ML20092F574

TVA Slides for Browns Ferry 50.69 License Amendment Request Presubmittal Meeting

ML20092F574
Person / Time
Site:	Browns Ferry
Issue date:	04/02/2020
From:	Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
References
Download: ML20092F574 (19)

Text

Browns Ferry Nuclear Plant Units 1, 2 and 3 Adoption of 10 CFR 50.69 April 2, 2020

Agenda

• 10 CFR 50.69 Background

• License Amendment Background

• Operating Experience

• Browns Ferry 50.69 Evaluation Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 2

10 CFR 50.69 Overview High Safety Reduce Significant Burden Areas It has the potential to provide the industry substantial cost savings Low Safety and drive the goals of Significant Increase Areas Focus the Delivering the Nuclear Promise Initiative From NEI Risk Informed Engineering Programs Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 3

Overview - Categorization Safety Related Low Risk 50.69 High Risk Non Safety Related From NEI Risk Informed Engineering Programs Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 4

Overview - Exempted Special Treatment Requirements From NEI Risk Informed Engineering Programs Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 5

License Amendment Background

• Delivering the Nuclear Promise Efficiency Bulletins (EB)

EB 17-09 LAR Submittal LAR Template EB 17-16 Process Implementation

• LAR Coordinating Committee Peer review prior to submittal Comments resolved prior to submittal Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 6

License Amendment Background - cont.

• Joint Owners Group Committee Collaboration Sharing Infrastructure Training Information Sharing Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 7

Operating Experience

• TVA has submitted 50.69 LARs for Sequoyah (Approved) and Watts Bar (In Review)

• NRC to date, 14 plants have received regulatory approval to adopt 50.69 into their operating licensing, including TVAs Sequoyah plant

• TVA has performed benchmarking with several utilities PLACE THE TITLE OF THE PRESENTATION HERE l 8

BFN 50.69 Evaluation PLACE THE TITLE OF THE PRESENTATION HERE l 9

HSS Component Determination Overview Determination of High Safety Significant (HSS)

Components for Indicated Events/Hazards

- Internal Events, Risk Imp. Measures & Sensitivity Studies

- Internal Flooding, Risk Imp. Measures & Sensitivity Studies

- Seismic Events, Risk Imp. Measures & Sensitivity Studies

- Internal Fire Risk, Risk Imp. Measures & Sensitivity Studies

- Other External Hazards, any System, Structure or Component (SSC) Credited by the IPEEE to Screen the Hazard

- Shutdown Risks, Key Safety Function Defense-In Depth Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 10

PRA Technical Adequacy Evaluation Internal Events & Internal Flooding PRA Models

- Peer reviewed in accordance with RG 1.200 Rev. 2 and ASME/ANS PRA Standard (2008) Addendum a

- Underwent Fact and Observation (F&O) Closure Process

- Ten Internal Events Open F&Os (Finding Level) which were assessed against the 50.69 application

- Eight Internal Flooding Open F&Os (Finding Level) which were assessed against the 50.69 application Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 11

PRA Technical Adequacy Evaluation cont.

Seismic PRA Model

- Full Scope Peer Review against the ASME/ANS PRA Code Case 1 (seismic)

- Underwent F&O Closure Process

- No Open F&Os (Finding Level)

Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 12

PRA Technical Adequacy Evaluation cont.

Fire PRA Model

- Full Scope Peer Review against the 2008 ASME/ANS PRA Standard Addendum a Part 4 (Fire)

- Has not been subjected to F&O Closure Process, planned to take place later this year

- Nine F&Os (Finding Level)

- BFN FPRA model developed in accordance with NFPA-0805 and NUREG-6850

- All FPRA credited NFPA-805 modifications have been installed in the as-built plant Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 13

Non-Modeled Hazards

• Other External Hazards - the BFN process will use the screening results from the IPEEE, reviewed against the current as-built, as-operated plant, for evaluation of safety significance related to:

- High Winds

- External Flooding

- Transportation and Nearby Facility Accidents

- Other External Initiating Events

• All SSCs credited in IPEEE Other External Hazards evaluation to allow the hazard to screen will be considered High Safety Significant (HSS)

PLACE THE TITLE OF THE PRESENTATION HERE l 14

Low-Power / Shutdown

• The BFN Categorization process will use the shutdown safety management plan described in NUMARC 91-06, for evaluation of safety significance related to low power and shutdown conditions.

• TVA process assesses the potential impact on shutdown risk o Focus on planning, conservative decision-making and maintaining defense-in-depth o Assessment of plant shutdown configurations for impact on Key Safety Functions PLACE THE TITLE OF THE PRESENTATION HERE l 15

Credit for FLEX Equipment

• BFN PRA modeling does not credit portable FLEX equipment

• A permanently installed cart that holds a nitrogen bottle for use to open a drywell vent valve on loss of control air is credited in the seismic model only PLACE THE TITLE OF THE PRESENTATION HERE l 16

Model Update and Maintenance TVA procedures ensure or provide:

- Model configuration, fidelity and realism

- Periodic update requirements

- Living model requirements

- PRA model updates

> PRA Maintenance

> PRA Upgrade (peer review required)

Brown Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 17

LAR Schedule

• Tentatively, week of 4/6/20-Draft 50.69 LAR to be reviewed by Industry Coordinating Committee

• Coordination with TSTF-425 Submittal

- It is expected that there will be review efficiencies gained because of the common PRA usage

- The BFN TSTF-425 LAR was submitted on March 27, 2020

• A one-year NRC review is requested

• Upon approval, the 50.69 License Amendment will be implemented within 60 days Browns Ferry 10 CFR 50.69 LAR Pre-Submittal Meeting With NRC l 18