ML18297A185

NEI Public Meeting Presentation October 25, 2018

ML18297A185
Person / Time
Site:	Nuclear Energy Institute
Issue date:	10/25/2018
From:	Nuclear Energy Institute
To:	NRC/NRR/DLP/PLPB
Holonich J
References
Download: ML18297A185 (36)

Text

OD/CAP Interface/

Eliminating Aspects Not Specifically Tied to Operability Determination / Definitions NRC PUBLIC MEETING October 25, 2018

© NEI

© 2018.

2018All rights NEI. Allreserved.

rights reserved.

Introduction

• Overview of the NEI 18-03 Operability Determination process

• Detailed discussion of six areas to gain predictability and efficiency Emphasizing that operability is the responsibility of the licensee

- Separating operability determinations from the Corrective Action Program (CAP)

- Defining common terms Establishing entry criteria

- Eliminating aspects not specifically tied to operability

- Ensuring operability is separate from ASME Code compliance (FUTURE)

• Overview of crosswalk between IMC 0326 and NEI 18-03

• Proposed engagement strategy and schedule

© NEI 2018. All rights reserved. 2

Introduction

• Clean sheet approach

- Use correct process tied to governing regulation and Technical Specifications (TS)

• If no process change, retained IMC 0326 concept/wording

• Guiding Principles

- Operability is a binary decision

- Operability is licensed operator responsibility

- OD is separate from CAP

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Purpose

• Discuss relationship between Operability Determination and the Corrective Action Process

• Discuss aspects not specifically tied to Operability Determination that were eliminated

• Review the defined terms in NEI 18-03

• Highlight the IMC-0326 similarities and differences

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OD/CAP Interface

• Operability process is separate from CAP:

- NEI 18-03 focuses on the determination of operability in order to apply the Technical Specifications

- CAP focuses on restoration of the deficient condition (10 CFR 50, App. B, Criterion XVI, Corrective Action)

• Consistent with IMC-0326, 6.03, "Operability is Separate from Corrective Action to Restore Full Qualification"

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OD/CAP Interface

• NEI 18-03 Appendix C, Additional Considerations for Corrective Actions of Deficient Conditions

- Reinforces the separation between OD and CAP

- Uses much of the information in IMC-0326-07, Corrective Action

• Timing of Corrective Actions consideration of Safety Significance

• Options for Final Corrective Actions (restore deficient condition, change CLB, procedure/facility modification, etc.)

• Compensatory Actions discussed in NEI 18-03, Appendix A, Specific Operability Considerations

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Items Eliminated in NEI 18-03

• Degraded Condition & Nonconforming Condition

• Functional - Functionality

• ASME Code Compliance

- Operability / ASME Code Compliance will be discussed in detail at a future meeting

• Other Definitions

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Introduction

• Fundamental Differences between NEI 18-03 and IMC-0326:

- IMC-0326 discusses operability, functionality, and corrective action

- NEI 18-03 only addresses operability determination

• Some defined terms are consistent with IMC-0326

• Some terms defined in IMC-0326 are not needed in NEI 18-03

• Some terms are defined differently or are new to NEI 18-03

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Consistent Definitions

• The following terms appear in the industry guidance and are utilized consistently with IMC-0326

- Current Licensing Basis

- Design Basis

- Mission Time

- Operability Declaration

- Reasonable Expectation (of Operability)

- Presumption of Operability

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Unneeded Definitions

• The following terms appear in IMC-0326 but are not needed in NEI 18-03

- Degraded Condition & Nonconforming Condition

• These terms have no regulatory basis

• NEI 18-03 is based on the TS definition of operability and the regulations

• The terms "Operable but Degraded" and "Operable but Nonconforming" are not relevant to the determination of operability

- Functional - Functionality

• NEI 18-03 only addresses operability of TS systems. Deficient conditions on necessary support systems are evaluated under the operability process

© NEI 2018. All rights reserved. 10

Unneeded Definitions

• The following terms appear in IMC-0326 but are not needed in NEI 18-03

- Fully Qualified

• This term is not relevant to Operability

- Defect, Flaw, High Energy System, Moderate Energy Systems, NDE Indication

• These terms are only used in discussion of ASME Code compliance

• ASME Code compliance is separate from operability determination

© NEI 2018. All rights reserved. 11

New or Different Definitions

• The following NEI 18-03 terms either do not appear in IMC-0326 or are defined differently in NEI 18-03

- Deficient SSC Condition

- Compensatory Actions

- Operable/Operability

- Necessary Support Function

- Specified Function/Specified Safety Function

© NEI 2018. All rights reserved. 12

New or Different Definitions

• NEI 18-03 Definition of Deficient SSC Condition

- "A deficient SSC condition is one which may compromise the required capabilities of the affected SSC. A subset of deficient SSC conditions will require an assessment of operability as described in Section 4."

© NEI 2018. All rights reserved. 13

New or Different Definitions

• NEI 18-03 Definition of Compensatory Actions

- "As used in this document, a compensatory action is any action taken in response to an identified deficient condition to restore or maintain the operability of an SSC until the deficient condition can be corrected."

- Consistent with the discussion of "compensatory measures" in Section 07.03 of IMC-0326

- NEI 18-03 does not include the IMC-0326 Section 07.03 discussion that is not related to determining operability, such as:

• operable but degraded or nonconforming conditions,

• timing of resolution when using compensatory measures,

• evaluation of temporary changes used as compensatory measures, or

• applicability of 50.59 to temporary changes used as compensatory measures

© NEI 2018. All rights reserved. 14

New or Different Definitions

• NEI 18-03 Definition of Operable/Operability

- "The STS define "Operable - Operability" as follows:

• A system, subsystem, train, component, or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified safety function(s), and when all necessary attendant instrumentation, controls, normal or emergency electrical power, cooling and seal water, lubrication, and other auxiliary equipment that are required for the system, subsystem, train, component, or device to perform its specified safety function(s) are also capable of performing their related support function(s).

- Plant-specific TS that are not based on the STS definition typically define "Operable -

Operability" as follows:

• A system, subsystem, train, component, or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified function(s), and when all necessary attendant instrumentation, controls, electrical power, cooling or seal water, lubrication and other auxiliary equipment that are required for the system, subsystem, train, component, or device to perform its specified safety function(s) are also capable of performing their related support function(s).

- As described above, a plant-specific definition may differ from that found in the STS. Any difference in the definition does not imply a significant difference in application of the plant-specific TS."

© NEI 2018. All rights reserved. 15

New or Different Definitions

• Operable/Operability

- The first definition is taken from the Standard Technical Specifications (NUREG-1430 through -1434, and -2194)

- The second definition is taken from Generic Letter 80-30 which required all licensees to adopt the definition of operability

- Some plants may have a slightly different definition, but the differences are not significant to the operability determination process

• The definitions and discussion of plant-specific definitions are consistent with IMC-0326.

© NEI 2018. All rights reserved. 16

New or Different Definitions

• Operable/Operability

- IMC-0326 includes additional statements not in the TS, such as:

• "In order to be considered operable, an SSC must be capable of performing the specified safety function(s) of its design, within the required range of physical conditions, initiation times, and mission times in the CLB."

• "A system is expected to be tested and maintained to perform as designed.

When an SSC capability is degraded to a point where it cannot perform with reasonable expectation or reliability, the SSC should be judged inoperable, even if at this instantaneous point in time the system could provide the specified safety function(s)."

- These concepts are incorporated in other locations of NEI 18-03

© NEI 2018. All rights reserved. 17

New or Different Definitions

• NEI 18-03 Definition of Necessary Support Function

- "The definition of operability embodies a principle that an SSC can perform its specified safety function(s) only when all its necessary support systems are capable of performing its related support function(s). A necessary support function is a function required for the supported TS system, subsystem, train, component, or device to perform its specified safety function."

• Consistent with the definition of operability and concepts in IMC-0326

• Establishes a consistent term in lieu of "support functions,"

"necessary and attendant functions," or "related support functions"

• Clarifies application of the operability determination process to support functions previously addressed by functionality

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New or Different Definitions: Specified Safety Function

• IMC-0326 Definition of Specified Function/Specified Safety Function

- "The definition of operability refers to the capability to perform the 'specified function' at non-improved TS plants or 'specified safety function' at improved STS plants. The specified function/specified safety function of an SSC is that specified safety function(s) in the CLB for the facility."

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New or Different Definitions: Specified Safety Function

• This is a circular definition

• The lack of clear definition has led to inconsistent application

• In NEI 18-03, the industry defined "specified safety function" based on the TS and the regulations

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New or Different Definitions: Specified Safety Function

• NEI 18-03 Definition of Specified Safety Function

- "A Specified Safety Function (SSF) is a function assumed to be performed by a system, structure, or component (SSC) in the analyses summarized in the Updated Final Safety Analysis Report, Chapters 6 and 15 (or the plant-specific equivalent chapters). SSFs are the subset of functions that meet one or more criterion in 10 CFR 50.36(c)(2)(ii) from all the functions performed by an SSC, as described in the NRC's Final Policy Statement on Technical Specifications Improvement. For plants with improved standard technical specifications, these functions are normally discussed in the TS Limiting Condition for Operation (LCO) Bases.

Note that not all functions or conditions of TS SSCs are considered SSFs, and the functions of non-TS SSCs are never considered SSFs.

The plant-specific SSF scope derives from the functions and design conditions for performance relied on by the licensee and the NRC when the TS were prepared, submitted, reviewed, and approved. The primary sources for deciding whether a function or design condition is an SSF are the application and supplements submitted by the licensee and the requests for additional information (RAIs) and safety evaluations prepared by the NRC.

Additional information regarding the derivation of this definition is provided in Appendix B."

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New or Different Definitions: Specified Safety Function

• The term specified safety function is only used in the TS and only applies when an LCO requires a system to be Operable

• Therefore, specified safety function is directly tied to the 10 CFR 50.36 requirements for LCOs

• NEI 18-03 uses the criteria for selecting LCOs in 10 CFR 50.36 as the regulatory basis for defining specified safety functions

© NEI 2018. All rights reserved. 22

New or Different Definitions: Specified Safety Function

• The four criteria in 10 CFR 50.36(c)(2)(ii) were added in August, 1995, and are based on the July 16, 1993, "Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors."

• The statements of consideration for the 10 CFR 50.36 rule change stated:

- "The Commission has decided not to withdraw the final policy statement because it contains detailed discussions of the four criteria and guidance on how the NRC staff and licensees should apply the criteria."

© NEI 2018. All rights reserved. 23

New or Different Definitions: Specified Safety Function

• The Final Policy Statement established four criteria describing requirements that should be captured in LCOs:

- Criteria 1: Installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary.

- Criteria 2: A process variable, design feature, or operating restriction that is an initial condition of a Design Basis Accident or Transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

- Criteria 3: A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a Design Basis Accident or Transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

- Criteria 4: A structure, system, or component which operating experience or probabilistic safety assessment has shown to be significant to public health and safety.

© NEI 2018. All rights reserved. 24

New or Different Definitions: Specified Safety Function

• The following approach is used in defining specified safety function:

1. 10 CFR 50.36(c)(2)(ii) requires an LCO be established on an SSC if it meets one of the criteria. CRITERIA = LCO

2. A TS LCO requires an SSC to be operable, equating LCO compliance with SSC operability. LCO = OPERABILITY

3. The TS definition of operability states that an operable SSC must be capable of performing its specified safety functions, equating operability with specified safety functions. OPERABILITY=SPECIFIED SAFETY FUNCTION

4. Therefore, the regulations and the TS establish a link between the criteria in 10 CFR 50.36(c)(2)(ii) and the specified safety functions of an SSC.

CRITERIA = LCO = OPERABILITY = SPECIFIED SAFETY FUNCTIONS

© NEI 2018. All rights reserved. 25

New or Different Definitions: Specified Safety Function Example:

• If the only purpose of a system was to respond to an ATWS (not included in Chapter 6 or 15 analyses), it wouldnt meet a 50.36 criteria and the system would not be in TS

• If a system had both Chapter 15 and ATWS functions, the Chapter 15 functions credited in the analysis are specified safety functions, but the ATWS functions are not

• A licensee would not declare the system inoperable because it cant perform the ATWS functions if it can perform the Chapter 15 functions.

- Any nonconforming ATWS functions would be addressed through the corrective action program

© NEI 2018. All rights reserved. 26

New or Different Definitions: Specified Safety Function Key Idea #1:

• A specified safety function must be a function that requires an LCO to be established

- An SSC can only be declared inoperable for failure to perform a function that requires an LCO to be established

© NEI 2018. All rights reserved. 27

New or Different Definitions: Specified Safety Function

• Definition Breakdown

- "A Specified Safety Function (SSF) is a function assumed to be performed by a system, structure, or component (SSC) in the analyses summarized in the Updated Final Safety Analysis Report, Chapters 6 and 15 (or the plant-specific equivalent chapters)."

• Source: Final Policy Statement

© NEI 2018. All rights reserved. 28

New or Different Definitions: Specified Safety Function

• Definition Breakdown

- "SSFs are the subset of functions that meet one or more criterion in 10 CFR 50.36(c)(2)(ii) from all the functions performed by an SSC, as described in the NRC's Final Policy Statement on Technical Specifications Improvement."

• Source: 10 CFR 50.36 and the Final Policy Statement

• Recognizes that specified safety functions are not all functions performed by a system

© NEI 2018. All rights reserved. 29

New or Different Definitions: Specified Safety Function

- From the NRC's 2005 internal training on RIS 2005-20:

© NEI 2018. All rights reserved. 30

New or Different Definitions: Specified Safety Function

• Making the distinction between the TS required specified safety functions and all CLB functions is also consistent with the Commission's Final Policy Statement on Technical Specifications Improvement, which made two points:

- Placing essentially all NRC requirements governing the operation of nuclear power plants in the TS has diverted both NRC staff and licensee attention from the more important requirements has resulted in an adverse but unquantifiable impact on safety

- TS are reserved for those conditions or limitations upon reactor operation necessary to obviate the possibility of an abnormal situation or event giving rise to an immediate threat to the public health and safety

© NEI 2018. All rights reserved. 31

New or Different Definitions: Specified Safety Function

• Definition Breakdown

- "The plant-specific SSF scope derives from the functions and design conditions for performance relied on by the licensee and the NRC when the TS were prepared, submitted, reviewed, and approved. The primary sources for deciding whether a function or design condition is an SSF are the application and supplements submitted by the licensee and the requests for additional information (RAIs) and safety evaluations prepared by the NRC."

• Source: Plant's Licensing Basis

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New or Different Definitions: Specified Safety Function Key Idea #2:

• The specified safety functions are plant-specific and depend on the TS-related licensing basis documentation.

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New or Different Definitions: Specified Safety Function

• Definition Breakdown

- "Additional information regarding the derivation of this definition is provided in Appendix B."

• Appendix B of NEI 18-03 provides the foundation of the definition of specified safety function.

• It traces the development of the term "operability" starting with the revision to 10 CFR 50.36 in 1968 that created modern TS

• It discusses the development of the 10 CFR 50.36 criteria put forth in the Commission's "Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors"

• It develops the definition of specified safety function

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New or Different Definitions: Specified Safety Function

• What about TS that meets Criteria 1 or 4?

- Only one TS that meets Criterion 1: RCS Leakage Detection

• SSF for each required leakage detection system is defined in the Bases

- The TS Bases describe the Criterion 4 specified safety functions a system

• Example: PWR Residual Heat Removal

• The LCO Bases state:

- "At least one RHR loop must be OPERABLE and in operation to provide:

a. Removal of decay heat,

b. Mixing of borated coolant to minimize the possibility of criticality, and

c. Indication of reactor coolant temperature."

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QUESTIONS / DISCUSSION

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