ML15244A704
| ML15244A704 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/17/1991 |
| From: | Weins L Office of Nuclear Reactor Regulation |
| To: | Miraglia F, Murley T, Russell W NRC |
| References | |
| NUDOCS 9112270128 | |
| Download: ML15244A704 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 December 17, 1991 Docket No. 50-269, 50-270 and 50-287 MEMORANDUM FOR: T. Murley J. Zwolinski B. Grimes F. Miraglia M. Virgilio Acting DD, DRIS W. Russell D. Crutchfield F. Congel J. Partlow W. Travers E. Butcher F. Gillespie C. Rossi J. Roe S. Varga J. Richardson C. Thomas J. Calvo B. D. Liaw W. Bateman, EDO G. Ldinas A. Thadani M. Slosson B. Boger G. Holahan Operations Center E4 Merschoff, RII THRU:
David J. Lange, Acting Director Project Directorate 11-3 Division of Reactor Projects -
1/11 FROM:
Leonard A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects 1 /11
SUBJECT:
DAILY HIGHLIGHT Oconee Unit 3 On December 15, 1991, while in cold shutdown, Duke Power discovered a leak in the suction piping of the Oconee Unit 3 decay heat removal system. The leak which is currently estimated at 1/10 GPM, is coming from a 3 inch crack that begins in a 314 inch relief line fillet weld connection to the 12 inch suction piping (schedule 10, 3/16 inch wall thickness, stainless steel pipe) and extends
- into the 12 inch piping. This portion of the decay heat removal system is isolable from the reactor coolant system by two motor operated valves. The leak.was found during rouqine inspection. DPC currently plans to cut out the affected portion of pipe (approximately 1-2 ft.) and weld in a replacement piece by approximately Sunday of this week. A patch weld fix was considered by the facility licensee but not implemented in order to perform a detailed failure analysis of the cracked pipe. To accomplish the repair, plans are currently under way to remove the head of the vessel and flood the refueling cavity using spent fuel cooling to provide suction to the decay heat removal system. The feasibility and safety analysis of this decay heat removal lineup 9112270128 911217 V PDR ADOCK 050m028 S
PDR~
2 December 17, 1991 is currently being evaluated by DPC under a 50.59 review. Oconee Unit 3 is currently in cold shutdown with the affected portion of the decay heat removal system in service at approximately 30 lbs of suction pressure. The leak can be isolated and suction transferred to the borated water storage tank if necessary. Region II (DRS) and NRR (Materials Branch) are closely monitoring the licensee's activities regarding this mat r.
Leonard A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects -
I/II cc: All NRR PDs A. Chaffee L. Plisco G. Imbro
cc: NRR Project Directors RCapra, 1482 CMiller, 14E21 WButler, 14D4 JStolz, 14D6 EAdensam, 14B20 HBerkow, 14H22 FHebdon, 14B21 LMarsh, 13D18 RBarrett, 13D6 JHannon, 13E21 JLarkins, 13H3 SBlack, 13H15 TQuay, 13E16 RPierson, 11H3 SWeiss, 11B20 JCraig, 11F23 JDyer, 11D23 CBerlinger, 8D22 CGrimes, 11E22 CYCheng, 7D4 JNorberg, 7E23 GBagchi, 7H15 SNewberry, 8H3 FRosa, 7E4 CMcCracken, 8D1 Rones, 8E23 LNorrholm, 9D4 PMcKee, 9D26 RErickson, 9H19 WBeckner, 10E4 LCunningham, 10D4 WBrach, 10A19 JWermiel, 10D24 RGallo, 10D22
-2 is currently being evaluated by DPC under a 50.59 review. Oconee Unit 3 is currently in cold shutdown with the affected portion of the decay heat removal system in service at approximately 30 lbs of suction pressure. The leak can be isolated and suction transferred to the borated water storage tank if necessary. Region II (DRS) and NRR (Materials Branch) are closely monitoring the licensee's activities regarding this matter.
Leonard A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects -
I/II cc:
All NRR PDs A. Chaffee L. Plisco G. Imbro DISTRIBUTION:
Docket File DLange NRC PDR LBerry PDI-3 LWiens Oconee R/F PDII-3:LA PD D(A):PDII-3 LBe y
L P
- cw DLange
/91 1e91
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/91 OFFICAL RECORD COPY Document Name:
DAILY HIGHLITE/OCONEE 3 12/17