ML20067D510
| ML20067D510 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 12/07/1982 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM 675, NUDOCS 8212130326 | |
| Download: ML20067D510 (2) | |
Text
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V VIMUINIA ELECTHIC AND Powan COMPANY Rsenwoxn,VINGlx!A 20261 W.L.Sraweer vic p....msrr December 7, 1982 Nrctuam DramAftops Mr. Harold R. Denton, Director Serial No. 675 Office of Nuclear Reactor Regulation N0/DWS,Jr.:acm Attn:
Mr, Darrell G. Eisenhut, Director Docket Nos. 50-338 Division of Licensing 50-339 U. S. Nuclear Regulatory Commission License Nos. NPF-4 Washington, D. C. 20555 NPF-7 Gentlemen:
NUREG-0737 POST-TMI REQUIREMENT-ITEM II.D.1 SAFETY VALVE ADJUSTMENTS NORTil ANNA 1 AND 2 Our letter of July 1, 1982 submitted the plant specific relief and safety valve report which indicates our intention to adjust the pressurizer code safety valves.
Available now are the ring settings from the Electric Power Research Institute test program.
Both the valve manufacturer Dresser Industries and our reviewing consultant Westinghouse Electric Corporation find these settings satisfactory.
During the current North Anna Unit I refueling outage adjustments have been made.
Prior to making these adjustments, the "AS FOUND" ring settings were recorded:
SAFETY VALVES A_
B, C
Upper ring
-22
-20
-22 Middle ring
+22 0
0 Lower ring
+7
-9 1/2
-9 Although no historical record of factory ring settings exist for any of the valves, for the "B" and "C" valves, the "AS FOUND" settings are the settings which Dresser personnel expected to find.
For the "A" valve, maintenance records indicate major repair and disassembly work in March 1981.
All three valves were calibrated at Wyle Labs in September 1976, only "A"
received rework since that time and consequently "A" ring settings were disturbed.
Electric Power Research Institute provided the "AS LEFT" ring settings. These l
settings represent conservative values for the Dresser Model No.
31759A valves.
"AS LEFT" settings are equivalent to a blowdown of 12.2%:
SAFETY VALVES A
B, C
Upper ring
-48
-48
-48 Middle ring
-55
-55
-55 Lower ring
+5
+10
+7 (Lower ring differences are due to maintaining n (6) notch clearence between the disc holder and the lower ring).
8212130326 821207 PDR ADOCK 0300033g gh PDR
V I
Vamosus4 Etscroic Ano Powsm Courawv to Harold R. Denton Both "AS FOUND" and "AS LEFT" settings were evaluated for safety significance.
"AS FOUND" settings were determined to provide acceptable performance. - AS LEFT" settings add increased conservatism to valve performance.
Currently we plan to adjust the. North Anna Unit.2 Safety Valves at the next refueling outage to the same settings as Unit one.
Ve truly yours, t
$N3hE)I' W. L. Stewart s
4 cc:
Mr. James P. O'Reilly Regional Administrator j
Office of Inspection and Enforcement Region II Mr. Robert A. Clark Operating Reactors Branch No. 3 Division of Licensing i
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