L-MT-04-012, Annual Report of Safety Relief Valve Failures and Challenges, January 1 Through December 31, 2003

Annual Report of Safety Relief Valve Failures and Challenges, January 1 Through December 31, 2003

ML040500405
Person / Time
Site:	Monticello
Issue date:	02/18/2004
From:	Thomas J. Palmisano Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-MT-04-012, NUREG-0737
Download: ML040500405 (2)

Text

Monticello Nuclear Generating Plant Operated by Nuclear Management Company, LLC February 18, 2004 L-MT-04-012 Technical Specification 6.7.A.6 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Monticello Nuclear Generating Plant Docket 50-263 License No. DPR-22 Annual Report of Safety Relief Valve Failures and Challenges January 1 through December 31, 2003 In accordance with Monticello Technical Specification Section 6.7.A.6 and NUREG-0737 Item II.K.3.3, the Annual Report of Safety Relief Valve Failures and Challenges is provided in Enclosure 1.

This letter contains no new NRC commitments, nor does it modify any prior commitments. Please contact John Fields, Senior Regulatory Affairs Engineer, at (763) 295-1663 if you require additional information concerning this report.

Thomas J. Palmisano Site Vice President, Monticello Nuclear Generating Plant Nuclear Management Company, LLC Enclosure cc: Administrator, Region III, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC Minnesota Department of Commerce 2807 West County Road 75

• Monticello, Minnesota 55362-9637 Telephone: 763.295.5151

• Fax: 763.295.1454

ENCLOSURE 1 Annual Report of Safety Relief Valve Failures and Challenges January 1 through December 31, 2003 In accordance with Monticello Nuclear Generating Plant (MNGP) Technical Specification Section 6.7.A.6 and NUREG-0737 Item II.K.3.3, the following Annual Report of Safety Relief Valve Failures and Challenges is provided:

Failures:

05/24/03 MNGP was shutdown and the topworks (pilot and second stage assembly) associated with main steam safety relief valve (SRV)

RV-2-71G was changed out due to suspected excessive leakage past the SRVs pilot or second stage seats. It was subsequently determined that the source of the leakage was past the SRVs main stage seat and not the pilot or second stage seats. The SRV main stage assembly was not changed out at this time.

06/14/03 MNGP was shutdown and SRV RV-2-71B and RV-2-71G were changed out in their entirety except for the SRVs respective actuators, which were re-used. RV-2-71G was changed out due to excessive leakage past the SRVs main stage seat. RV-2-71B was changed out due to suspected excessive main stage seat leakage as well. However, it was later determined that the source of the leakage past RV-2-71B was past its pilot or second stage seats.

Challenges:

05/24/03 Following the 2003 refueling outage, all eight main steam safety relief valves (RV-2-71A through RV-2-71H) were manually opened at a reactor pressure of approximately 150 psig in accordance with a surveillance test performed during plant startup.

05/24/03 RV-2-71G was manually opened a 2nd time on the same day at a reactor pressure of approximately 150 psig in accordance with a surveillance test in an attempt to stop leakage past the SRVs discharge.

05/26/03 RV-2-71G was manually opened at a reactor pressure greater than 600 psig in accordance with a post maintenance test performed during plant startup following replacement of the SRVs topworks (pilot and second stage assembly).

06/16/03 RV-2-71B and RV-2-71G were manually opened at a reactor pressure of approximately 150 psig in accordance with a post maintenance test performed during plant startup following replacement of both SRVs.

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