05000346/FIN-2011002-04: Difference between revisions

Finding

Title

Licensee-Identified Violation

Description

Technical Specification 3.7.5 B requires that an inoperable auxiliary feedwater train be restored to operable status in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Contrary to this, in August 2010, the licensee determined that auxiliary feedwater train 2, because of a failed position controller board for the pumps discharge valve, had been inoperable for a period of approximately 18 days. The licensees investigation determined that the failure was attributable to the controller board experiencing a voltage higher than the boards design for a period of time sufficient to cause failure and that the higher voltage was caused by a ground on the dc bus power supply to the board. The licensee also determined that there was a previous failure of the same board for the same reason and that the licensee had failed to recognize the potential significance of a direct current bus ground and failed to assign proper priority for finding and eliminating the ground. The licensee documented the condition in CR 10-81273. Inspection Manual Chapter 0609,Significance Determination Process, screening indicated a need to perform Phase 3 internal and external events analyses for determining the significance of the event. These analyses were performed by the Region III Senior Reactor Analyst staff. The total estimated delta core damage frequency (CDF) for the 18-day exposure time was the sum of the internal events contribution (4.2E-7/yr) and the external events contribution (3.4E-7/yr) or 7.6E-7/yr. Based on the Phase 3 analysis, the inspectors determined that the finding was of very low safety-significance.

04
Site:	Davis Besse
Report	IR 05000346/2011002 Section 4OA7
Date counted	Mar 31, 2011 (2011Q1)
Type:	NCV: Green
cornerstone	Mitigating Systems
Identified by:	Licensee-identified
Inspection Procedure:
Inspectors (proximate)	J Rutkowski A Wilson D Kimble T Go J Cameron
INPO aspect
'
v • d • e

Finding - Davis Besse - IR 05000346/2011002

501(0)1(0)2(4)3(1)4(6)5(7)6(0)7(0)8(0)9(0)10(0)11(0)12(1)201(0)301(0)403(0)404(0)405(1)406(0)407(1)501(0)502(0)4(0)

IR 05000346/2011002: 1 2 3 4

Finding List (Davis Besse) @ 2011Q1

CCA Matrix: 2011Q1

	Q	CCA	Title
05000346/FIN-2010008-01	2010Q3	H.2	Unqualified PT Procedure For CRDM Nozzle Repair Welds
05000346/FIN-2010008-02	2010Q3	H.2	Unqualified Weld Repair Applied For CRDM Nozzle No. 4
05000346/FIN-2010008-03	2010Q3	H.2	Inadequate Procedure For Viewing of Remote PT on Nozzle No. 61 Repair Welds
05000346/FIN-2010004-02	2010Q3		Compliance with Spent Fuel Pool Storage Requirements
05000346/FIN-2010201-01	2010Q3	H.7	Security
05000346/FIN-2010004-01	2010Q3	H.13	Failure to Assess and Manage Risk During Conservative Grid Operations
05000346/FIN-2010008-04	2010Q3		Control Rod Drive Nozzle PWSCC and Pressure Boundary Leakage
05000346/FIN-2010008-05	2010Q3		Technical Specification (TS) Leakage Requirements
05000346/FIN-2011002-02	2011Q1	H.12	Containment ECCS Recirculation Sump Reliability Degraded Due to Unfastened Debris Gate
05000346/FIN-2011002-01	2011Q1	H.7	Failure to Adequately Control Construction Material Adjacent to the Switchyard
05000346/FIN-2011002-03	2011Q1	H.7	Inadvertent Removal of Control Power to Containment Air Cooler Isolation Valve

Self-Identified List (Davis Besse)

	Q	Title
05000346/FIN-2011002-04	2011Q1	Licensee-Identified Violation

[Davis Besse Findings full list]

@@ Line 1: / Line 1: @@
 {{finding
-| title = LICENSEE-IDENTIFIED Violation
+| title = Licensee-Identified Violation
 | docket = 05000346
 | inspection report = IR 05000346/2011002

05000346/FIN-2011002-04: Difference between revisions

Latest revision as of 10:42, 30 May 2018

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05000346/FIN-2011002-04: Difference between revisions

Latest revision as of 10:42, 30 May 2018

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