ML20079R793
| ML20079R793 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/19/1984 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 8402020358 | |
| Download: ML20079R793 (3) | |
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PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 JOHN S. KEMPER VICE PRESID ENT emessese n.no Asso mass ancn Mr. Thomas E. Murley, Director Office of Inspection and Enforcement - Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Subject:
Limerick Generating Station, Units 1 & 2 Final Significant Deficiency Report No. 126 Feedwater/Safernard Fill System Check Valves Installed Bac' swards
Reference:
Telecon - P. K. Pavlides/PECo to Walt Baunack/NRC, dated 12/19/83 File:
QUAL 2-10-2 (SDR No. 126)
Dear Mr. Murley:
In compliance with 10CFR50.55e, enclosed is the final report on the subject potential deficiency. Your office was informed of this matter on December 19, 1983 by the referenced telecon.
Sincerely, Copy to: Director of Inspection and Enforcement United States Nuclear Regulatory Commission Washington, DC 20555 S. Chadhary, Resident NRC Inspector (Limerick)
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I 8402020358 840119 ADR ADOCK 05000352
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O Limerick Generating Station, Units 1 & 2 Significant Deficiency Report No. 126 Feedwater/ Safeguard Fill System Check Valves Installed Backwards I.
, Introduction This is a final report concerning a deficiency in orientation of two check valves installed in the Safeguard Piping Fill System at Limerick.
The stop-check valves were supplied by Rockwell International and instelled by Bechtel Power Corporation, the Architect-Engineer for the Limerick project. The valves are on one inch diameter, Nuclear Class 1 lines.
II.
Description of Deficiency On November 11, 1983, during a start-up review of the local leak rate test procedures for the Limerick Generating Station, it was discovered that check valves 41-1036 A and B were installed backwards. The reversed check valves were in the Safeguard Piping Fill System connection to the reactor feedwater system. The connection is at the outboard containment isolation check valve (41-1F074 A and B) for the feedwater injection line. The reversed valves identify a problem in both construction and the quality control process since the system was turned over from Bechtel construction to Philadelphia Electric's start-up organ 12ction.
III. Corrective Action The reversed check valves have been cut out, oriented correctly, and reinstalled in accordance with original design requirements. The new welds will be inspected to the requirements for Nuclear Class 1 piping. To ensure that this problem was not extensive, the level 1 Quality Control Engineer (ANSI 45.2.6) who gave final approval for the system was given an oral and practical examination by his supervisor which showed he was familiar with the system and the points of inspection which should be covered when inspecting any system. The orientation of equipment is a check point for any system and was part of the inspection process for this particular one.
Also, a level 2 Quality Control Engineer reviewed 20 other small pipe installation records from the level 1 Quality Control Engineer who approved the system.
The review included greater than 330 feet of pipe and 38 various valves. No other problems were found.
IV.
Safety Implications The purpose of Safeguard Piping Fill System connection is to supply sealing water to the containment isolation check valves following a LOCA, such that containment bypass leakage through this line is precluded.
As installed, the check valves (41-1036 A and B) would not allow the Safeguard Piping Fill System to fulfill its design safety function.
If lef t uncorrected, the reversed check valves would prevent Safeguard Piping Fill scaling water flow to the feedwater containment isolation Not assvring that these valves are scaled could lead to check valves.
a potential offsite expcsures exceeding the limits of 10CFR part 100 under design basis LOCA conditions.
Since the check valves have been removed and reinstalled with the correct orientation, there are no further safety implications. Also, by testing the Quality Control Engineer who approved the system with reversed check talves, and by satisfactorily reviewing other work performed by him, this condition is considered to be an isolated event.
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