ML18151A103
| ML18151A103 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/06/1987 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-629, NUDOCS 8710140023 | |
| Download: ML18151A103 (2) | |
Text
e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 W. L. STEWART VICE PRESIDENT NucLEAB OPERATIONS October 6, 1987 U. s. Nuclear Regulato:ry Connnission Attn: Document Control Desk Washington, D.C.
20555 Gentlemen:
VIRG1NIA ~C AND 1DER CDIPANY SORRY IOER. S'm'I'IOO' UNIT 1 REX:mm1 FOR DisrnEI'IONARY mFORCEl4ENl' Serial No.87-629 NO/JIH:vlh
- R2 Docket No.
50-280 License No.
DPR-32 Virginia Electric and Pc:Mer Company requests that NRC Region II exercise discretiona:cy enforcement regarding SUr:ry Unit 1 compliance with Technical Specification 4. 7, Main Steam Line Trip Valves. 'lhe basis for our request is discussed belCM.
On October 2, 1987, while at full power, maintenance personnel were confinning torque measurements on the SUr:ry Unit 1 "C" Main steam Trip Valve (MSTV) body-to-bonnet studs.
During that evolution, two of the twenty-four studs were identified to be in a degraded condition, including one broken stud.
An evaluation was i.nunediately conducted regarding the operability and safety of the MSTV.
Although the evaluation concluded that valve integrity was assured provided twenty-two of the twenty-four studs were intact, station management decided to shutdown the unit to perfonn additional evaluations and investigation of the degraded studs.
Non-destructive examinations were perfonned on the "C" MSTV, as well as the "A" and "B" MSTVs.
Two additional degraded studs were identified on the "C" MSTV; no degraded studs were identified in the other two valves. All studs on the "C" MSTV were replaced.
Metallurgical evaluations of the degraded studs are in progress.
In preparation for restart we have perfo:rmed the required smveillance test on the MSTVs in the cold shutdown condition.
'!he results were similar to those provided to you in our October 2, 1987 (Serial No.87-616) letter.
Although the most recent tunes were a slight improvement, ranging from 4.89 to 6.41 seconds (conpared to the previous results of 5.37 to 7.22 seconds), and demonstrate that there is no degradation in valve closure times, two of the MSTVs are still not capable of meeting the acceptance criterion of five seconds or less specified in the current SUr:ry Technical Specifications.
e Based on our current schedule for Unit 1, we plan to leave cold shutdown today, achieve criticality tomorrow morning (October 7, 1987) and be on-line tomorrow evening.
Even if the test were to be repeated in the hot shutdown condition with steam flow, we do not expect sufficient.ilnprovernent in valve response, based on previous experience, to be able to satisfy the current acceptance criteria.
Accordingly, we request that NRC exercise discretionary enforcement to pennit restart of SUny 1 on or about October 7, 1987.
We understand that this is a one-ti.me only approval.
As committed to during a conference call on October 6, 1987 with NRC management, we will submit a proposed Technical Specification change regarding the MS'IVs by October 7, 1987.
Included in that proposed change will be sufficient justification for NRR to process the proposed change on an emergency basis should another MS'IV sui::veillance test be required prior to NRC approval of the proposed change.
In the interim, we have evaluated the ability of the MS'IVs to perfonn their safety function in the event of a main stearnline break event and conclude that, based on the closure times doct.nnented in the most recent sui::veillance test, the offsite dose consequences remain a small fraction of the 10 CFR Part 100 guidelines and the conclusions of the current accident analyses remain valid.
Very truly yours,
~L~=
W. L. Stewart Attachments cc:
U. S. Nuclear Regulato:ry Commission Region II 101 Marietta Street, N. W.
SUite 2900 Atlanta, Georgia 30323 Mr. W. E. Holland NRC Senior Resident Inspector SUny Power station