ML11090A091

Plant Hatch Fire Risk Monitoring

ML11090A091
Person / Time
Site:	Hatch
Issue date:	04/05/2011
From:	Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation
Bowen, Jeremy
Shared Package
ML11090A079	List: ML11090A087 ML11090A089 ML11090A091
References
NUMARC 93-01, Rev 4
Download: ML11090A091 (11)

Text

Plant Hatch -Fire Risk Monitoring Tabletop Pilot Process Primary objectives Identify Equipment Create Communications Plan Determination of Risk Impacts Provide Insights Process Lessons Learned

E.I. Hatch Fire Risk Equipment Identification Process

• Qualitative Evaluation of Fire Risk with regards to daily work planning was not considered

• Lack recently updated Fire PRA

• Only the equipment associated with the three H t h safe Hatch f shutdown h td paths th was considered id d forf Fire Risk monitoring

• Selected approach provides a qualitative look at the status of the equipment used to safely shut the plant down during and after a fire

• Does not explicitly address core damage or large early release

E.I. Hatch Fire Risk Equipment Identification Process Questions to address in process Will the selection of equipment be adequate to cover the requirements of (a)(4)?

Is the concept of only evaluating fire shutdown path equipment equipmentnot core damage---

damage ---acceptable?

acceptable?

How should we focus safe shutdown equipment list?

E.I. Hatch Fire Risk Equipment Identification Process (Component List)

A and B RHR pumps RCIC HPCI A and B RHR Service Water ppumps p

A and B Plant Service Water pumps SRVs A, C, G, and H Core Spray Diesel Generators Room Ventilation for RHR Service Water pumps and Plant Service Water Pumps and Diesel Generators.

Fire Risk Evaluation and RMA Basis Current process includes quantitative risk assessment plus defense defense--in in--depth status panel Monitoring of these components would be via the EOOS system (color coded qualitative approach) used at the site for work planning.

Preliminary plans are a logic model evaluating the availability of equipment and its effect on the 3 paths.

Risk Management Actions (RMA) based on a RMA decision tree would be implemented

Identification of Fire Scenarios A qualitative tree implemented within EOOS Used to Identify removal of critical SSCs needed for Safe Shutdown (SSD)

Determine number of paths available (A train versus B train)

Communication of RMAs The Plan of the Day will communicate areas with high fire risk impact.

In place of the roving fire watch Work directly related to shutdown paths will be acknowledged via a checklist.

Communication of RMAs Implement a list of actions based on possible safe shutdown degradation Work Planning should notify Fire Protection Engineering for any unanticipated cases Fire Protection Engineering evaluates if additional fire protection is merited/justified

Fire Protection Engineering Evaluation Fire Protection Engineering is best equipped to determine whether additional fire protection actions should be taken for any unanticipated cases Assessing Safe Shutdown paths at Work Planning Stage provides additional assurance of maintenance of safe shutdown capability

Insights/Lessons Learned Need thoughtful approach to combine qualitative approach with internal events model Fire Protection Program g needs to be credited when evaluating fire risk as part of (a)(4) program Need to develop method for addressing large number of critical fire areas when a safe shutdown path is impacted