ML20086Q997
| ML20086Q997 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 02/24/1975 |
| From: | Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Moseley M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML20086Q984 | List: |
| References | |
| HLWR, SR-S1-75-01, SR-S1-75-1, NUDOCS 8402280644 | |
| Download: ML20086Q997 (4) | |
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VIRGINIA EI.ucTurc ann Pownu COMI%NY 0 b [f yE
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February 24, 1975
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Mr. Norman C. Moseley, Director Serial No. 442 Directorate of Regulatory Operations P0&M/JTB:clw United States Nuclear Regulatory Commission Region II - Suite 818 Docket No. 50-280 230 Peachtree Street, Northwest License No. DPR-32 Atlanta, Georgia 30303
Dear Mr. Moseley:
The Virginia Electric and Power Company hereby submits forty (40) copics of Special Report No. SR-SI-75-01.
The substance of this report has been reviewed by the Station Nuclear.
Safety and Operating Committee and vill be placed on the agenda for the next meeting of the System Nuclear Safety and Operating Committee.
Very truly yours, fd$u n/
C. M. Stallings Vice President -Power Supply and Production Operations Enclosure cc:
Mr. K. R. Goller 39 copies SR-SI-75-01 8402280644 750320 PDR ADOCK 05000200 S
PDR 218E
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4 SPECIAL REPORT i
SR-SI-75-01 4
I DEBRIS IN REACTOR VESSEL DOCKET NO. 50-280 LICENSE NO. DPR-32 i
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I SURRY POWER STATION VIRGINIA ELECTRIC AND POWER COMPANY-t I
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INTRODUCTION This report is written at the request of the United States Nuclear Regulatory Commission, Directorate of Regulatory Operations, Region II.
Its purpose is to provide further information regarding the incident which involved the partial collap:te of a removable concrete wall inside the containment structure during a refueling outage of Unit No. 1.
At the time of the incident the reactor head had been removed for refueling and the upper internals and all fuel had been removed from the vessel.
II.
DISCUSSION On November 20, 1974, approximately 45 concrete blocks fell from the top two rows of a concrete block wall on the north side of the pressurizer cubicle in Unit No. I containment during removal of the cover over the cubicle. One block fell into the reactor cavity approximately three feet from the reactor vessel on the side nearest to the pressurizer cubicle.
Other debris ranging in size from approximately two inches in diameter down to small chips was deposited primarily in the southeastern corner of the reactor cavity within the reactor vessel, and on the upper. internals which had been placed alongside the vessel in its refueling storage position.
A five man team was assigned to remove the concrete slab. Due to the overlapping design of the ' segmented roof, the northern most section was to be removed first.
Four men were positioned around the roof to assure proper lif ting; however, it was very_ difficult for any of the men to observe the -
bonded joint between the roef section and the concrete wall due to its physical location.
The section had been raised several inches when
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'per rows of concrete blocks separated from the wall and fell approximately 15 feet to the operating floor level in the containment.
One block, along with small pieces of debris, fell into the reactor cavity.
The reactor vessel and cavity were surveyed with a videotape camera following the incident; and all concrete particles were removed from the lower support plate, diffuser plate, upper internals, and the reactor vessel bottom head utilizing an eductor.
A second complete videotape survey was filmed following the cleanup operation to assure thoroughness of the procedure.
The videotapes which indicate that all debris was removed from the vessel were thoroughly reviewed by our operating and quality assurance staff's.
Both confirmed that the cleanup operations were fully successful.
III. CONCLUSION The reactor vessel or associated systems were not damaged and all debris has been renaved.
The wall is being rebuilt to preclude a aimilar occurrence. This event did not affect the safe operation of the station or the health and safety of the general public.