ML19241A680
| ML19241A680 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 06/21/1979 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| References | |
| TR-790621, NUDOCS 7907090283 | |
| Download: ML19241A680 (1) | |
Text
r POWER AUTHORITY OF THE STATE OF NEW YORK 10 CoLUMaus CIRCLE NEW YORK. N. Y.1o019 (212) 397 6200 July 3, 1979 IPN-79-43 Director, Office of Nuclear Reactor Regulation U.
S.
Nuclear Regulatory Commission Washington, D.
C.
20555 Attention:
Mr. Albert Schwencer, Chief Operating Reactors Branch No. 1 Division of Operating Reactors
Subject:
Indian Point 3 Nuclear Power Plant Docket 50-286 Supplementary Information for I&E Bulletin No. 79-07
Dear Sir:
In accordance with the reporting commitment made by the Authority in its letter of May 31, 1979, the following is reported.
On July 3, 1979 at 11:05 A.M.
the Authority determined that four backing plates and anchor bolt assemblies, when the flexibility criteria of I&E Bulletin No. 79-02 were considered, do not possess sufficient conservatism with respect to Design Basis Earthquake (DBE) loads.
These four assemblies are associated with the following snubbers on the feedwater lines indicated:
Line No.
Snubber No.
5 BFD-R-5-1-H 6
BFD-R
-H 7
BFD-R-7-1 309 057 8
BFD-R-8-1-h
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4 7907 090MS
U.
S.
Nuclear Regulatory Commission IPN-79-43 While these supports are associated both with snubbers reportable as a Technical Specification matter and with seismic piping stress reanalysis efforts, and even though this matter was identified during the 79-07 reanalysis, it is more a matter of concern under 79-02 and not one reportable in accordance with the Authority's commitments.
Nevertheless, the Authority is reporting it at this time rather than as a part of its 79-02 submittal.
A reanalysis using the absolute summation method of the piping with the snubber assembly omitted shows that the pipe s tresses are less than the allowable limits for the Design Basis Earthquake (DBE).
This indicates that the piping system will retain its integrity during a DBE even if the snubber supports were to fail.
The snubbers themselves are adequate for both OBE and
'BE loads, but with the backing plate flexibility criteria and anchor bolt factor of safety of four of 79-02 applied, the anchor bolts have insufficient capability.
The modifications to increase the backing plate and anchor bolt capability above the conservative values are now being designed.
A knee brace for line 5 and gusset plates for lines' 6, 7 and 8 are considered likely solutions.
Field repairs will begin as soon as possible.
It is expected that these modifi-cations will be completed expeditiously.
The Authority considers that its analysis and corrective actions already in progress support its determination that the Ir'ian Point 3 plant ray continue to operate without undue risk to the public health and safety.
Very truly_yours, s
/// -
/ mm Paul J.
Early,'
Assistant Chief Engineer-Projects cc:
Mr. Boyce Grier, Director Office of Inspection and Enforcement Region I U.S.
Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pa.
19406 309 058
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- Catawb3 1 and 2 50-414-A.
June 21, 1979 8:57 am & 10:44 am D C~.
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3 SIP- !ECT:
CDR - Control Panel Weld Deficiencies n:
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Cracks have been observed in 1/4" welds of bracing ise in prefabricated bare control panels supplied by Frank Electric Co.,
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York, Pa.
New weld design and procedures to repair are being
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t developed. Seismic an'aly1;is and model testing to be performed by Wylie Laboratory.
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hL 10 CFR 50.55(e), report due 7-21-79 w
Wylie lab anatysj,s to be performed within<th,e n, ext few months; Low-level 2
excitation tests to verify the, computer model are to be concucteo at Catawba late 1979 or early 1980. Bare panets suppliec cy tranK cteccd c.
Seismic qualified items put on panets oy owne.
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Inspector Harc.icx on site nas coserweg aveve. i e s.
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413/79-12) 10:44 am Applicaote to coin un.s a...
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