ML20003B781
| ML20003B781 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/24/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NCR-2436, NCR-2437, NCR-2438, NCR-2440, NCR-2441, NCR-2442, NCR-2443, NCR-2447, NCR-2448, NCR-2449, NCR-2457, NCR-2462, NUDOCS 8102250504 | |
| Download: ML20003B781 (2) | |
Text
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b 400 Chestnut Street Tcwer II Dece:ber 24, 1980 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement 4
U.S. Nuclear Regulatory Cc= mission Region II - Suite 3100 101 Marietta Street Atlanta, Georgia 30303
Dear Mr. O'Reilly:
SEOUOYAH NUCLEAR PLANT UNIT 2 - IMPROPERLY PRESSURIZED HYDR 0 STATIC TESTS -
NCR'S 2436, 2437, 2438, 2440-2443, 2447, 2448, 2449, 2457, AND 2462 -
FINAL REPORT The subject deficiencies were initially reported to NRC-0IE Inspector
-M. Thomas en Nove=ber 26, 1980, in accordance with 10 CFR 50.55(e).
Enclosed is our final report.
If you have any questiens, please get in touc.1 with D. L. La bert at FTS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure Ut s
cc:
Mr. Victor Stello, Director (Enclosure) p
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Office of Inspection and Enforcement
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ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 IMPROPERLY PRESSURIZED HYDROSTATIC TESTS NCR'S 2436, 2437, 2438, 2440-2443, 2447, 2448, 2449, 2457, AND 2462 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Approximately 12 hydrostatic tests in safety-related systems were conducted in which a portien of the piping in each test was subjected to the incorrect test pressure. The cause of this problem is the difficulty in establishing the appropriate pressure boundaries. Secticns of piping at areas of transition between high pressure and low pressure piping were tested at the incorrect pressure. Also, there was no formal QA document which detailed the procedure for conducting a hydecstatic test. There are three cases involved:
(1) Piping subjected to pressures higher than required for hydecstatic testing, (2) piping subjected to pressures lower than required for hycrostatic testing but higher than the system design pressure, and (3) piping subjected to pressures lower than design pressure.
Safety I:plications Case 1: A review of vendor documentation reveals that all conpenents were hydro tested to pressures higher than the TVA system hydro test pressure. Therefore, this case could not have caused da age to any eczpenents and the system has been shown to be adequate for its intended service. As a result, this case could not have adversely affected plant safety.
Case 2: Because this case resulted in piping being subjected to pressures at least as high as the system design pressure, there is assurance that the piping is adequate to perform its intended function and, therfore, could not have adversely affected plant safety.
Case 3: Because this case results in the system being pressurized at I
levels below the system design pressures, there is no assurance that the piping is adequate to perform at the required pressure. Therefore, this piping could sustain l
_ leaks during high pressure operation such as midht accc=pany an accident. Therefore, this condition could have adversely affected plant safety.
Corrective Action r
Case 1: Piping which falls into this category will be dispositioned to "use as is" and no changes are required.
Cases 2 and 3: Piping in these categories will be retested as necessary after establishing the proper pressure boundaries in accordance with the instructions described below. All l
tests will be performed before fuel leading.
l Additicnally, Sequoyah Nuclear Plant Inspection Instructicn (SNP II) 41 has been revised to provide instructions for properly carrying cut the hydrostatic tests.' SNP II 41 provides for a review of the pressure boundaries and test requirements (including G-29M require =ents) before L
gerfer:ange of the test.