NLS2012057, Response to Nuclear Regulatory Commission Request for Additional Information Relief Request RV-01 Revision 1

Response to Nuclear Regulatory Commission Request for Additional Information Relief Request RV-01 Revision 1

ML12178A062
Person / Time
Site:	Cooper
Issue date:	06/22/2012
From:	O'Grady B Nebraska Public Power District (NPPD)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NLS2012057, TAC ME7021
Download: ML12178A062 (5)

Text

N Nebraska Public Power District Always there when you need us 50.55a NLS2012057 June 22, 2012 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Response to Nuclear Regulatory Commission Request for Additional Information Re: Relief Request RV-01 Revision 1 (TAC No. ME7021)

Cooper Nuclear Station, Docket No. 50-298, DPR-46

References:

1. Letter from Lynnea E. Wilkins, U.S. Nuclear Regulatory Commission, to Brian J. O'Grady, Nebraska Public Power District, dated June 11, 2012, "Cooper Nuclear Station - Second Request for Additional Information Re:

Request for Relief for the Fourth 10-Year Pump and Valve Inservice Testing Program (TAC NO. ME7021 )"

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

Nuclear Regulatory Commission, dated August 24, 2011, "10 CFR 50.55a Request Numbers RV-07, Revision 0, and RV-01, Revision 1"

Dear Sir or Madam:

The purpose of this letter is for Nebraska Public Power District to submit a response to a request for additional information (RAI) from the Nuclear Regulatory Commission (NRC) (Reference 1). The RAI requested information in support of NRC's review of a 10 CFR 50.55a relief request for the Cooper Nuclear Station (CNS) concerning the High Pressure Coolant Injection Pump and Valve Fourth 10-Year Interval Inservice Testing Program (Reference 2).

Responses to the specific RAI questions are provided in the Attachment to this letter. No regulatory commitments are made in this submittal. If you have any questions concerning this matter, please contact David Van Der Kamp, Licensing Manager, at (402) 825-2904.

Sincerely, Brian J. O'Grady Vice President - Nuclear and Chief Nuclear Officer A4cf7 COOPER NUCLEAR STATION P.0. Box 98 / Brownvill, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd.com

NLS2012057 Page 2 of 2

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Attachment:

Response to Nuclear Regulatory Commission Request for Additional Information Re: Relief Request RV-01 Revision 1 (TAC No. ME7021) cc: Regional Administrator w/ attachment USNRC - Region IV Cooper Project Manager w/ attachment USNRC - NRR Project Directorate IV-1 Senior Resident Inspector w/ attachment USNRC - CNS NPG Distribution w/o attachment CNS Records w/ attachment

NLS2012057 Attachment Page 1 of3 Attachment Response to Nuclear Regulatory Commission Request for Additional Information Re: Relief Request RV-01 Revision 1 (TAC No. ME7021)

Cooper Nuclear Station, Docket No. 50-298, DPR-46 NRC Question #1 Please describe any significantdifferences in the operationalconditions and the relative physical locations to each otherfor HPCI-SOV-SSV64 and HPCI-SOV-SSV87.

Response

There are no significant differences in the operational conditions for solenoid operated valves (SOV) HPCI-SOV-SSV64 and HPCI-SOV-SSV87. The two valves are in parallel 1"drip leg drain lines that come off the 2" drip leg piping. Flow downstream of HPCI-SOV-SSV64 enters the High Pressure Coolant Injection (HPCI) gland seal condenser and is prevented from continuing on downstream to the Torus by two closed containment isolation valves. Flow downstream of HPCI-SOV-SSV87 would pass through non-essential SOV, HPCI-SOV-SSV88, onward to an equipment drain.

Based on Cooper Nuclear Station (CNS) isometric drawing, X-2614-200, the physical locations of these two valves are approximately 15" apart, at the same elevation.

NRC Question #2 Pleaseprovide the reasonfor the replacement of HPCI-SOV-SSV87 in June 2005.

Response

Initially, non-essential SOV, HPCI-SOV-SSV88, was being disassembled when the valve body insert was identified as "frozen in place." Maintenance personnel were unable to remove the valve body insert and visually inspect it as instructed by the preventive maintenance (PM) instructions. The system engineer recommended the valve be replaced online during a future HPCI work window. The remainder of the PM was completed and the replacement valve was verified to function correctly.

Due to the close proximity of the HPCI-SOV-SSV87 and HPCI-SOV-SSV88 valves (currently 6" centerline to centerline), which are in series and welded, CNS decided that the HPCI-SOV-SSV87 valve would also be replaced at the same time as HPCI-SOV-SSV88. However, there were no functional issues associated with HPCI-SOV-SSV87. Since the three SOVs (SSV64, SSV87, and SSV88) were identical in design and only different in end-use application, a part evaluation was performed to demonstrate the replacement valve would perform acceptably in the essential locations of HPCI-SOV-SSV87 and HPCI-SOV-SSV64 in addition to the non-essential

NLS2012057 Attachment Page 2 of 3 location of HPCI-SOV-SSV88. The HPCI-SOV-SSV87 and HPCI-SOV-SSV88 valves were both replaced in June of 2005.

NRC Question #3 The licensee's letter dated August 24, 2011, states, in part, that, "Forinstance,solenoid valve, HPCI-SOV-SSV87, was replacedin June 2005, and has had an acceptable disassembly and examination completed in November 2006, March 2008, August 2009, andMarch 2011. "

Pleaseprovide the acceptance criteriaand resultsfor thesefour examinations ofHPCI-SOV-SSV87 and describe anyfuture acceptance criteria changesfor HPCI-SOV-SSV64 andHPCI-SOV-SSV87.

Response

In-service Test examination acceptance criteria (AC) from surveillance procedure 6.HPCI.404 are provided below. Based on these criteria, the four examinations of HPCI-SOV-SSV87 from November 2006 through March of 2011 resulted in "SAT" results for all visual examinations. In each case, the plunger and stem assembly did not have to be replaced and the coil was also not replaced. AC for future examinations for SSV64 and SSV87 will not change.

[AC] Visually examine disassembled solenoid valve parts as follows, recording any discrepanciesfound:

Valve body for damage, erosion, corrosion, and cleanliness.

[]SAT; [ ] UNSAT Insert for damage, erosion, or wear. [] SA T; [ ] UNSAT Piston for damage, erosion, corrosion, wear, or scoring. Replace if any of the above is evident.

[]SAT;[ ]UNSAT Plungerand stem assembly for erosion, corrosion, and freedom of movement.

[]SAT;[ ]UNSAT If plunger and stem assembly is found defective, replace with a new assembly.

Ensure stem spring returns piston rod link to full extended position when depressedand released.

[]SAT;,[ UNSAT Completed By:

NLS2012057 Attachment Page 3 of 3

[AC] An Electrician or qualified Valve Team Technician shall check continuity and physical condition of the coil, recording any discrepanciesfound. Record continuity check results as SAT or UNSA T.

[ ] SAT;[ ]UNSAT Completed By:

[AC] If coil is replaced,check resistanceof replacement coil, recording any discrepanciesfound. The resistancecheck is to compare the originalcoil to the replacement coil to ensure it is the correctreplacement.

[ ]SAT;[ JUNSAT Completed By.-

NRC Question #4 If the disassembly and examination interval is extended to 36 months and issues/problemsare discovered in HPCI-SOV-SSV64 or HPCI-SOV-SSV87, please state any planned disassembly and examination interval change. If the disassembly and examination interval is decreased, pleaseprovide the criteriaused to return to a 36-month interval.

Response

If an issue is discovered with HPCI-SOV-SSV64 or HPCI-SOV-SSV87 (failure of AC) during the 36-month examination, the affected valve will be repaired or replaced and returned to a nominal 18-month frequency. If the valve has an acceptable examination after 18 months, the valve may be returned to a 36-month frequency. The basis for any frequency change will be documented. This is consistent with the Condition Monitoring Appendix II section of the American Society of Mechanical Engineers Operating and Maintenance Code for check valves.