05000412/LER-2005-001, Re Containment Isolation Valve Relay Failure Unknowingly Leads to Technical Specification Noncompliance
| ML052650353 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 09/16/2005 |
| From: | Pearce L FirstEnergy Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-05-153 LER 05-001-00 | |
| Download: ML052650353 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4122005001R00 - NRC Website | |
text
FENOC FrstEnergy Nuclear Operating Company Beaver Valley Power Station PO. Box 4 Shippingport, PA 15077-0004 L. Wil/iam Pearce Vice President 724-682-5234 Fax: 724-643-8069 September 16, 2005 L-05-153 Beaver Valley Powper Station, Unit No. 2 Docket ANo. 50-412 License No. APF-73 LER 2005-001-00 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 In accordance with Appendix A, Beaver Valley Technical Specifications, the following Licensee Event Report is submitted:
LER 2005-001-00, 10 CFR 50.73(a)(2)(i)(B), "Containment Isolation Valve Relay Failure Unknowingly Leads to Technical Specification Noncompliance."
- - 11iam Pearce Attachment c:
Mr. T. G. Colburn, NRR Senior Project Manager Mr. P. C. Cataldo, NRC Sr. Resident Inspector Mr. S. J. Collins, NRC Region I Administrator INPO Records Center (via electronic image)
Mr. L. E. Ryan (BRP/DEP)
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NRC ORM366U.S.NUCEARREGLATOY CMMISIO
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Abstract
On July 14, 2005, one of the two Main Steam System isolation valves (2MSS-SOV1 05C) on the steam supply line from 21 C steam generator leading to the steam turbine-driven auxiliary feedwater pump (TDAFWP) unexpectedly opened at Beaver Valley Power Station (BVPS) Unit No. 2. The control room verified that no start signal to the TDAFWP existed or was necessary and that the redundant steam isolation valve (2MSS-SOV105F) on that steam line remained closed. 2MSS-SOV1 05C was declared inoperable. During follow-up investigation actions, it was determined that a sequence of three cascading component failures occurred, the third of which was a passive failure of an auxiliary control circuit relay (3D-SSRAB) in such a manner as to prevent it from being able to perform its intended automatic containment isolation signal transfer function. This passive failure was not discovered until July 19, 2005.
Since it was unknown on July 14, 2005 that Relay 3D-SSRAB failed making four containment isolation valves inoperable, the containment penetrations associated with these four valves were not isolated with a deactivated closed valve within four hours as required by Technical Specification 3.6.3.1 Action a. This is a condition prohibited by plant Technical Specification, and is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B). The plant risk associated with the BVPS Unit 2 event that occurred on July 14, 2005 is considered to be very low.
NRC FORM 366 (5-2004)
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CORRECTIVE ACTIONS
- 1. Based on the lack of a failure history in both BVPS and the vendors records, the vendor's testing of supplied coils, the Beta laboratory failure analysis, the BVPS extent of condition review for similar failures in the industry, and on a visual evaluation of the crimped connection, it was concluded that this poor connection was an isolated case and the hardware issue has been dispositioned by replacement of the coil and the damaged relays.
- 2. A design change will be initiated to provide a barrier to prevent a physical failure of one relay from cascading to nearby relays, where relays associated with the seal-in function of the 2MSS-SOV1 05A through F control circuits are located in close proximity.
- 3. An operating experience report has been issued on the subject providing the details of the event and component failures.
Completion of the above and other corrective actions are being tracked through the BVPS corrective action program.
PREVIOUS SIMILAR EVENTS
A review found one potential prior BVPS Unit No. 1 and one potential BVPS Unit No. 2 Licensee Event Report within the last five years involving either relay or containment isolation valve discrepancies.
is BVPS Unit 1 LER 2000-007, "Technical Specification Non-Compliance Due to Misinterpretation of Containment Isolation Valve Requirements for GDC 57 Penetrations."
BVPS Unit 2 LER 2001-003, "Condition Inadvertently Exceeds Technical Specification Allowed Outage Time."
BVPS Unit 1 LER 2000-007 is not similar to this LER because it involved the human error of not complying with the containment isolation valve Technical Specification as written and misapplied previous NRC correspondence. BVPS Unit 2 LER 2001-003 is not similar to this LER because it involved a human error in not declaring an undervoltage relay inoperable due to not recognizing the importance of unexpected status light indications which signaled a failed solid state input/ protection channel.
COMMITMENTS
There are no new commitments made by FirstEnergy Nuclear Operating Company (FENOC) for BVPS Unit No. 2 in this document.