ENS 50475
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ENS Event | |
|---|---|
18:53 Sep 19, 2014 | |
| Title | Unanalyzed Condition Due to Missing Fire Barriers |
| Event Description | As part of an extent of condition review related to ENS 50362 (Unanalyzed Condition Due to Lack of Appropriate Fuse Protection), it was identified that, within the past three years, three additional examples existed of missing fire barriers that could have impacted separation of redundant safe shutdown trains. For the affected areas associated with each of the three missing barriers, compensatory measures (hourly fire watches) had been in place for three years prior to the discovery of the condition. However, it was determined the missing barriers met the reporting criteria for 10 CFR 50.72(b)(3)(ii)(B) as unanalyzed conditions that significantly degraded plant safety.
The first condition was the use of rodofoam material in Auxiliary Building seismic joint seals. Rodofoam is a combustible foam material and does not provide a fire rating equivalent to the barriers in which it was used. This issue was corrected in a plant modification. The second condition is the lack of required fire dampers in ventilation supply ducts to the Aux. Feedwater (AFW) Pump Rooms (Fire areas 31 and 32). An engineering change package has been approved to implement a plant modification to install the required dampers as part of the NFPA-805 transition. The third condition is a gap where the ventilation duct passes through the wall from the Bus 150/160 room into the AFW pump room. An engineering change package has been approved to implement a plant modification to correct this condition as part of the NFPA-805 transition. The protection of the health and safety of the public was not affected by this issue. In all cases, compensatory measures existed to ensure the protection of safe shutdown equipment. The licensee has notified the NRC Senior Resident Inspector.
Northern States Power Company (NSPM) has determined that the missing fire damper and the wall gap (the second and third identified conditions) are not separating redundant equipment and no longer meet the regulatory definition of an unanalyzed condition. This was identified when it was determined that the redundant pressurizer heater cables credited for safe shutdown were routed through the same fire area. This was reported under EN 50531 (Unanalyzed Condition Due To Missing Fire Barrier). Since the missing fire barrier does not separate redundant equipment, the condition does not degrade plant safety, and is no longer reportable. The protection of the health and safety of the public was not affected by this issue. The licensee has notified the NRC Resident Inspector. Notified R3DO (Peterson). |
| Where | |
|---|---|
Prairie Island  Minnesota (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+-0.98 h-0.0408 days <br />-0.00583 weeks <br />-0.00134 months <br />) | |
| Opened: | Darrell Lapcinski 17:54 Sep 19, 2014 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Nov 18, 2014 |
| 50475 - 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 526382017-03-20T21:39:00020 March 2017 21:39:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Historical Event Related to Past Operability ENS 518772016-04-21T20:50:00021 April 2016 20:50:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Missing Fire Barriers ENS 516422016-01-08T01:00:0008 January 2016 01:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Appendix R Credited Procedures Not in Place ENS 516162015-12-21T22:25:00021 December 2015 22:25:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Non-Compliant Fire Protection Manual Operator Actions ENS 514982015-10-26T12:03:00026 October 2015 12:03:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Associated with a High Energy Line Break ENS 509942015-04-19T22:45:00019 April 2015 22:45:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Non Compliance with 10 Cfr 50 App R ENS 508012015-02-10T08:50:00010 February 2015 08:50:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Voids Identified That Result in an Unanalyzed Condition ENS 505312014-10-13T19:25:00013 October 2014 19:25:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to a Missing Fire Barrier ENS 505232014-10-10T22:17:00010 October 2014 22:17:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Missing Fire Barrier ENS 504752014-09-19T18:53:00019 September 2014 18:53:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Missing Fire Barriers ENS 503622014-08-08T15:26:0008 August 2014 15:26:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Lack of Appropriate Fuse Protection ENS 496852013-12-31T15:33:00031 December 2013 15:33:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Removal of Multiple Steam Generator Lateral Support Shims and Bumpers ENS 493612013-09-19T17:20:00019 September 2013 17:20:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition No Documented Plan in Place to Receive Additional Fuel Oil During Maximum Probable Flood Condition ENS 491282013-06-17T21:15:00017 June 2013 21:15:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Unanalyzed Condition - Carbon Dioxide Fire Suppression System Does Not Meet Design Requirements ENS 479492012-05-22T21:30:00022 May 2012 21:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Identified During a Fire Protection Review ENS 475222011-12-09T17:59:0009 December 2011 17:59:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition- Degraded Fire Barrier Between Fire Areas ENS 466992011-03-25T15:53:00025 March 2011 15:53:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Unanalyzed Condition Due to Power Level Greater than Limit ENS 465082010-10-23T00:49:00023 October 2010 00:49:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Battery Chargers May Lockup During a Design Basis Event ENS 463182010-10-07T18:52:0007 October 2010 18:52:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Degraded Fire Barrier ENS 462612010-09-16T18:43:00016 September 2010 18:43:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Degraded Fire Barrier Identified ENS 458552010-04-19T03:25:00019 April 2010 03:25:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Lco 3.0.3 Entry and Loss of Safety Function Due to Loss of Turbine Building High Energy Line Break Compensatory Measure ENS 455672009-12-14T18:00:00014 December 2009 18:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Related to Certain Fire Conditions ENS 449312009-03-23T22:00:00023 March 2009 22:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for Postulated Missile Hazard That Could Disable Both Trains of Component Cooling ENS 447732009-01-14T17:30:00014 January 2009 17:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Manual Actions for Fire Not in Compliance ENS 443792008-07-31T18:45:00031 July 2008 18:45:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated High-Energy Line Break That Could Disable Both Trains of Component Cooling ENS 435922007-08-24T16:30:00024 August 2007 16:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Fire Barrier Separation Criteria Not Met for Afwp Rooms ENS 434042007-06-04T21:00:0004 June 2007 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Identified Non Compliant Fire Protection Manual Operator Actions ENS 430102006-11-25T01:45:00025 November 2006 01:45:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition ENS 413772005-02-06T02:46:0006 February 2005 02:46:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 4160 Volt Relaying and Metering Single Failure Vulnerability 2017-03-20T21:39:00 | |
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