ML20079K003
| ML20079K003 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 12/14/1982 |
| From: | Root R WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Sternberg D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, G1-82-806, GO1-82-0806, GO1-82-806, NUDOCS 8212280428 | |
| Download: ML20079K003 (2) | |
Text
DockSt N3. 50-460
,,_.. # A 50.55(o) R port
//g l'c 'ED Washington Public Power Supply System
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P.O. Box 968 3000 GeorgeWashingtonWay Richtand. Washington 99352 (509)37 [
Dp' p Docket Number 50-460
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p December 14, 1982 Responds to:
G01-82-0806 Response required by: NA Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 120 Walnut Creek, California 94596 Attention:
Mr. D. M. Sternberg, Chief Reactcr Projects Branch No. 1
Subject:
NUCLEAR PROJECT NO. I 10CFR50.55(e) P0TENTIALLY REPORTABLE CONDITION REACTOR VESSEL FLANGE STUD H0LES
Reference:
Telecon, C.R. Edwards, Supply System to A. D'Angelo, Region V, Nuclear Regulatory Conuission, 11/15/82 In the above reference, the Supply System informed your office of a potentially reportable deficiency in accordance with the requirements of 10CFR50.55(e).
Attachment A includes a brief description of the identified potential deficiency and the Project's planned corrective action.
Due to the extented construction delay of the WNP-1 Project, implementation of any corrective actions will not occur until restart of construction.
In the interim, when the noted deficiencies have been dispositioned, we will provide your office with a status report.
If you have any questions or desire further information, please advise.
R. W. Root, Acting Assistant Program Director RWR:RL:pp cc: JP Laspa, Bechtel (861)
V Mani, UE&C (897)
V Stello, Director of Inspection, NRC A Toth, NRC (917Q)
FDCC (899)
ORM (847) bch 8212280428 821214 PDR ADOCK 05000460 S
A ATTACHENT A WNP-1 DOCKET NO. 50-460 POTENTIALLY REPORTABLE CONDITION PER 10CFR50.55(e)
REACTOR VESSEL FLANGE STUD H0LES
Background
As a result of an extended construction delay of WNP-1, a program was undertaken for the preservation and long term layup of major plant equipment.
During the course of this program, a rusting condition was detected in the noncorrosion resistant surfaces of the reactor vessel flange stud holes.
A controlled process was established to perform cleaning and inspection on each of the stud holes.
Description of Deficiency
~
One of the inspection requirements kis to check the internal diameter and the machined surface of each of the stud holes to determine if the rusting had affected the base metal and thread form. When cleaning of a sufficient number of stud holes verified the presence of pitting type corrosion on the thread form, the decision was reached to inform your office of the potential deficiency.
Safety Implications The reactor vessel flange stud holes form a part of the mechanical interface for locking the reactor closure head to the reactor vessel.
Discrepancies in the stud hole thread form could possibly affect the design requirements for maintaining the integrity of the primary reactor coolant pressure boundry.
However, to date it is indeterminant as to whether the design requirements have been affected.
Corrective Action Under technical direction from the vessel manufacturer (B&W) and the Engineer (United Engineers & Constructors), the cleaning operation was continued in order to complete the inspections and gather the relevant
- data, i.e.,
pitch diameters and surface impressions.
As individual inspections were completed, formal nonconformance reports (CNCR's) were issued on each reactor vessel stud hole that exhibited deficiencies in the thread form. When all inspections are complete, the stud holes will be preserved in accordance with B&W's instructions.
It is expected that all data gathering will be completed by December 1982, and that preliminary evaluations from B&W will be available during 1983.
The Project will continue to track this as an open item during the extended construction delay and will provide you with a final report when a decision of final corrective action, if required, is reached.
.