05000275/FIN-2010007-06

Finding

Title

Second Level Undervoltage Relay Time Delay to Initiate Load Shed and Sequencing Upon the Diesel Generator is Adequate to Assure Plant Safety

Description

The team identified a noncited violation of 10 CFR Part 50. Appendix B. Criterion III, \"Design Control.\" for failure to ensure that plant conditions were consistent with design calculation inputs and assumptions. The licensee failed to assure and verify that Technical Specification 3.3.5 (SR3.3.5.3) pertaining to the second level undervoltage relay time delay to initiate load shed and sequencing upon the diesel generator was adequate to assure plant safety. Supplemental Safety Evaluation Report 09, Section 8.1. requires that a second level of under voltage protection for the onsite power system be provided. Subsection (1)(c)(i), reads: \"The allowable second level undervoltage relay time delay, including margin. shall not exceed the maximum time delay that is assumed in the Final Safety Analysis Report Update accident analyses.\" Contrary to the above, as of March 4. 2010. the licensee failed to adequately implement the requirements of Supplemental Safety Evaluation Report 09. The second level undervoltage relay time delay setpoint for the emergency diesel generator of less than or equal to 20 seconds, assuming a safety injection signal concurrent with a degraded off site power source, exceeded the Final Safety Analysis Report Update accident analysis. This item identified in the licensee\'s corrective action document Notification 50301167. Failure to ensure that plant conditions were consistent with design calculation inputs and assumptions is a performance deficiency. Using Inspection Manual Chapter 0612, Appendix E, Section 3 Example j, the vioiation was determined to be more than minor because the engineering calculation error results in a condition where there is now a reasonable doubt on the operability of a system or component. These deficiencies represented reasonable doubt regarding the mitigation of an accident by being in an unanalyzed condition. Using Inspection Manual Chapter 0609, \"Significance Determination Process,\" Phase 2, the finding was determined to have very low safety significance (Green), did not represent an actual loss of a system safety function, did not result in exceeding a technical specification allowed outage time, and did not affect external event mitigation. The team reviewed the finding for crosscutting aspects and none were identified.

06
Site:	Diablo Canyon
Report	IR 05000275/2010007 Section 1R21
Date counted	Jun 30, 2010 (2010Q2)
Type:	NCV: Green
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71111.21
Inspectors (proximate)	T Farnholtz S Makor B Correll S Hedger R Kbpriva
INPO aspect
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v • d • e

Finding - Diablo Canyon - IR 05000275/2010007

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 05000275/2010007: 1 2 3 4 5 6 7 8 9 10 11

Finding List (Diablo Canyon) @ 2010Q2

CCA Matrix: 2010Q2

	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-2009005-03	2009Q4	P.2	Inadequate 50.59 Evaluation for Steam Generator Tube Rupture Analysis
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-2009005-01	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
05000323/FIN-2009009-02	2010Q1	P.2 P.1(a)	Failure to Conduct an Adequate Post-Modification Test
05000275/FIN-2010402-02	2010Q1		Security
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-2010002-04	2010Q1	P.2	Less Than Adequate Evaluation Following a Failure of Both Motor Driven Auxiliary Feedwater Trains
05000323/FIN-2009009-01	2010Q1	P.2	Failure to Follow Design and Configuration Control Requirements
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-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-2010003-02	2010Q2		Inadequate Corrective Actions Following Identification of a Nonconservative Technical Specification
05000275/FIN-2010003-03	2010Q2	P.2	Failure to Report a Condition that Could Have Prevented the Fulfillment of a Safety Function
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-2010007-07	2010Q2		Nonconservative Inputs into Motor Operated Valve Calculation
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-2010007-05	2010Q2	P.2	Inadequate Operability Determination Associated With the Offsite Degraded Voltage Protection Scheme
05000275/FIN-2010007-03	2010Q2	H.14	Non-Conservative Decision Making resulted in a Violation of Technical Specification
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-2010007-04	2010Q2	P.2	Failure to Update the Final Safety Analysis Report Update with the Current Plant Design Bases Section
05000275/FIN-2010007-09	2010Q2		Failure to Update Feedwater Rupture Accident Analysis in the Final Safety Analysis Report Update
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-2010003-01	2010Q2	P.2	Failure to Perform Unit 1 Containment Concrete Inspections

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
05000275/FIN-2010007-11	2010Q2	Licensee-Identified Violation
05000275/FIN-2010003-04	2010Q2	Licensee-Identified Violation

[Diablo Canyon Findings full list]

05000275/FIN-2010007-06

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