ML20021A314
| ML20021A314 | |
| Person / Time | |
|---|---|
| Issue date: | 01/21/2020 |
| From: | Shawn Campbell NRC/NRR/DRO/IRIB |
| To: | |
| Campbell S, 415-3353, NRR/DRO | |
| References | |
| Download: ML20021A314 (15) | |
Text
Reactor Oversight Process (ROP) for Inspecting Vogtle Site with AP1000 Design January 22, 2020 Public Meeting 1
Key Messages
- The AP1000 has fewer components, a passive and simpler design, leading to enhanced safety over the reactors in the current fleet.
- The staff applied the same rationale for determining sample sizes for inspection and used a multi-step process to evaluate and adjust Inspection Procedure sample sizes commensurate with the design and colocation with Vogtle Units 1 and 2.
- The AP1000 ROP inspection process will be robust, similar to the ROP for current operating plants; including resident and regional inspectors implementing a similar suite of oversight activities.
2
NRC Performance Goals
- Safety: Ensure adequate protection of public health and safety and the environment.
- Security: Ensure adequate protection in the secure use and management of radioactive materials.
3
Reactor Oversight Process Safety Cornerstones Baseline Inspection Results Significance Threshold Action Matrix Significance Threshold Performance Indicator Results Regulatory Response Strategic Performance Areas Safety Cornerstones Baseline Inspection Results Significance Threshold Action Matrix Significance Threshold Performance Indicator Results Regulatory Response Strategic Performance Areas 4
The Cornerstones have supporting inspections.
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The AP1000 passive design provides overall safety enhancements.
6 Image of AP1000' - Westinghouse Nuclear The above illustration is an artist rendering and may not depict actual design and layout Passive versus Active Components AC power is not required for safe shutdown No need for human interaction for the first 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Operator action is not required for safe shutdown Elimination of safety-related motor operated valves Elimination of AC powered safety-related pumps Uses natural forces such as gravity, convection and condensation cooling
Simpler design results in the need for an inspection procedure reassessment.
7
Inspection oversight for Units 3 and 4 considers current inspection at Units 1 and 2 8
U 3
4 U
1 2
Image of Vogtle 1-4, Waynesboro Georgia - Georgia Power, A Southern Company http://www.multivu.com/players/English/7464951-ga-power-project-vogtle/
9 NRC used a three step process to determine proposed inspection sizes.
- Began with the current Minimum, Nominal, and Maximum sample sizes and existing guidance for sample size adjustment for conventional plants in all procedures.
Current Procedures
- Assess unique aspects of the passive technology
- Overall component numbers and accessibility.
New Technology
- Assess for common programs across the site due to colocation with conventional plant.
Evaluate Common Programs
Inspection procedures are either individual or site wide, and ranges were addressed accordingly.
Procedure Category Analysis Individual Reactor Safety Baseline Inspection Procedures (BIPs)
Staff used technology specific component analysis and risk information inherent from the design of the two AP1000 units to develop inspection ranges in accordance with Inspection Manual Chapter 2515 Common Site-Wide Program BIPs Staff evaluated and adjusted, if necessary, the maximum inspection range to provide an adequate number of samples across the two different designs 10
Example of changes to BIPs which are conducted on 2-Unit PWR and 2-Unit AP1000 independently.
IP 71111.22 Surveillance Testing - Design Specific 17 7
BIP Nominal Samples Current 2-Unit AP1000 2-Unit IP 71111.11 Licensed Operator Requalification and Performance - Design Independent 8
8 BIP Nominal Samples Current 2-Unit AP1000 2-Unit 11
Example of BIPs which are conducted as 4 unit site:
Vogtle Site Common Engineering Inspections.
71111.21N.02 Design Basis Capability of Power Operated Valves
- Current BIP sample range is 8-12 for existing units
- Staff assessment of AP1000 identified BIP sample range of 3-5
- Increase BIP sample maximum to 16 samples for Vogtle site with samples from all 4 units.
71111.21M Design Basis Assurance
- Will require separate samples from Units 1&2 and Units 3&4 but existing maximum sample size is sufficient to account for all units.
- Vogtle inspection at maximum sample size.
- No change to baseline inspection.
12
The staff has identified the number of samples for U3&4 based on the number of AP1000 components, risk characteristics, and co-location on an existing site.
Individual BIP Site Wide BIP 181 51 Nominal Inspection Samples for Units 1&2 Individual BIP Site Wide BIP 79 25 Additional Nominal Inspection Samples for Units 3&4 13 Subject to additional NRC evaluation of Vogtle Site organizational structure for the applicable programs.
Key Messages
- The AP1000 has fewer components, a passive and simpler design, leading to enhanced safety over the reactors in the current fleet.
- The staff applied the same rationale for determining sample sizes for inspection and used a multi-step process to evaluate and adjust Inspection Procedure sample sizes commensurate with the design and colocation with Vogtle Units 1 and 2.
- The AP1000 ROP inspection process will be robust, similar to the ROP for current operating plants; including resident and regional inspectors implementing a similar suite of oversight activities.
Questions?
14
Reference Sources
- Reactor Oversight Process
- https://www.nrc.gov/reactors/operating/oversight.html Public Electronic Reading Room
- http://www.nrc.gov/reading-rm.html Public Document Room 800-397-4209 (Toll Free) 15