ML20212M786
| ML20212M786 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 08/22/1986 |
| From: | Capstick R VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Rooney V Office of Nuclear Reactor Regulation |
| References | |
| FVY-86-77, NUDOCS 8608270159 | |
| Download: ML20212M786 (2) | |
Text
VERMONT YANKEE o
NUCLEAR POWER CORPORATION RD 5, Box 169 Ferry Road, Brattleboro, VT 05301 nepty ro:
. y ENGINEERING OFFICE 1671 WORCESTER ROAD y
FRAMINGHAM, MASSACHUSETTS 01701 August 22, 1986 rettpsonesi7 7243oo FVY 86-77 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Office of Nuclear Reactor Regulation Mr. V. L. Rooney, Senior Project Manager BWR Project Directorate No. 2 Division of BWR Licensing
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, VYNPC to USNRC, FVY 84-139, dated November 27, 1984 (c) Letter, USNRC to VYNPC, NVY 86-104, dated May 27, 1986 (d) Letter, VYNPC to USNRC, FVY 86-68, dated August 1,1986 (e) Letter, GE to YAEC, dated August 5,1986
Subject:
Supplemental Response to NRC Request for Additional Information
- Inservice Inspection Program
Dear Sir:
By letter, dated May 27,1986 [ Reference (c)], you requested additional information in order to complete your review of Vermont Yankee's proposed Inservice Inspection Program [ Reference (b)]. In our August 1,1986 response to your request { Reference (d)], we stated that the General Electric information supporting Relief Request H-21 (Question No. 8) would be provided when it became available. Accordingly, enclosed please find a copy of the subject information transmitted by letter, dated August 5,1986.
We trust that this information is sufficient to allow you to complete your review; however, should you have any questions or require additional information, please do not hesitate to contact this office.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION N
R. W. Capstick Licensing Engineer RWC/bil g k(,
Enclosure
' k
- wwn, G
i
GENER AL h ELECTRIC NUCLEAR ENERGY BUSINESS OPERATIONS GENERAL ELECTRIC COMPANY
- 175 CURTNER AVENUE
- SAN JOSE, CAUFORNIA 95105 August 5, 1986 Mr. Robert L. Smith Yankee Atomic Electric Co.
1671 Worcester Road Framington, Mass.
01701
Dear Robert:
Subject:
Isolation of HCU During SDV Hydro Test Per your request, GE has reviewed the claim of a previous GE recommendation endorsing the closure of the HCU scram discharge riser isolation valves (V112) during the hydrostatic pressure test of the SDV.
GE still maintains that closure of the V112 valves is preferred and would be in good engineering practice to minimize reversed pressurization of the scram outlet valves.
It was reported that the SDV would be hydrostatic pressure tested to a pressure of approximately 1563 psig. With th'e V112 valve opened, the scram discharge riser pipe would be pressurized up to the HCU scram discharge check valve (V114). However, due to the slight leakage that is likely to occur through the check valve, the scram outlet valve would be subjected to the SDV hydrostatic pressure. During normal reactor operation, the bottom side of the scram outlet valve plug is subjected to reactor pressure.
On the other hand, the SDV hydrostatic pressure acts on the top side of the valve plug and in turn, exerts additional load against the valve seat. This added load may lead to subsequent valve leakages during normal reactor operation. Furthermore, the scram outlet valve purchase specification depicts a maximum operating differential pressure of 1250 psi.
Therefore, for added precaution, it is deemed good engineering practice to isolate the HCUs via closure of the Vll2 valve during the SDV hydrostatic pressure test.
r
.Very truly yours, Gibo G:.N:.RAL ELECTRIC CO.
~
cc:
C Cameron, LY Chang, TJ Wilders, WA Pitt, HI Russell