ML070530387
| ML070530387 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie, Seabrook, Turkey Point, Duane Arnold  |
| Issue date: | 02/28/2007 |
| From: | Raghavan L NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Stall J Florida Power & Light Co |
| Feintuch K, NRR/DORL/LPL3-1, 415-3079 | |
| References | |
| TAC MD3821, TAC MD3822, TAC MD3823, TAC MD3824, TAC MD3825, TAC MD3826 | |
| Download: ML070530387 (9) | |
Text
February 28, 2007 Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, FL 33408-0420
SUBJECT:
DUANE ARNOLD ENERGY CENTER, ST. LUCIE NUCLEAR PLANT, UNITS 1 AND 2, SEABROOK STATION, AND TURKEY POINT NUCLEAR PLANT, UNITS 3 AND 4 - APPLICATION TO USE EFFECTIVE DOSE EQUIVALENT WEIGHTING FACTORS FOR EXTERNAL EXPOSURE (TAC NOS. MD3821, MD3822, MD3823, MD3824, MD3825, MD3826)
Dear Mr. Stall:
By letter dated December 11, 2006, you requested the U.S. Nuclear Regulatory Commission's (NRC's) approval for the use of the weighting factors provided in the American National Standard Institute HPS N13.41-1997 (the Standard) for external radiation exposures when demonstrating compliance with total effective dose equivalent, based on requirements in Part 20 of Title 10 to the Code of Federal Regulations (10 CFR) for Duane Arnold Energy Center, St.
Lucie Nuclear Plant, Units 1 and 2, Seabrook Station, and Turkey Point Nuclear Plant, Units 3 and 4.
On the basis of its review, the NRC staff finds your request acceptable. The enclosed safety evaluation documents the staffs findings.
If you have any questions, please contact Karl Feintuch 301-415-3079.
Sincerely,
/RA/
L. Raghavan, Chief Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-331, 50-335, 50-389, 50-443, 50-250, and 50-251 cc: See next page
Page 1 of 3 Florida Power and Light Company ST. LUCIE PLANT TURKEY POINT PLANT SEABROOK STATION, UNIT NO. 1 DUANE ARNOLD ENERGY CENTER cc:
Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420 Mr. William E. Webster Vice President, Nuclear Operations Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Senior Resident Inspector St. Lucie Plant U.S. Nuclear Regulatory Commission P.O. Box 6090 Jensen Beach, Florida 34957 Craig Fugate, Director Division of Emergency Preparedness Department of Community Affairs 2740 Centerview Drive Tallahassee, Florida 32399-2100 M. S. Ross, Managing Attorney Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Marjan Mashhadi, Senior Attorney Florida Power & Light Company 801 Pennsylvania Avenue, NW., # 220 Washington, DC 20004 Terry O. Jones, Site Vice President Turkey Point Nuclear Plant Florida Power and Light Company 9760 SW. 344th Street Florida City, FL 33035 Douglas Anderson, County Administrator St. Lucie County 2300 Virginia Avenue Ft. Pierce, Florida 34982 Mr. Christopher R. Costanzo Plant General Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 James Connolly, Licensing Manager Florida Power and Light Company Turkey Point Nuclear Plant 9760 SW. 344th Street Florida City, FL 33035 Becky Ferrare Licensing Department Administrator Florida Power and Light Company Turkey Point Nuclear Plant 9760 SW. 344th Street Florida City, FL 33035 Mr. William A. Passetti, Chief Department of Health Bureau of Radiation Control 2020 Capital Circle, SE, Bin # C21 Tallahassee, Florida 32399-1741 Mr. Gordon L. Johnston Site Vice President St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 Attorney General Department of Legal Affairs The Capitol Tallahassee, Florida 32304 Senior Resident Inspector Turkey Point Nuclear Plant U.S. Nuclear Regulatory Commission 9762 SW. 344th Street Florida City, Florida 33035 Michael O. Pearce Plant General Manager Turkey Point Nuclear Plant Florida Power and Light Company 9760 SW. 344th Street Florida City, FL 33035
Page 2 of 3 Florida Power and Light Company ST. LUCIE PLANT TURKEY POINT PLANT SEABROOK STATION, UNIT NO. 1 DUANE ARNOLD ENERGY CENTER cc:
County Manager Miami-Dade County 111 Northwest 1 Street, 29th Floor Miami, Florida 33128 Mr. Seth B. Duston Training Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957-2000 Mr. Terry L. Patterson Licensing Manager St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957 Mark Warner, Vice President Nuclear Operations Support Florida Power and Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Rajiv S. Kundalkar Vice President - Nuclear Engineering Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. J. Kammel Radiological Emergency Planning Administrator Department of Public Safety 6000 Southeast Tower Drive Stuart, Florida 34997 Mr. Peter Brann Assistant Attorney General State House, Station #6 Augusta, ME 04333 Gene St. Pierre, Site Vice President Seabrook Station FPL Energy Seabrook, LLC P.O. Box 300 Seabrook, NH 03874 Resident Inspector U.S. Nuclear Regulatory Commission Seabrook Nuclear Power Station P.O. Box 1149 Seabrook, NH 03874 Town of Exeter 10 Front Street Exeter, NH 03823 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Office of the Attorney General One Ashburton Place, 20th Floor Boston, MA 02108 Board of Selectmen Town of Amesbury Town Hall Amesbury, MA 01913 Ms. Deborah Bell Federal Emergency Management Agency Region I J. W. McCormack P.O. &
Courthouse Building, Room 401 Boston, MA 02109 Mr. Tom Crimmins Polestar Applied Technology One First Street, Suite 4 Los Altos, CA 94019 Mr. Stephen McGrail, Director ATTN: James Muckerheide Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399
Page 3 of 3 Florida Power and Light Company ST. LUCIE PLANT TURKEY POINT PLANT SEABROOK STATION, UNIT NO. 1 DUANE ARNOLD ENERGY CENTER cc:
Philip T. McLaughlin, Attorney General Steven M. Houran, Deputy Attorney General 33 Capitol Street Concord, NH 03301 Mr. Bruce Cheney, Director New Hampshire Office of Emergency Management State Office Park South 107 Pleasant Street Concord, NH 03301 Mr. Michael Kiley Station Director Seabrook Station FPL Energy Seabrook, LLC P.O. Box 300 Seabrook, NH 03874 James M. Peschel Regulatory Programs Manager Seabrook Station FPL Energy Seabrook, LLC PO Box 300 Seabrook, NH 03874 Mr. R. E. Helfrich Senior Attorney Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. W. E. Webster Vice President, Nuclear Operations Florida Power & Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 John Bjorseth Site Director Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 Steven R. Catron Manager, Regulatory Affairs Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 U. S. Nuclear Regulatory Commission Resident Inspectors Office Rural Route #1 Palo, IA 52324 Regional Administrator, Region III U.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4351 Mr. D. A. Curtland Plant Manager Duane Arnold Energy Center 3277 DAEC Rd.
Palo, IA 52324-9785 Daniel McGhee Iowa Department of Public Health Bureau of Radiological Health 321 East 12th Street Lucas Office Buildings, 5th floor Des Moines, IA 50319-0075 Chairman, Linn County Board of Supervisors 930 1st Street SW Cedar Rapids, IA 52404 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064
February 28, 2007 Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, FL 33408-0420
SUBJECT:
DUANE ARNOLD ENERGY CENTER, ST. LUCIE NUCLEAR PLANT, UNITS 1 AND 2, SEABROOK STATION, AND TURKEY POINT NUCLEAR PLANT, UNITS 3 AND 4 - APPLICATION TO USE EFFECTIVE DOSE EQUIVALENT WEIGHTING FACTORS FOR EXTERNAL EXPOSURE (TAC NOS. MD3821, MD3822, MD3823, MD3824, MD3825, MD3826)
Dear Mr. Stall:
By letter dated December 11, 2006, you requested the U.S. Nuclear Regulatory Commission's (NRC's) approval for the use of the weighting factors provided in the American National Standard Institute HPS N13.41-1997 (the Standard) for external radiation exposures when demonstrating compliance with total effective dose equivalent, based on requirements in Part 20 of Title 10 to the Code of Federal Regulations (10 CFR) for Duane Arnold Energy Center, St.
Lucie Nuclear Plant, Units 1 and 2, Seabrook Station, and Turkey Point Nuclear Plant, Units 3 and 4.
On the basis of its review, the NRC staff finds your request acceptable. The enclosed safety evaluation documents the staffs findings.
If you have any questions, please contact Karl Feintuch 301-415-3079.
Sincerely,
/RA/
L. Raghavan, Chief Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-331, 50-335, 50-389, 50-443, 50-250, and 50-251 cc: See next page Distribution:
PUBLIC LPL1-2 R/F LPL2-2 R/F LPL3-1 R/F RidsNrrPMKFeintuch RidsNrrDorlLpl1-2 RidsNrrDorlLpl2-2 RidsNrrDorlLpl3-1 TFrye RidsNrrLACRaynor RidsNrrLABClayton RidsNrrLATHarris KStreit RidsNrrPMGMiller RidsNrrPMBMoroney RidsNrrPMREnnis RidsRgn1MailCenter RidsRgn2MailCenter RidsRgn3MailCenter RidsAcrsAcnwMailCenter RidsEdoMailCenter RidsOgcRp ADAMS ACCESSION NO: ML070530387 OFFICE LPL3-1/PM LPL3-1/LA IHPB/BC OGC LPL3-1/BC NAME KFeintuch THarris TFrye LRaghavan DATE 02/23/07 02/23/07 02/26/07 02/27/07 02/28/07 OFFICIAL RECORD COPY
ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE APPROVAL TO USE WEIGHTING FACTORS FOR EXTERNAL RADIATION EXPOSURES FOR FLORIDA POWER & LIGHT COMPANY, FLORIDA POWER & LIGHT ENERGY SEABROOK, AND FLORIDA POWER & LIGHT ENERGY DUANE ARNOLD DOCKET NOS. 50-335, 50-389, 50-250, 50-251, 50-443, AND 50-331
1.0 INTRODUCTION
By letter to the Nuclear Regulatory commission (NRC) dated December 11, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession no. ML063480330), Florida Power & Light Company (FPL); FPL Energy Seabrook, LLC (FPL Energy Seabrook); and FPL Energy Duane Arnold, LLC, (the licensees) requested an approval to use weighting factors provided in the American National Standards Institute (ANSI) HPS N13.41-1997 (the Standard, Reference 1), for external radiation exposures when demonstrating compliance with total effective dose equivalent (TEDE), based requirements in Title 10 of the Code of Federal Regulations (10 CFR) Part 20 (Reference 2), for Duane Arnold Energy Center, St. Lucie Nuclear Plant, Units 1 and 2, Seabrook Station, and Turkey Point Nuclear Plant, Units 3 and 4.
The effect of granting this request would be to allow the licensees the option to control TEDE using the weighted external exposure measurements in those cases where it is a more accurate predictor of the risk from occupational radiation exposure.
2.0 REGULATORY EVALUATION
The radiation protection approach and dose limits contained in 10 CFR Part 20, are based on the recommendations of the International Commission on Radiation Protection (ICRP) in their 1977 Publication No. 26 (Reference 3). For stochastic effects, the ICRPs recommended dose limitation is based on the principle that the risk should be equal, whether the whole body is irradiated uniformly or there is non-uniform irradiation (such as when radioactive materials are taken into the body and, depending on their physical and chemical properties, concentrate in certain tissues and organs). Therefore, the ICRP 26 recommendations are based on controlling the sum of the risk weighted doses to selected organs.
Section 20.1003 of 10 CFR defines effective dose equivalent (EDE or HE) as the sum of the products of the dose equivalent to the organ or tissue (HT) and the weighting factors (WT) applicable to each of the body organs or tissues that are irradiated (E = TT ).
For the purposes of implementing workplace controls, and due to the difference in dosimetry, 10 CFR Part 20 breaks this EDE into two components: (1) dose resulting from radioactive sources internal to the body, and (2) dose resulting from sources external to the body. Dose limits and other requirements in 10 CFR Part 20 are based on the sum of these external and internal exposures. For radioactive material taken into the body, the occupational dose limit is based on the resulting dose equivalent integrated over 50 years, or committed effective dose equivalent (CEDE).
The TEDE is defined in 10 CFR 20.1003 as the sum of the deep-dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures).
TEDE = deep-dose equivalent (DDE) + TT,50 (CEDE)
The organ dose weighting factor (WT) for an organ or tissue is the proportion of the risk of stochastic effects resulting from irradiation of that organ or tissue to the total risk of stochastic effects when the whole body is irradiated uniformly. There are eight weighting factors defined in 10 CFR 20.1003. The weighting factors are applicable to the organs and tissues whether the dose results from radiation sources internal or external to the body. However, measuring the dose to the various organs and tissues with a dosimeter worn outside the body, presents some practical difficulties. If the body is irradiated uniformly, the external component of TEDE can be determined with a single DDE measurement on any part of the whole body. However, if the body is not irradiated uniformly, a single dose measurement can not determine the dose to the various organs and tissues for an accurate determination of the external EDE (EDEex). To ensure a conservative determination of TEDE, 10 CFR 20.1201(c) requires that the DDE component be determined from the part of the whole body receiving the highest exposure.
In addition, footnote 2 to the Organ Dose Weighting Factors table in 10 CFR 20.1003, states that, [f]or the purpose of weighting the external whole body dose (for adding to the internal dose), a single weighting factor, of T = 1.0, has been specified. The use of other weighting factors for external exposure will be approved on a case-by-case basis until such time as specific guidance is issued.
This conservative approach to determining TEDE can be overly conservative for extremely non-uniform-irradiations (i.e., when only a small portion of the whole body is irradiated). As discussed in NRC Regulatory Issue Summaries 2002-06, 2003-04, and 2004-01, the NRC has approved several methods for determining EDEex, and has encouraged the use of EDEex in place of DDE for demonstrating compliance with the TEDE requirements in 10 CFR Part 20.
3.0 TECHNICAL EVALUATION
The NRC staff has reviewed the technical approach for estimating EDEex provided in the Standard. This multiple dosimetry method divides the whole body into seven separate compartments. Each compartment, or composite compartment (since the Standard allows combining adjacent compartments), is monitored separately. The results of the dose measurement for each compartment are weighted with an associated compartment factor.
The resulting weighted doses are then summed to determine the EDEex for the whole body.
The compartment factors are listed in Table 1 of the Standard. The factor for each compartment was developed by summing the stochastic weighting factors given in ICRP 26 (Part 20 organ weighting factors) for all the organs located within that compartment. For each tissue that resides in more than one compartment (e.g., red bone marrow), the weighting factor was apportioned between the compartments based on the fraction of the total mass of the tissue residing in each, using the information in ICRP 23 (Reference 4).
The NRC staffs review of the Standard determined that the Standards criteria for monitoring each compartment are not sufficiently clear to ensure that a conservative estimate of EDEex will result. Although not stated in the Standard, fundamental to this compartment method of determining EDEex are the following assumptions: (1) the average dose to the tissues in each compartment can be reasonably measured (with one or more dosimeters), and (2) that the dose distribution across the compartment is sufficiently constant so that this average dose can be applied to each tissue in the compartment. The body compartments defined in the Standard are such that under most normal exposure situations these assumptions are met and a single determination of DDE in each compartment is sufficient. However, this may not be the case in those unusual situations where a significant dose gradient exists across one or more compartments (particularly the thorax and abdomen compartments). In these cases, the number and placement of dosimeters in each compartment become critical to ensuring that the EDEex is not underestimated.
In response to this concern, the licensees have stated that in most normal exposure situations, they intend to provide one dosimeter for a combined thorax-abdomen composite compartment, consistent with the Standard and their current multi-badging practice. This composite compartment will be called the chest compartment. To ensure that the estimates of EDEex are conservative, the licensee has committed to measuring the dose to each compartment (or composite compartment) by locating the dosimeter at the highest exposed part of that compartment. The dosimeter location for each compartment will be subject to the same criteria currently used for demonstrating compliance with 10 CFR 20.1201(c). In addition, the dosimeters will be calibrated to measure DDE.
4.0 CONCLUSION
S The NRC staff concludes that calculating TEDE using EDEex in place of DDE provides a more accurate estimate of the risk associated with the radiation exposures experienced by radiation workers at a nuclear power plant. The NRC staff finds that limiting TEDE such that:
TEDE = EDEex + CEDE is consistent with the basis for the dose limits, and footnote 2 to the Organ Dose Weighting Factors table in 10 CFR Part 20.1003.
Additionally, the NRC staff concludes that the multiple dosimetry method to estimate EDEex using the weighting factors listed in Table 1 of ANSI/HPS 13.41-1997, as proposed by the licensees, is technically sound and is acceptable for the purposes of demonstrating compliance with the TEDE-based requirements in 10 CFR Part 20.
5.0 REFERENCES
- 1.
ANSI-HPS N13.41-1997, An American National Standard - Criteria for Performing Multiple Dosimetry, Health Physics Society, December 1996.
- 2.
Title 10 of the Code of Federal Regulations (10 CFR) Part 20, Title 10 Code of Federal Regulations Part 20 - Standards for Protection Against Radiation.
- 3.
ICRP 26, ICRP Publication 26 - Recommendations of the International commission on Radiation Protection, January 17, 1977, Pergamon Press.
4.
ICRP 23, ICRP Publication 23 - Reference Man: Anatomical, Physiological and Metabolic Characteristics, April 18, 1975, Pergamon Press.
Principal Contributor: K. Streit Date: February 28, 2007