05000275/FIN-2010002-04

Finding

Title

Less Than Adequate Evaluation Following a Failure of Both Motor Driven Auxiliary Feedwater Trains

Description

The inspectors identified a noncited violation of 10 CFR, Part 50, Appendix B, Criteria XVI, Corrective Actions, after Pacific Gas and Electric failed to implement adequate corrective actions following a protection system failure. On June 29, 2009, a protection system card failure resulted in the inoperability of both motor-driven auxiliary feedwater trains. The licensee concluded that the failure of the auxiliary feedwater trains were expected as part of the protection system design and limited corrective actions to replacing the failed card. The inspectors concluded that the protection system design did not meet the design basis, which required that no single active failure would prevent the auxiliary feedwater system from meeting the safety function. The licensee entered this issue into the corrective action program as Notifications 50251823, 50298491 and 50254412. The inspectors concluded that the finding is greater than minor because the vulnerability of auxiliary feedwater to a single failure is associated with the design control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors determined the finding to have very low safety significance because the condition did not represent a loss of system safety function. While the single failure of the protection system card resulted in the inoperability of both motor-driven auxiliary feedwater trains, the turbine-driven auxiliary feedwater train was available to perform the safety function. This finding has a crosscutting aspect in the area of problem identification and resolution, associated with the corrective action program component because the licensee failed to perform an adequate evaluation of the auxiliary feedwater failure such that the resolutions address causes and extent of conditions, as necessary P.1(c)

04
Site:	Diablo Canyon
Report	IR 05000275/2010002 Section 4OA3
Date counted	Mar 31, 2010 (2010Q1)
Type:	NCV: Green
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71153
Inspectors (proximate)	G Guerra M Brown M Peck G Miller
CCA	P.2, Evaluation
INPO aspect	PI.2
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Finding - Diablo Canyon - IR 05000275/2010002

1(0)2(6)3(4)4(5)5(12)6(5)7(11)8(0)201(7)301(0)402(2)403(2)501(0)28(0)

IR 05000275/2010002: 1 2 3 4 5 6

Finding List (Diablo Canyon) @ 2010Q1

CCA Matrix: 2010Q1

	Q	CCA	Title
05000275/FIN-2009004-04	2009Q3	P.1 P.1(a)	Failure to Update the Final Safety Analysis Report Update with Current Accident Analysis
05000275/FIN-2009004-03	2009Q3	H.7	Failure to Follow Emergency Operating Procedures Following a Reactor Trip
05000275/FIN-2009004-02	2009Q3	P.5 P.2(a)	Failure to Perform Corrective Actions Resulted in an Unplanned Trip
05000275/FIN-2009004-01	2009Q3	P.2	Failure to Identify and Correct a Degraded Fire Barrier
05000275/FIN-2009008-01	2009Q3	H.7	Safe Shutdown Procedure Not Consistent With Safe Shutdown Analysis
05000275/FIN-2009005-04	2009Q4	P.1 P.1(a)	Less than Adequate Replacement Reactor Head Modification Design Control
05000275/FIN-2009005-01	2009Q4	H.4 H.9	Less Than Adequate Work Planning Resulted in the Release of Two Gas Decay Tanks
05000275/FIN-2009005-02	2009Q4	H.5	Failure to Properly Plan a Maintenance Activity
05000275/FIN-2009005-05	2009Q4	P.2	Less than Adequate Change Evaluation to the Facility as Described in the Final Safety Analysis Report Update
05000275/FIN-2009005-03	2009Q4	P.2	Inadequate 50.59 Evaluation for Steam Generator Tube Rupture Analysis
05000275/FIN-2010002-05	2010Q1	P.2	Failure to Submit a LERE for a Common-Cause Inoperability of Independent Trains or Channels
05000275/FIN-2010002-04	2010Q1	P.2	Less Than Adequate Evaluation Following a Failure of Both Motor Driven Auxiliary Feedwater Trains
05000275/FIN-2010002-03	2010Q1		Failure to Report a Condition That Could Have Prevented the Fulfillment of a Safety Function
05000275/FIN-2010002-02	2010Q1	P.2	Failure to Update the Final Safety Analysis Report with the Current Plant Design Bases
05000323/FIN-2009009-03	2010Q1	P.2	Failure to Evaluate a Change to the Facility as Described in the Final Safety Analysis Report Update Associated with the Addition of Manual Actions in the Safety Analysis
05000275/FIN-2010002-01	2010Q1	P.3	Failure to Effectively Implement the Seismically-Induced Systems Interaction Program
05000275/FIN-2010402-01	2010Q1		Security
05000275/FIN-2010402-02	2010Q1		Security
05000323/FIN-2009009-02	2010Q1	P.2 P.1(a)	Failure to Conduct an Adequate Post-Modification Test
05000323/FIN-2009009-01	2010Q1	P.2	Failure to Follow Design and Configuration Control Requirements

Self-Identified List (Diablo Canyon)

	Q	Title
05000275/FIN-2009403-01	2009Q4	Licensee-Identified Violation
05000275/FIN-2009005-06	2009Q4	Licensee-Identified Violation
05000275/FIN-2010002-06	2010Q1	Licensee-Identified Violation

[Diablo Canyon Findings full list]

05000275/FIN-2010002-04

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