ML21291A185

HEAF - RES

ML21291A185
Person / Time
Issue date:	10/20/2021
From:	Kenneth Hamburger NRC/RES/DRA
To:	Lingham S NRC/NRR/DORL/LPL4
LIngham S
Shared Package
ML21291A179	List: ML21291A180 ML21291A181 ML21291A182 ML21291A183 ML21291A185
References
EPID: L-2021-NFO-0007
Download: ML21291A185 (10)

Text

NRC/EPRI HEAF Working Group Update Kenneth Hamburger, P.E.

Public Workshop October 20th, 2021

Working Group Members EPRI Ken Fleischer (Fleischer Consultants)

Jason Floyd (Jensen Hughes)

Ashley Lindeman Dane Lovelace (Jensen Hughes)

Shannon Lovvern (TVA)

Marko Randelovic Tom Short NRC JS Hyslop Nicholas Melly Kenn Miller Gabriel Taylor Chris LaFleur (SNL)

Kenneth Hamburger

Working Group Charter

• Characterize the primary factors that influence the occurrence and severity of arcing fault events (arc flash, arc blast, or HEAF).

• Develop tools and methods to assess the risk posed by arcing fault events based on experimental data, operating experience, and engineering judgement.

Public Website

• Provides the most up-to-date information about NRCs HEAF Research activities.

• Detailed project plan available for download.

https://www.nrc.gov/about-nrc/regulatory/research/fire-research/heaf-research.html

Summary of Working Group Deliverables Deliverable Lead Org Public Comment Scheduled Publication (Draft)

Fragility Testing Data Report SNL No Complete Fragility Testing Methodology Report NRC/EPRI Yes November 2021 KEMA Testing Data Report NIST No December 2021 Modeling Report, Hazard Tables, and ZOIs NRC/EPRI Yes March 2022 Final PRA Methodology Report NRC/EPRI Yes June 2022

Fragility Testing Data Report

• Objective was to characterize the magnitude and durations of high flux, short duration exposures required to fail common PRA targets.

• 53 tests run between May of 2020 and February of 2021 at Sandia National Laboratories Solar Thermal Test Facility.

• Report published in September 2021, and available on the NRCs HEAF Research Website.

Fragility Testing Methodology Report Objective is to use the data from the fragility test report, expert judgement, and modeling to determine the damage criteria for common PRA targets.

The selected damage criteria will be coupled with the results of the hazard modeling to determine the Zone of Influence (ZOI) for HEAF events.

Report will also include fragility of bus ducts and ERFBS protection.

Draft publication for public comment scheduled for end of November 2021.

KEMA Testing Data Report Objective is to document the full-scale tests performed at KEMA Laboratories.

Report consists of three parts: Medium-voltage switchgear tests, open-box tests, and low-voltage switchgear tests.

Each report will document the temperatures, pressures, heat fluxes, spectrometry, videography, and damage states evolved during testing.

Joint NIST/SNL/NRC report scheduled for publication by the end of December 2021.

Modeling Report, Hazard Tables, and ZOIs

• Objective is to model HEAFs, generate tables of environmental conditions, and calculate ZOIs based on target fragility criteria.

• Model in use is Fire Dynamics Simulator, which is widely used in fire PRA.

• Benchmarks being performed against test data for validation of low voltage switchgear, medium voltage switchgear, and bus ducts.

• Report will document modeling assumptions, methodology, and results. Draft publication for public comment scheduled for end of March 2022.

Final PRA Methodology Report

• Objective is to provide the updated data, tools, and methods to analyze HEAFs in fire PRA.

• Includes an updated frequency and suppression rate based on review of OE.

• Defines scenarios and event trees based on fault location within plant electrical distribution system (EDS). Includes credit for EDS protective elements.

• Will incorporate the results of the other deliverables: modeling, fragility, and ZOIs.

• Report to be published for public comment by the end of June 2022.