ML061870512

Letter and Safety Evaluation to Entergy Operations, Inc. - Application to Use Effective Dose Equivalent Weighting Factors for External Exposure

ML061870512
Person / Time
Site:	Arkansas Nuclear, FitzPatrick
Issue date:	07/19/2006
From:	Terao D NRC/NRR/ADRO/DORL/LPLIV
To:	Buford F Entergy Operations
Vaidya B, NRR/DORL/LP4, 415-3308
References
TAC MD1737, TAC MD1738
Download: ML061870512 (11)

Text

July 19, 2006Mr. F. G. BurfordActing Director Nuclear Safety and Licensing Entergy Operations, Inc.

1340 Echelon Parkway Jackson, MS 39213-8298

SUBJECT:

ARKANSAS NUCLEAR ONE, UNIT 2, AND JAMES A. FITZPATRICK NUCLEARPOWER PLANT - APPLICATION TO USE EFFECTIVE DOSE EQUIVALENT WEIGHTING FACTORS FOR EXTERNAL EXPOSURE (TAC NOS. MD1737 AND MD1738)

Dear Mr. Burford:

By letter dated May 16, 2006, Entergy Operations, Inc. and Entergy Nuclear Operating, Inc.(Entergy or the licensee) 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 (ANSI) HPS N13.41-1997 (the standard) for external radiation exposures when demonstrating compliance with total effective dose equivalent (TEDE), based on requirements in Part 20 of Title 10 to the Code of Federal Regulations (10 CFR) for Arkansas Nuclear One,Unit 2 (ANO-2), and James A. Fitzpatrick Nuclear Power Plant (JAF).The NRC staff has completed its review. Enclosed is the NRC staff's related Safety Evaluationthat concludes that your request for the use of the weighting factors provided in the standard forexternal radiation exposures when demonstrating compliance with TEDE, based on requirements in 10 CFR Part 20 for ANO-2 and JAF is acceptable.

F. G. Burford Please contact me at (301) 415-1302 or Bhalchandra K. Vaidya at (301) 415-3308, if you haveany questions on this matter. Sincerely,

/RA/

David Terao, ChiefPlant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-368 and 50-333

Enclosure:

Safety Evaluation cc w/encl: See next page F. G. Burford Please contact me at (301) 415-1302 or Bhalchandra K. Vaidya at (301) 415-3308, if you haveany questions on this matter. Sincerely,

/RA/

David Terao, ChiefPlant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-368 and 50-333

Enclosure:

Safety Evaluation cc w/encl: See next pageDISTRIBUTION

PUBLICRidsAcrsAcnwMailCenterRidsNrrDorlLpl1-1 (RLaufer)

LPLIV r/fLPLI-1 r/fRPedersen, DIRS RidsNrrDorlLpl4 (DTerao)RidsNrrLALFeizollahiRidsNrrLASLittle RidsNrrPMBVaidyaRidsNrrPMDHollandRidsNrrPMJBoska RidsDorlDprJLamb (RIV)BSosa (RI)

RidsRgn4MailCenter (DGraves) RidsOgcRpRidsRgn1MailCenter (ECobey)SBernal, DIRSACCESSION NO: ML061870512NRR-106 OFFICENRR/LPL4/PMNRR/LPL4/LANRR/IHPB/BC OGCNRR/LPL4/BCNAMEBVaidyaLFeizollahi TFreyMLemoncelliDTeraoDATE07/13/0607/13/0606/23/0607/17/0607/19/06OFFICIAL RECORD COPY SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIONRELATED TO THE APPROVAL TO USE WEIGHTING FACTORSFOR EXTERNAL RADIATION EXPOSURES ENTERGY OPERATIONS, INC. AND ENTERGY NUCLEAR OPERATING, INC.ARKANSAS NUCLEAR ONE, UNIT 2, ANDJAMES A. FITZPATRICK NUCLEAR POWER PLANTDOCKET NOS. 50-368 AND 50-33

31.0 INTRODUCTION

By letter dated May 16, 2006 (Agencywide Documents Access and Management System(ADAMS) Accession No. ML061430359), Entergy Operations, Inc. and Entergy Nuclear Operating, Inc. (Entergy or the licensee) requested the U.S. Nuclear Regulatory Commission's(NRC's) approval for the use of the weighting factors provided in the American NationalStandard Institute (ANSI) HPS N13.41-1997 (the standard) for external radiation exposures when demonstrating compliance with total effective dose equivalent (TEDE), based on requirements in Part 20 to Title 10 of the Code of Federal Regulations (10 CFR) for ArkansasNuclear One, Unit 2 (ANO-2), and James A. Fitzpatrick Nuclear Power Plant (JAF). The effect of granting this request would be to allow the licensee 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.

2.0REGULATORY EVALUATION

The radiation protection approach and dose limits contained in 10 CFR Part 20 are based onthe recommendations of the International Commission on Radiation Protection (ICRP) in their1977 Publication No. 26 (ICRP 26). For stochastic effects, the ICRP's recommended dose limitation is based on the principle that the risk should be equal, whether the whole body isirradiated 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. Effective dose equivalent (EDE or E) is defined in 10 CFR 20.1003 as "the sum of the productsof the dose equivalent to the organ or tissue (T) and the weighting factors (W T) applicable toeach of the body organs or tissues that are irradiated (E = W 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 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) defined in 10 CFR 20.1003 as W TT , 50.The TEDE is defined in 10 CFR 20.1003 as the "sum of the deep-dose equivalent (DDE) (forexternal exposures) and the committed effective dose equivalent (for internal exposures)."TEDE = DDE + CEDEThe organ weighting factors (W T) are the proportion of the risk of stochastic effects resultingfrom the dose to that organ or tissue to the total risk of stochastic effects when the whole body is irradiated uniformly. 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 cannot determine the dose tothe various organs and tissues for an accurate determination of the external EDE (EDE ex). Toensure 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.Authority to permit use of other weighting factors is found in footnote 2 to the table of organweighting factors in 10 CFR 20.1003 states, "[f]or the purpose of weighting the external wholebody dose (for adding to the internal dose), a single weighting factor, of W T = 1.0, has beenspecified. 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 approach to determining TEDE can be overly conservative for extremely non-uniformirradiations (i.e., when only a small portion of the whole body is irradiated). As discussed in the

NRC Regulatory Issue Summaries 2002-06, 2003-04, and 2004-01, the NRC has approvedseveral methods for determining EDE ex, and has encouraged the use of EDE ex in place of DDEfor demonstrating compliance with the TEDE requirements in 10 CFR Part 20.

3.0 TECHNICAL EVALUATION

3.1EvaluationThe NRC staff has reviewed the technical approach for estimating EDEex provided in thestandard. 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 EDE ex 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.The ANSI/HPS 13.41 multiple dosimeter method of determining EDE ex is based on theassumptions that (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 compartments defined in the standard are small enough so 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 EDE ex is notunderestimated.To ensure that the estimates of EDEex are conservative, the licensee has committed tomeasuring the dose to each compartment (or composite compartment) by locating the dosimeter, calibrated to DDE, at the highest exposed portion 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).The licensee has stated that in most normal exposure situations they intend to provide onedosimeter for a combined thorax-abdomen composite compartment, consistent with the standard and their current multi-badging practice. 3.2Regulatory CommitmentsThe following table identifies the regulatory commitments made by Entergy. List of Regulatory Commitments COMMITMENTTYPE(Check one)SCHEDULEDCOMPLETIONDATE (IfRequired)ONE-TIMEACTIONCONTINUINGCOMPLIANCEEntergy will monitor the part of the whole bodywithin each compartment (and/or composite compartment) that receives the highest dose.

Entergy is developing a fleet wide Nuclear Management Manual procedure EN-RP-204, "Special Monitoring Requirements," for determining dosimeter selection and placement. This procedure guidance will beconsistent with that found in NRC InspectionProcedure 71121.01, issue date 03/06/02.

xBased on the NRC's approval of this request,Entergy will account for dose consistent withthe guidance of the standard as follows:The DDE for each compartment will bedetermined from dosimeters worn at that location. When no dosimeter is worn at a particular compartment, the DDE will be determined from the dosimeter positioned where the exposure is judged to be similar.

The assigned EDE will be the sum of eachDDE measurement multiplied by its appropriate compartment factor.The assigned lens dose equivalent (LDE) willbe the higher of the head or chest dosimeters.

The assigned shallow dose equivalent (SDE) will be the highest of any whole bodydosimeter.

xThe NRC staff finds that reasonable controls for the implementation and for subsequentevaluation of proposed changes pertaining to the above regulatory commitments are provided by the licensee's administrative processes, including its commitment management program.

Should the licensee choose to incorporate a regulatory commitment into the emergency plan, Updated Final Safety Analysis Report, or other documents with established regulatory controls, the associated regulations would define the appropriate change-control and reportingrequirements. The NRC staff has determined that the commitments do not warrant the creationof regulatory requirements, which would require prior NRC approval of subsequent changes. The NRC staff has agreed that Nuclear Energy Institute 99-04, Revision 0, "Guidelines forManaging NRC Commitment Changes," provides reasonable guidance for the control ofregulatory commitments made to the NRC staff (see Regulatory Issue Summary 2000-17,"Managing Regulatory Commitments Made by Power Reactor Licensees to the NRC Staff,"dated September 21, 2000). The commitments should be controlled in accordance with industry guidance or comparable criteria employed by a specific licensee. The NRC staff maychoose to verify the implementation and maintenance of these commitments in a future inspection or audit.

4.0 CONCLUSION

SThe NRC staff concludes that calculating TEDE using EDE ex in place of DDE provides a moreaccurate 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 thatEDE ex + CEDE < 5 remis consistent with the basis for the dose limits, and footnote 2 to the "Organ Dose WeightingFactors" table in 10 CFR Part 20.1003.Additionally, the NRC staff concludes that the multiple dosimetry method to estimate EDE exusing the weighting factors listed in Table 1 of the standard, as proposed by the licensee, istechnically sound and is acceptable for the purposes of demonstrating compliance with the TEDE-based requirements in 10 CFR Part 20.Therefore, based on the above discussion and the information provided by Entergy in itssubmittal, the NRC staff approves the use of the weighting factors provided in the ANSI HPSN13.41-1997 (the standard) for external radiation exposures when demonstrating compliance with total effective dose equivalent (TEDE), based on requirements in 10 CFR Part 20 for ANO-2 and JAF.Principal Contributor: R. Pedersen Date: July 19, 2006

September 2005Arkansas Nuclear One cc: Senior Vice President & Chief Operating Officer Entergy Operations, Inc.

P. O. Box 31995 Jackson, MS 39286-1995Director, Division of Radiation Control and Emergency Management Arkansas Department of Health 4815 West Markham Street, Slot 30 Little Rock, AR 72205-3867Winston & Strawn1700 K Street, N.W.

Washington, DC 20006-3817Senior Resident InspectorU.S. Nuclear Regulatory Commission

P. O. Box 310 London, AR 72847Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064County Judge of Pope County Pope County Courthouse Russellville, AR 72801Vice President, Operations SupportEntergy Operations, Inc.

P. O. Box 31995 Jackson, MS 39286-1995Wise, Carter, Child & Caraway P. O. Box 651 Jackson, MS 39205Mr. Jeffrey S. ForbesSite Vice President Arkansas Nuclear One Entergy Operations, Inc.

1448 S. R. 333 Russellville, AR 72801 FitzPatrick Nuclear Power Plant cc:

Mr. Gary J. TaylorChief Executive Officer Entergy Operations, Inc.

1340 Echelon Parkway Jackson, MS 39213Mr. John T. HerronSr. VP and Chief Operating Officer Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Mr. Peter T. DietrichSite Vice President Entergy Nuclear Operations, Inc.

James A. FitzPatrick Nuclear Power Plant

P.O. Box 110 Lycoming, NY 13093Mr. Kevin J. MulliganGeneral Manager, Plant Operations Entergy Nuclear Operations, Inc.

James A. FitzPatrick Nuclear Power Plant

P.O. Box 110 Lycoming, NY 13093Mr. Oscar LimpiasVice President Engineering Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Mr. Christopher SchwarzVice President, Operations Support Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Mr. John F. McCannDirector, Licensing Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Ms. Charlene D. FaisonManager, Licensing Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Mr. Michael J. ColombDirector of Oversight Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Mr. David WallaceDirector, Nuclear Safety Assurance Entergy Nuclear Operations, Inc.

James A. FitzPatrick Nuclear Power Plant

P.O. Box 110 Lycoming, NY 13093Mr. James CostedioManager, Regulatory Compliance Entergy Nuclear Operations, Inc.

James A. FitzPatrick Nuclear Power Plant

P.O. Box 110 Lycoming, NY 13093Assistant General CounselEntergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601Regional Administrator, Region IU.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406Resident Inspector's OfficeJames A. FitzPatrick Nuclear Power Plant U. S. Nuclear Regulatory Commission

P.O. Box 136 Lycoming, NY 13093 FitzPatrick Nuclear Power Plant cc:

Mr. Charles Donaldson, EsquireAssistant Attorney General New York Department of Law 120 Broadway New York, NY 10271Mr. Peter R. Smith, PresidentNew York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399Mr. Paul EddyNew York State Dept. of Public Service 3 Empire State Plaza Albany, NY 12223-1350Oswego County Administrator Mr. Steven Lyman 46 East Bridge Street Oswego, NY 13126SupervisorTown of Scriba Route 8, Box 382 Oswego, NY 13126Mr. James H. SniezekBWR SRC Consultant 5486 Nithsdale Drive Salisbury, MD 21801-2490Mr. Michael D. LysterBWR SRC Consultant 5931 Barclay Lane Naples, FL 34110-7306Mr. Garrett D. Edwards814 Waverly Road Kennett Square, PA 19348Mr. Michael KanslerPresident Entergy Nuclear Operations, Inc.

440 Hamilton Avenue White Plains, NY 10601