ML20138C821

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Forwards Proposed Rev 5 to Inservice Insp Program for First 10-yr Interval,Deferring Specific Hydrostatic Pressure Test Under IWD-5000 to Next Refueling Outage After Receipt of Replacement Isolation Boundary Valves
ML20138C821
Person / Time
Site: Zion File:ZionSolutions icon.png
Issue date: 10/15/1985
From: Leblond P
COMMONWEALTH EDISON CO.
To: Harold Denton
Office of Nuclear Reactor Regulation
References
0772K, 772K, NUDOCS 8510230055
Download: ML20138C821 (3)


Text

a [N Commonwealth Edison (O

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) One First Nationrj Ptira, Chicrgo. lilinoia 7 Address Reply to: Post Othee Box 767

\ j Chicago, Illinois 60690 October 15, 1985' Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Zion Generating Station Unit 2 Inservice Inspection Program for the First Ten Year Interval NRC Docket No~. 50-304 -

Reference:

June 6, 1985 letter from S. A. Varga to D. L. Farrar.

Dear Mr. Denton:

Attached is Revision 5 to the Zion Generating Station Inservice Inspection Program for the First Ten Year Interval as that program applies to Unit 2. . The proposed revision provides relief to defer a specific hydrostatic pressure test under IWD-5000 to the next refueling outage followina receipt of necessary replacement isolation boundary valves. This request Is submitted in accordance with the provisions of Technical Specification 4.3.4.C.3 and 10 CFR 50.55a (g)(5)(iii).

A similiar request for Unit I has recently been approved in the referenced letter. Should you have any further questions regarding this matter, please contact this office.

Sincerely, ed;LeBlondMLJ P. C.

Nuclear Licensing Administrator im cc: J. Norris - NRR Resident Inspector - Zion Attachment 0 h b4 PDR

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0772K L

a ATTACHMENT REVISION 5 TO ZION GE E RATING STATION INSERVICE INSPECTION PROGRAM FOR THE FIRST TEN-YEAR INTERVAL Relief Recuest from IwD-5000 Relief is requested to defer the system hydrostatic pressure test on a portion of the auxiliary feedwater system from the auxiliary feedwater pumps (2A, 2B, and 2C) to 2MOV-FWOO50, 51, 52, 53, 54, 55, 56, 57 until the next Unit 1 refueling outage. This is currently scheduled for the Winter of 1986/87.

Code Requirements IWD-5000 The pressure retaining components within the Class III bouncary are subject to the hydrostatic test requirements of InD-5000 each inspection interval.

Basis for Relief Zion's original design for the auxiliary feedwater system had air operated valves (A0V) for controlling the auxiliary feedwater flow. Due to safety concerns, Zion disconnected the air lines to these A0Vs, failing open the valves, and used the motor operated valves (MOV) downstream of the A0Vs to throttle and control the auxiliary feedwater flow. Because these MOVs were not specifically designed for throttling, after many years the valves' seat eroded. This was confirmed during periodic operation of the pumps when flow gauges indicated flow past the MOVs even though the valves were closed. The valves' locations did not permit easy repair, but Zion did disassettle a few valves and found the seat area eroced beyond repair. The Station initiated an auxiliary feedwater system modification in October,1983 so the MOVs would be more accessible for maintenance and have throttling capabilities. The modification requires an extensive outage due to the time frame required with the auxiliary feedwater system out of service; it is, therefore, scheduled for installation during a refueling outage.

4 Zion must' delay the hydrostatic test for the auxiliary feedwater discharge piping until the new MOVs are installed because the existing MOVs cannot hold the test pressure. The delivery of the new valves was delayed due to unexpected manufacturing difficulties and revisions to the procedural control of the valves' manufacture.

While seven of the eight valves have been delivered, the modification can longer be performed without extending the current outage beyond January of 1986. The eighth valva is being remanufactured due to an inadequate casting. Zion will hydrostatically test the discharge piping after the new MOVs are installed. The ADVs cannot be used as a pressure boundary since they have not been used in ten years and some of their components have been removed from the valves making them inoperable.

This matter has received station On-Site and Off-Site reviews. All other required hydrostatic tests are expected to be completed within the required time frame. Based on the above, it has been determined that deferral of the auxiliary feedwater system hydrostatic test will have no significant effect upon the probability or consequences of an accident or upon the health and safety of the public.

0772K