ML19242C268
| ML19242C268 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/1979 |
| From: | NRC OFFICE OF STANDARDS DEVELOPMENT |
| To: | |
| References | |
| REGGD-08.019, REGGD-8.019, NUDOCS 7908100144 | |
| Download: ML19242C268 (12) | |
Text
Revision 1 U.S. NUCLEAR REGULATORY COMMISSION June 1979 y
(&g) REGi.ATORY G L J E
+eeo-OFFICE OF STANDARDS DEVELOPMENT REGULATORY GUIDE 8.19 OCCUPATIONAL RADIATION DOSE ASSESSMENT IN LIGHT-WATER REACTOR POWER PLANTS DESIGN STAGE MAN-REM ESTIMATES A.
INTRODUCTION forming an assessment of collective occupationa!l radiation dose as part of the ongoing design i Section 50.31,
" Con t e n t., of A pplication s ;
review process involved in designing a light-Technical In fo rm a tion, " of 10 CFR Part 50, wa t er-cooled power reactor (LWR) so that
" Licensing of Production and Utilintion Facil-occu pational radiation exposures will Se; ities," requires that each applicant for a permit ALARA.
to construct a nuclear power reactor provide a preliminary safety analysis report (PSAR) and 15.
DISCUSSION that each applicant for a licen se to operate such a facility provide a final safety analysis report (FSAR).
Section 50.34 s;mcifie s in The dose assessment process requires a good general terms the information to be supplied in working knowledge of (1) the principal factors these reports.
c ont ributing to occu pa tional radiation expo-sures that occur at a nuclear reactor power A more detailed description of the information plant and (2) methods and techniques for needed by the NRC staff in its evaluation of ensuring that the occupatimal radiation expo-applications is given in Regulatory Guide 1.70, sure will be ALARA.
Revision 3,
" Standard Format and Content of Safety Analysis Reports for Nuclear Power in assessing the collective occupational dose Plan t s. " Section 12.4, " Dose Asses smen t," of at a plant, the apphcant evaluates each poten-Regulatory Guide 1.70, Revision 3, states that tially significant dose-causing activity at that the safety analysis report should provide the plant (i. e., activities that result in greater estimated annual radiation exposure to person-than one man-rem per year). The applicant
, nel at the proposed plant during normal opera-specifically examines such th.ngs as design,
tions. The man-rem estimate requirement is an s hieldin g,
plant layout, traffic pa t te rn s,
important par t of the overall, ongoing radiation expected main tenan ce,
and radioactivity Q~h
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erotection design review. The purpose of this sources. This evaluation p roces s is aimed at equirement is to p rovide that adequate the con sideration of eliminating unnecessary detailed attention is given during the prelimi-ex pc su re s, minimizing foreseen required doses fnary design stage (as described in the PS AR),
(individual and collective), and examining the m
y' -
,as well as during construction af ter completion cost-effectiveness of each dose-reducing meth-of design (as described in the FSAR), to dose-od and technique. This evaluation process and rausing activities to ensure that personnel the dose reductions that may be expected to
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f exposures will be as low as reasonably achiev-result are the principal objectives of the dose able ( AL AR A). The safety analysis report pr -
assessment. The dose assessments prepared in vides an opportunity for the applicant t accordance with this guide are intended for use
. demonstrate the adequacy of that attention and as an aid in what should be a continuing search to describe whatever design and procedural for dose-reducing techniques and not for NRC changes have resulted from the dose assess-regulatory enforcement purposes.
itent process.
The objective of this guide is to describe a The principal benefits arising from this eva-Aethod acceptable to the NRC staff for per-luation process occur during the period of pre-liminary design since many of the ALARA prac-
, Lnes mirate obstanuve changes Im prerwus assue tices are part of the design process. On the 1
USNRC REGULATORY GUIDES comments shoud be eers to the secretary of the commrssion U S Nuclear Reguantory Commensort Westungton. D C. 20566 Atter tm Docketog ergi
. Pagustory Gudes are eeued to dancrd>e and meme svedetde to the pubec sauce Branch, meWitw1s actaptatwo to the NRC staff of impeerwentmg spec #c parts of tre O
K l Omv*essor s regutetsons. to deareste techrNues s and by 94 sta'? et evalu-The gustles are eeued m the feeloeng ten broad dwesons g
sting speafe probeerm or postutsted ac: dents. or to provide gudence to vsCl').
1 Power Resctors 6 Prodtxts uhtecents Re@6 story Guedes are not ymstitutes for regulatans. ad com.
-t ience wth Wem e not requesd. Metrods and solutione dif+erord from thoen 2 Research and Test Reacto.s
- 7. Transportatson d
3 Fvets and Matenes Fec,irties 8 Occupstumal Haskt
, get out in Ow guedes mE be accevate sf N, prowds a base for the fmdogs
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ntquerte to the usuance or contaw ca of a permet or lerenne by to 4 Eevronmental and sstog 9 Ant. trust and F inarcal Rev,cw 5 Meteneas and Plant Protecton 4 Gened camies.nn Ramsests for sang.a copses of emuod puedes (wheth may be reproduced) or for
. m ent on an auto _matr detributhm ks_t for sangne copses of futes gudos
.- and - borie fru - v- - m these poes are errouraged at and suggest y.
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- 1yw! so eenact tww enformatum or experenre. This gude was reveed as a remuft Commsmeson. Washmgion. O C.
20Ff6, At'entorr De actor, Dmeson Of w constanove comments racerved from es puenc.nd serimm staff rev T.chn.canneormaton and oocument cm-tros 790M001y
other hand, additional benefits can also accrue dose assessment include steam ge nerator tube during advanced design stages and even dur-plu ggin g and main t ena nce, rep:iirs, inservice ing early construction stages, as be tter evalu-inspection, and replacement of pumps, valves,
ation of dose-causing operr.tions are available and gas ket s.
Doses from r on ro u t in e activities and further design refinements can be id e n ti-that are an t icipa t ed or c ra t ion al occurrences fie d. In a d dition, operations that w ill need shoulu be included in the a p plica n t 's A L All A special planning and careful dose control can dose analy sis. Itadiation sources and personnel be identified at the preoperational stage when activities that contribute significantly to occu-the applicant can take advantage (>f all design pa t ional radiation exposures should be clearly options for reducing the occupational dose, identified and analyzed with respect to simila r e x po s u re s that have occurred under simila r C.
REGULATORY POSITION conditions at other operating facilities. In this manner, corrective measures can be incorpora-This guide describes the format and content ted in the design at an early stage.
for assessments of the total annual occupational
( m a n -rem ) dose at an LWit--principally during Tables I t hrou gh 8 are e x am ple s of work-the design stage. The dose assessment at this sheets for t a b ula t ion of data in the dose s t age should include es t ima t ed annual assessment process to indiccite the factors con-personnel exposures during nonnal operation sid e re d. The actual numbers used in the tabu-and du rin g anticipated op e ra tional occur-lations will depend on plant-specific information rences. It should include estimates of the fre-developed in the course of the dose assessment quency of occurrence, the existing er resulting revie w.
radiation levels, the manpower requirer ent s,
and the duration of such activities. Th
. er ti-An objective of the dose assessment process mates can be based on operating experience at should be to develop sunilar plan ts.
Ilow evei,
to the extent
- po s sible, estimates should include consideration 1.
t completed summary table of occupa-lof the design of the proposed plant, inclu din g tional radiation exposur-estimates (such i radia t ion field in t en sit ie s calculated on the as Table 1),
l basis of the plant-specific shieldin g design,
taking into account the effect any dose-2.
Sufficient illust rative detail (such as that i
- reducing design changes.
shown in Tables 2 through 8) to explain how the ra dia t ion e x pos u re assessment The dose assessment process and the con-process was performed, comitant dose reduction analysis should invo,. e individuals trained in plant sy s tem de sign,
3.
A systematic process for considering and shield de sign, plant operation, and health evaluating possible dose-reducing design ph ysics. Knowledge from all these disciplines changes and asseeiated operating proce-should be applied to the dose assestment and du re changes as part of the comprehen-to the entire radiation protection design review sive ongoing design review, and in determining cost-effective dose reduc.ons.
1.
A re. co rd of the review p roce d u res,
plant e x pe riea ce provides usef ul inforation documentation requirements, and identi-on the numbers of people needed for jobs, the fication of p rin cipal AI. A lt A-related duration of different jobs, and the frequency change: resulting from the dose assess-of the jobs as well as on actual occupational ment. 'I his record should be included in {
radiation exposure e x perien c e. The applicant the assessment as a demonstration of the i should use personnel exposure data for specific steps taken to ensure exposures will be kinds of work and job functions available from A L A ll A.
simila r opera tin g LWit s.
- Useful reports on these data have been published by the Atomic Du ring the final design stage, dose assess-Industrial Forum, Inc. and the Electric Power ment should be updated to take into account !
Itesearca Institute, and a summary report on any major design changes. In particular, com-occupational radiation exposures at nuclear pleted shielding design and hyout of equipment power plant s is distributed annually by the should permit better estimates of radiation field Nuclear Itegulatory Commission.
intensities in locations where work will be per-fo rmed.
I The occupational dose assessment should
! nclude p roj ec t e d doses during normal opera-Analysis of the elements of the man-rem esti-i I tions, anticipated operational occurrences, and mate (e.g.
ra diation levels, task du ration,
l shutdowns and should be based on anticipated and frequency), treated qualitatively, can be j radiation conditions af ter at least 5 years of of significant value in m aking engineerin g i plant operation. Some of the exposure-causing ju dgmen ts rega rding design changes fo r activities that should be considered in t his AL Alt A purposes. As a result of the dosej assessment p rocess described herein, it is to be expected that various dose-reducing design
- See Regutatory Guide 1.16, " Report.mg of Operatng infor-matwo-- Appenda A Technncan Spenfvatmns,' for exampics of changes and innovations will be incorporated
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work and yb functons.
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The precision of the man-rem estimate is of D.
IMPLEMENTATION secondary importance. That estimate's relation-ship to actual man-rem doses received during subsequent plant operation will depend pri-The purpose of this section is to provide in-marily on operating experience and maintenance formation to applicants regarding the NItC and repair problems encountered rather than staff's plans for using this regulatory guide.
on design projections, however precise.
Entries in the tables should be identified and their basis explained in the text of the report, This guide reflects current NRC staff prac-e.g.,
available data from similar plan ts,
tice. Therefore, except in those cases in which expected (reduced) values due to design, and the applicant proposes an acceptable alterna-engineering improvements. Such information tive method for complying with specified por-will readily identify those areas in which tions of the Commission's regulations, the ALARA efforts are to be made or have been method described herein is being and will con-tinue to be used in the evaluation of submittals made. Additionally, it would be of value to indicate whether the reduced values in appli-in connection with applications for construction cable cases were derived on the basis of permits or operating licenses until this guide is physical (or other) models, This would alert revised as a result of suggestions from the individuals concerned with the analy:is of the public or additional staff review. For construc-occupational radiation dose assessment report tion pennits, the review will focus principally in determining whether the well-intended im-on design considerations ;
for operatin g provements are productive or counterproduc.
Licenses, the review will focus principally on tive.
administrative and procedural considerations.
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8.19-3
. TABLE 1 TOTAL OCCUP ATIONAL RADIATION EXPOSURE ESTIMATES Dose Activity (man-rem s/ yea r)
Iteactor operations and surveillance (see Tables 2 & 3)
Itoutine maintenance (see Table 4)
Waste processing (see Table 5)
Itefueling (see Table 6)
Inservice inspection (see Table 7)
Special maintenance (see Table 8)
Total man-rems / year
- Occupational exposures from Tables 2 through 8 are entered in Table 1 and added to obtain the facility's estimated total yearly occupational dose.
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TABLE 2 OCCUPATIONAL DOSE ESTIMATES DURING ROUTINE OPERATIONS AND SURVEILLANCE Average Exposure Number of Number of Dose dose rate time per workers events
( man-rem s /y ea r )
Activity (mrem /hr) event (hr) Utilit y Contractor per year U tility Contractor Walking in radiation zones Checking systems and equipment:
Containment cooling system Boron acid (B A) makeup system Fuel pool system Control rod drive (CRD) system
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Other systems (specify):
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Pumps :
CRD Residual heat removal Accumulators Pressurizer valves Other equipment (specify):
Total
+
=
- The list of activities is for illustrative purposes only, is not all inclusive, and would be expected to vary from plant to plant.
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TABLE 3 OCCUPATIONAL DOSE ESTIMATES DURING NONROUTINE OPERATION AND SURVEILLANCE Average Exposure Number of Number of Dose dose rate time per workers events (man-rems / year)
Activit y (mrem /hr) event (hr) Utility Contractor per year Utility Contractor Operation of systems equipment:
Safety injection system Feedwater pumps & turbine In:,trument calibration Other (specify):
Collection of radioactive samples:
oc Liquid
?
m Gas Soud Radiochemistry Radwaste operation Health physics Other (specify):
(*
Total
+
= -
(
>A ej The list of activities is for illustrative purposes only, is not all inclusive, and would be expected to vary from plant to plant.
)
9 9
TABLE 4 OCCUPATIONAL DOSE ESTIMATES DURING ROUTINE MAINTENANCE Average Exposure Number of Number of Dose dose rate time per workers events (man-rems / year)
Activity (mrem /hr) event (hr) U tility Contractor per year Utility Cont ractor Changing filters:
Waste futer Laundry filter Boron acid futer Pressure valves B A makeup pump BA holding pump e.o 4
Instrumentation and controls:
Transmitter inside containment Transmitter outside containment Radwaste processing system Other (specify):
Total
+
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The list of activities is for illustrative purposes only, is not all inclusive, and would be expected to vary from plant to plant.
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TABLE 5 OCCUPATIONAL DOSE ESTIMATES DURING WASTE PROCESSING Average Exposure Number of Number of Dose dose rate time per workers events (man-rems / year)
Activity
(. m_rempr) event (hr)_ litility Cqn t ractor p_er_ p ar
_li t gity Co_n t ractor Control room Sampling and filter changing Panel operation, inspection and testing Operation of waste processing and packaging equipment Other (Specify):
co G
Total
+
= -
E
- The list of activities is for illustrative purposes only, is not all inclusive, and would be expected to vary from plant to plant.
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T. 6 OCCUPATIONAL DOSE ESTIMATES DURING REFUELING Average Exposure Number of Number of Dose dose rate time per workers events (man-rems / year)
Activity (mrem /h r) event (hr) Utility Cont ractor per yeari Utilit y Contractor Reactor pressure vessel head and internals--
removal and installation Fuel preparation Fuel handhng Fuel shipping Other (speedy):
Total
+
= -
E S
- The list of activities is for illustrative purposes only, is not all inclusive, and would be expected to vary from plant to plant.,
Most work functions performed during refueling, and the associated occupational dose received, will vary depending on facility design (BWR or PWR), reactor pressure vessel size, and number of fuel assemblies in the reactor core. For a detailed description of pre-planned activities, time, and manpower schedule, refer to the " critical path for refueling tasks," which should be available from the Nuclear Steam Suppl 3 System (NSSS) supplier.
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TABLE 7 OCCUPATIONAL DOSE ESTIM ATES DURING INSERVICE INSPECTION Average Exposure Number of Number of Dose dose rate time per workers events (man-rems /vear)
Activity (mrem /hr) event (hr) U tility Contractor per year U tility, Cont ractor Providing access: installation of platforms, ladders, etc.,
removal of thermal insulation Inspection of welds Follow up: installation of thermal insulation, platform removal, and cleanup Total
+
=
cm G
i 5
The list of activities is for illustrative purposes only, is not all inclusive, and would be expected to vary from plant to plant.
Estimates should be based on average yearly values over a 10-year period. Variations are expected as a consequence of reactor size, design, number of welds to be inspected yearly, and the degree of equipment automation available for remote examination of welds.
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TABLE 8 OCCUPATIONAL DOSE ESTIMATES DURING SPECIAL MAINTENANCE Average Exposu re Number of Number of Dose dose rate time per workers events (man-rems / year)
Activity (mrem /hr) event (hr) U tilit y Contractor per year U tilit y Con tractor Servicing of control rod drives Servicing of in-core detectors liep.acement of control blades Dechanneling of spent and channeling of new fuel assemblies co Steam generator repairs
~
~
Other (specify):
Total
+
= -
V The list of activities is for illustrative purposes only, is not all inclu sive, and would be expected to vary significantly from plant to plant.
Most preplanned (or routine) maintenance activities during outage are described in the " critical pcth for refueling tasks,"
which should be availaole from the NSSS supplier, and are performed in parallel with the critical pat" refueling tasks to shorten reactor outage time.
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