ML20128C058
| ML20128C058 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 06/10/1985 |
| From: | Root R WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| GO1-85-0134, GO1-85-134, NUDOCS 8507030433 | |
| Download: ML20128C058 (2) | |
Text
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Washington Public Power Supply System P.O. Box 968 3000 GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000 June 10, 1985 G01-85-0134 Mr. J. B. Martin Regional Administrator Nuclear Regulatory Commission Region V
'1450 Maria Lane, Suite 210 Walnut Creek, Calif. 94596
Subject:
NUCLEAR. PROJECT N0. 1 AND 4 DOCKET NOS. 50-460 AND 50-513 POTENTIALLY REPORTABLE CONDITION 10CFR50.55(e)
MAIN STEAM AND FEEDWATER VALVE ACTUATORS
Reference:
Telecon, C.R. Edwards, Supply System to R.T. Dodds, NRC, same subject, dated May 21, 1984 In the noted reference, the Supply System informed your office of a potentially reportable deficiency in accordance with the requirements of 10CFR50.55(e). Attachment A provides a statement of the identified condition and ' a brief description of our planned actions to correct the identified deficiency.
Based on the construction status at WNP-1/4, the Supply System will not be able to issue a final report at this time.
An update will be provided at construction restart.
If you have any questions or desire further information, please advise.
R. W. Root, Jr.
WNP-1 Program Director (821)
RWR:LCO:pp Attachments cc:
A.D. Edmondson, UE&C (898)
E.C. Haren, UE&C (895)
NRC Document Control Desk, DC FDCC (899) 8507030433 850610 PDR ADOCK 05000460 S
PDR l
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4 ATTAC K NT A DOCKET N0'S. 50-460 & 50-513 P0TENTIALLY REPORTABLE CONDITION PER 10CFR50.55(e)
MAIN STEAM AND FEEDWATER VALVE ACTUATORS DESCRIPTION OF DEFICIENCY The WNP-1/4 design has two steam generators per plant.
Each steam generator is isolated from the Feedwater System by two Feedwater Isolation Valves (FWIV's) in series for a total of four FWIV's per plant (FWS-V-16B,17A, 28B, and 29A).
Each steam generator has two outlet lines containing one Main Steam Isolation Valve (MSIV) per line for a total of four MSIV's per plant (MSS-V-lC, 2C, 3C, and 4C).
These eight valves per plant are all located just outside containment in the Main Steam and Feedwater Isolation Area (MSFIA) which is an enclosed structure.
All eight valves were supplied by Anchor Darling Valve Company.
The pneumatic < hydraulic valve actuators for each of the eight valves are similar in design and are also supplied by Anchor Darling.
Per LER No.
85-027-00, the Byron Project notified the NRC of an event associated with the failure of these valves to operate upon a slow loss of pneumatic air supply pressure (see also IE Notice 85-35).
The deficiency is apparently caused by small Parker-Hannifin air check valves which fail to seat properly upon a slow loss of supply air pressure.
ANALYSIS OF SAFETY IMPLICATION If these check valves leak, the MSIV's and FWIV's may be inoperable following loss of the nuclear instrument air system. Further in-depth analysis of the potential safety implications will not be performed as these small check valves will be replaced.
CAUSE OF DEFICIENCY The Supply System has not been notified of specific details concerning the failure of the small check valves to properly seat.
CORRECTIVE ACTION The deficient Parker-Hannifin check valves will be replaced by a Parker-Hannifin check valve of modified design.
ACTION TO PREVENT RECURRENCE A review of other safety related components will be performed to verify that the problem does not exist in other components.
The results of this review will be provided in a subsequent report.
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