ML13269A005
| ML13269A005 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 09/26/2013 |
| From: | Baradaran R, Schrader K, Shepard M Pacific Gas & Electric Co |
| To: | Office of Nuclear Reactor Regulation |
| Rankin J | |
| References | |
| TAC MF2632, TAC MF2633 | |
| Download: ML13269A005 (18) | |
Text
11 DIABLO CANYON POWER PLANT Pre-application Meeting, Risk-Informed Technical Specification Completion Times (TSTF-505)
License Amendment Request September 26, 2013 Rasool Baradaran Engineering Supervisor, PRA Pacific Gas & Electric Co.
rubd@pge.com 805-545-3132 Ken Schrader Regulatory Services Pacific Gas & Electric Co.
kjse@pge.com 805-545-4328 Matthew Shepard PRA Pacific Gas & Electric Co.
m6s7@pge.com 805-545-4546
2 Agenda
License Amendment Request (LAR) scope and schedule
Plant-specific design TS changes
Correction of TSTF-505 editorial errors
Summary of the Diablo Canyon probabilistic risk assessment model
Implementation of risk-informed completion times
Station Training and Communication
Staff Feedback
3 LAR scope and schedule
PG&E plans to submit TSTF-505 LAR in Fourth Quarter 2013 and request approval within one year
Scope of changes will include components directly modeled in PRA or via an appropriate surrogate
Only TSTF-505 scope systems are being proposed (there are a few Diablo Canyon plant specific TS conditions evaluated)
4 Plant-specific design TS changes (not part of standard TS)
Plant-specific Limiting Conditions for Operations proposed to apply the risk-informed TS completion time (RICT)
TS 3.3.2 Function 6.D.2 (Condition M) for SG Water Level - Low Low Trip Time Delay
TS 3.3.2 Function 7 Condition K for RHR pump trip on Refueling Water Storage Tank Level - Low
TS 3.6.6 for Containment Sprays and Containment Fan Cooling Units (CFCUs)
Appropriate surrogates to be used
5 Plant-specific design TS changes
TS 3.3.2 Function 6.D.2 (Condition M) for SG Water Level - Low Low Trip Time Delay
For the Required Action M.2 to place affected channel in trip
SG Water Level - Low Low Trip Time Delay is a plant-specific AFW actuation function not contained in the Standard TS or TSTF-505
TS 3.3.2 Condition M required action to place affected channel in trip similar to other engineered safety feature actuation system (ESFAS) TS Actions to place channel in trip
6 Plant-specific design TS changes
TS 3.3.2 Function 7 Condition K for RHR pump trip on Refueling Water Storage Tank Level (RWST) - Low
For the Required Action K.1.2 to return channel to operable status
RHR pump trip on RWST Level - Low is a plant-specific function not contained in the Standard TS or TSTF-505
TS 3.3.2 Condition K required action to return channel to operable status similar to other ESFAS TS Actions to return channel to operable status
7 Plant-specific design TS changes
TS 3.6.6 for Containment Sprays and Containment Fan Cooling Units (CFCUs)
Add a plant specific Condition to address additional combinations of inoperable spray and CFCUs
Diablo Canyon design has five CFCUs so Tech Specs have additional combinations of containment sprays and CFCUs inoperable
TS 3.6.6 Condition applying the RICT to the action to restore the inoperable equipment to operable status similar to other containment cooling TS Actions to return channel to operable status
8 Plant-specific design TS changes
For TS 3.3.1 Conditions, proper use of "channels", "trains", etc. (TS various) consistent with use of "channels" and "trains" in Diablo Canyon TS Table 3.3.1-1 and Conditions
Diablo Canyon TS Table 3.3.1-1 uses trains instead of channels for Functions 17 (SI input from ESFAS), 18.b (interlock for low power reactor trips block, P-7), 19 (reactor trip breakers), and 21 (automatic trip logic)
9 TSTF-505 generic issues
Several generic TSTF-505 editorial issues will be identified and corrected
Missing conditions for "two or more channels inoperable" for some Functions (TS 3.3.1 Function 6 - 10, 12 - 14, 17, 19 - 21)
TS structure of TS 3.5.1, Accumulators, Required Action D.1 and D.2 shutdown actions
TS 3.7.2.C.1 mode 3 shutdown not correct
10 10 PRA model
Current model consists of Internal Events, Internal Flooding, Seismic, and Fire
NFPA-805 LAR submitted June 26, 2013
Shutdown modes will not be included in LAR scope (no plant specific shutdown model at this time)
11 11 PRA model
Diablo PRA developed and peer reviewed against Capability Category II per ASME/ANS PRA standard (ASME/ANS RA-Sa-2009) and RG 1.200, Rev. 2
Peer review findings/observations have either been closed or will be addressed in the LAR with a resolution path identified with respect to RMTS application
PRA model is under configuration control with approved procedures for periodic and immediate updating to reflect as-built, as-operated station
12 12 PRA model
Seismic PRA Model
Regulatory Guide 1.200, Revision 2 peer reviewed in January 2013
Peer review resulted in 61 Findings and Observations with 5 best practices, 19 suggestions and 37 findings
Seismic PRA model update in progress and scheduled to complete within the time frame required for the Fukushima 2.1 response
Significant progress made on the seismic hazard (SSHAC Level 3 review in progress)
Structural analysis and SSC fragilities in progress
13 13 Fire impact on RICT calculations
NFPA-805 fire model credits several future plant changes to reduce fire risk
Incipient fire detection added within cable spreading and Solid State Protections System (SSPS) rooms in cabinets
Safe Shutdown Reactor Coolant Pump (RCP) seals (or alternate seal cooling methods)
Hot shutdown panel modifications
Additional fire wrap and cable rerouting
14 14 Fire impact on RICT calculations
Interim fire risk comp. measures in place until NFPA-805 modifications complete
For the incipient detection, additional fire wrap, cable rerouting and hot shutdown panel modifications, the following fire compensatory measures will be taken in the interim during use of a RICT:
A continuous fire watch will be stationed in the cable spreading and SSPS rooms.
Welding and cutting will be prohibited in fire-areas pre-identified for each RICT
15 15 Fire impact on RICT calculations
For the safe shutdown RCP seals, the credit for these seals will be removed from the CRMP model used to calculate RICTs, till this modification or an alternate modification is in place
16 16 PRA model
Configuration Risk Calculations
Riskman software used for PRA quantification and model development
EPRI Phoenix Risk Monitor will be used for Risk Managed Tech Specs, Configuration Risk Management Program (CRMP), and RICT/RMAT calculations
Maintenance Rule (a)(4) plans to use same calculation method and tool for non-RMTS conditions
17 17 Risk-Informed Technical Specification Completion Times
The Risk-informed TS Completion Time processes and technical approach to be structured similar to South Texas Project (Operations/Work Control centered)
Software tools and procedures will be implemented to ensure compliance with requirements
Organization and position specific training and communication plan established to appropriately train plant staff
18 18 18 Staff Feedback
Thank you
Any questions?