ML20148F090
| ML20148F090 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 05/29/1997 |
| From: | Mccoy C SOUTHERN NUCLEAR OPERATING CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-REGGD-01.133, RTR-REGGD-1.133 LCV-1047, NUDOCS 9706040097 | |
| Download: ML20148F090 (2) | |
Text
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3 C. K. McCoy SouthIrn Nuclear Vice President Operating Comptny,Inc.
Vogtle Project 40 inverness Center Parkway R0. Box 1295 Birmingham. Alabama 35201 I
Tel 205 992.7122 Fax 205 992.0403 SOUTHERN L COMPANY Energy to Serve Your World" LCV-1047 May 29, 1997 Docket No.
50-425 1
U. S. Nuclear Regulatory Conimission ATTN: Document Control Desk Washington, D. C. 20555 Ladies and Gentlemen:
VOGTLE ELECTRIC GENERATING PLANT l
CONFIRMED LOOSE PART 14-DAY REPORT In accordance with the requirements of the Vogtle Electric Generating Plant Final Safety Analysis Report and Regulatory Guide 1.133, Southern Nuclear submits the enclosed report concerning the discovery of a loose part.
Sincerely, 7
C. K. McCoy CKM/NJS Enclosure xc:
Southern Nuclear Ooeratine Comnany Mr. J. B. Beasley, Jr.
i Mr. M. Sheibani NORMS i
U. S. Nuclear Reculatorv Commission 1
Mr. L. A. Reyes,'Regiorial Administrator
. hg f v
l Mr. L. L. Wheeler, Licensing Project Manager, NRR Mr. C. R. Ogle, Senior Resident inspector, Vogtle 9706040097 970529 i
PDR ADOCK 05000425 S
PDR.
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VOGTLE ELECTRIC GENERATING PL.dT - UNIT 2 CONFIRMED LOOSE PART 14-DAY REPORT A.
REQUIREMENT FOR REPORT This report is required in accordance with the Vogtle Electric Generating Plant Final Safety Analysis Report, Chapter 1.9, and Regulatory Guide 1.133, Section C6. This regulatory guide requires the submittal of a follow-up report within 14-days of the initial notification of the confirmation of a loose part. The regulatory guide requires the report to include the following information:
- 1) a summary of data obtained in the manual and automatic data acquisition modes;
- 2) a summary of the analysis, inspections, and correlations with operating data that were performed to evaluate data from the loose part detection program;
- 3) a summary of conclusions and a description of modifications or other actions planned or already performed to evaluate the safety implication of a loose part or to ensure that system and component safety functions are not impaired.
B.
DESCRIPTION OF EVENT
- 1) On May 13,1997, control room personnel began receiving intermittent alarms from a digital metal impact monitoring system (DMIMS) annunciator. The impacts were only seen on channel 753, whose detector is located in the bottom of the reactor vessel. Monitoring found that numerous impacts were occurring with a few of these of sufficient magnitude to trigger the alarm. A recording was made and sent to the NSSS vendor for analysis.
- 2) On May 16,1997, at 1553 EDT, an initial vendor analysis was completed and transmitted to the plant. It indicated a small metal object had been responsible for the impacts recorded. The object's location is the reactor vessel lower plenum and the frequency spectrum of the impacts indicates the object is smaller than one-quarter pound. A second recording containing data from May 17,18, and 19,1997, was analyzed and revealed mostly similar data as the first, except that the impacts displayed slightly less amplitude.
On May 16,1997, at 1636 EDT, the NRC Operations Center was notified of a loose part condition. Although this was reported as a 1-hour non-emergency condition, further review shows that this, and a similar condition reported on May 28,1996, for Unit 1, should have been reported as a 24-hour " prompt notification" per the requirements of Reg. Guide 1.133.
- 3) In the reactor vessel lower plenum, where the object is believed to be located, fluid velocities may be inskfricient to lift the object out of the region, and reactor internals and fuel provide sufficient r strictions to the motion of the object. Operation of the unit with the object present has been evaluated using the guidance of NSAC-125 and 10 CFR 50.59(a)(2). This evaluation concludes that the plant components and safety systems will not be adversely affected during normal operation and accident conditions due to the presence of the object. Therefore, this situation does not represent an unreviewed safety question. Monitoring of the impacts is continuing and a search for the object and an inspection for damage will be performed at the next refueling outage.
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