05000346/FIN-2012002-02: Difference between revisions

Finding

Title

Failure to Maintain Safety-Related DC Systems Design Control

Description

The inspectors identified a finding, with two examples, of very low safety significance and associated Non-Cited Violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, for the failure to maintain the electrical separation of the redundant safety-related direct current (DC) systems in compliance to the design and licensing bases. The licensee initiated corrective actions including opening the breakers to the non-safety-related loads inside containment and setting the automatic transfer switches (ATSs) to prevent auto-transfer of loads. The performance deficiency was determined to be more than minor because the issue was associated with the Mitigating Systems Cornerstone attribute of design control, and affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to address the impact of high-impedance ground faults in non-safety equipment on safety-related DC sources and the failure to maintain compliance to RG1.6 when installing ATSs between redundant DC power sources impacted the reliability of the DC power system. The inspectors evaluated the finding to be of very low safety significance (Green) using IMC 0609, Appendix A, Attachment 1, Significance Determination of Reactor Inspection Findings for At-Power Situations. Using the Phase 1 SDP worksheet for the Mitigating Systems Cornerstone, the inspectors answered no to all five screening questions. Based on the date of occurrence of this violation (more than 20 years old), the inspectors did not identify a cross-cutting aspect as the finding was not representative of current performance.

02
Site:	Davis Besse
Report	IR 05000346/2012002 Section 1R21
Date counted	Mar 31, 2012 (2012Q1)
Type:	NCV: Green
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71111.21
Inspectors (proximate)	A Wilson C Brown D Kimble J Beavers J Cameron J Neurauter M Holmberg M Mitchell P Smagacz R Jones
INPO aspect
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v • d • e

Finding - Davis Besse - IR 05000346/2012002

1(0)2(4)3(2)4(4)5(4)7(0)8(1)9(0)10(0)402(2)403(1)405(1)501(0)31(0)

IR 05000346/2012002: 1 2 3 4

Finding List (Davis Besse) @ 2012Q1

CCA Matrix: 2012Q1

	Q	CCA	Title
05000346/FIN-2011004-02	2011Q3	H.7	Failure to Control ECCS Room Cooler Valve Position
05000346/FIN-2011004-03	2011Q3	P.3	Failure to Take Timely Corrective Actions
05000346/FIN-2011004-04	2011Q3	H.2	Inadequate Weld Records for CRDM Housings
05000346/FIN-2011004-05	2011Q3		Code Surface Examination Requirements Not Applied to Closure Head Stud Holes
05000346/FIN-2011004-01	2011Q3		Plant Transient During HPI Flow Instrument String Checks
05000346/FIN-2011012-01	2011Q3		Unable to Locate Fatigue Analysis for Class I Valves
05000346/FIN-2011005-04	2011Q4		Reactivity Manipulations Performed By Non-Licensed IndividuaL
05000346/FIN-2011005-01	2011Q4	H.2	Inadequate Control of Weld Filler Metal Electrodes
05000346/FIN-2011005-02	2011Q4	H.5	Decay Heat Pump 1-1 Damaged and Rendered Inoperable By Personnel Climbing on Equipment
05000346/FIN-2011005-03	2011Q4	H.7	Air Voids in Component Cooling Water System Caused By Inadequate Fill and Vent Procedure
05000346/FIN-2011005-05	2011Q4	H.7	Inadequate Information on Valve Interlocks Resulted in Inadvertent Operation and Loss of Component Cooling Water Surge Tank Inventory
05000346/FIN-2011005-06	2011Q4	P.3	Inadequate Procedure Resulted in Water Intrusion Into Safety-Related Motor Control Center
05000346/FIN-2011005-07	2011Q4	H.14	Incomplete Surface Examination of the RRVCH
05000346/FIN-2011407-01	2011Q4	H.14	Security
05000346/FIN-2012002-01	2012Q1	H.5	Seismic Instrumentation Unavailable for Emergency Event Classification
05000346/FIN-2012002-02	2012Q1		Failure to Maintain SAFETY-RELATED DC Systems Design Control

Self-Identified List (Davis Besse)

	Q	Title
05000346/FIN-2011004-06	2011Q3	Licensee-Identified Violation
05000346/FIN-2012002-03	2012Q1	Additional Emergency Diesel Generator Inoperability Caused by Inadequate Maintenance Procedure Instructions
05000346/FIN-2012002-04	2012Q1	Inadequate Control of Locked High Radiation Area Key

[Davis Besse Findings full list]

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 {{finding
-| title = Failure To Maintain Safety-Related Dc Systems Design Control
+| title = Failure to Maintain Safety-Related DC Systems Design Control
 | docket = 05000346
 | inspection report = IR 05000346/2012002

05000346/FIN-2012002-02: Difference between revisions

Revision as of 19:45, 20 February 2018

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05000346/FIN-2012002-02: Difference between revisions

Revision as of 19:45, 20 February 2018

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