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 Strategic Performance Areas Safety Cornerstones Baseline Inspection Performance Indicator Results Results Significance Significance Threshold Threshold Action Matrix Regulatory Response 4
The Cornerstones have supporting inspections.
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The AP1000 passive design provides overall safety enhancements.
- 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 Image of AP1000' - Westinghouse Nuclear The above illustration is an artist rendering and may not depict actual design and layout 6
Simpler design results in the need for an inspection procedure reassessment.
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Inspection oversight for Units 3 and 4 considers current inspection at Units 1 and 2 U
3 U
& 1 4 &
2 Image of Vogtle 1-4, Waynesboro Georgia - Georgia Power, A Southern Company http://www.multivu.com/players/English/7464951-ga-power-project-vogtle/
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NRC used a three step process to determine proposed inspection sizes.
New Technology
- Began with the current
- Assess for common Minimum, Nominal, and programs across the site due Maximum sample sizes and
- Assess unique aspects of the to colocation with existing guidance for sample passive technology conventional plant.
size adjustment for
- Overall component numbers conventional plants in all and accessibility.
procedures.
Current Evaluate Common Procedures Programs 9
Inspection procedures are either individual or site wide, and ranges were addressed accordingly.
Procedure Category Analysis Individual Reactor Safety Baseline Staff used technology specific component Inspection Procedures (BIPs) 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 IP 71111.11 Licensed Operator Requalification Specific and Performance - Design Independent BIP Nominal Samples BIP Nominal Samples 17 7 8 8 Current 2-Unit AP1000 2-Unit 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 71111.21M Design Basis Assurance Capability of Power Operated Valves
- Current BIP sample range is
- Will require separate 8-12 for existing units samples from Units 1&2 and
- Staff assessment of AP1000 Units 3&4 but existing identified BIP sample range maximum sample size is of 3-5 sufficient to account for all
- Increase BIP sample units.
maximum to 16 samples for
- Vogtle inspection at Vogtle site with samples maximum sample size.
from all 4 units.
- No change to baseline inspection.
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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.
Nominal Inspection Samples for Additional Nominal Inspection Units 1&2 Samples for Units 3&4 181 79 51 25 Individual BIP Site Wide BIP Individual BIP Site Wide BIP Subject to additional NRC evaluation of Vogtle Site organizational 13 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