ENS 47561
ENS Event | |
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02:09 Dec 30, 2011 | |
Title | Lpci Instrumentation Required Repair and Recalibration |
Event Description | Surveillance testing on Low Pressure Coolant Injection (LPCI) Loop Select logic yielded results requiring repairs to 3 of the 4 Recirculation Riser Differential Pressure instruments and calibration of all four. The instrument conditions were such that there was not reasonable assurance that the safety function of LPCI could be fulfilled during a design basis Loss Of Coolant Accident (LOCA). As such, this condition is reportable under 10 CFR 50.72(b)(3)(v)(D).
The four instruments support the LPCI Loop Select logic by providing input that successfully identifies and directs LPCI flow to the unbroken recirculation loop so that core reflooding is accomplished in time to ensure that the fuel peak cladding temperature remains below the limits of 10CFR50.46. The instruments are arranged in a one-out-of-two-twice logic. The instruments were last calibrated September 26-29, 2011. At that time, pre-planned maintenance was performed to improve instrument reliability. Current testing indicates a repetitive issue with instrument drift. Repair and recalibration of each degraded instrument has been completed as the surveillance test has progressed such that the current status supports fulfillment of the safety function. The instrument type (Barton) is used in several safety systems, but there has been no notable degradation in other applications. The licensee has notified the NRC Resident Inspector. |
Where | |
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Duane Arnold Iowa (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
Time - Person (Reporting Time:+0.42 h0.0175 days <br />0.0025 weeks <br />5.75316e-4 months <br />) | |
Opened: | Jeff Miell 02:34 Dec 30, 2011 |
NRC Officer: | John Knoke |
Last Updated: | Dec 30, 2011 |
47561 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
Duane Arnold with 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
WEEKMONTHYEARENS 528812017-08-01T14:34:0001 August 2017 14:34:00
[Table view]10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection Steam Supply Valve Failed to Reposition ENS 516972016-01-29T15:20:00029 January 2016 15:20:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Offsite Power Declared Inoperable Due to Lowering Generator Voltage ENS 510062015-04-23T15:50:00023 April 2015 15:50:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Safety Systems Declared Inoperable Due to Equipment Malfunction ENS 508912015-03-13T17:30:00013 March 2015 17:30:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Low Pressure Coolant Injection Declared Inoperable ENS 501542014-05-30T15:43:00030 May 2014 15:43:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection Pump Received an Invalid Isolation Signal ENS 495662013-11-21T08:29:00021 November 2013 08:29:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Diesel Generator Inoperability ENS 480642012-07-02T20:05:0002 July 2012 20:05:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Declared Inoperable ENS 475612011-12-30T02:09:00030 December 2011 02:09:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Lpci Instrumentation Required Repair and Recalibration ENS 466452011-02-26T15:48:00026 February 2011 15:48:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection System Inoperable ENS 450102009-04-23T00:45:00023 April 2009 00:45:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) System Declared Inoperable ENS 436922007-10-05T09:08:0005 October 2007 09:08:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Loss of Both Emergency Service Water Pumps ENS 436022007-08-27T05:00:00027 August 2007 05:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident One Channel of Low Main Steam Line Pressure Signal Mistakenly Removed from Service for 33 Minutes ENS 433312007-05-01T01:17:0001 May 2007 01:17:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Declared Inoperable Due to Primary Containment Nitrogen Leak ENS 432622007-03-28T18:41:00028 March 2007 18:41:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Hpci Inoperable Due to Surveillance Test Failure ENS 431612007-02-12T16:52:00012 February 2007 16:52:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Both Standby Filter Units Inoperable ENS 431182007-01-24T15:55:00024 January 2007 15:55:00 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)(A), Seriously Degraded Missing Pipe Clamp Bolt Found on High Pressure Coolant Injection (Hpci) System ENS 428352006-09-08T09:01:0008 September 2006 09:01:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Containment Atmospheric Dilution (Cad) System Inoperable ENS 420252005-09-29T20:34:00029 September 2005 20:34:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident High Pressure Coolant Injection (Hpci) Declared Inoperable 2017-08-01T14:34:00 | |