ML20113B875

Provides Correction to RAI Re Util Response to GL 95-07, Pressure Locking & Thermal Binding of SR Power-Operated Gate Valves

ML20113B875
Person / Time
Site:	Vermont Yankee
Issue date:	06/26/1996
From:	Duffy J VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-96-83, GL-95-07, GL-95-7, NUDOCS 9606280044
Download: ML20113B875 (3)

Text

. VisRMONT YANKEE ~

' NUCLEAR POWER CORPORATION '

Ferry Road, Brattleboro. VT 05301-7002 REP (YTO ENGINEERING OFFICE 580 MAIN STREET DoLToN, MA 01740 (508) 779-6711 June 26,1996 BVY 96-83 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington,DC 20555

References:

(a) License No. DPR-28 (Docket No. 50-271)

(b) Letter, USNRC to VYNPC, NVY 96-100, dated May 23,1996 (c) Letter, VYNPC to USNRC, BVY 96-07, dated February 8,1996 (d) Letter, VYNPC to USNRC, BVY 95-107, dated October 16,1995 (e) NRC Generic Letter 95-07, NVY 95-110, dated August 17,1995 (f) Letter, VYNPC to USNRC, BVY 96-81, dated June 21,1996

Subject:

Correction to Request for Additional Information - Vermont Yankee's Response to NRC Generic Letter 95-07," Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves" The purpose of this letter is to provide a correction to Reference (f). This letter supersedes Reference (f) in its entirety and constitutes the information requested by the NRC in Reference (b) )

regarding Vermont Yankee's response to Generic Letter 95-07 [ Reference (e)].

In Reference (b), NRC requested licensees to " describe evaluations and training for plant personnel that have been conducted for each design or procedural modification completed to address potential pressure locking or thermal binding concerns."

As reported in our 90-day response to Generic Letter 95-07 [ Reference (d)], six valves were modified during our 1995 refueling outage to address pressure-locking or thermal-binding

. concerns. These modifications were completed in accordance with our comprehensive Appendix B Engineering Design Change Request (EDCR) process. This process includes:

scoping and development of the design change; a complete, independent technical review; additional, multi-discipline reviews by Engineering, Operations and Technical Services departments; development of an installation and test (l&T) procedure; safety evaluation of the design change and I&T procedure in accordance with 10CFR50.59; review of the design change, i I&T and accompanying safety evaluation by the Plant Operations Review Committee; and j approval of the design change and I&T by the Vermont Yankee Plant Manager. Once approved,  ;

the design change is implemented and tested in accordance with the approved I&T procedure. 1 Finally, upon completion of the design change, Vermont Yankee provides training of plant i 9606290044 960626 PDR ADOCK 05000271

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4 VERMONT YANKEE NUCLEAR POWER CORPORATION

. United States Nuclear Regulate Commission June 26,1996 Page 2 of 3 personnel on the design modifications. In the case of the six valve modifications described above, Vermont Yankee provided formal training on the valve modifications to plant operators prior to plant startup from the 1995 refueling outage. Reference (d) also mentions a plant procedure that was revised to address thermal-binding concerns. The Pla..: Operations Review Committee approved this procedure change and a description of the procedure change was placed in Operations Department Night Orders for operator review. Our Training department also provided formal training on the procedure revision to plant operators.

In our 180-day response to Generic Letter 95-07 [ Reference (c)] we reported the identification of four valves potentially susceptible to pressure locking or thermal binding. As stated in Reference )

(c), Vermont Yankee will modify these valves using the comprehensive EDCR process described above to address pressure locking / thermal binding concerns. Three of the four valves will be modified during our 1996 refueling outage; the remaining valve will be modified during our 1998 refueling outage. Interim actions completed for these four valves, described in Reference (c), are described below:

RCIC Iniection Valve V13-20 and HPCI Injection Valve 23-20

• Condition was described in Operations Department Night Orders for room operator review; e Caution tags have been placed on the valve controls to alert operators to special operating instructions; ,

e HPCI system is declared inoperable when V23-20 is closed; e RCIC system is declared inoperable when V13-20 is closed; e HPCI V23-20 will be modified during the 1996 refueling outage; e RCIC V13-20 will be modified during the 1998 refueling outage; Lower Drvwell Sprav Outboard Isolation Valve V10-26A e Plant management has reviewed and approved an Operability Evaluation (BMO 95-11);

e Condition was described in Operations Department Night Orders for operator review; e Caution tags have been placed on the valve controls to alert operators to special operating instructions; e Valve operation has been restricted to preclude pressure locking; e V10-26A will be modified during the 1996 refueling outage; HPCI Steam Admission Valve V23-14

• Changed plant procedure OP-0111," Reactor and Generation Systems Heatup to Low Power,"

to preclude pressure locking and potential thermal binding of V23-14 during plant heatup;

• Plant Operations Review Committee has reviewed and approved the Safety evaluation (SE 95-

61) supporting the procedure change;

• Procedure change was described in Operations Department Night Orders for operator review, l I

• V23-14 will be modified during the 1996 refueling outage; .

-. . . . . . - . . - . . . . - - . . ~ - - . - . . . - . . . - - . - - . . - . .-

VERMONT YANKEE NUCLEAR POWER CORPORATION

• United States Nuclear Regulatory Commission June 26,1996 Page 3 of 3 In summary, as described above, Vermont Yankee has performed extensive evaluation and training for plant personnel for all design and procedural modifications completed or planned to address potential pressure locking or thermal binding concerns.

We trust that the information provided is acceptable; however, should you have any questions, please contact this office.

Sincerely, VERMONT YANKEE NUCLEAR POWER CORPORATION c l# W < <

James J. Duffy Licensing Engineer c: USNRC Region I Administrator USNRC Resident Inspector - VYNPS USNRC Project Manager - VYNPS

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