ENS 47564
ENS Event | |
|---|---|
10:00 Dec 31, 2011 | |
| Title | Fire Barrier Rating of Vital Swtichgear Walls May Not Meet Standards |
| Event Description | On December 31, 2011 at 0200 PST, a plant employee indentified the fire barrier material in each unit was potentially not qualified as a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated fire barrier as specified by the Diablo Canyon power plant fire protection program. The fire barrier material in question is installed between the block wall portion of the barrier and the door frames in the walls separating three of the 480 Volt switchgear buses and separating the three vital instrument AC inverters. The condition was discovered by a plant employee who questioned the configuration while performing a routine tour of that area. Operators confirmed existing fire watches were in place and established additional fire watches as compensatory measures as required by the Diablo Canyon fire protection program.
A review of the Appendix R fire protection analysis is in progress to confirm the rating of the installed configuration. The licensee has notified the NRC Resident Inspector.
This is an update to EN 47564 reported on 12/31/11 where it was reported that plant personnel had identified rated fire barriers were not qualified as a three hour rated barrier as required by the DCPP Fire Protection Program. On 1/3/12 plant personnel provided barrier design drawings to the manufacturer of the DCPP fireproofing material. The manufacturer reviewed the design detail and confirmed that the barrier design depicted on the drawing is qualified as a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> barrier. Therefore no unanalyzed condition that significantly degraded plant safety existed. This event is being retracted. The licensee notified the NRC Resident Inspector. Notified R4DO (Vasquez). |
| Where | |
|---|---|
| Diablo Canyon California (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+1.88 h0.0783 days <br />0.0112 weeks <br />0.00258 months <br />) | |
| Opened: | Michael Kennedy 11:53 Dec 31, 2011 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Jan 4, 2012 |
| 47564 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 544172019-11-30T19:00:00030 November 2019 19:00:00
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