05000395/LER-2002-002, Incorrect Value in Fuel Handling Accident Analysis
| ML021770036 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 06/13/2002 |
| From: | Byrne S South Carolina Electric & Gas Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 02-002-00 | |
| Download: ML021770036 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 3952002002R00 - NRC Website | |
text
A SCANA COMPANY Stephen A. Byrne Senior Vice President, Nuclear Operations 803.345.4622 June 13, 2002 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 Gentlemen:
Subject:
VIRGIL C. SUMMER NUCLEAR STATION DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 LICENSEE EVENT REPORT (LER 2002-002-00)
INCORRECT VALUE IN FUEL HANDLING ACCIDENT ANALYSIS Attached is Licensee Event Report (LER) No. 2002-001-00, for the Virgil C. Summer Nuclear Station (VCSNS). The report describes the discovery that an incorrect value was used to quantify the environmental release following a postulated Fuel Handling Accident (FHA) Inside Containment. This report is being submitted in accordance with the requirements of 10 CFR 50.73(A)(2)(v).
Should you have any questions, please call Mr. Mel Browne at (803) 345-4141.
Very truly yours, Stephen A. Byrne PAR/SAB Attachment c:
N. 0. Lorick N. S. Cams T. G. Eppink (w/o attachment)
R. J. White L. A. Reyes K. R. Cotton NRC Resident Inspector F. E. Rehrig Paulette Ledbetter D. L. Abstance EPIX Coordinator K. M. Sutton INPO Records Center J&H Marsh & McLennan NSRC RTS (0-C-02-1005)
File (818.07)
DMS (RC-02-0107) fly/
SCE&G I Virgil C. Summer Nudear Station. P. 0. Box 88. Jenkinsville, South Carolino 29065 -T (803) 345.5209. www.scono.om
Abstract
On April 18, 2002, while performing an evaluation on control room habitability after a Fuel Handling Accident (FHA) for a NRC request for information related to the Spent Fuel Pool Expansion Project, it was discovered that a prior evaluation used a non-conservative input in the calculation.
The prior evaluation concluded the resulting activity release from a postulated FHA could be rapidly detected and contained within the reactor containment via rapid closure of the purge supply and exhaust isolation valves. This conclusion was based, in part, on the minimum transit time within the exhaust ventilation ducting from the reactor cavity to the purge isolation valves. The transit time has now been determined to be less than the credited time to close the isolation valves, thus creating the potential for an environmental release.
The cause was determined to be an assumption that the FHA occurred in the vicinity of the reactor cavity whereas the new calculation considered more limiting locations within the refueling canal.
Corrective actions were taken to establish administrative controls to restrict operation of the reactor cavity and refueling canal surface ventilation system during periods of core alterations and fuel movement inside containment. This action is expected to have little or no impact on ALARA since plant operating experience has indicated that airborne contamination being emitted from the cavity/canal water surface is not significant.
NHU FUOM 366 (7-2U01)
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
OTHER CORRECTIVE ACTIONS Upon completion of the evaluation of this issue, administrative controls were implemented to restrict operation of the reactor cavity and refueling canal surface ventilation system during periods of core alteration and fuel movement inside containment. This was captured in Surveillance Test Procedure STP 110.001, Pre-Core Alteration Verifications The surveillance test procedure (STP 01 30.05B) that governs the performance of the stroke time test for the Reactor Building purge supply and exhaust isolation valves will be revised to assure that the analysis assumption for closing time is maintained.
PRIOR OCCURRANCES None
-- ---- I NRU Form 36bA (/-ZUU1)