05000275/FIN-2010005-05

Finding

Title

Less than Adequate Containment Recirculation Sump Design Control

Description

The inspectors identified a noncited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, after Pacific Gas and Electric failed to ensure Calculation STA-255, Minimum Required Refueling Water Storage Tank Level for GE Sumps, Revision 2, demonstrated adequate available refueling water storage tank inventory. On October 19, 2010, the inspectors identified that emergency core cooling post accident flow path from the reactor cavity to the containment sumps was blocked by a large steel plug on Unit 1. The accident analysis assumed this 35 square foot path was open to allow coolant from a pipe break inside the biological shield to communicate with containment sumps during the recirculation mode of emergency core cooling. The licensee credited the inventory from the reactor cavity when determining the minimum required refueling water storage tank volume in Calculation STA-255. Pacific Gas and Electric used Calculation STA-255 as the basis for determining the minimum required refueling water storage tank volume specified by Technical Specification 3.5.4, Refueling Water Storage Tank. The inspectors identified that the recirculation flow path was also blocked on Unit 2. The inspectors concluded that the most significant contributor to the violation was inaccurate plant drawings used by plant engineers during the performance of Calculation STA-255. The licensees corrective actions included completion of a prompt operability assessment justifying continued operation of Unit 2 and replacement of the shield plug with a movable platform on Unit 1 prior to plant restart The inspectors concluded that the performance deficiency was more than minor because the finding affected the Mitigating Systems Cornerstone plant modification 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 performance deficiency involved a design deficiency 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 resources component because Pacific Gas and Electric failed to use complete, accurate and up-to-date drawing for Calculation STA 255 H.2(c).

05
Site:	Diablo Canyon
Report	IR 05000275/2010005 Section 1R18
Date counted	Dec 31, 2010 (2010Q4)
Type:	NCV: Green
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71111.18
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.7, Documentation
INPO aspect	WP.3
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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-2010005-05

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