ML18176A042

2018-6-20 Public Meeting - NEI Presentation - an Alternate Approach to NUMARC 93-01 (ML18166A093)

ML18176A042
Person / Time
Site:	Nuclear Energy Institute
Issue date:	06/25/2018
From:	Vaughn S Nuclear Energy Institute
To:	Division of Inspection and Regional Support
Lewin A, NRR/DIRS, 415-2259
References
Download: ML18176A042 (20)

Text

An Alternate Approach to NUMARC 93-01 Chuck Sibley (Wolf Creek)

Jenna Burr (Exelon)

Jim Zapetis (Exelon)

Mike McLain (APS)

Larry Ellgass (TVA)

Roy Linthicum (PWROG)

Steve Vaughn (NEI)

June 20, 2018

© NEI 2018. All rights reserved. For use by NEI members only.

Outline

• Background

• Purpose

• Proposed Changes

• Overall Process

• Proposed Pilot Effort

• Challenges

• Project Schedule

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Background===

• Delivering the Nuclear Promise Initiative (early 2017)

• Focus resources on high safety significant functions

• Gain efficiencies in the interface between the Maintenance Rule program and other station programs

• Leverage improvements in data collection/analysis and system monitoring

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Purpose

• Provide members with a risk-informed framework that supports the implementation and monitoring of a maintenance effectiveness program that complies with 10 CFR 50.65, effectively and efficiently leverages utility resources, and is focused on equipment performance commensurate with safety.

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Proposed Changes

• Leverage the effectiveness of maintenance strategies and lessons learned from the equipment reliability process

- Address every High Safety Significant functional failure in near real time

- Trend Low Safety Significant failures in CAP and evaluate in the (a)(3) assessment

- Leverage the (a)(4) configuration risk management program (i.e.,

CDF Trending) for unavailability insights during the (a)(3) assessment

• Consider using the Birnbaum importance measure as an additional tool in determining safety significance

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Proposed Changes

• Perform causal evaluations commensurate with safety

- All HSS functional failures and Plant Level Events warrant a near real time causal evaluation

- A trend of low safety significant failures warrants an appropriate causal evaluation.

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Overall Process - The Start

• Scoping

• Safety Significance Determination

- Establish HSS and LSS functions/SSCs considering insights from the Birnbaum importance measure (evaluated during pilot)

• Establish/Implement Maintenance Strategy

- Currently well-established equipment reliability program

• (a)(1)-(a)(2) Determination

- Based on the effectiveness of the component-specific maintenance strategy

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Overall Process - Steady State

• (a)(1)-(a)(2) Determination

- Based on the effectiveness of the component-specific maintenance strategy

• (a)(1)

- Components that are not currently effectively controlled via effective maintenance strategy

• (a)(2)

- Components that are currently effectively controlled via effective maintenance strategy

• Perform Maintenance Strategy

- Execute the defined maintenance strategy

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Overall Process - Reacting to Failures - Part I

• Issue Report (IR)/Condition Report (CR) Initiated

• Plant Level Events (PLEs) receive Yes a CAP cause evaluation

• If the failure is associated with an HSS SSC and is either a No Maintenance Rule Functional Yes Failure (MRFF) or a Condition Yes Monitoring Event (CME) a CAP cause evaluation is performed

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Overall Process - Reacting to Failures - Part II Yes

• LSS failures are inputs for trending under the (a)(3)

No No assessment

• HSS failures that are not MRFF or CME are inputs to determine adverse trends under the (a)(3) assessment

• If an adverse trend is identified, a Yes CAP cause evaluation is performed

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Overall Process - (a)(1) Loop

• (a)(1) process is essentially the same

• Ensure that monitoring performance to goals is focused on the effectiveness of changes to the Maintenance Strategy No Yes

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Overall Process - CDF Trending

• Core Damage Frequency (CDF)

Trending uses the (a)(4) configuration risk management process to provide unavailability Yes data for evaluation

• Both a high-level and detailed assessment of unavailability data No

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Overall Process - CDF Trending

• Actual average CDF compared to present limits

• Evaluate periods of higher risk

- Could they have been avoided?

- Indications of higher than average risk

- If evaluation results in changes to maintenance strategy, evaluate for (a)(1)

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Overall Process - Example #1

• Component: HPSI Injection Valve

• Function: Indirect Radiation Release

• Safety Significance: High

Description:

Body to bonnet leak estimated to exceed the TRM limit. Determined to be a MRFF. Cause: failure to follow work instructions resulting in an inadequate weld.

• NUMARC 93-01: Performance criteria: 3 failures, 36 months, remained in (a)(2).

• Proposed Process: (a)(1)-(a)(2) determination would consider changes to the maintenance strategy given the ineffectiveness of maintenance (inadequate weld).

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Overall Process - Example #2

• Component: Radiation Monitor RU148 (Containment Monitor)

• Function: Monitor plant radiological conditions for assessment of site boundary radiation exposure levels

• Safety Significance: Low

Description:

Monitor taken offline due to excessive spiking and several ALERT alarms - due to apparent electronic interference.

• NUMARC 93-01: Third failure against performance criteria of 4 failures in 12 months - remain in (a)(2).

• Proposed Process: LSS failure would be slated for review in (a)(3)

Assessment. CAP trending or (a)(3) review could identify or determine adverse trend.

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Overall Process - Example #3

• Component: Station Battery

• Function: Provide 125V DC for use in EOPs

• Safety Significance: HSS

Description:

Failure is unacceptable. Use condition monitoring (i.e., CME). Specific gravity and other parameters are monitored to detect adverse trends and allow corrective actions prior to failure.

• NUMARC 93-01: Criteria: 2 CMEs in 24 months.

• Proposed Process: Each battery CME has a CAP cause evaluation performed and assess for (a)(1) - (a)(2)

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Proposed Pilot Effort

• At least one pilot in each Region

• Some stations will pilot the entire MR program while others will pilot just several systems

• Pilots are not required to implement the NUMARC 93-01 process in parallel for the systems being piloted

• Pilot starts in 4th quarter 2018 or 1st quarter 2019

• Continued interactions with the staff

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Challenges

• Change management

- Impact to other station processes

- Defining responsibilities

- Other efficiencies

• Applicability of current enforcement and inspection guidance

• 50.65 is a performance-based rule

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Project Schedule

• September- Workshop/Training for pilot plants

• Fall 2018 - Pilots develop station procedures

• 4th quarter 2018/1st quarter 2019 - Begin pilot process (1 year duration)

• 1st quarter 2019 - Public meeting to review initial pilot plant results

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QUESTIONS?

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