ML102240064

License Amendment Request to Revise Technical Specification 3/4.9.3.1, Decay Time

ML102240064
Person / Time
Site:	Millstone
Issue date:	07/21/2010
From:	Price J Dominion, Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
10-061, FOIA/PA-2011-0115
Download: ML102240064 (13)

Text

Dominion Nuclear Connecticut, Inc.

D 5000 Dominion Boulevard, Glen Allen, Virginia 23060 om nion Web Address: www.dom.com July 21, 2010 U.S. Nuclear Regulatory Commission Serial No 10-061 Attention: Document Control Desk NSSL/MLC RO Washington, DC 20555 Docket No.

50-336 License No.

DPR-65 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2 LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION 314.9.3.1, "DECAY TIME" In accordance with the provisions of 10 CFR 50.90, Dominion Nuclear Connecticut, Inc. (DNC) is submitting a license amendment request to revise Technical Specification (TS) 3/4.9.3.1, "Decay Time" for Millstone Power Station Unit 2 (MPS2). The proposed change would revise TS 3/4.9.3.1 by reducing the minimum decay time for irradiated fuel prior to movement in the reactor vessel from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />.

A reduction in the minimum decay time requirement is requested to provide additional flexibility in outage planning such that irradiated fuel can be moved from the reactor vessel to the spent fuel pool (SFP) earlier in an outage.

The decay time proposed for TS 3/4.9.3.1 is consistent with the radiological consequences of the limiting design basis fuel handling accident (FHA).

The current licensing basis for MPS2 assumes a minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> for the FHA using the alternate source term methodology. The 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> decay time assumption was reviewed and approved by the NRC as part of License Amendment 284 (Selective Implementation of Alternate Source Term) and License Amendment 298 (Full Implementation of AST). The analyses showed that, based on a 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> decay time, the radiological consequences of a FHA will remain within applicable regulatory limits and will not present any undue hazard to the health and safety of the public, or to control room operations. provides a description and assessment of the proposed change. provides the MPS2 marked-up TS pages.

The proposed amendment does not involve a Significant Hazards Consideration pursuant to the provisions of 10 CFR 50.92.

The Facility Safety Review Committee has reviewed and concurred with the determinations herein.

Issuance of this amendment is requested by August 1, 2011, with the amendment to be implemented within 60 days.

In accordance with 10 CFR 50.91(b), a copy of this license amendment request is being provided to the State of Connecticut.

Serial No: 10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time Page 2 of 3 Should you have any questions in regard to this submittal, please contact Ms.

Wanda Craft at (804) 273-4687.

Sincerely, J. Alen Price.

President - Nuclear Engineering COMMONWEALTH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. Alan Price, who is Vice President - Nuclear Engineering of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this _2L4day of

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Notary Public Attachments:

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2. Marked-Up Technical Specification Pages

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COWNionExpiresApr 30, 2013 Commitments made in this letter: None

Serial No: 10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time Page 3 of 3 cc:

U.S. Ndclear Regulatory Commission Region I Regional Administrator 475 Allendale Road King of Prussia, PA 19406-1415 C. J. Sanders NRC Project Manager U.S. Nuclear Regulatory Commission, Mail Stop 08B3 One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station Director Bureau of Air Management Monitoring and Radiation Division Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127

Serial No.10-061 Docket No. 50-336 ATTACHMENT I LICENSE AMENDMENT REQUEST TO REVISE TS 314.9.3.1, "DECAY TIME" EVALUATION OF PROPOSED LICENSE AMENDMENT DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 1 of 7 LICENSE AMENDMENT REQUEST TO REVISE TS 314.9.3.1, "DECAY TIME" EVALUATION OF PROPOSED LICENSE AMENDMENT

1.0 INTRODUCTION

In accordance with the provisions of 10 CFR 50.90, Dominion Nuclear Connecticut, Inc. (DNC) is submitting a license amendment request to revise Technical Specification (TS) 3/4.9.3.1, "Decay Time" for Millstone Power Station Unit 2 (MPS2).

The proposed change would revise TS 3/4.9.3.1 by reducing the minimum decay time for irradiated fuel prior to movement in the reactor vessel from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />.

A reduction in the minimum decay time requirement is requested to provide additional flexibility in outage planning such that irradiated fuel can be moved from the reactor vessel to the spent fuel pool (SFP) earlier in an outage.

2.0 PROPOSED CHANGE

S Proposed Change to TS 3/4.9.3.1: Deleted text is struck through and added text is italicized and bold.

LIMITING CONDITION FOR OPERATION 3.9.3.1 The reactor shall be subcritical for a minimum of 1-49 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to movement of irradiated fuel in the reactor pressure vessel.

APPLICABILITY:

MODE 6.

ACTION:

With the reactor subcritical for less than 450 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, suspend all operations involving movement of irradiated fuel in the reactor pressure vessel.

SURVEILLANCE REQUIREMENTS 4.9.3.1 The reactor shall be determined to have been subcritical for at least 1-50 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> by verification of the date and time of subcriticality prior to movement of irradiated fuel in the reactor pressure vessel.

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 2 of 7

3.0 BACKGROUND

DNC has evaluated the required activities and plant configuration needed to commence movement of irradiated fuel from the reactor vessel earlier in an outage.

Based on these evaluations, DNC has concluded that movement of fuel could safely occur prior to the current TS 3.9.3.1 fuel movement constraint of 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> after subcriticality.

The MPS2 current licensing basis for the fuel handling accident (FHA) analyses is presented in Section 14.7.4 of the MPS2 Final Safety Analysis Report (FSAR). The FHA analyses are based on the alternate source term (AST) methodology assumptions derived from 10 CFR 50.67, "Accident Source Term," and Regulatory Guide (RG) 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors," which were approved for MPS2 as part of License Amendment 284 (Selective Implementation of Alternate Source Term -

Reference 7.1) and License Amendment 298 (Full Implementation of Alternate Source Term - Reference 7.2).

As shown in FSAR Tables 14.7.4-1, "Assumption for Fuel Handling Accident in the Spent Fuel Pool," and 14.7.4-2, "Assumption for Fuel Handling Accident inside Containment," the FHA analyses are based on a decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />. Using this assumption, the analyses showed that the radiological consequences of a FHA at MPS2 were within the dose limits of 10 CFR 50.67 and RG 1.183 for the Exclusion Area Boundary (EAB), Low Population Zone (LPZ), and control room.

Additionally, FSAR Section 9.5.2, "Spent Fuel Pool Cooling System Description," has been revised to reflect a reanalysis of the capability of the SFP cooling system to maintain SFP temperatures below the maximum normal operating temperature of 150 0F, with a reactor subcritical time less than 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br />. The reanalysis demonstrates the ability to maintain SFP temperature less than 150°F with a subcriticality time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> and Reactor Building Closed Cooling Water (RBCCW) temperature within an acceptable control range for system operation.

4.0 TECHNICAL ANALYSIS

Before movement of any irradiated fuel from the reactor pressure vessel, a period of in-vessel decay is required due to post-design basis accident radiation -dose consequence limitations. The longer the fuel assemblies are allowed to decay within the reactor pressure vessel before being moved, the lower the dose consequence of a radioactive release resulting from a FHA.

The bases for the decay time specified in TS 3.9.3.1 is to ensure the radiological consequences of a FHA are limited to the design basis FHA of the current licensing

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 3 of 7 basis. The MPS2 safety analysis for the FHA (FSAR Chapter 14.7.4.) involves dropping of a single irradiated fuel assembly with resulting damage and release of the gap activity from the entire assembly. The minimum time requirement for reactor subcriticality prior to movement of irradiated fuel assemblies in the reactor vessel ensures that sufficient time has elapsed to allow the radioactive decay of short-lived fission products such that the radiological dose consequences from the FHA are within regulatory dose limits.

The current licensing basis for MPS2 assumes a minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> for the FHA. This assumption supports the proposed change to reduce the minimum decay time in TS 3/4.9.3.1 from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />. Based on a minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, the radiological consequences of a FHA at MPS2 are within the dose limits of 10 CFR 50.67 and RG 1.183 for the EAB, LPZ, and control room.

Therefore, a design basis FHA will continue to not present any undue hazard to the health and safety of the public, nor will it compromise control room operations.

Separately from the accident analysis, FSAR Section 9.5.2 describes the capability of the SFP cooling system to remove decay heat generated by the stored spent fuel assemblies and maintain pool temperature below the maximum normal operating temperature of 150'F. The design basis allows fuel movement to commence at 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> with Reactor Building Closed Cooling Water (RBCCW) temperature within an acceptable control range for system operation. Consistent with the NRC Final Policy Statement on Technical Specification Improvements for Nuclear Power Reactors [58 FR 39132], Criterion 2 of 10 CFR 50.36(C)(2)(ii) does not apply to the FSAR Section 9.5.2 SFP decay heat load evaluations. This policy statement indicates that Criterion 2 of 10 CFR 50.36(C)(2)(ii) applies to ANSI N18.2 Condition II, Ill or IV (or equivalent) events presented in Chapters 6 and 15 (or equivalent chapters) of the FSAR that either assume or present a challenge to the integrity of a fission product barrier.

Following issuance of the license amendment associated with this request, plant procedures will allow a variable subcriticality time as a function of RBCCW inlet temperature. This variable subcriticality decay time will not be less than the proposed 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> decay time required to support the fuel handling accident dose consequence analysis discussed above.

5.0 REGULATORY ANALYSIS

The proposed amendment modifies MPS2 TS 3/4.9.3.1, "Decay Time," by reducing the minimum time irradiated fuel must decay prior to movement in the reactor vessel.

Specifically, the proposed amendment would reduce the minimum decay time from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />. A reduction in the minimum decay time requirement is desired to provide additional flexibility in outage planning.

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 4 of 7 The proposed decay time required by TS 3/4.9.3.1 is based on the radiological consequences of a design basis FHA. MPS2 FSAR Chapter 14.7.4 describes the current licensing basis analysis for a FHA. Although the current TS limit for decay time is 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br />, the accident analysis of record assumes a fuel decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> which bounds the minimum decay time proposed in this amendment request.

The MPS2 analysis for the FHA is based on use of AST methodology in accordance with 10 CFR 50.67, "Accident Source Term," and guidance in Regulatory Guide (RG) 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors." Implementation of the AST methodology for MPS2 was approved by the NRC as part of License Amendment 284 (Selective Implementation of Alternate Source Term - ADAMS Accession No. ML042360671) and License Amendment 298 (Full Implementation of Alternate Source Term - ADAMS Accession No. ML071450053). At that time, the NRC staff evaluated the use of the 100-hour decay time on the radiological consequences for a FHA and approved the acceptability of the revised analysis results using the 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> assumption.

Specifically, the NRC staff concluded that the EAB, LPZ, and control room doses are within the applicable regulatory limits using a 100-hour decay time and that there is reasonable assurance that the radiological consequences analysis for the design basis accident for MPS2 will continue to provide sufficient safety margins with adequate defense-in-depth to address unanticipated events and to compensate for uncertainties in accident progression and analysis assumptions and parameters (Section 3.7 of Reference 7.2).

5.1 NO SIGNIFICANT HAZARDS CONSIDERATION The NRC has provided standards for determining whether a significant hazards consideration exists as stated in 10 CFR 50.92(c). A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with a proposed amendment would not: 1) involve a significant increase in the probability or consequences of an accident previously evaluated; or 2) create the possibility of a new or different kind of accident from any accident previously evaluated; or 3) involve a significant reduction in a margin of safety. DNC has evaluated whether or not a significant hazards consideration (SHC) is involved with the proposed change. A discussion of these standards as they relate to this change request is provided below.

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 5 of 7 Criterion 1 Will operation of the facility in accordance with the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The accident of concern related to the proposed change is the FHA. This accident assumes a dropped fuel assembly with resulting damage and release of the gap activity from the entire assembly. The FHA assumes that fuel movement is delayed for some time period after shutdown to accommodate for radioactive decay of the short-lived fission products. The probability of a FHA occurrence is dependent on moving fuel not when the fuel movement occurs. Reducing the decay time required by TS 3/4.9.3.1 from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> does not increase the probability of a FHA since the timing of fuel movement in the reactor pressure vessel does not alter/impact the manner in which fuel assemblies are handled.

Reducing the decay time requirement in TS 3/4.9.3.1 from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> does not change the consequences of the offsite dose and control room dose projections for the currently approved design basis FHA analysis. The current FHA analysis presented in FSAR Section 14.7.4 and approved in License Amendment 298 assumes a minimum 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> decay time. Therefore, the dose results of this FHA analysis are unchanged, and remain within applicable regulatory limits.

Based on the reasons presented above, operation of the facility in accordance with the proposed amendment would not involve a significant increase in the probability or consequences of an accident previously evaluated.

Criterion 2 Will operation of the facility in accordance with this proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated. No new accident will be created as a result of reducing the decay time requirement in TS 3/4.9.3.1. Plant operation, including fuel handling, will not be affected by the proposed change, as to when fuel is moved and no new failure modes will be created. Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 6 of 7 Criterion 3 Will operation of the facility in accordance with this proposed change involve a significant reduction in the margin of safety?

Response: No.

The proposed change does not significantly reduce the margin of safety. The current analysis of record for the FHA already accounts for irradiated fuel with at least 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> of decay. This approved analysis has shown that the projected doses will remain within applicable regulatory limits; therefore, the margin of safety is unchanged.

Conclusion Based on the above, DNC has determined that the prol5osed change does not represent a significant hazards consideration under the standards set forth in 10 CFR 50.92(c).

5.2 APPLICABLE REGULATORY REQUIREMENTS/CRITERIA FSAR Section 14.7.4 describes the current licensing basis analysis for a FHA at MPS2. The current analysis uses a fuel decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> which bounds the minimum decay time proposed in this amendment request.

The MPS2 analysis for the FHA is based on use of AST methodology in accordance with the following codes, guides and standards:

10 CFR Part 50.67, "Accident Source Term" 0 RG 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors" 10 CFR Part 50, Appendix A, "General Design Criterion for Nuclear Power Plants'": GDC 19, "Control Room" SRP Section 15.0.1, "Radiological Consequence Analyses Using Alternative Source Terms" Other applicable regulatory codes, guides and standards are as follows:

0 RG 1.23, "Onsite Meteorological Programs"

Serial No.10-061 Docket No. 50-336 Revision to TS 3/4.9.3.1, Decay Time, Page 7 of 7 RG 1.52, "Design, Testing, and Maintenance Criteria for Post Accident Engineered-Safety-Feature Atmosphere Cleanup System Air Filtration and Adsorption Units of Light-Water-Cooled Nuclear Power Plants" RG 1.78, "Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release" RG 1.194, "Atmospheric Relative Concentrations for Control Room Radiological Habitability Assessments at Nuclear Power Plants"

" NUREG-0800, "Standard Review Plan," Section 6.4, "Control Room Habitability Systems"

" SRP Section 2.3.4, "Short-Term Diffusion Estimates for Accidental Atmospheric Releases"

6.0 ENVIRONMENTAL CONSIDERATION

DNC has determined that the proposed amendment would change requirements with respect to use of a facility component located within the restricted area, as defined by 10 CFR 20, or an inspection or surveillance requirement. DNC has evaluated the proposed change and has determined that the change does not involve (i) a significant hazards consideration, (ii)a significant change in the types or significant increase in the amounts of any effluent that may be released off site, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need to be prepared in connection with the proposed amendment.

7.0 REFERENCES

7.1 Letter dated September 20, 2004, from V. Nerses, USNRC, to D. A. Christian, Dominion Nuclear Connecticut, Inc., "Millstone Power Station, Unit No. 2 -

Issuance of Amendment Re: Selective Implementation of Alternate Source Term (TAC No. MB6479).

7.2 Letter dated May 31, 2007, from J. Hughey, USNRC, to D. A. Christian, Dominion Nuclear Connecticut, Inc., "Millstone Power Station, Unit No. 2 -

Issuance of Amendment Regarding Alternate Source Term (TAC No. MD2346).

Serial No.10-061 Docket No. 50-336 ATTACHMENT 2 LICENSE AMENDMENT REQUEST TO REVISE TS 314.9.3.1.

"DECAY TIME" MARKED-UP TECHNICAL SPECIFICATION PAGES DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2

REFUELING OPERATIONS 8,

O DECAY TIME LIMITING CONDITION FOR OPERATION 3.9.3.1 The reactor shall be subcritical for a minimum of*0"hours prior to movement of irradiated fuel in the reactor pressure vessel.

APPLICABILITY:

MODE 6.

ACTION:

With the reactor subcritical for less than 4--hours, suspend all operations involving movement of irradiated fuel in the reactor pressure vessel.

SURVEILLANCE REQUIREMENTS too 4.9.3.1 The reactor shall be determined to have been subcritical for at least 4.-hours by verification of the date and time of subcriticality prior to movement of irradiated fuel in the reactor pressure vessel.

ýMLLSTONE - UNIT 2 3/4.9L.3 Amendment No. 44,f45