ENS 46735
ENS Event | |
|---|---|
19:30 Apr 6, 2011 | |
| Title | Degraded Fire Barrier |
| Event Description | During walk downs for a planned site modification on April 6, 2011 at 1530 EDT, two degraded fire barrier seals were identified in the wall between the Auxiliary Building Basement and the Charging Pump Room. The wall is listed as an Appendix R wall between Fire Area (FA) ABBM and FA CHG. The wall separates redundant safe shutdown equipment.
Two cylindrical six inch penetrations through the wall did not contain the required material to conform to a 3-hour fire rated barrier. This has been identified as a missing fire barrier such that the required degree of separation for redundant safe shutdown trains is lacking. A fire watch was established as a compensatory measure on 4/6/11. The discovery of this non-compliance is being reported as an unanalyzed condition as defined by 10 CFR 50.72(b)(3)(ii)(B). The NRC Resident Inspector has been notified of this event.
The purpose of this report is to retract the event discussed in Emergency Notification System report #46735 submitted on April 6th, 2011. The ENS notification reported an inadequate fire barrier penetration seal discovered on April 6th, 2011 when maintenance inspected the penetration in preparation for a modification. Initial investigation concluded that the fire barrier penetration seal between the Charging Pump room and Auxiliary Building Basement was inoperable because there was inadequate seal material to provide the required three hour barrier rating. It appeared that when looking in the penetration sleeve that a fire board from the opposite room was visible and no foam material was present. Subsequently, an engineering review of the penetration has been completed. The review determined that a minimum of 8 inches of foam is required to maintain a 3-hour rating. Engineering identified that the design also requires a fire board on each side of the foam. Upon measurement it was confirmed that at least 11 inches of the penetration was filled, with a fire board on each side. Based on these measurements, the fire barrier met design requirements and was operable. The individuals performing the initial investigation did not recognize the thickness of the wall. On April 7th, Maintenance proceeded to penetrate the fire barrier for the modification and it was confirmed that foam was behind the fire board. With a 24 inch thick wall, a large portion at the penetration sleeve can be void of material and still meet the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rating. As such, the April 6th, 2011 event is being retracted. The licensee notified the NRC Resident Inspector. Notified the R1DO (Caruso) |
| Where | |
|---|---|
Ginna  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+1.83 h0.0763 days <br />0.0109 weeks <br />0.00251 months <br />) | |
| Opened: | Mike Slaby 21:20 Apr 6, 2011 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Apr 7, 2011 |
| 46735 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 499142014-03-13T20:30:00013 March 2014 20:30:00
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