ML19322D899
| ML19322D899 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/02/1980 |
| From: | Wilson R METROPOLITAN EDISON CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML19322D898 | List: |
| References | |
| GQL-1583, NUDOCS 8003100054 | |
| Download: ML19322D899 (2) | |
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O Metropolitan Edison Company Post Office Box 480 (j
Middletown, Pennsylvania 17057 717 9444041 Writer's Direct Dial Number January 2, 1980 GQL 1583 Mr. B. H. Grier, Director Office of Inspection & Enforcement Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406
Dear Sir:
Three Mile Island Nuclear Station, Unit II (TMI-2)
Operating License No. DPR-73 Docket No. 50-320 Inspection Report No. 79-26 This letter is in response to the subject inspection report resulting from Mr. H. Kister's inspection of September 19 - October 22, 1979 and the request for a plan for corrective action concerning the findings in para-graphs 7 and 8 thereof.
tacagraph 7 An inspection of Firewall 50 Penetration Seals using Surveillance Procedure SP2331-R3, Fire Barrier Seal Inspection, was completed on December 20, 1979.
Of the 238 seals that have been installed using Firewall 50 material,149 seals are presently accessible with no radiation exposure. Fifty-four of these 149 accessible seals were found to exhibit problems typical of those reported in LER 79-12/3L.
One seal developed separation through the full depth of the seal since our last inspection during March, 1979.
This seal (#3-068-80) was repaired using silicon foam in accordance with our seal repair procedure M.P. 1410-Y-43 and job ticket #C-1062.
A firewatch was stationed in accordance with the action statement of T.S. 3.7.11.a when it was determined that the seal did not meet the acceptance criteria.
On December 17, 1979, representatives of Chemtrol Corporation (the seal installer) and Western Chemical Corporation (the material manufacturer),
inspected Firewall 50 seals.
Seals which exhibited problems typical of those reported in LER 79-12/3L were selected for the purpose of taking core bore samples for analysis by Western Chemical Corporation.
Since the cause of the problem has not yet been positively identified, the nature of permanent repairs and a time schedule for completion of these repairs cannot be given at this time. However, following analysis of the samples by Western Chemical Corporation, Chemtrol Corporation will suggest a course of action for repair or replacement of the seals. Any repairs made will be 8 00310 0 0 5 cy.
Metropolitan Ecson Company is a Member of the General Public Utihttes System
s.
B. H. Gricr Dxcembsr 31, 1979 GQL 1583 qualified by 3-hour fire testing (ASTM-E119) and the test results reviewed for acceptability by Met-Ed and American Nuclear Insurers (ANI) prior to their use in the plant.
As indicated during discussions with Mr. P. Koltay of your staff, the NRC will accept ANI's approval of the repairs as an adequate qualification review.
Paragraph 8 A job order has been issued to remove the Kaowool fibre material from the penetration seals and to fill the voids created with new silicon foam. ANI has concurred with this course of action and has also agreed that a complete removal of all Kaowool fibres from an individual void is not necessary since the mineral wool fibres are compatible with the silicon foam and is qualified as a damming material.
The present scope of this work is limited to those seals in the floor of the Control Room, since this is the only plant area in which the use of chafing guards has been observed. Our current estimate of the date of completion of this work is July 25, 1980.
ce ely, 6
.. F. W lson Director, TMI-II RFW:JRS: hah i
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