NRC-91-0106, Withdraws Commitment to Replace Vent Line Isolation Valves on Scram Discharge Vol

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Withdraws Commitment to Replace Vent Line Isolation Valves on Scram Discharge Vol
ML20082J123
Person / Time
Site: Fermi DTE Energy icon.png
Issue date: 08/23/1991
From: Orser W
DETROIT EDISON CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-91-0106, CON-NRC-91-106 NUDOCS 9108270177
Download: ML20082J123 (2)


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Ec ison ==1,n,.-- - m, August 23, 1991 NRC-91-0106 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

.ferences: 1) Fermi 2 NRC Docket No. 50-341 1

NRC License No. NPP-43

2) Detroit Edison letter NRC-90-0022,

" Report of Reactor Containment Building Test Results", dated Februaly 2, 1990.

3) Detroit Edison letter NRC-90-0164,

" Change in Schedule-for a Commitment to Replace Two Scram Discharge Volume Vent Line Isolation Valves", dated November 26, 1990.

Subject:

Deletion of Commitment to Replace the Scram Discharge Volume Vent Line Isolation Valves The purpose of this letter is to withdraw Detroit Edison's previous commitment to replace the vent line isolation valves on the Scram Discharge Volume (SDV).

In Reference 1, Detroit Edison committed to replacing two SDV vent line isolation valves, i.e., C1100-F010 and C1100-F180, at the Second Refueling Outage due to previous failures of Type "C" local leak rate air tests required by 10 CFR 50, Appendix J. Later, in Reference 2, this commitment was deferred to the Third Refueling Outage due to design installation limitations. In the interim, design changes were implemented which replaced the SDV drain line isolation valves and added test taps and block valves to better facilitate valve local leak rate tests.

Prior to the implementation of the design changes, the Type "C" air tests were performed on each SDV vent / drain valve pair as one unit.

The addition of the test taps and block valves allows the vent line isolation valves to be individually leak rate tested.

Based upon the results of the successful individual Type "C" air tests performed during the Second Refueling Outage the new configuration provides adequate leak-tightness to meet the design isolation requirements. Therefore, it has been determined that the design changes already implemented have resolved the original concern.

l Detroit Edison is no longer pursuing replacement of the SDV vent line isolation valves.

l 9108270177 910823 PDR ADOCK 05000341 PDR phl i

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U. S. Nuclear Regulatory Commission August 23, 1991

, NRC-91-0106 Page 2 If there are any questions, please contact Terry L. Riley, Supervisor Compliance and Special Projects, at (313) 586-1684.

Sincerely, cc: A. B. Davis td L' u R. W. DeFayette J. F. Stang S. Stasek Region Ill

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