ML20079G410
| ML20079G410 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Ginna |
| Issue date: | 05/21/1982 |
| From: | Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | |
| Shared Package | |
| ML20079F227 | List: |
| References | |
| FOIA-83-363, TASK-PII, TASK-SE SECY-82-206, NUDOCS 8206110164 | |
| Download: ML20079G410 (3) | |
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s,.....f "a v 2' "82 POLICY ISSUE SECY-82-206 (Information)
FOR:
The Commissioners FROM:
William J. Dircks Executive Director for Operations
SUBJECT:
RESTART OF THE R. E. GINNA NUCLEAR POWER PLANT PURPOSE:
To inform the Commission that the staff review of the January 25, 1982, steam generator tube rupture event at R. E. Ginna Nuclear Power Plant has been completed and that it plans to grant pemission to restart Ginna.
DISCUSSION:
The staf f.has completed its review of the steam generator tube rupture event that occurred at the R. E. Ginna Nucle'ar Power Plant.
It has been detemined that a large foreign object acting in conjunction with nomal thermal and hydraulic loadings initiated a sequence of events that led to the plugging of a number of tubes at or near the periphery, and eventually to the tube rupture.
The wall thinning which led to the rupture occurred as a result of contact wear with an adjacent tube which had previously been plugged and which subsequently severed.
The staff has reviewed Rochester Gas and Electric Corporation's steam generator repair and inspection program. Post rupture examination revealed that severe damage had occurred to 26 tubes in the periphery of steam generator B.
The damage to these tubes was felt by the licensee to be of such extent as to warrant removal of those tubes to prevent further damage to sound tubes.
In addition one tube that was slightly damaged as a result of the peripheral tube removal along with 13 other interior tubes with degradation due to IGA were plugged. The staff has concluded that the contact:
SECY NOTE: Copies of this paper were distributed to J. Lyons Commissioner' Technical Assistants on x-24362 Friday afternoon, May 21, 1982 SZbb IIO/(s h
XA Copy Has Been Sent to PDR
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The Commissioners..
safety and integrity requirements of the active tubes are satisfied by the existing inspection and repair program for steam generator tubing. Additionally the licensee plans to shutdown af ter 120 effective full power days for follow-up eddy current and video inspections to assure that the corrective actions taken to preclude further peripheral tube degradation have been successful. '
During the transient following the tube rupture, other pro-blems were encountered at Ginna.
The staff has reviewed these and the following is a list of some of the more signifi-cant areas and their resolution:
o Pressurizer PORV - Failed open due to a restriction in the exhaust line of a PORY ccatrol air solenoid valve.
The restriction has been removed and a check valve with holes drilled in the disc has been installed in each line between the solenoid valve and the PORY actuator.
o Thermal Transient on the Reactor Pressure Vessel - The staff has concluded that the reactor vessel was not subjected to pressurized thermal shock.
o Operator Response and Written Procedures - To a large degree these were consistent with predicted and accepted guidelines. Significant deviations from the procedures were consciously made following a study of their consequences and management approval.
Subsequent review of the deviations has resulted in short term modifications and a commitment to review for needed long term modifications.
o Radiological Assessment - The radiological consequences of this incident were below the levels calculated originally in the Final Design Safety Analysis and reanalyzed as a part of the Systematic Evaluation Program. The staff concludes that the licensee should reduce the technical specifications for reactor coolant iodine concentrations to ensure that releases from a potential future event are kept well within acceptable guidelines.
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The Commissioners -
The ACRS was briefed by the staff on May 6,1982 concerning the cause of the event and staff actions relative to the restart.
At the conclusion of the meeting, the Chairman noted that they had no further questions before the plant returned to operation.
Rochester Gas and Electric Corporation expects the facility to be ready for restart of Ginne this weekend (:1ay 22/23,1982), pending the staff approval for restart.
William. Dircks Executive Director for Operations DISTRIBUTION:
Commissioners OPE OGC OCA OIA OPA ACRS Secretariat e
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