ML20073B704
| ML20073B704 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 09/13/1994 |
| From: | Vonk M COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-93-002, IEB-93-2, NUDOCS 9409220186 | |
| Download: ML20073B704 (3) | |
Text
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g 1400 Opus Place Downers Grove. Illinois 60515 September 13, 1994 U.S. Nuclear Regulatory Commission Washington, DC 20555 Attention:
Document Control Desk
Subject:
Braidwood Station Units 1 and 2 Braidwood Station Supplemental Response to USNRC Bulletin 93-02, " Debris Plugging of Emergency Core Cooling Suction Strainers" Docket Numbers 50-456 and 50-457
References:
(1)
USNRC Bulletin 93-02, " Debris Plugging of Emergency Core Cooling Suction Strainers" dated May 11, 1993 (2)
USNRC Bulletin 93-02 Supplement 1,
" Debris Plugging of Emergency Core Cooling Suction Strainers" dated February 18, 1994 (3)
D.J. Chrzanowski letter to USNRC dated June 7,
1993, Braidwood Station Response to Bulletin 93-02, " Debris Plugging of Emergency Core Cooling Suction Strainers" Reference (3) contained Commonwealth Edison's response to the subject bulletin.
In that response, Commonwealth Edison committed to performing a walkdown of the Unit 2 containment during the next subsequent outage of sufficient duration and informing the NRC of the results of that walkdown.
That walkdown was completed on May 23, 1994 by station engineering staff and this letter documents the results of that walkdown.
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Document Control Desk (2)
September 13, 1994 1.
Insulated Piping:
Previous Unit 1 inspections identified missing several.small portions of stainless steel lagging covering insulation on the chilled water i
system.
The Unit 2 inspections identified one section of the lagging missing.
This section was also on the chilled water system and was approximately 4 feet long.
In both cases, the exposed insulation is-the Armaflex.
II Foam Retardant Plastic which is considered permanent and is a non-fibrous material.
Consequently, it was not necessary to remove the insulation or reinstall the lagging in these areas prior to unit startup as required by the Bulletin 93-02 for fibrous materials.
In addition, the exposed portions of the Armaflex insulation are firmly adhered to the piping and show no i
signs of degradation.
However, as a housekeeping measure, the missing lagging will be replaced during future Unit 1 and 2 outages.
2.
Lead Shielding Storage Area Outside the Missile Barrier (397'):
The lead shielding was found to be stacked in.
an orderly fashion with in the designated storage cage.
The shielding is cross stacked and is in good-condition.
The shielding and storage area were inspected and no signs of torn or frayed shielding blankets were detected.
The door to the storage area I
was securely closed and locked.
3.
Containment Recirculation Sumps:
The Containment Recirculation Sump screens were inspected and found to be in place and free of debris.
4.
Charcoal Filter Units:
The filter housings were found to be intact.
5.
Temporary Fibrous Material:
A section of freeze blanket was found affixed to line 2CCA8B-2, Outside the Missile Barrier at the 397' elevation R37.
This blanket was removed.
I
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Document Control Desk (3)
September 13, 1994 Paint was noted peeling off the RCFC stacks and the SI accumulators outside the missile barrier.
An analysis was performed by System Material Analysis and Site Engineering of the coating failure and it was determined that the failure did not impact sump blockage.
A reassessment of the need for coating material repair will be made for the next refueling outage (A2R04).
The remainder of the containment was inspected and no other temporary fibrous material was discovered.
The results of this inspection are consistent with the
.recent evaluation of the ECCS Suction Strainer Blockage issue for PWRs.
Based on this inspection, no additional activities are required.
To the best of my knowledge and belief, the statements contained in this document are true and correct.
In some respects, these statements are not based on my personal knowledge, but on information furnished by other Comed employees, contractor employees, and/or consultants.
Such information has been reviewed in accordance with company practice, and I believe it to be reliable.
If there are any questions or comments, please contact me at (708) 663-7292.
Sincerely,
?
31
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Marti,n J. Vonk Generic Issues Administrator Nuclear Regulatory Services cc:
J. Martin, USNRC Regional Administrator, Region III R. Assa, Braidwood Project Manager, NRR S. DuPont, Braidwood Station Senior Resident Inspector k / dave /breces.wpf/3