 and 2.4 calculated as follows:

of the guide, the transfer fraction (TFi) of inhaled activity to the first transfer compartment for a Class D

compound may be calculated as follows:

TFi (Class Y) = 0.05 + 0.58 x fjj where:

TFi (Class D) = 0.48 + 0.15 x fli where: 0.05 = fraction of inhalation intake that is cleared directly from the lung to the blood for Class Y compounds TFi = transfer fraction of inhaled activity to the 0.58 = fraction of inhaled radionuclide that is first transfer compartment cleared from the lung to the GI tract for Class Y compounds f1 i gut-to-blood transfer factor for radionuclide i (from Appendix B to the guide). The total blood uptake can be calculated in the same manner as discussed above for the Class D com

0.48 = fraction of inhalation intake that is cleared pound.

directly from the lung to the blood for Class D compounds For uranium, the f, value from Appendix B to the guide is 0.05. Applying the above equations, the

0.15 = fraction of inhaled radionuclide that is amounts of m2U transferred to the blood as a func cleared from the lung to the GI tract for tion of gestation period are presented in the following Class D compounds table:

D-7

Transfer Fraction and Transfer Fraction and Blood Uptake Blood Uptake Stage of Gestation at (Class D) (Class Y)

Time of Intake Transfer Blood Transfer Blood (days) Fraction Uptake Fraction Uptake (TFi) (AiCi) (TFi) (xCi)

61 - 90 0.49 0.0186 0.079 0.00703

91 - 120 0.49 0.0299 0.079 0.0111

121 - 150 0.49 0.0735 0.079 0.0276

4.3 Calculating Embryo/Fetus Dose Equivalent Class Y Inhalation Intake

4.3.1 Simplified Method The dose to the embryo/fetus is calculated by us Dose Equivalent = Intake x TF1 x DFi ing Equation 2 from the regulatory position in Section

2.5 of the guide. From Appendix A, the dose factor Third-month intake for 238U is 5.10E-01 rem/4Ci (in blood). Applying this dose factor along with the monthly transfer frac tions (as calculated above) results in the following 0.089 pCi x 0.079 x 5.10E-01 rem/giCi dose calculations: = 0.004 rem Class D Inhalation Intake Fourth-month intake Dose Equivalent = Intake x TFi x DFi 0.14 jiCi x 0.079 x 5.10E-01 rem/4Ci

= 0.006 rem Third-month intake

0.038 gCi x 0.49 x 5.10E-01 rem/4Ci Fifth-month intake

= 0.009 rem Fourth-month intake 0.35 j+/-Ci x 0.079 x 5.10E-01 rem/liCi

= 0.014 rem

0.061 p.Ci x 0.49 x 5.10E-01 rem/p.Ci

= 0.015 rem TOTAL = 0.024 rem Fifth-month intake The dose to the embryo/fetus resulting from each

0.15 gCi x 0.49 x 5.10E-05 rem/jiCi single-month intake should be determined by adding

= 0.037 rem the Class D component with the Class Y component.

The total gestation period dose is the sum of the TOTAL = 0.061 rem cumulated dose resulting from each monthly intake.

Class D Dose Class Y Dose Total Dose Gestation Month (rem) (rem) (rem)

3rd Month (61 - 90 days) 0.009 0.004 0.013

4th Month (91 -120 days) 0.015 0.006 0.021

5th Month (121 -150 days) 0.037 0.014 0.051 TOTAL 0.085 rem

4.3.2 Method Using Revision 1 to in a manner similar to the Simplified Method above.

NUREG/CR-5631 However, as discussed in the regulatory position Using the methods of Revision 1 to NUREG/ specified in Section 3.2, the dose factor should be CR-5631, the dose to the embryo/fetus is calculated taken from Appendix C for the period representing D-8

the time of intake relative to stage of gestation. Table corresponding cumulated dose to the embryo/fetus C23 of Appendix C presents the gestation-time de for the remainder of the gestation period per unit ac pendent dose factors for 238U. In this table, the left tivity introduced into the maternal blood. From Table most column specifies the beginning time for each C23, the 238U cumulated dose factors for intakes in monthly gestation period (e.g., 0 for 0-30 days, 31 the respective month of gestation are presented be for 31-60 days). The right-most column presents the low:

Stage of Gestation at Cumulated Dose Factor for Remainder Time of Gestation Period of Intake (rad/gCi, blood)

3rd Month (61 - 90 days) 4.75E-03

4th Month (91 -120 days) 7.98E-03

5th Month (121 -150 days) 1.31E-02 Using these gestation-time dependent dose fac Class Y Inhalation Intake tors, the dose equivalent to the embryo/fetus is calcu lated using the regulatory position specified in Section Dose Equivalent = Intake x TF1 x DFi

3.2 of the guide. A radiation quality factor of 20 x 20 rem/rad should be used for MU as specified in the regulatory position in Section 3.2.1. The dose equivalent is cal Third-month intake culated on a monthly basis as follows:

Class D Inhalation Intake 0.089 RCi x 0.079 x 4.75E-03 rad/gCi x 20 rem/rad = 0.001 rem Dose Equivalent = Intake x TF1 x DFi Fourth-month intake x 20 rem/rad Third-month intake 0.14 gCi x 0.079 x 7.98E-03 rad/gCi x 20 rem/rad = 0.002 rem

0.038 gCi x 0.49 x 4.75E-03 rad/ixCi x 20 rem/rad = 0.002 rem Fifth-month intake Fourth-month intake 0.35 ACi x 0.079 x 1.31E-02 rad/;iCi x 20 rem/rad = 0.007 rem

0.061 jtCi x 0.49 x 7.98E-03 rad/LCi x 20 rem/rad = 0.005 rem TOTAL = 0.010 rem Fifth-month intake The dose to the embryo/fetus resulting from each

0.15 gCi x 0.49 x 1.31E-02 rad/tCi single-month intake should be determined by adding x 20 rem/rad = 0.019 rem the Class D component with the Class Y component.

The total gestation period dose is the sum of the TOTAL = 0.026 rem cumulated dose resulting from each monthly intake.

Class D Dose Class Y Dose Total Dose Gestation Month (rem) (rem) (rem)

3rd Month (61 - 90 days) 0.002 0.001 0.003

4th Month (91 -120 days) 0.005 0.002 0.007

5th Month (121 -150 days) 0.019 0.007 0.026 TOTAL 0.036 rem D-9

CASE 5 PRE-EXISTING MATERNAL BODY BURDEN AT TIME OF PREGNANCY

5.1 Exposure Scenario r ,.. I A.

va~-u pi W-existung rjurclefl)

x DFi A declared pregnant woman is determined to have an existing body burden of 137Cs at the time of = 2.8 jxCi x 5.94E-02 pregnancy. The burden is a result of an acute inhala rem/gCi tion intake that occurred around 2 months prior to = 0.166 rem the pregnancy. Extrapolating from bioassay measure ments, the body burden at the time of pregnancy is 5.4.2 Method Using Revision 1 to estimated to be 2.8 gCi. NUREG/CR-5631 Similar to the calculation above, the dose to the

5.2 Evaluating the 1% ALI Threshold embryo/fetus is calculated by multiplying the body burden existing at time of pregnancy by the appropri ate gestation-time dependent dose factor. Table C19 The regulatory position specified in Section 1.6 of Appendix C to this guide presents the gestation of the guide states that if a body burden existing at time dependent dose factors for ' 37Cs. In this table, time of pregnancy exceeds 1% of the stochastic ALI the left-most column specifies the beginning time for for the appropriate mode of intake (ingestion or inha each monthly gestation period (e.g., 0 for 0-30 days, lation), the dose to the embryo/fetus from this burden 31 for 31-60 days). The right-most column presents should be evaluated. From Appendix B to 10 CFR the corresponding cumulated dose to the embryo/fe

20.1001-20.2401, the inhalation* stochastic ALI tus for the remainder of the gestation period for unit value for 137Cs is 200 p.Ci (Column 2 entry under Ta activity introduced into the maternal blood. As stated ble 1 of the appendix). Since the existing burden of in the regulatory position specified in Section 3.2.3 of

2.8 jiCi is larger than 1% of this ALI value, the dose the guide, the uptake in the blood for burdens exist to the embryo/fetus should be evaluated. ing at time of pregnancy should be assumed to occur during the first month of pregnancy.

  • From this table,

5.3 Determining Blood Uptake the cumulated dose factor for a 137 Cs intake during the first month of gestation is 5.83E-02 rad/4Ci up take into blood. As discussed in Section 3.2.1 of the

.The regulatory position specified in Section 2.6 guide, a radiation quality factor of 1.0 should be used of the guide states that the total burden determined to for 13 7Cs. The dose equivalent to the embryo/fetus is exist at the time of pregnancy should be assumed to calculated as follows:

be available for uptake in the blood of the woman.

Therefore, for this example, blood uptake should be assumed to be the same as the existing body burden Dose Equivalent = Ai (pre-existing burden)

of 2.8 p.Ci. x DFi x 1.0 rem/rad

= 2.8 gCi x 5.83E-02

5.4 Calculating the Embryo/Fetus rad/p.Ci x 1.0 rem/rad

= 0.163 rem Dose Equivalent

5.4.1 Simplified Method

  • The regulatory position specified in Section 3.2.3 of the guide allows the use of time-dependent release kinetics for estimat With the assumption that the blood uptake ing the uptake in the maternal blood. This in-depth evaluation equates to the body burden existing at the time of may be warranted for unusual exposure situations; however, for this example, the simplifying assumption of total uptake pregnancy, the dose to the embryo/fetus is calculated during the first month will be used. Also, note that for certain simply by multiplying the burden by the radionuclide radionuclides a blood uptake at the beginning of the gestation period results in a negligible dose contribution to the embryo/

dose factor. From Appendix A to the guide, the dose fetus. For these radionuclides, per guidance of the regulatory factor for 137CS is 5.94E-02 rem/ACi (in blood); position specified in Section 3.2.3 and Appendix C, the cumu therefore, the dose is calculated as follows: lated dose value for the second month of the gestation period (i.e., the 31-day gestation time) should be used.

L

D-10

CASE 6 MATERNAL CHRONIC EXTERNAL EXPOSURE AND INHALATION INTAKE

.1 Exposure Scenario embryo/fetus become applicable. Once declared, past exposures incurred during the gestation period and During the processing of byproduct material any burdens existing at time of pregnancy should be specimens, a woman receives periodic exposure to evaluated.

airborne levels of 137Cs and 144Ce. The lung clearance class for all compounds of cesium is Class D; and for The licensee evaluates the dosimetry records for cerium the chemical compound is determined to be the declared pregnant woman, including air sample an oxide, thereby representing a "Y" lung clearance data and bioassay measurements. It is determined class. The woman becomes pregnant. However, she that at the time of pregnancy the woman had an exist does not inform her employer (the licensee) until the ing body burden of 1.14 gCi of 1

37 Cs and 0.12 p.Ci of third month of the gestation period. At this time, she 144Ce. Intakes during the first, second, and third becomes a declared pregnant woman and the more months of the gestation period are determined and restrictive dose limits of 10 CFR 20.1208 for the are presented in the following table:

Total Intake Stage of Gestation at (ACi)

37 1 Time of Intake 1 CS "Ce (days) (Class D) (Class Y)

Pre-Existing 1.14 0.12

0 - 30 0.48 0.078

31 - 60 0.76 0.14

61 - 90 0.23 0.093 The declared pregnant woman's external expo 6.2.2 Determining Blood Uptake sure is evaluated and is determined to be 0.285 rem from the time of pregnancy to the time of declaration. The regulatory position specified in Section 2.6 After declaration, the licensee imposes radiological of the guide states that the total burden determined to controls to ensure that additional exposures are kept exist at the time of pregnancy should be assumed to to a minimum, pending a thorough evaluation of the be available for uptake in the blood of the woman.

woman's exposures and the resultant embryo/fetus Therefore, for this example, blood uptake should be dose equivalent. assumed to be the same as the existing body burdens of 1.14 iCi of 137 Cs and 0.12 giCi of 144Ce.

6.2 Evaluating Embryo/Fetus Dose Equivalent

6.2.3 Calculating the Embryo/Fetus Dose from Pre-Existing Body Burden Equivalent from Pre-Existing Burden

6.2.1 Evaluating the 1% ALI Threshold Only the Simplified Method will be used in this example for calculating the embryo/fetus doses. For The regulatory position specified in Section 1.6 ' 37 Cs, the approach for using the gestation-time of the guide states that if a body burden existing at dependent method (Revision 1 to NUREG/CR-5631 time of pregnancy exceeds 1% of the stochastic ALI method) would be similar to the calculations pre for the appropriate mode of intake (ingestion or inha sented in Case 5, Section 5.4.2. For '44Ce, gekiation lation), the dose to the embryo/fetus from this burden time dependent dose factors have not been devel should be evaluated. From Appendix B to 10 CFR oped.

20.1001-20.2401, the inhalation stochastic ALI

value for 13 7Cs is 200 gtCi, and for Class Y 144Ce is 10 With the assumption that the blood uptake ptCi (Column 2 entry under Table 1 of the appendix). equates to the body burden existing at the time of Since the sum of the existing burdens of 1.14 p.Ci of pregnancy, the dose to the embryo/fetus is calculated

"-17Cs and 0.12 ptCi of 1'4Ce divided by their respec simply by multiplying the burden by the radionuclide e ALI values is larger than 0.01 (i.e., Y (bur dose factor. From Appendix A to the guide, the dose

,.eni -- ALIi ) > 0.01), the dose to the embryo/fetus factor for 13 7 Cs is 5.94E-02 rem/p.Ci (in blood) and resulting from the maternal pre-existing burden for 144Ce is 3.79E-0 1 rem/pLCi (in blood). The dose is should be evaluated. calculated as follows:

D-11

TFi (Class D) = 0.48 + 0.15 x fl,i Dose Equivalent = 7 Ai (pre-existing burden x DFi where:

= (1.14 gCi x 5.94E-02 rem/ACi) TFi = transfer fraction of inhaled activity to the

+ (0.12 gCi first transfer compartment x 3.79E-01 rem/gCi)

= 0.068 + 0.045 rem fij = gut-to-blood transfer factor for radionuclide

= 0.113 rem i (from Appendix B to this guide)

0.48 = fraction of inhalation intake that is cleared

6.3 Calculating the Embryo/Fetus Dose Equiv directly from the lung to the blood for Class alent from Intakes During Pregnancy D compounds

0.15 = fraction of inhaled radionuclide that is

6.3.1 Evaluating 1% ALI Threshold cleared from the lung to the GI tract for Class D compounds Based on the requirements of 10 CFR

The resultant total blood uptake is calculated by

20.1502(b) (2) and the regulatory position specified in Section 1.1 of this guide, the dose to the embryo/ multiplying the TFi value by the inhalation intake:

fetus is to be evaluated if intakes during the year by the declared pregnant woman are likely to exceed 1% Blood Uptake = TFi x Inhalation Intake of the stochastic ALIs. Without having to consider For a Class Y compound, the transfer fraction is other intakes by the woman during the year, the 1%

threshold is exceeded based on the intakes by the de calculated as follows:

clared pregnant woman during the first 3 months of the pregnancy. Therefore, an evaluation of the em TFi (Class Y) = 0.05 + 0.58 x flj bryo/fetus dose is required.

where:

With multiple intakes occurring during a single 0.05 = fraction of inhalation intake that is cleared monthly period, the intakes may be modeled as cu mulative intakes within each specified gestational monthly period.

directly from the lung to the blood for Class Y compounds

0.58 = fraction of inhaled radionuclide that is L

cleared from the lung to the GI tract for

6.3.2 Determining Blood Uptake Class Y compounds The calculation of the dose to the embryo/fetus is The total blood uptake can be Calculated in the based on the amount of the intake that is available for same manner as discussed above for the Class D com uptake within the first transfer compartment (i.e., pound.

blood). Also, the transfer to the blood is a function of the lung clearance class. Applying the guidance of the For cesium, the f, value from Appendix B to this regulatory positions specified in Sections 2.3 and 2.4, guide is 1.0; for cerium, the value is 3E-04. Applying the transfer fraction (TFi) of inhaled activity to the the above equations, the amounts of 137Cs and 144Ce first transfer compartment for a Class D compound that are transferred to the blood as a function of ges may be calculated as follows: tation period are presented in the following table:

Transfer Fraction and Transfer Fraction and Blood Uptake of 137Cs Blood Uptake of 144Ce Stage of Gestation at (Class D) (Class Y)

Time of Intake Transfer Blood Transfer Blood (days) Fraction Uptake Fraction Uptake (TFi0) (3Aci) (TFi) (00Ci)

0 - 30 0.63 0.30 0.050 0.0039

31 - 60 0.63 0.48 0.050 0.0070

61 - 90 1 0.63 0.14 0.050 0.0046 I

D-12

6.3.3 Calculating Embryo/Fetus Dose Third-month intake Equivalent from Maternal Intakes

0.23 gCi x 0.63 x 5.94E-02 rem/gCi Only the Simplified Method will be used in this = 0.009 rem

.xample

13 7 for calculating the embryo/fetus doses. For

- Cs, the approach of the gestation-time dependent TOTAL = 0.055 rem method (the method in Revision 1 to NUREG/

CR-5631) would be similar to the calculations pre Class Y Inhalation Intake--144Ce sented in Case 4, Section 4.3.2, of this Appendix D.

For 144Ce, gestation-time dependent dose factors Dose Equivalent = Intake x TF 1 x DFi have not been developed. The dose to the embryo/fe First-month intake tus is calculated by using Equation 2 from the regula tory position specified in Section 2.5 of this guide. 0.078 gCi x 0.050 x 3.79E-01 rem/RCi From Appendix A, the dose factor for 137Cs is = 0.001 rem

5.94E-02 rem/;Ci (in blood) and for 144Ce is

3.79E-01 rem/jCi (in blood). Applying these dose Second-month intake factors along with the monthly transfer fractions (as 0.14 gCi x 0.050 x 3.79E-01 rem/jxCi calculated above) results in the following dose calcu = 0.003 rem lations:

Third-month intake Class D Inhalation Intake- 137Cs

0.093 pCi x 0.050 x 3.79E-01 rem/gCi Dose Equivalent = Intake x TF1 x DFi - 0.002 rem First-month intake TOTAL = 0.006 rem

0.48 gCi x 0.63 x 5.94E-02 rem/pgCi

= 0.018 rem 6.4 Summing Internal and External Doses Second-month intake The doses to the embryo/fetus for the existing maternal burden, the maternal inhalation intakes,

0.76 jCi x 0.63 x 5.94E-02 rem/gCi and the deep-dose equivalent to the declared preg

= 0.028 rem nant woman are summarized in the following table:

Exposure Pathway and Embryo/Fetus Dose Equivalent Stage of Gestation (rem)

137 Cs 1

44Cs Total Pre-Existing Body Burden 0.068 0.045 0.113 Inhalation Intakes 0.018 0.001 0.019

(0 - 30 days)

Inhalation Intakes 0.028 0.003 0.031

(31 - 60 days)

Inhalation Intakes 0.009 0.002 0.011

(61 - 90 days)

Deep-Dose Equivalent 0.285

(0 - 90 days)

Total 0.459 The sum of the deep-dose equivalent to the de ternal exposures). This total of 0.459 rem is within clared pregnant woman and the embryo/fetus dose 0.05 rem of the 0.5 rem limit for the embryo/fetus.

resulting from the inhalation intakes of the declared Therefore, the dose limit for the embryo/fetus for the pregnant woman represents the total dose equivalent remainder of the gestation period is an additional to the embryo/fetus (i.e., 0.285 rem deep-dose dose of 0.05 rem from the date of the declared preg equivalent, plus 0.174 rem dose equivalent from in- nancy (refer to 10 CFR 20.1208(d)).

D-13

REGULATORY ANALYSIS

A separate regulatory analysis was not prepared copy of the "Regulatory Analysis for the Revision of for this regulatory guide. The regulatory analysis pre 10 CFR Part 20" (PNL-6712, November 1988) is pared for 10 CFR Part 20, "Standards for Protection available for inspection and copying for a fee at the Against Radiation" (56 FR 23360), provides the regu NRC Public Document Room, 2120 L Street NW.,

latory basis for this guide and examines the costs and Washington, DC, as an enclosure to Part 20 (56 FR

benefits of the rule as implemented by the guide. A 23360).

RA-1

THIS DOCUMENT WAS PRINTED USING RECYCLED PAPER

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