NLS2012100, Response to Request for Additional Information Regarding License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of TSTF-493, Revision 4, Option a

Response to Request for Additional Information Regarding License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of TSTF-493, Revision 4, Option a

ML12268A168
Person / Time
Site:	Cooper
Issue date:	09/17/2012
From:	O'Grady B Nebraska Public Power District (NPPD)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NLS2012100
Download: ML12268A168 (4)

Text

N Nebraska Public Power District Always there when you need us 50.90 NLS2012 100 September 17, 2012 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001

Subject:

Response to Request for Additional Information Regarding License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of TSTF-493, Revision 4, Option A Cooper Nuclear Station, Docket No. 50-298, DPR-46

References:

1. E-mail from Lynnea Wilkins, U.S. Nuclear Regulatory Commission, to Edward L. McCutchen, Nebraska Public Power District, dated September 6, 2012, "ME7169- Request for Additional Information RE: CNS 24 Month Fuel Cycle LAR - TS 5.5.2"

2. Letter from Brian J. O'Grady, Nebraska Public Power District, to U.S.

Nuclear Regulatory Commission, dated September 16, 2011, "License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of TSTF-493, Revision 4, Option A" (NLS2011071)

Dear Sir or Madam:

The purpose of this letter is for the Nebraska Public Power District (NPPD) to respond to the Nuclear Regulatory Commission (NRC) Request for Additional Information (Reference 1) relating to the Cooper Nuclear Station (CNS) License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of Technical Specification Task Force (TSTF) Traveler TSTF-493, Revision 4, Option A (Reference 2). The NPPD response is attached.

No commitments are made in this submittal. Should you have any questions concerning this matter, please contact Mike Boyce, CNS Strategic Initiatives Project Manager, at (402) 825-5100.

COOPER NUCLEAR STATION o P 0. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd.com w"e" -

NLS2012 100 Page 2 of 2 I declare under penalty of perjury that the foregoing is true and correct.

Executed on: 72& 6,7'1/,7 (Date)

Sincerely, Brian J. O'AradyA" Vice President - Nuclear and Chief Nuclear Officer BJO/wv

Attachment:

Response to Request for Additional Information Regarding License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of TSTF-493, Revision 4, Option A cc: Regional Administrator w/Attachment USNRC - Region IV Cooper Project Manager w/Attachment USNRC - NRR Project Directorate IV-I Senior Resident Inspector w/Attachment USNRC - CNS Nebraska Health and Human Services w/Attachment Department of Regulation and Licensure NPG Distribution w/o Attachment CNS Records w/Attachment

NLS2012100 Attachment Page 1 of 2 Attachment Response to Request for Additional Information Regarding License Amendment Request for Implementing a 24-Month Fuel Cycle and Adoption of TSTF-493, Revision 4, Option A The Nuclear Regulatory Commission (NRC) Request for Additional Information regarding the subject License Amendment Request is shown in italics. The Nebraska Public Power District's (NPPD) response to the request is shown in block font.

Question The NRC staff has a question regardingthe statement, "The surveillance history review did not find any cases where the requiredintegratedleak tests were not petformed within the 18-month interval (includingthe 25% grace period). " It is the staff's understandingthat the history review is intended to identify if there were any failures of the SR over the last 5 cycles or that would not have been otherwise detected by SR or routineplant activities (not if the tests have been faithfully petformedper schedule, as stated). Please clarify the results ofpast SR performances, notjust that they had been performed within requiredperiodicity. Additionally, please clarify i your conclusion that the impact of the frequency change on safety is small based in largepart on the fact that morefrequent walkdowns of the system and contaminationsurvey efforts should pick up on any developing leakage.

TS 5.5.2. Systems Integrity Monitoring Program The program shall include the following:

b. Integratedleak test requirementsfor each system at 18 month intervalsor less.

The test interval of this TS is being increasedfrom once every 18 months to once every 24 monthsfor a maximum interval of 30 months, including the 25% grace period afforded by TS SR 3.0.2.

This requirementestablishes a program to reduce leakagefrom those portions of systems outside containment that could contain highly radioactivefluids during a serious transientor accident to as low as practicallevels. Specifically, the program requiresan "Integratedleak test requirementfor each system at 18 month intervals or less. "The surveillance history review did notfind any cases where the required integratedleak tests were not performed within the 18-month interval (including the 25% graceperiod). The change to 24-month operatingcycles will increasethe testing interval. This change to the testing requirementhas been evaluated and determined that the impact, ifany, on safety is small. This conclusion is based on the fact that most portionsof the subject systems included in the program are visually

NLS2012 100 Attachment Page 2 of 2 walked down, while the plant is operating,duringplant testing and/or operator/system engineer walkdowns. In addition, housekeeping/safety walkdowns also serve to detect any gross leakage. If leakage is observed from these systems, corrective actions will be taken to repairthe leakage. Finally, the plant radiological surveys will also identify any potentialsources of leakage. Based on more frequent inspections previously described,and the ability to readily detect system leakage petformance deficiencies, the impact of this change on safety, if any, is small.

Response

As described in the above excerpt, the Technical Specification (TS) 5.5.2 Systems Integrity Monitoring Program provides controls to minimize leakage from those portions of systems outside containment that could contain highly radioactive fluids during a serious transient or accident to levels as low as practicable. The 18-month integrated leak test performed under this program does not meet the definition of a Surveillance Requirement, per 10 CFR 50.36(c)(3). It is more properly characterized as a TS-required programmatic inspection requirement. The inspection consists of walkdowns of certain portions of Emergency Core Cooling System (ECCS) during the performance of ECCS Surveillance Requirements (SR) (typically performed during each refueling outage), and noting leakage from such sources as pipe flanges, pump seals, and valve packing. The procedural acceptance criterion is that any ECCS leakage is recorded as a discrepancy, with walkdown results provided to the Core Cooling Engineering Supervisor for further review. Thus, the typical five cycle SR review criteria for Frequency extension is not strictly applicable. Notwithstanding, the CNS design/licensing basis maximum allowable ECCS leakage criteria is 3000 cc/minute. NPPD has established an administrative limit of 800 cc/min total ECCS leakage to provide margin to that design value. ECCS leakage has not exceeded the 800 cc/min limit since the adoption of this TS in 1998. In addition to the discussion in the License Amendment Request regarding the more frequent walkdowns and radiological surveys that are performed, this inspection history contributes to the conclusion that this change to the testing requirement will have a small impact.