ML19326C624
| ML19326C624 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/12/1980 |
| From: | Dauce H, Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| References | |
| PNO-II-80-039, PNO-II-80-39, NUDOCS 8004240250 | |
| Download: ML19326C624 (1) | |
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9 PRELIMINARY NOTIFICATION
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March 12, 1980 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-II-80-39
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.This preliminary notification constitutes EARLY notice of an ' event of POSSIBLE ufety or public interest significance. The information presented is as initially roceived without verification or evaluatico and is basically all that is known by TE staff as of this date FACILITY: Tennessee Valley Authority I
Sequoyah 1 Docket No. 50-327 8
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Hamilton County, Tennessee I
SUBJECTj POTENTIAL START-UP DELAYS i
There are two issues currently being pursued with TVA which may result in delays in the start-up of Unit 1.
The first issue involves an informal recommendation by Westinghedse to TVA to replace split positioning pins used to mount the control rod guide tubes to the upper core support assembly. The possible problem involves the heat treatment of the installed split pins. There are 140 pins involved, 2 for each guide
_, tube. Should TVA decide to replace these pins, Region II estimates that a
'11.2 period of 2 weeks may be required to change the pins. Pin replacement requires i
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removal of the upper internals but would not require removal of the fuel from the vessel.
The other issue involves work previously done on a pipe from the pressurizer to one of the pressurizer relief valves.
During the original hydrostatic testing of the reactor coolant system, the pressurizer relief line (6" Type 316 stainless steel) was deformed due to a movable support remaining rigid. TVA repaired the pipe using a weld draw bead i
technique. At the request of RII, TVA reported the repair to'NRR to obtain relief from further hydro testing. TVA later provided a detailed report of the i
welding technique employed, results of " mockup testing" and stress analysis to NRR. The repair was accepted by NRR based on this report. NRR is reevaluating the acceptance of the repair technique based on subsequent metallurgical exami-nation. A meeting on this issue is scheduled with TVA on March 13. The impact on startup schedule of the further repair or replacement of this line is not
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known at this time. Sequoyah I has just completed its initial fuel loading and has not yet achieved initial criticality.
Neither the NRC nor the licensee plan to issue a press release at this time.
i The State of Tenner::ee has been informed.
Region II (Atlanta) received netification of this occurrence by telephone from t.he resident inspector on site and NRR staff meihers ou March 12. "
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Contact:
R. Martin, RII 242-5534; M. Dance, R1I 242-5536 zooy220250
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