ML11090A091
| 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: |
| References | |
| NUMARC 93-01, Rev 4 | |
| Download: ML11090A091 (11) | |
Text
Plant Hatch Plant Hatch --Fire Risk Monitoring Fire Risk Monitoring
Tabletop Pilot Process Tabletop Pilot Process Primary objectives Primary objectives Identify Equipment Identify Equipment Create Communications Plan Create Communications Plan Determination of Risk Impacts Determination of Risk Impacts Determination of Risk Impacts Determination of Risk Impacts Provide Insights Provide Insights Process Process Lessons Learned Lessons Learned
E.I. Hatch Fire Risk Equipment E.I. Hatch Fire Risk Equipment Identification Process Identification Process
- Qualitative Evaluation of Fire Risk with regards Qualitative Evaluation of Fire Risk with regards to daily work planning was not considered to daily work planning was not considered
- Only the equipment associated with the three Only the equipment associated with the three H t h f
h td th id d f H t h f
h td th id d f Hatch safe shutdown paths was considered for Hatch safe shutdown paths was considered for Fire Risk monitoring Fire Risk monitoring
- Selected approach provides a qualitative look Selected approach provides a qualitative look at the status of the equipment used to safely at the status of the equipment used to safely shut the plant down during and after a fire shut the plant down during and after a fire
- Does not explicitly address core damage or large Does not explicitly address core damage or large early release early release
E.I. Hatch Fire Risk Equipment E.I. Hatch Fire Risk Equipment Identification Process Identification Process Questions to address in process Questions to address in process Will the selection of equipment be Will the selection of equipment be adequate to cover the requirements of adequate to cover the requirements of (a)(4)?
(a)(4)?
(a)(4)?
(a)(4)?
Is the concept of only evaluating fire Is the concept of only evaluating fire shutdown path equipment shutdown path equipment not core not core damage damage---
---acceptable?
acceptable?
How should we focus safe shutdown How should we focus safe shutdown equipment list?
equipment list?
E.I. Hatch Fire Risk Equipment E.I. Hatch Fire Risk Equipment Identification Process (Component List)
Identification Process (Component List)
A and B RHR pumps A and B RHR pumps RCIC RCIC HPCI HPCI A and B RHR Service Water pumps A and B RHR Service Water pumps p
p p
p A and B Plant Service Water pumps A and B Plant Service Water pumps SRVs A, C, G, and H SRVs A, C, G, and H Core Spray Core Spray Diesel Generators Diesel Generators Room Ventilation for RHR Service Water pumps Room Ventilation for RHR Service Water pumps and Plant Service Water Pumps and Diesel and Plant Service Water Pumps and Diesel Generators.
Generators.
Fire Risk Evaluation and RMA Fire Risk Evaluation and RMA Basis Basis Current process includes quantitative risk Current process includes quantitative risk assessment plus defense assessment plus defense--inin--depth status panel depth status panel Monitoring of these components would be via the Monitoring of these components would be via the EOOS system (color coded qualitative approach)
EOOS system (color coded qualitative approach)
EOOS system (color coded qualitative approach)
EOOS system (color coded qualitative approach) used at the site for work planning.
used at the site for work planning.
Preliminary plans are a logic model evaluating the Preliminary plans are a logic model evaluating the availability of equipment and its effect on the 3 availability of equipment and its effect on the 3 paths.
paths.
Risk Management Actions (RMA) based on a RMA Risk Management Actions (RMA) based on a RMA decision tree would be implemented decision tree would be implemented
Identification of Fire Scenarios Identification of Fire Scenarios A qualitative tree implemented within A qualitative tree implemented within EOOS EOOS Used to Identify removal of critical SSCs Used to Identify removal of critical SSCs needed for Safe Shutdown (SSD) needed for Safe Shutdown (SSD) needed for Safe Shutdown (SSD) needed for Safe Shutdown (SSD)
Determine number of paths available (A Determine number of paths available (A train versus B train) train versus B train)
Communication of RMAs Communication of RMAs The Plan of the Day will communicate The Plan of the Day will communicate areas with high fire risk impact.
areas with high fire risk impact.
In place of the roving fire watch In place of the roving fire watch Work directly related to shutdown Work directly related to shutdown paths will be acknowledged via a paths will be acknowledged via a checklist.
checklist.
Communication of RMAs Communication of RMAs Implement a list of actions based on Implement a list of actions based on possible safe shutdown degradation possible safe shutdown degradation Work Planning should notify Fire Work Planning should notify Fire Protection Engineering for any Protection Engineering for any unanticipated cases unanticipated cases Fire Protection Engineering evaluates if Fire Protection Engineering evaluates if additional fire protection is additional fire protection is merited/justified merited/justified
Fire Protection Engineering Fire Protection Engineering Evaluation Evaluation Fire Protection Engineering is best equipped Fire Protection Engineering is best equipped to determine whether additional fire to determine whether additional fire protection actions should be taken for any protection actions should be taken for any unanticipated cases unanticipated cases unanticipated cases unanticipated cases Assessing Safe Shutdown paths at Work Assessing Safe Shutdown paths at Work Planning Stage provides additional Planning Stage provides additional assurance of maintenance of safe shutdown assurance of maintenance of safe shutdown capability capability
Insights/Lessons Learned Insights/Lessons Learned Need thoughtful approach to combine Need thoughtful approach to combine qualitative approach with internal events qualitative approach with internal events model model Fire Protection Program needs to be Fire Protection Program needs to be g
credited when evaluating fire risk as part of credited when evaluating fire risk as part of (a)(4) program (a)(4) program Need to develop method for addressing Need to develop method for addressing large number of critical fire areas when a large number of critical fire areas when a safe shutdown path safe shutdown path is impacted is impacted