05000259/FIN-2010004-01

Finding

Title

Uncontrolled Materials Adversely Impacted the Capability of the EDG Building Emergency Drainage System to Mitigate an Internal Flooding Event

Description

The inspectors identified an unresolved item (URI) regarding a variety of materials left unattended, unanchored and improperly stored in the lower corridors of both of the Unit 1/2 and Unit 3 EDG buildings that could have adversely impacted the capability of the emergency drainage systems credited in the licensees internal flooding analysis for these buildings. During an internal flood protection walk-down of the Unit 1 and 2 EDG building, and the Unit 3 EDG building, the inspectors identified unattended and loose materials in the lower corridors that contain the EECW North and South supply header piping. The inspectors observed a 24-inch emergency drain in the Unit 1/2 EDG building lower corridor located in the Southwest corner. This drain emptied into the yard area just west of the Unit 1/2 EDG building and was shown on drawing 0-47E851-1, Rev. 29. In addition, the inspectors observed two 18-inch drains in the Unit 3 DG building lower corridor floor. These drains emptied into the yard area just east of the Unit 3 DG building and were shown on drawing 0-47E851-4, Rev. 13. The uncontrolled materials identified by the inspectors were of sufficient type and quantity to potentially obstruct the lower corridor emergency drains that were designed to mitigate the consequences of an internal flood due to the rupture of an EECW header. Furthermore, none of the doors that provide access to the four EDG rooms from the lower corridor were designed to be watertight. The inspectors reviewed the licensees Probabilistic Risk Analysis (PRA) for Internal Flooding as described in calculation number NDN-000-999-2007-0031, Rev 0. This analysis stated Flooding in the diesel-generator buildings could result from failure of the EECW headers that pass through the buildings. The diesel-generator buildings, however, are provided with a 24-inch emergency drain in the wall that empties into a culvert in the yard. It further states The common [i.e.- Unit 1/2 ] diesel generator building corridor has sump pumps and 24-inch drains. These are adequate to mitigate floods and major floods in the common corridors, so only one DG can be impacted by a flood. In the summary of qualitative screening results, the licensee concluded that a flood in the DG building lower corridor would result in no submergence due to large drains and no impacted SSCs. The inspectors also reviewed the licensees detailed design criteria document for the diesel generators, BFN-50-7082, Rev. 15. Section 3.7.4 stated that the EDG units shall be located in separate rooms to ensure that flooding, resulting from a postulated failure in the pressure boundary of any water systems, would not prevent the standby DG system from performing its safe shutdown function. The licensee initiated PER 256390 to evaluate the impact of the loose materials on the function of the EDG building lower corridor emergency drains. Additionally, the licensee removed the materials from the EDG buildings and added a daily requirement for the auxiliary unit operators (AUOs) to verify no unattended loose material in the EDG buildings lower corridors. This issue is unresolved pending further inspection to determine more specifically the adverse impact of the improperly stored materials in the EDG building lower corridors upon the drainage system, the availability and capability of other internal flooding mitigation features (e.g., sump level alarms), and the current licensing basis for moderate energy line breaks (MELB) in the EDG buildings. The URI for this issue is identified as 05000259, 260, and 296/2010004-01, Uncontrolled Materials Adversely Impacted the Capability of the EDG Building Emergency Drainage System to Mitigate an Internal Flooding Event.

01
Site:	Browns Ferry
Report	IR 05000259/2010004 Section 1R06
Date counted	Sep 30, 2010 (2010Q3)
Type:	URI:
cornerstone	Mitigating Systems
Identified by:	NRC identified
Inspection Procedure:	IP 71111.06
Inspectors (proximate)	E Guthrie J Eargle J Hamman J Wray L Jarriel L Pressley M Pribish P Niebaum R Williams S Walker T Ross W Deschaine C Fletcher C Kontz C Stancilt Rosse Guthrie S Walker M Pribish J Hamman C Kontz C Fletcher P Niebaum R Williams J Eargle L Pressley W Deschaine J Wray L Jarriel C Stancila Rogersc Kontz C Stancil E Guthrie E Lea G Johnson J Wray L Jarriel L Pressley M King P Niebaum R Baldwin T Ross
INPO aspect
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v • d • e

Finding - Browns Ferry - IR 05000259/2010004

2(8)3(0)4(7)5(3)6(6)8(0)201(0)301(0)402(0)502(0)14(0)

IR 05000259/2010004: 1 2 3 4 5 6 7

Finding List (Browns Ferry) @ 2010Q3

CCA Matrix: 2010Q3

	Q	CCA	Title
05000259/FIN-2009005-01	2009Q4	P.2	Failure to Report an Automatic RPS Actuation While Shutdown Per 10 CFR 50.73
05000259/FIN-2009005-03	2009Q4	H.7	Inadequate Operating Procedures Cause Partial Loss of Reactor Feedwater Which Results In Unit 2 Manual Reactor Scram
05000259/FIN-2009008-02	2009Q4		Violation of 10CFR50, Appendix B, Criterion V for Inadequate Procedure for Emergency Equipment Cooling Water System Flow Balancing
05000259/FIN-2009008-01	2009Q4	P.5	Violation of Technical Specification 5.4.1 for Failure to Develop Adequate Procedures to Ensure Tornado Depressurization Protection of the Emergency Diesel Generators
05000259/FIN-2009005-04	2009Q4	P.1 P.1(a)	Unit 2 RCIC System Inoperable Beyond the Technical Specification Allowed Outage Time
05000259/FIN-2009009-02	2009Q4	H.5	Failure to Establish Adequate Compensatory Measures for an Out-of-Service Hose Station
05000259/FIN-2009009-01	2009Q4	H.5	Deficiencies with Emergency Lighting Units
05000259/FIN-2009008-03	2009Q4		Safety-Related Molded Case Circuit Breakers
05000259/FIN-2009009-04	2009Q4	P.2	Failure to Meet the Requirements of 10 CFR Part 50, Appendix R, Section III.G.1 for 20 Fire Areas
05000259/FIN-2009009-03	2009Q4	P.3	Failure to Protect Cables of Systems Necessary to Achieve and/or Maintain Post-Fire Safe Shutdown Conditions for Fire Areas Subject to the Requirements of 10 CFR Part 50, Appendix R, Section III.G.2
05000259/FIN-2009005-02	2009Q4	P.3	Failure to Report a Safety System Functional Failure Per 10 CFR 50.73
05000259/FIN-2010002-02	2010Q1	H.8	New Fuel Receipt Inspection and Refueling Operations Supervised By Non-qualified Senior Reactor Operators
05000259/FIN-2010002-03	2010Q1	H.12	Operators Failed to Correctly Monitor and Assess RPV Beltline Temperatures During RPV Hydrostatic/In-service Leak Test
05000259/FIN-2010002-04	2010Q1	H.7	Inadequate Surveillance Procedure To Ensure All Relevant RPV Metal Temperatures Were Monitored During RPV Hydrostatic/In-service Leak Testing
05000259/FIN-2010002-01	2010Q1	P.2	Failure to Effectively Maintain Performance of the A3 EECW Pump as Required by 10 CFR 50.65(a)(2)
05000259/FIN-2010002-05	2010Q1	P.3	Untimely Corrective Actions to Restore Compliance of EECW Pump In-Service Testing with ASME OM Code Requirements
05000259/FIN-2010004-01	2010Q3		Uncontrolled Materials Adversely Impacted the Capability of the EDG Building Emergency Drainage System to Mitigate an Internal Flooding Event
05000259/FIN-2010004-04	2010Q3	P.2	Failure to Perform Functional Evaluations for Gas Identified During Venting
05000259/FIN-2010006-04	2010Q3	P.3	Failure to Correct a Condition Adverse to Quality Associated Cooling Water Flow Degradation in the 1B Core Spray Room Cooler
05000259/FIN-2010006-01	2010Q3	P.2	Failure To Correct The EECW Valves Throttled Below Analyzed Condition
05000259/FIN-2010006-03	2010Q3	P.3	Failure to Correct a Condition Adverse to Quality Associated with the 2D Residual Heat Removal (RHR) Room Cooler
05000259/FIN-2010006-05	2010Q3	H.7	Failure to maintain an Adequate Surveillance Procedure to Prevent an Unplanned HPCI Isolation
05000259/FIN-2010006-06	2010Q3	H.7	Inadequate Maintenance Procedure for Siemens Horizontal Vacuum Circuit Breakers Circuit Breakers
05000259/FIN-2010004-02	2010Q3	H.8	Failure to Adequately Assess Online Risk Associated With Maintenance Activities on Risk Significant SSCs
05000259/FIN-2010006-02	2010Q3	H.8	Failure to Implement the Provisions of Preventative Maintenance (PM) Program Which Contributed to a Manual Reactor Scram
05000259/FIN-2010004-03	2010Q3	P.3	Failure to Adequately Test Molded Case Circuit Breakers

Self-Identified List (Browns Ferry)

	Q	Title
05000259/FIN-2009008-04	2009Q4	Licensee-Identified Violation
05000259/FIN-2010002-07	2010Q1	Licensee-Identified Violation
05000259/FIN-2010002-06	2010Q1	Licensee-Identified Violation
05000259/FIN-2010002-08	2010Q1	Licensee-Identified Violation
05000259/FIN-2010004-05	2010Q3	Licensee-Identified Violation
05000259/FIN-2010004-06	2010Q3	Licensee-Identified Violation
05000259/FIN-2010004-07	2010Q3	Licensee-Identified Violation

[Browns Ferry Findings full list]

05000259/FIN-2010004-01

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