ML20007D677

AP1000 Public Presentation Entitled Reactor Oversight Process (ROP) for Inspecting Vogtle Site with AP1000 Design

ML20007D677
Person / Time
Site:	Vogtle
Issue date:	01/08/2020
From:	Jeffrey Bream NRC/NRR/DRO/IRIB
To:
Bream J, 610-337-5212, NRR/DRO
References
Download: ML20007D677 (14)

Text

Reactor Oversight Process (ROP) for Inspecting Vogtle Site with AP1000 Design January 14 and 22, 2020 Public Meetings 1

The AP1000 passive design provides overall safety enhancements.

• Passive versus Active Components

• AC is not required for safe shutdown

• Elimination of safety-related motor operated valves

• Elimination of AC powered safety-related pumps

• Simpler Design - 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 />

• 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 2

Simpler design results in the need for an inspection sample range reassessment.

• 50% fewer safety-related valves

• 35% fewer pumps

• 80% less safety related piping

• 85% less control cable

• 45% less seismic building volume 3

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.

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Reactor Oversight Process Strategic Performance Areas Safety Cornerstones Baseline Inspection Performance Indicator Results Results Significance Significance Threshold Threshold Action Matrix Regulatory Response 5

The Cornerstones have supporting inspections.

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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 sample 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.

Evaluate Common Current Sample Programs 8

Inspection procedures are either individual or site wide, and samples were addressed accordingly.

Procedure Category Sample Size 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 sample size ranges in accordance with Inspection Manual Chapter 2515 Common Site-Wide Program BIPs Staff evaluated and adjusted, if necessary, the maximum sample size to provide an adequate number of samples across the two different designs 9

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 10

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 12 structure for the applicable programs.

The NRC review identified appropriate modifications to the baseline inspection program for the Vogtle site.

• The three step process considered current baseline, passive design, and co-location with an operating reactor.

• Appropriate sample sizes were identified for each inspection procedure to establish reasonable assurance of adequate protection.

• NRC identified inspection procedures for individual and site wide implementation.

Questions?

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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) 14