ML19158A120
| ML19158A120 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/10/2019 |
| From: | Rafferty-Czincila S, Reynolds R, Sloane B Exelon Nuclear, Exelon Nuclear Generation Corp |
| To: | Office of Nuclear Reactor Regulation |
| Marhsall M, NRR/DORL/LPL, 415-2871 | |
| References | |
| Download: ML19158A120 (15) | |
Text
NMP 2 RICT & 50.69 LARs NRC Pre-submittal Meeting 6/10/19 Shannon Rafferty-Czincila Ron Reynolds Barry Sloane
Introduction
- Desired Meeting Outcomes
-Discuss license amendments
-Variances from TSTF-505-A Rev. 2
-Timeline for submittals
-PRA Technical Adequacy
-Evaluation of PRA uncertainties and assumptions
-External hazards
-Discuss efficiencies 1
Discuss License Amendments
-No deviation from LAR template (except seismic)
- RICT LAR based on TSTF-505-A Rev. 2
-New TS Section 6.0
-NMP2 is a BWR/5 reactor design
-TS markups follow TSTF for BWR/4
- Variances from TSTF-505
-NMP2 TS are ITS
-Variances from TSTF-505 are mostly nomenclature and section number sequencing
-TSTF-505 LCOs/Conditions not in NMP2 TS
-RICT added to plant-specific LCOs not in TSTF-505 2
Variances from TSTF-505 TSTF-505 LCOs/Conditions not in NMP2 TS
- TS 3.3.6.3 - Low-Low Set (LLS) Instrumentation
- TS 3.5.1.D.1 - HPCI System inoperable and Condition A entered.
- TS 3.6.1.7 - Reactor Building-to-Suppression Chamber Vacuum Breakers
- TS 3.6.3.1 - Drywell Cooling System Fans
- TS 3.7.1 - Residual Heat Removal Service Water (RHRSW) System
- TS 3.7.2.B - One [PSW] Pump in each subsystem inoperable
- TS 3.7.2.C - One or more cooling towers with one cooling tower fan inoperable 3
Variances from TSTF-505 (contd)
TSTF-505 LCOs/Conditions not in NMP2 TS
- TS 3.8.1.F - [One [required] [automatic load sequencer]
- TS 3.8.4.A.3 - One [or two] battery chargers on one division inoperable
- TS 3.8.4.C - One DC electrical power subsystem inoperable 4
Variances from TSTF-505 (contd)
TSTF-505 LCOs/Conditions added but not in TSTF-505
- TS 3.3.7.2 - Mechanical vacuum Pump instrumentation
- TS 3.6.1.4 - Drywell and suppression Chamber Pressure
- TS 3.6.1.5 - Drywell Air Temperature
- TS 3.6.1.6 - Residual Heat Removal (RHR) Drywell Spray System
- TS 3.6.2.1 - Suppression Pool Average Temperature
- TS 3.6.2.2 - Suppression Pool Water Level
- TS 3.6.2.3 - Residual Heat Removal (RHR) Suppression Pool Cooling
- TS 3.6.2.4 - Residual Heat Removal (RHR) Suppression Pool Spray 5
Time Line for Submittal NMP 2 - 50.69 and RICT LARs
- Submittal will consist of 2 separate applications
- Submittal on the same day (or close to same day)
- End of July, Beginning of August.
6
PRA Tech Adequacy
- Closure review performed
- 3 resolved but not closed Finding F&Os (will be closed in 2019 model update)
- Closure review performed
- No Open Finding F&Os
- NRC observed F&O closure and Final report (Feb 2019 and May 2019, respectively) 7
Evaluation of PRA Uncertainties and Assumptions
- Both NMP2 submittals will follow the process defined in NUREG 1855 Rev. 1, and the guidance in EPRI 1016737 and EPRI 1026511, including:
- Identification of Internal events/internal flooding PRA model plant-specific sources, and generic sources per EPRI 1016737
- Identification of Internal Fire PRA model plant-specific sources, and generic sources per Appendix B of EPRI 1026511
- Consideration of generic Level 2 model sources per Appendix E of EPRI 1026511, as applicable to LERF
- Assessment of potential sources that are key to the respective applications, and disposition or treatment for the application
- Consideration of Parameter and Completeness uncertainties 8
External Hazards Screening Process
- IPEEE Initial Screening
- Reviewed Current Hazard Information
- Updated Analysis Using Part 6 Screening Criteria of ASME/ANS PRA Standard RA-Sa-2009
- Performed conservative or bounding analyses where appropriate
- Justify exclusion of external risk sources from the PRA models based on their insignificance to the calculation of configuration risk
- 50.69 - Incorporates NEI 00-04 guidance Figure 5-6, Other External Hazards
- Seismic will use EPRI alternative approach (TR 3002012988) for Tier 1 plants 9
External Hazards - Flooding
- Screens Out
- Event damage potential is < events for which plant is designed (C1)
- Design basis for the event meets the criteria in the NRC 1975 Standard Review Plan (PS2)
- Note: for 50.69 - Several personnel doors are credited to screen out local intense precipitation
- These doors will be treated as HSS per NEI 00-04 Figure 5-6 10
External Hazards - Extreme Wind or Tornado / Missiles
- Screens Out
- Event Damage Potential Is < Events For Which Plant Is Designed (C1)
-50.69 - No SSCS Credited to Screen Except for Seismic Category I Structures (HSS) 11
External Hazards - Seismic
- Not Screened
- Seismic hazard is relatively low
- 50.69 - Has SMA SSEL if needed, but will submit as an EPRI Seismic Alternative Tier 1 Plant For 50.69 Tier 1 - GMRS peak acceleration derived from the seismic hazard is at or below 0.2g or where the GMRS is below or equal to the SSE between 1.0 Hz and 10 Hz.
NMP2 meets this second criteria and only slightly exceeds the first criteria (0.2g) above 7 Hz.
12
Efficiencies
- Overlaps in level of PRA acceptability in applications 13
Efficiencies
- 50.69 - No deviation from LAR template (except seismic)
- Common assessment of PRA technical adequacy and sources of uncertainty for both applications
- Assessments are application-specific but related in terms of details to be considered
- External Hazards
- Common screening of hazards that can be screened
- Application-specific assessment of screening impact but related in terms of details to be considered
- Same PRA teams reviewing common information 14