United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for March 15, 2005

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Part 21 2005-0009 - Potential Non-Conformance of Diaphragm Disc Used in Certain ASCO Scram Pilot Valves and Rebuild Kits

Licensee/Facility:


ASCO

Dockets:

License No:
Notification:

MR Number: H-2005-0010
Date: 02/16/2005


Source Document: Letter

Reviewer: TABATABAI, OMID

Discussion:

Part 21 2005-0009 - Potential Non-Conformance of Diaphragm Disc Used in Certain ASCO Scram Pilot Valves and Rebuild Kits

Issue:

The issue relates to potential non-conformance of diaphragm disc used in certain ASCO scram pilot valves and rebuild kits. The non-conformance was discovered during evaluation of a diaphragm disc. The valve from which the disc was removed had been aged the equivalent of 40 years. A Thermogravimetric Analysis (TGA) was performed on the disc material and results suggested that the material was non-conforming because the values exceeded those specified on the disc drawing.

A review of the records for the parts revealed that for the lot received in May 2004, a TGA test had not been performed during incoming inspection at ASCO, nor had it been performed by the vendor. A review of receiving records revealed that all previous receipts of diaphragm discs had been properly tested and documented in accordance with ASCO drawings and procedures, and were within specification

Although ASCO is unable to determine if this non-conformance would have an adverse affect on valve performance, this non-conformance could result in degradation of valve response time or, in worst case, failure of the diaphragm to move off the valve seat. ASCO recommended that this product be retrieved from the field and replaced with conforming discs.

Corrective Action:

All 31 rebuild kits containing diaphragm discs from the May 2004 lot have been returned to ASCO from GE's inventory and will be replaced. Ten of the 14 valves that included discs from the May 2004 lot have been installed at Hope Creek Nuclear Power Generating Station. ASCO has begun accelerated qualification testing to determine if the installed valves can remain in operation until they can be conveniently replaced. The four uninstalled valves will be returned to ASCO for retrofit.

Please see ADAMS accession number, ML050560237, for complete report.

Accession Numbers:

Accession No Accession Date
ML050560237 02/16/2005

Contacts:

Name Office Abbrev Phone No E-Mail
TABATABAI, OMID NRR (301) 415-6616 OTY@nrc.gov
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