ML20113C153

Provides Request for Addl Info Re Util Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves

ML20113C153
Person / Time
Site:	Vermont Yankee
Issue date:	06/21/1996
From:	Duffy J VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-96-81, GL-95-07, GL-95-7, NUDOCS 9606280259
Download: ML20113C153 (3)

Text

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VERMONT YANKEE NUCLEAR POWER CORPORATION

.- Ferry Road, Brattleboro, VT 05301-7002 REPLYTO ENGINEERING OFFICE 580 MAIN STREET BOLTON, MA 01740 (500) 77S-6711 June 21,1996 BVY 96-81 United States Nuclear Regulatory Commission ATrN: 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

Subject:

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" .

I The purpose of this letter is to provide 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 i 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 concems. 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 (I&T) procedure; safety evaluation of the design change and I&T procedure in accordance with 10CFR50.59; review of the design change, I&T and accompanying safety evaluation by the Plant Operations Review Committee; and 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.

Finally, upon completion of the design change, Vermont Yankee provides training of plant personnel on the design modifications. In the case of the valve modifications describe above, Vermont Yankee provided formal training on the valve modifications to plant operators prior to 9606290259 960621 Q PDR ADOCK 05000271 1 P PDR

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, VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission )

June 19,1996  !

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l concerns. Modifications to three of the four valves will be performed during our 1996 refueling outage; the remaining valve will be modified during our 1998 refueling outage. Modifications to I all four valves will be evaluated in accordance with 10CFR50.59 and will be approved by the  !

Plant Operations Review Committee. Interim solutions, described in Reference (c), include

. operability evaluations, procedure changes and administrative controls. Specific actions taken for each valve are described below:

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

• RCIC system declared inoperable when V13-20 is closed:

• HPCI system declared inoperable when V23-20 is closed;

• Caution tags placed on valve controls to alert operators;

• Condition described in Operations Department Night Orders for control room operator )

review;

• HPCI V23-20 will be modified during the 1996 Refueling outage;  !

• RCIC V13-20 will be modified during the 1998 Refueling outage; 1

1 Lower Drvwell Spray Outboard Isolation Valve V10-26A

• Plant management has reviewed and approved Operability Evaluation (BMO 95-11);.

• Valve operation restricted to preclude pressure locking;

• Caution tags placed on valve controls to alert operators; Condition described in Operations Department Night Orders for control room operator review;

• V10-26A will be modified during the 19% Refueling outage; HPCI Steam Admission Valve V23-14

• Have revised 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 j (SE 95-61) supporting procedure changes;

• Plant management has reviewed and approved the procedure changes;

• Procedure change issued and changes described in Operations Department Night Orders for control room operator review;

• V23-14 will be modified during the 19% Refueling outage; ,

In summary, as demonstrated above, Vermont Yankee has performed extensive evaluation and training for plant operators for all design and procedural modifications completed to address potential pressure locking or thermal binding concerns.

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VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission June 21,1996 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 Gr%41 ames J. Duffy Licensing Engineer c: USNRC Region I Administrator )

USNRC Resident Inspector - VYNPS USNRC Project Manager - VYNPS I