ML19325D418
| ML19325D418 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 10/16/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19325D419 | List: |
| References | |
| NUDOCS 8910240010 | |
| Download: ML19325D418 (2) | |
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UNITED STATES j
NUCLEAR REGULATORY COMMISSION rn l
WASHINGTON, D. C. 20555 i
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING ASME CODE RELIEF REQUEST - SERVICE WATER SYSTEM CAROLINA POWER & LICHT COMPANY I
BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO. 2 I
DOCKET NO. 50-324
1.0 INTRODUCTION
On July 3,1988, during Brunswick Steam Electric Plant (Brunswick), Unit 2 i
operation, a through-wall leak was detected in a weld in the Service Water Sy stem. Ultrasonic thickness measurements were made on this weld and six similar welds on the A and B se+vice water loops for both Brunswick units.
The only indication of significance was 11.5 inches long and 66% through-wall in the area of the through-wall leak.
'A temporary repair was mece by welding Carbon steel split Collar over the defective drea of the ' service W4ter-d piping.
Ccde repair or piping replacement would have required unit shutdown.
A justification for continued operation was prepared and approved by the Plant t
Nuclear Sofety Comittee.
Design calculations verified that tull structural l
and seismic integrity of the piping would be maintained by the repair. A hydrostatic test was not performed immediately after the repair.
NRC Inspection Report 50-324/88-26 and 50-325/88-26, dated August 22, 1988, I
inoicoted that the licensee was questioned whether Nuclear Regulatory Conmiis-i sion (NRC) approval was obtained prior to deviating from the ASME Boiler and Pressure Vessel Code,Section XI. The licensee response was that prior NRC approval hao not been obtained, but that a relief request was being prepared.
By letter dated November 4,1988, the licensee requested relief f rom the Code requirements for repairs and hydrostatic testing.
2.0 EVALUATION The licensee requested relief from the ASME Section XI Code requirements for an alternate noncode repair procedure and for not performing the hydrostatic test after the repair on the basis of impracticability and unnecessary hardship.
The welded split collar repair is considered a temporary repair to stop leakage until the permanent ASME Code-approved repair can be made during the next Brunswick Unit 2 refueling outage. The licenset is committed to replace the defective service water piping during the refueling outage scheduled to begin in September 1989.
The hydrostatic test required by paragraph IWA-4400 of the ASME Boiler and Pressure Vessel Code was not perforned since an isolable hydrostatic test boundery coulo not be achieved during unit operation. As an alternative, a 4 -
system inservice pressure test was performed in accordance with paragraph IWA-5213(c).
In addition, the licensee connitted to monthly visual inspections until the piping is replaced during the Septenber 1989 Unit 2 refueling out6ge.
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' As a result of the inspection reported in NRC Inspection Report Nos. 50-324/88-26 and 50-325/88-26, the licensee has consnitted to revise plant procedures to require NRC approval prior to deviation froni the ASME Code.
3.0 ' CONCLUSION The staff has reviewtd the licensee's request for relief from the requiren=nts of the ASME Boiler and Pressure Vessel Code,Section XI for Brunswick Unit 2.
On the basis of'the provisions of 10 CFR 50.55a(a)(3) and 50.55a(g)(6)(i) which allcw relief from the requirements of the ASME Boiler and Pressure Vessel Code,Section XI, when compliance with the specified requirements would be impractical or would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety, the staff concludes that the tem acceptable. porary repair and lock of hyorostatic testing of the repair is The staff understands that this is a teaporary repair to stop leakage until a permanent ASME Code-approved repair is made during the Brunswick Unit 2 refueling outage in September 1989. This relief is authorized by law and will not endanger life or property or tht; conmon defense and security and is othemise in the public interest given due consideration to i
the burden upon the licensee that could result if the requirements were imposed on the facility.
.The licensee has revised plant procedures to assure NRC approval of ASME Code l
r(lief requests to avoid 6 similar recurrence. This is acceptable.
Principal Contributor:
F. Witt Dated: October 16, 1989 l
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