05000275/FIN-2010005-04

Finding

Title

Description

The inspectors identified a noncited violation of 10 CFR Part 50, Appendix B, Criteria V, Instructions, Procedures, and Drawings, after Pacific Gas and Electric failed to adequately evaluate two nonconforming conditions for operability as required by Procedure OM7.ID12, Operability Determination. On October 15, 2010, the inspectors identified a less than adequate technical evaluation supporting Prompt Operability Assessment 50350918, Unit 2 - Insulation in Bio-Wall Penetration. Engineering personnel failed to adequately evaluate the extent of condition after technicians identified about 632 pounds of Temp-Mat and 60 pounds of Min-K fibrous insulation in the Unit 1 reactor coolant loop biological shield wall penetrations. This fibrous material could have potentially been transported and plugged the emergency core cooling containment sump screen. The licensee performed the prompt operability assessment for Unit 2, which was operating at the time. The inspectors concluded that the engineering personnel inappropriately applied the leak-before-break methodology to exclude about 87 percent of this material from the extent of condition review in the prompt operability assessment.

The second example involved Prompt Operability Assessment Notification 50355265, RHR Sump Margin, which was completed by the licensee on October 23, 2010. In this example, engineering personnel failed to identify and demonstrate that the specified safety function of the refueling water storage tank could be maintained as required by the plant operability procedure. The inspectors identified that the post accident flow path from the reactor cavity to the containment sump was blocked by a large shield plug. This blockage reduced the amount of post accident inventory available at the containment sump at the time of transition from injection to recirculation mode of emergency core cooling operation. Engineering personnel failed to demonstrate that the safety function to ensure full sump submergence was maintained with the blocked flow path. Full submergence of the sump was used by the NRC as the basis for approval of Technical Specification 3.5.4, Refueling Water Storage Tank, inventory requirements. The licensee entered the violation into the corrective action program as Notification 50369117 and revised the prompt operability assessments using assumptions consistent with the current licensing bases.

The inspectors concluded that the performance deficiency was more than minor because the finding affected the Mitigating Systems Cornerstone initial design control attribute and objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors concluded that the finding was of very low safety significance (Green) because the finding was confirmed not to result in the loss of operability or functionality. This finding had a crosscutting aspect in the area of human performance associated with the decision making component because Pacific Gas and Electric did not use conservative assumptions in decisions to demonstrate component operability in either example H.1(b).

04
Site:	Diablo Canyon
Report	IR 05000275/2010005 Section 1R15
Date counted	Dec 31, 2010 (2010Q4)
Type:	NCV: Green
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71111.15
Inspectors (proximate)	E Wong P Goldberg L Ricketson M Brown M Peck C Graves R Kopriva D Allen C Osterholtz I Anchondo D Reinert C Alldredge B Latta
CCA	H.14, Conservative Bias
INPO aspect	DM.2
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Finding - Diablo Canyon - IR 05000275/2010005

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)

IR 05000275/2010005: 1 2 3 4 5 6 7 8 9 10 11 12

Finding List (Diablo Canyon) @ 2010Q4

CCA Matrix: 2010Q4

	Q	CCA	Title
05000275/FIN-2010402-02	2010Q1		Security
05000323/FIN-2009009-01	2010Q1	P.2	Failure to Follow Design and Configuration Control Requirements
05000323/FIN-2009009-02	2010Q1	P.2 P.1(a)	Failure to Conduct an Adequate Post-Modification Test
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-2010002-02	2010Q1	P.2	Failure to Update the Final Safety Analysis Report with the Current Plant Design Bases
05000275/FIN-2010002-03	2010Q1		Failure to Report a Condition That Could Have Prevented the Fulfillment of a Safety Function
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-2010402-01	2010Q1		Security
05000275/FIN-2010002-01	2010Q1	P.3	Failure to Effectively Implement the Seismically-Induced Systems Interaction Program
05000275/FIN-2010003-02	2010Q2		Inadequate Corrective Actions Following Identification of a Nonconservative Technical Specification
05000275/FIN-2010007-03	2010Q2	H.14	Non-Conservative Decision Making resulted in a Violation of Technical Specification
05000275/FIN-2010003-01	2010Q2	P.2	Failure to Perform Unit 1 Containment Concrete Inspections
05000275/FIN-2010007-05	2010Q2	P.2	Inadequate Operability Determination Associated With the Offsite Degraded Voltage Protection Scheme
05000275/FIN-2010007-06	2010Q2		Second Level Undervoltage Relay Time Delay to Initiate Load Shed and Sequencing Upon the Diesel Generator is Adequate to Assure Plant Safety
05000275/FIN-2010007-08	2010Q2	P.2	Inadequate Drawings and Procedures to Align Emergency Makeup Water Supply from Diablo Canyon Creek to Support the Auxiliary Feedwater System
05000275/FIN-2010007-07	2010Q2		Nonconservative Inputs into Motor Operated Valve Calculation
05000275/FIN-2010007-10	2010Q2		Failure to Update Text to Reflect Credited Design Class I Makeup Flowpath to Component Cooling Water Expansion Tank in the Final Safety Analysis Report Update
05000275/FIN-2010007-09	2010Q2		Failure to Update Feedwater Rupture Accident Analysis in the Final Safety Analysis Report Update
05000275/FIN-2010007-04	2010Q2	P.2	Failure to Update the Final Safety Analysis Report Update with the Current Plant Design Bases Section
05000275/FIN-2010007-02	2010Q2	P.2	Failure to Adequately Evaluate Changes to the Diesel Testing as Described in the Final Safety Analysis Report Update
05000275/FIN-2010007-01	2010Q2	H.14	Less than Adequate Change Evaluation to the Facility as Described in the Final Safety Analysis Report Update
05000275/FIN-2010003-03	2010Q2	P.2	Failure to Report a Condition that Could Have Prevented the Fulfillment of a Safety Function
05000275/FIN-2010201-02	2010Q3	H.12	Security
05000275/FIN-2010004-05	2010Q3		Inadequate Design Control for the Auxiliary Saltwater System
05000275/FIN-2010004-04	2010Q3	P.2	Inadequate Operability Determination
05000275/FIN-2010004-03	2010Q3	H.8	Inadequate Risk Assessment during Planned Maintenance Activities
05000275/FIN-2010004-02	2010Q3	P.3	Inadequate Risk Management during a Planned Auxiliary Saltwater Pump Outage
05000275/FIN-2010004-01	2010Q3	P.1	Failure to Identify a Degraded Fire Barrier
05000275/FIN-2010201-06	2010Q3		Security
05000275/FIN-2010201-01	2010Q3	H.14	Security
05000275/FIN-2010201-03	2010Q3	P.6	Security
05000275/FIN-2010006-03	2010Q3	P.2	Failure to Submit Complete and Accurate Information for a Requested License Amendment
05000275/FIN-2010006-01	2010Q3	H.14	Inadequate Design Control for the Emergency Diesel Generator
05000275/FIN-2010006-02	2010Q3	H.14	Failure to Maintain Proficiency of Operators to Meet the Time Critical Operator Actions
05000275/FIN-2010006-04	2010Q3	H.14	Untimely and Inadequate Corrective Actions for the Emergency Diesel Generators
05000275/FIN-2010006-05	2010Q3	P.2	Failure to Appropriately Evaluate Failed Residual Heat Removal Surveillance Test
05000275/FIN-2010201-04	2010Q3		Security
05000275/FIN-2010403-01	2010Q3	P.1	Security
05000275/FIN-2010403-02	2010Q3		Security
05000275/FIN-2010201-05	2010Q3		Security
05000275/FIN-2010201-07	2010Q3		Security
05000275/FIN-2010005-07	2010Q4	P.6 P.3(c)	Inadequate Quality Verification Audits
05000275/FIN-2010005-03	2010Q4		Corrosion of Containment Fan Cooler Unit Cooling Coil Casings
05000275/FIN-2010005-01	2010Q4	P.3	Failure to Maintain a Fire Barrier
05000275/FIN-2010005-02	2010Q4	H.7	Inadequate Transient Combustibles Procedure
05000275/FIN-2010005-04	2010Q4	H.14	Inadequate Operability Determinations
05000275/FIN-2010005-05	2010Q4	H.7	Less than Adequate Containment Recirculation Sump Design Control
05000275/FIN-2010005-06	2010Q4	P.2	Inadequate Emergency Diesel Generator Surveillance Testing

Self-Identified List (Diablo Canyon)

	Q	Title
05000275/FIN-2010002-06	2010Q1	Licensee-Identified Violation
05000275/FIN-2010007-11	2010Q2	Licensee-Identified Violation
05000275/FIN-2010003-04	2010Q2	Licensee-Identified Violation
05000275/FIN-2010005-08	2010Q4	Licensee-Identified Violation
05000275/FIN-2010005-09	2010Q4	Licensee-Identified Violation
05000275/FIN-2010005-10	2010Q4	Licensee-Identified Violation
05000275/FIN-2010005-11	2010Q4	Licensee-Identified Violation
05000275/FIN-2010005-12	2010Q4	Licensee-Identified Violation

[Diablo Canyon Findings full list]

05000275/FIN-2010005-04

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