05000306/FIN-2011005-05

Finding

Title

Potential Safety System Functional Failure Due to Steam Exclusion Damper Issues

Description

At the Prairie Island Nuclear Generating Plant, certain ventilation systems were designed with steam exclusion dampers. These dampers automatically closed during high energy line break (HELB) events to ensure that safety-related equipment remained protected from the impacts of high temperature steam. On August 24, 2011, steam exclusion control damper (CD) 34197 failed to fully close during surveillance testing. The licensee entered the appropriate Technical Requirements Manual (TRM) Action Statement, which directed that the redundant damper be closed within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The inspectors verified that the redundant damper was closed within the required time. The inspectors observed the licensees repair and PM testing of CD-34197 to ensure that the damper was properly returned to service. On September 21, 2011, the licensee tested CD-34187 and CD-34188 which were used to protect equipment located on the 695 foot elevation of the auxiliary building from a HELB. During this testing CD-34187 closed, but gaps were identified between several damper blades. The licensee documented this condition in CAP 1304753. The inspectors verified that the licensee entered the appropriate TRM Action Statement and that the redundant damper (CD-34188) was closed within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . While performing maintenance activities on CD-34187 on September 22, 2011, the licensee identified that the blades of damper CD-34188 also contained gaps. As a result, the licensee could not credit the closure of CD-34188 to meet the TRM Action Statement. The licensee immediately installed a blind flange to ensure that safety-related equipment remained protected from a HELB event. The licensee documented this condition in CAP 1305151. Since both dampers contained gaps, the inspectors were concerned that the condition of the dampers could have constituted a safety system functional failure or could have resulted in an unintended safety system functional failure of equipment located in the auxiliary building. The licensee was continuing to review the inspectors concerns at the conclusion of the inspection period. As a result, this item will remain unresolved pending a review of documentation evaluating whether the safety-related equipment remained protected from HELBs even though both dampers contained gaps

05
Site:	Prairie Island
Report	IR 05000306/2011005 Section 3S03
Date counted	Dec 31, 2011 (2011Q4)
Type:	URI:
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71130.03
Inspectors (proximate)	C Moore C Thomas D Passehl D Szwarc J Beavers J Jandovitz K Riemer K Stoedter M Phalen P Zurawski R Langstaff V Myers A Dunlop A Shaikhr Bakers Bell D Mcneil D Oliver K Riemer K Stoedter M Phalen P Voss P Zurawski
INPO aspect
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v • d • e

Finding - Prairie Island - IR 05000306/2011005

2(4)3(13)4(9)5(9)6(0)7(0)8(0)9(0)10(1)11(0)12(2)201(0)202(0)403(1)404(0)405(2)406(0)502(1)14(0)

IR 05000306/2011005: 1 2 3 4 5 6 7 8 9

Finding List (Prairie Island) @ 2011Q4

CCA Matrix: 2011Q4

	Q	CCA	Title
05000282/FIN-2011002-04	2011Q1		Evaluation of Equipment Stored near Safety-Related Equipment
05000282/FIN-2011002-01	2011Q1	H.4 H.5	Flammable Gas Cylinders Stored in Safety-Related Area
05000282/FIN-2011002-02	2011Q1	P.3	Failure to Appropriately Complete an Operability Recommendation for the Unit 1 Battery Calculations
05000282/FIN-2011002-03	2011Q1	P.2	Failure to Appropriately Complete an Operability Recommendation on the Unit 1 Fuel Oil System
05000282/FIN-2011003-05	2011Q2		Evaluation of Equipment Stored near Safety-Related Equipment
05000282/FIN-2011403-01	2011Q2	H.8	Security
05000282/FIN-2011010-01	2011Q2		Failure to Ensure that the Train A and Train B DC Electrical Power Subsystems Remained Operable in Modes 1 through 4
05000282/FIN-2011003-10	2011Q2	H.5	Failure To Prescribe Appropriate Procedure For In-Service Testing of Check Valves
05000282/FIN-2011003-09	2011Q2	H.2	Alternate Methods Were Not Developed for Monitoring Inaccessible Susceptible Locations
05000282/FIN-2011003-08	2011Q2	P.5	Failure to Evaluate the Effects of Dynamic Loads at the CS Discharge Piping
05000282/FIN-2011003-07	2011Q2	P.5	GL 2008-01 Evaluations Did Not Adequately Verify the Design for Susceptible Locations of Gas Accumulation in Piping Systems
05000282/FIN-2011003-06	2011Q2		No Full Flow Testing of PORV Air Supply Check Valves
05000282/FIN-2011003-02	2011Q2		Failure to Assess the Impact of Changes in the Plants Isotopic Profile
05000282/FIN-2011003-01	2011Q2	H.2	Failure to Maintain Reactor Head Height/Distance Limitation From Reactor Vessel
05000282/FIN-2011502-01	2011Q2		Incomplete and Inaccurate Emergency Action Level Change Submittal
05000306/FIN-2011003-03	2011Q2		Unit 2 Reactor Trip during Severe Weather
05000306/FIN-2011003-04	2011Q2		Multiple SAMG Procedures not Consistent with Industry Guidance
05000306/FIN-2011004-01	2011Q3	H.14	Radiation Monitors Not Fully Scoped Into or Assessed by the Maintenance Rule Program
05000306/FIN-2011004-05	2011Q3		Failure to Incorporate Revised Battery Room Temperature Information into Existing Operability Recommendation
05000306/FIN-2011004-08	2011Q3	P.5	Unit 2 Reactor Trip due to Mis-operation of Substation Breakers
05000282/FIN-2011004-07	2011Q3		Failure to Provide Complete and Accurate Information in a Licensee Event Report
05000282/FIN-2011004-04	2011Q3	H.8	Failure to Make Eight Hour Report Pursuant to 10 CFR 50.72
05000306/FIN-2011004-02	2011Q3	H.8	Corrective Action Assignments Closed Without Completion of Tasks
05000306/FIN-2011004-06	2011Q3		Failure to Provide Complete and Accurate Information in a Licensee Event Report
05000306/FIN-2011004-03	2011Q3	H.8	Failure to Make Eight Hour Report Pursuant to 10 CFR 50.72
05000306/FIN-2011005-04	2011Q4	H.14	Failure to Complete Immediate Operability Determination on Molded Case Circuit Breakers
05000282/FIN-2011012-01	2011Q4		Flammable Gas Bottles Installed and/or Stored in the Auxiliary Building
05000282/FIN-2011012-02	2011Q4	H.13	Failure to Correct a Condition Adverse to Quality
05000306/FIN-2011005-01	2011Q4		Potential Technical Specification NON-COMPLIANCE While Completing Repairs on Motor Damper 32421
05000306/FIN-2011005-03	2011Q4		Potential Maintenance Rule Scoping Issue for Residual Heat Removal Pump Pit Sump Pumps and Level Switches
05000306/FIN-2011005-05	2011Q4		Potential Safety System Functional Failure Due to Steam Exclusion Damper Issues
05000306/FIN-2011005-02	2011Q4		Appendix R Fire Barrier Degraded Between Fire Areas 118 and 128
05000282/FIN-2011405-01	2011Q4	H.14	Security

Self-Identified List (Prairie Island)

	Q	Title
05000282/FIN-2011003-11	2011Q2	Licensee-Identified Violation
05000282/FIN-2011003-12	2011Q2	Licensee-Identified Violation
05000282/FIN-2011003-13	2011Q2	Licensee-Identified Violation
05000306/FIN-2011004-09	2011Q3	Licensee-Identified Violation
05000306/FIN-2011005-07	2011Q4	Licensee-Identified Violation
05000282/FIN-2011405-02	2011Q4	Security
05000306/FIN-2011005-06	2011Q4	Licensee-Identified Violation
05000306/FIN-2011005-08	2011Q4	Licensee-Identified Violation
05000306/FIN-2011005-09	2011Q4	Licensee-Identified Violation

[Prairie Island Findings full list]

05000306/FIN-2011005-05

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