ML20135H084
| ML20135H084 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 06/29/2020 |
| From: | Mahesh Chawla NRC/NRR/DORL/LPL4 |
| To: | Sawatzke B Energy Northwest |
| Lingam S | |
| References | |
| EPID L-2019-LLA-0178, TSTF-563 | |
| Download: ML20135H084 (24) | |
Text
June 29, 2020 Mr. Bradley J. Sawatzke Chief Executive Officer Energy Northwest 76 North Power Plant Loop P.O. Box 968 (Mail Drop 1023)
Richland, WA 99352-0968
SUBJECT:
COLUMBIA GENERATING STATION - ISSUANCE OF AMENDMENT NO. 260 RE: REVISE TECHNICAL SPECIFICATIONS TO ADOPT TSTF-563, REVISION 0, REVISE INSTRUMENT TESTING DEFINITIONS TO INCORPORATE THE SURVEILLANCE FREQUENCY CONTROL PROGRAM (EPID L-2019-LLA-0178)
Dear Mr. Sawatzke:
The U.S. Nuclear Regulatory Commission (NRC, the Commission) has issued the enclosed Amendment No. 260 to Renewed Facility Operating License No. NPF-21 for the Columbia Generating Station. The amendment consists of changes to the Technical Specifications (TSs) in response to your application dated August 15, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19227A397), as supplemented by letters dated September 12, 2019, and February 19, 2020 (ADAMS Accession Nos. ML19255H995 and ML20050V454, respectively).
The amendment revises the current instrumentation testing definitions of channel calibration and channel functional test to permit determination of the appropriate frequency to perform the surveillance requirement based on the devices being tested in each step. The proposed changes are based on Technical Specifications Task Force (TSTF) Traveler TSTF-563, Revision 0, Revise Instrument Testing Definitions to Incorporate the Surveillance Frequency Control Program, dated May 10, 2017. The NRC issued a final safety evaluation approving TSTF-563, Revision 0, on December 4, 2018. TSTF-563 revises the language for the channel calibration and channel function test definitions in Columbia TS Section 1.0, Definitions.
By letter dated November 3, 2016, the NRC approved Amendment No. 238 to incorporate the Surveillance Frequency Control Program into the Columbia Generating Station TSs.
B. Sawatzke A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions biweekly Federal Register notice.
Sincerely,
/RA Siva P. Lingam for/
Mahesh L. Chawla, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-397
Enclosures:
- 1. Amendment No. 260 to NPF-21
- 2. Safety Evaluation cc: Listserv
ENERGY NORTHWEST DOCKET NO. 50-397 COLUMBIA GENERATING STATION AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 260 License No. NPF-21
- 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment by Energy Northwest (the licensee), dated August 15, 2019, as supplemented by letters dated September 12, 2019 and February 19, 2020, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the Commissions rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.
The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.
- 2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Renewed Facility Operating License No. NPF-21 is hereby amended to read as follows:
(2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 260 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated in the renewed license. The licensee shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3.
The license amendment is effective as of its date of issuance and shall be implemented within 60 days from the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Jennifer L. Dixon-Herrity, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Renewed Facility Operating License No. NPF-21 and Technical Specifications Date of Issuance: June 29, 2020 Jennifer L.
Dixon-Herrity Digitally signed by Jennifer L. Dixon-Herrity Date: 2020.06.29 12:29:59 -04'00'
ATTACHMENT TO LICENSE AMENDMENT NO. 260 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-21 COLUMBIA GENERATING STATION DOCKET NO. 50-397 Replace the following pages of the Renewed Facility Operating License No. NPF-21 and Appendix A, Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change.
Renewed Facility Operating License REMOVE INSERT Technical Specification REMOVE INSERT 1.1-1 1.1-1 1.1-2 1.1-2 1.1-3 1.1-3 1.1-4 1.1-4 1.1-5 1.1-5 1.1-6 1.1-6
Renewed License No. NPF-21 Amendment No. 260 (2)
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 260 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated in the renewed license. The licensee shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- a. For Surveillance Requirements (SRs) not previously performed by existing SRs or other plant tests, the requirement will be considered met on the implementation date and the next required test will be at the interval specified in the Technical Specifications as revised in Amendment No. 149.
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Definitions 1.1 Columbia Generating Station 1.1-1 Amendment No. 149,169 225 260 1.0 USE AND APPLICATION 1.1 Definitions
NOTE-----------------------------------------------------------
The defined terms of this section appear in capitalized type and are applicable throughout these Technical Specifications and Bases.
Term Definition ACTIONS ACTIONS shall be that part of a Specification that prescribes Required Actions to be taken under designated Conditions within specified Completion Times.
AVERAGE PLANAR LINEAR The APLHGR shall be applicable to a specific planar height HEAT GENERATION RATE and is equal to the sum of the LHGRs for all the fuel rods in (APLHGR) the specified bundle at the specified height divided by the number of fuel rods in the fuel bundle at the height.
CHANNEL CALIBRATION A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the channel output such that it responds within the necessary range and accuracy to known values of the parameter that the channel monitors. The CHANNEL CALIBRATION shall encompass the entire channel, including the required sensor, alarm, display, and trip functions, and shall include the CHANNEL FUNCTIONAL TEST. Calibration of instrument channels with resistance temperature detector (RTD) or thermocouple sensors may consist of an inplace qualitative assessment of sensor behavior and normal calibration of the remaining adjustable devices in the channel.
The CHANNEL CALIBRATION may be performed by means of any series of sequential, overlapping, or total channel steps, and each step must be performed within the Frequency in the Surveillance Frequency Control Program for the devices included in the step.
CHANNEL CHECK A CHANNEL CHECK shall be the qualitative assessment, by observation, of channel behavior during operation. This determination shall include, where possible, comparison of the channel indication and status to other indications or status derived from independent instrument channels measuring the same parameter.
CHANNEL FUNCTIONAL A CHANNEL FUNCTIONAL TEST shall be the injection of a TEST simulated or actual signal into the channel as close to the sensor as practicable to verify OPERABILITY of all devices in the channel required for channel OPERABILITY. The CHANNEL FUNCTIONAL TEST may be performed by means of any series of sequential, overlapping, or total channel steps,
Definitions 1.1 Columbia Generating Station 1.1-2 Amendment No. 190,199 225 251 260 1.1 Definitions CHANNEL FUNCTIONAL and each step must be performed within the Frequency in the TEST (continued)
Surveillance Frequency Control Program for the devices included in the step.
CORE ALTERATION CORE ALTERATION shall be the movement of any fuel, sources, or reactivity control components within the reactor vessel with the vessel head removed and fuel in the vessel.
The following exceptions are not considered to be CORE ALTERATIONS:
- a.
Movement of source range monitors, local power range monitors, intermediate range monitors, traversing incore probes, or special movable detectors (including undervessel replacement); and
- b.
Control rod movement, provided there are no fuel assemblies in the associated core cell.
Suspension of CORE ALTERATIONS shall not preclude completion of movement of a component to a safe position.
CORE OPERATING LIMITS The COLR is the unit specific document that provides cycle REPORT (COLR) specific parameter limits for the current reload cycle. These cycle specific limits shall be determined for each reload cycle in accordance with Specification 5.6.3. Plant operation within these limits is addressed in individual Specifications.
DOSE EQUIVALENT I-131 DOSE EQUIVALENT I-131 shall be that concentration of I-131 (microcuries/gram) that alone would produce the same Total Effective Dose Equivalent (TEDE) dose as the quantity and isotopic mixture of I-131, I-132, I-133, I-134, and I-135 actually present. The dose conversion factors used for this calculation shall be those listed in Federal Guidance Report (FGR) 11, Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion, 1988.
DRAIN TIME The DRAIN TIME is the time it would take for the water inventory in and above the Reactor Pressure Vessel (RPV) to drain to the top of the active fuel (TAF) seated in the RPV assuming:
a)
The water inventory above the TAF is divided by the limiting drain rate;
Definitions 1.1 Columbia Generating Station 1.1-3 Amendment No. 149,169 225 243 251 260 1.1 Definitions Drain Time (continued) b)
The limiting drain rate is the larger of the drain rate through a single penetration flow path with the highest flow rate, or the sum of the drain rates through multiple penetration flow paths susceptible to a common mode failure (e.g., seismic event, loss of normal power, single human error), for all penetration flow paths below the TAF except:
- 1.
Penetration flow paths connected to an intact closed system, or isolated by manual or automatic valves that are locked, sealed, or otherwise secured in the closed position, blank flanges, or other devices that prevent flow of reactor coolant through the penetration flow paths;
- 2.
Penetration flow paths capable of being isolated by valves that will close automatically without offsite power prior to the RPV water level being equal to the TAF when actuated by RPV water level isolation instrumentation; or
- 3.
Penetration flow paths with isolation devices that can be closed prior to the RPV water level being equal to the TAF by a dedicated operator trained in the task, who is in continuous communication with the control room, is stationed at the controls, and is capable of closing the penetration flow path isolation devices without offsite power.
c)
The penetration flow paths required to be evaluated per paragraph b) are assumed to open instantaneously and are not subsequently isolated, and no water is assumed to be subsequently added to the RPV water inventory; d)
No additional draining events occur; and e)
Realistic cross-sectional areas and drain rates are used.
A bounding DRAIN TIME may be used in lieu of a calculated value.
EMERGENCY CORE The ECCS RESPONSE TIME shall be that time interval from COOLING SYSTEM (ECCS) when the monitored parameter exceeds its ECCS initiation RESPONSE TIME setpoint at the channel sensor until the ECCS equipment is capable of performing its safety function (i.e., the valves travel to their required positions, pump discharge pressures reach their required values, etc.). Times shall include diesel generator starting and sequence loading delays, where
Definitions 1.1 Columbia Generating Station 1.1-4 Amendment No. 149,169 225 251 260 1.1 Definitions ECCS Response Time applicable. The response time may be measured by means of (continued) any series of sequential, overlapping, or total steps so that the entire response time is measured.
END OF CYCLE The EOC-RPT SYSTEM RESPONSE TIME shall be that time RECIRCULATION PUMP interval from initial signal generation by the associated turbine TRIP (EOC-RPT) SYSTEM throttle valve limit switch or from when the turbine governor RESPONSE TIME valve hydraulic control oil pressure drops below the pressure switch setpoint to complete suppression of the electric arc between the fully open contacts of the recirculation pump circuit breaker. The response time may be measured by means of any series of sequential, overlapping, or total steps so that the entire response time is measured.
INSERVICE TESTING The INSERVICE TESTING PROGRAM is the licensee PROGRAM program that fulfills the requirements of 10 CFR 50.55a(f).
ISOLATION SYSTEM The ISOLATION SYSTEM RESPONSE TIME shall be that RESPONSE TIME time interval from when the monitored parameter exceeds its isolation initiation setpoint at the channel sensor until the isolation valves travel to their required positions. The response time may be measured by means of any series of sequential, overlapping, or total steps so that the entire response time is measured.
LEAKAGE LEAKAGE shall be:
- a.
Identified LEAKAGE
- 1.
LEAKAGE into the drywell such as that from pump seals or valve packing, that is captured and conducted to a sump or collecting tank; or
- 2.
LEAKAGE into the drywell atmosphere from sources that are both specifically located and known either not to interfere with the operation of leakage detection systems or not to be pressure boundary LEAKAGE;
- b.
Unidentified LEAKAGE All LEAKAGE into the drywell that is not identified LEAKAGE;
- c.
Total LEAKAGE Sum of the identified and unidentified LEAKAGE; and
Definitions 1.1 Columbia Generating Station 1.1-5 Amendment No. 169 225, 228 241 251 253 260 1.1 Definitions Leakage (continued)
- d.
Pressure Boundary LEAKAGE LEAKAGE through a nonisolable fault in a Reactor Coolant System (RCS) component body, pipe wall, or vessel wall.
LINEAR HEAT GENERATION The LHGR shall be the heat generation rate per unit length of RATE (LHGR) fuel rod. It is the integral of the heat flux over the heat transfer area associated with the unit length.
LOGIC SYSTEM A LOGIC SYSTEM FUNCTIONAL TEST shall be a test of all FUNCTIONAL TEST required logic components (i.e., all required relays and contacts, trip units, solid state logic elements, etc.) of a logic circuit, from as close to the sensor as practicable up to, but not including, the actuated device, to verify OPERABILITY. The LOGIC SYSTEM FUNCTIONAL TEST may be performed by means of any series of sequential, overlapping, or total system steps so that the entire logic system is tested.
MINIMUM CRITICAL POWER The MCPR shall be the smallest critical power ratio (CPR) that RATIO (MCPR) exists in the core for each class of fuel. The CPR is that power in the assembly that is calculated by application of the appropriate correlation(s) to cause some point in the assembly to experience boiling transition, divided by the actual assembly operating power.
MODE A MODE shall correspond to any one inclusive combination of mode switch position, average reactor coolant temperature, and reactor vessel head closure bolt tensioning specified in Table 1.1-1 with fuel in the reactor vessel.
OPERABLE - OPERABILITY A system, subsystem, division, 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, division, component, or device to perform its specified safety function(s) are also capable of performing their related support function(s).
PHYSICS TESTS PHYSICS TESTS shall be those tests performed to measure the fundamental nuclear characteristics of the reactor core and related instrumentation. These tests are:
- a.
Described in Chapter 14, Initial Test Program of the FSAR;
Definitions 1.1 Columbia Generating Station 1.1-6 Amendment No. 149,169 225 251 260 1.1 Definitions PHYSICS TESTS (continued)
- b.
Authorized under the provisions of 10 CFR 50.59; or
- c.
Otherwise approved by the Nuclear Regulatory Commission.
RATED THERMAL POWER RTP shall be a total reactor core heat transfer rate to the (RTP) reactor coolant of 3544 MWt.
REACTOR PROTECTION The RPS RESPONSE TIME shall be that time interval from SYSTEM (RPS) RESPONSE when the monitored parameter exceeds its RPS trip setpoint at TIME the channel sensor until de-energization of the scram pilot valve solenoids. The response time may be measured by means of any series of sequential, overlapping, or total steps so that the entire response time is measured.
SDM shall be the amount of reactivity by which the reactor is subcritical or would be subcritical throughout the operating cycle assuming that:
- a.
The reactor is xenon free;
- b.
The moderator temperature is 68F, corresponding to the most reactive state; and
- c.
All control rods are fully inserted except for the single control rod of highest reactivity worth, which is assumed to be fully withdrawn. With control rods not capable of being fully inserted, the reactivity worth of these control rods must be accounted for in the determination of SDM.
STAGGERED TEST BASIS A STAGGERED TEST BASIS shall consist of the testing of one of the systems, subsystems, channels, or other designated components during the interval specified by the Surveillance Frequency, so that all systems, subsystems, channels, or other designated components are tested during n Surveillance Frequency intervals, where n is the total number of systems, subsystems, channels, or other designated components in the associated function.
THERMAL POWER THERMAL POWER shall be the total reactor core heat transfer rate to the reactor coolant.
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 260 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-21 ENERGY NORTHWEST COLUMBIA GENERATING STATION DOCKET NO. 50-397
1.0 INTRODUCTION
By letter dated August 15, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19227A397), as supplemented by letters dated September 12, 2019, and February 19, 2020 (ADAMS Accession Nos. ML19255H995 and ML20050V454, respectively), Energy Northwest (the licensee) submitted a license amendment request (LAR) to revise the technical specifications (TSs) for Columbia Generating Station (Columbia).
The amendment would revise the current instrumentation testing definitions of channel calibration and channel functional test to permit determination of the appropriate frequency to perform the surveillance requirement (SR) based on the devices being tested in each step. The proposed changes are based on Technical Specifications Task Force (TSTF) Traveler TSTF-563, Revision 0, Revise Instrument Testing Definitions to Incorporate the Surveillance Frequency Control Program, dated May 10, 2017 (ADAMS Accession No. ML17130A819).
The U.S. Nuclear Regulatory Commission (NRC or the Commission) issued a final safety evaluation (SE) approving TSTF-563, Revision 0, on December 4, 2018 (ADAMS Accession No. ML18333A144).
A Surveillance Frequency Control Program (SFCP) was incorporated into the Columbia TSs by Amendment No. 238 by letter dated November 3, 2016 (ADAMS Accession No. ML16253A025).
In the LAR dated August 15, 2019, the licensee stated that it is not proposing any variations from the TS changes described in TSTF-563 or the applicable parts of the NRC staffs SE dated December 4, 2018. The licensee, however, proposes to delete language from the channel calibration and channel functional test definitions in Columbia TS Section 1.0, Definitions.
Because there are no deletions in TSTF-563 and the SEs for TSTF-563 neither describe nor provide a technical evaluation of any TS text deletions, the NRC staff finds the proposed language deletion to be a variation from TSTF-563. The variations are described in Section 2.2.1 of this SE and evaluated in Section 3.1.
The supplemental letter dated February 19, 2020, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the NRC staffs original proposed no significant hazards consideration determination as published in the Federal Register on November 5, 2019 (84 FR 59658).
2.0 REGULATORY EVALUATION
2.1 Description of Surveillance Frequency Control Program and Instrument Testing The TSs require the surveillances for instrumentation channels be performed within the specified frequency, using any series of sequential, overlapping, or total channel steps. A prior amendment approved by the NRC on November 3, 2016, revised the TSs to relocate all periodic surveillance frequencies to licensee control. Changes to the relocated surveillance frequencies are made in accordance with the TS program referred to as the SFCP. The SFCP allows a new surveillance frequency to be determined for the channel, but that frequency must consider all components in the channel and applies to the entire channel.
A typical instrument channel consists of many different components, such as sensors, rack modules, and indicators. These components have different short-term and long-term performance (drift) characteristics, resulting in the potential for different calibration frequency requirements. Under the current TSs, the most limiting component calibration frequency for the channel must be chosen when a revised frequency is considered under the SFCP. As a result, all components that makeup a channel must be calibrated at a frequency equal to the channel component with the shortest (i.e., most frequent) surveillance frequency.
Some channel components, such as pressure transmitters, are very stable with respect to drift and could support a substantially longer calibration frequency than the other components in the channel. Currently, the SRs in many plants are performed in steps (e.g., a pressure sensor or transmitter is calibrated during a refueling outage and the rack signal conditioning modules are calibrated while operating at power). The proposed change extends this concept to permit the surveillance frequency of each step to be determined under the SFCP based on the component(s) surveilled in the step instead of all components in the channel. This will allow each component to be tested at the appropriate frequency based on the components long-term performance characteristics.
Allowing an appropriate surveillance frequency for performing a channel calibration on each component or group of components could reduce radiation dose associated with inplace calibration of sensors, reduce wear on equipment, reduce unnecessary burden on plant staff, and reduce opportunities for calibration errors.
2.2 Proposed Changes to the Technical Specifications Currently, the channel calibration and channel functional test may be performed by any series of sequential, overlapping or total channel steps. The proposed changes to the TSs would revise the definitions of channel calibration and channel functional test to indicate that the step must be performed within the most limiting frequency for the components included in that step by adding the phrase, and each step must be performed within the Frequency in the Surveillance Frequency Control Program for the devices included in the step, at the end of the last sentence of each definition.
The following paragraph denotes the changes to the channel calibration definition. Deletions are shown in strikeout and additions in bold italics:
A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the channel output such that it responds within the necessary range and accuracy to known values of the parameter that the channel monitors. The CHANNEL CALIBRATION shall encompass the entire channel, including the required sensor, alarm, display, and trip functions, and shall include the CHANNEL FUNCTIONAL TEST. Calibration of instrument channels with resistance temperature detector (RTD) or thermocouple sensors may consist of an inplace qualitative assessment of sensor behavior and normal calibration of the remaining adjustable devices in the channel. The CHANNEL CALIBRATION may be performed by means of any series of sequential, overlapping, or total channel steps, and each step must be performed within the Frequency in the Surveillance Frequency Control Program for the devices included in the step so that the entire channel is calibrated.
The following paragraph denotes the changes to the channel functional test definition.
Deletions are shown in strikeout and additions in bold italics:
A CHANNEL FUNCTIONAL TEST shall be the injection of a simulated or actual signal into the channel as close to the sensor as practicable to verify OPERABILITY, including required alarm, interlock, display, and trip functions, and channel failure trips. The CHANNEL FUNCTIONAL TEST may be performed by means of any series of sequential, overlapping, or total channel steps, and each step must be performed within the Frequency in the Surveillance Frequency Control Program for the devices included in the step so that the entire channel is tested.
The various instrumentation functions in the TSs require surveillances to verify the correct functioning of the instrument channel. The proposed changes would revise the definitions above to permit the surveillance frequency of each step to be determined under the SFCP based on the component(s) surveilled in the step instead of all components in the channel. This will allow each component to be tested at the appropriate frequency based on the components long-term performance characteristics.
The proposed changes would also allow the licensee to control the frequency of associated components being tested in each step. The SR for the overall instrumentation channel remains unchanged. The proposed change would have no effect on the instrument channels design, fabrication, use, or methods of testing, and will not affect the ability of the instrumentation to perform the functions assumed in the safety analysis.
These instrumentation testing definitions would state that, The [test type] may be performed by means of any series of sequential, overlapping, or total channel steps. The surveillance frequency of these subsets would be established based on the characteristics of the components in the step rather than the most limiting component characteristics in the entire channel. Each of these steps would be evaluated in accordance with the SFCP.
2.2.1 Variations from TSTF-563 The following are variations from the TS changes described in TSTF-563 or the applicable parts of the NRC staffs SE of TSTF-563. The licensee proposes to delete the language, so that the entire channel is calibrated, from the Channel Calibration definition and revise the Channel Functional Test definition in Columbia TS Section 1.0 so that both definitions align with the language in NUREG-1433, Revision 4.0, Standard Technical Specifications, General Electric BWR [Boiling Water Reactor]/4 Plants, Volume 1, Specifications, and Volume 2, Bases, dated April 2012 (ADAMS Accession Nos. ML12104A192 and ML12104A193, respectively).
The NRC staff finds that these variations do not affect the applicability of TSTF-563 or the NRC staffs SE to the proposed LAR and evaluates the changes below in Section 3.1 of this SE.
2.3 APPLICABLE REGULATORY REQUIREMENTS AND GUIDANCE Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(a)(1) requires each applicant for a license authorizing operation of a utilization facility to include the proposed TSs in the application.
The regulation at 10 CFR 50.36(b) requires:
Each license authorizing operation of a production or utilization facility of a type described in § 50.21 or § 50.22 will include technical specifications. The technical specifications will be derived from the analyses and evaluation included in the safety analysis report, and amendments thereto, submitted pursuant
§ 50.34 [Contents of applications; technical information]. The Commission may include such additional technical specifications as the Commission finds appropriate.
The categories of items required to be in the TSs are provided in 10 CFR 50.36(c). One such category is SRs. SRs are defined in 10 CFR 50.36(c)(3) as requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation [LCOs] will be met.
A prior Columbia amendment replaced specific surveillance frequencies with references to a SFCP required by TS 5.5.15 (ADAMS Accession No. ML16253A025). That TS requires the licensee to establish, implement, and maintain an SFCP to ensure that TS SRs are performed at intervals listed in, and controlled by, the SFCP. TS 5.5.15 also requires that changes to surveillance frequencies listed in the SFCP be made in accordance with NRC staff-approved Topical Report (TR) Nuclear Energy Institute (NEI) 04-10, Revision 1, Risk-Informed Technical Specifications Initiative 5b, Risk-Informed Method for Control of Surveillance Frequencies, Industry Guidance Document, dated April 2007 (ADAMS Accession No. ML071360456).
TR NEI 04-10, Revision 1, describes an evaluation process and a multi-disciplinary plant decisionmaking panel that considers the detailed evaluation of proposed surveillance frequency revisions. The evaluations are based on operating experience, test history, manufacturers recommendations, codes and standards, and other deterministic factors, in conjunction with risk insights. The evaluation considers all components being tested by the SR. Process elements are included for determining the cumulative risk impact of the changes, updating the licensees probabilistic risk assessment (PRA) models, and for imposing corrective actions, if necessary, following implementation of a revised frequency.
The NRC staffs guidance for the review of TSs is in Chapter 16.0, Revision 3, Technical Specifications, dated March 2010 (ADAMS Accession No. ML100351425) of NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants:
LWR [Light-Water Reactor] Edition (SRP). As described therein, as part of the regulatory standardization effort, the NRC staff has prepared Standard Technical Specifications (STS) for each of the LWR nuclear designs. Accordingly, the NRC staffs review includes consideration of whether the proposed changes are consistent with the applicable reference STS (i.e., the current STS), as modified by NRC-approved TSTF travelers. In addition, the guidance states that comparing the change to previous STS can help clarify the intent of the TSs.
Regulatory Guide (RG) 1.174, Revision 2, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, dated May 2011 (ADAMS Accession No. ML100910006), describes an acceptable risk-informed approach for assessing the nature and impact of proposed permanent licensing basis changes by considering engineering issues and applying risk insights. This RG also provides risk acceptance guidelines for evaluating the results of such evaluations.
RG 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decisionmaking:
Technical Specifications, dated May 2011 (ADAMS Accession No. ML100910008), describes an acceptable risk-informed approach specifically for assessing proposed TS changes.
RG 1.200, Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, dated March 2009 (ADAMS Accession No. ML090410014), describes an acceptable approach for determining the technical adequacy of PRAs.
The NRC staffs guidance for evaluating the technical basis for proposed risk-informed changes is provided in SRP, Section 19.2, Review of Risk Information Used to Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance, dated June 2007 (ADAMS Accession No. ML071700658). The NRC staffs guidance for evaluating PRA technical adequacy is provided in SRP, Section 19.1, Revision 3, Determining the Technical Adequacy of Probabilistic Risk Assessment for Risk-Informed License Amendment Requests After Initial Fuel Load, dated September 2012 (ADAMS Accession No. ML12193A107). More specific guidance related to risk-informed TS changes is provided in SRP, Section 16.1, Revision 1, Risk-Informed Decision Making: Technical Specifications, dated March 2007 (ADAMS Accession No. ML070380228), which includes changes to surveillance test intervals (STIs) (i.e., surveillance frequencies) as part of risk-informed decisionmaking. Section 19.2 of the SRP references the same criteria as RG 1.177, Revision 1, and RG 1.174, Revision 2, and states that a risk-informed application should be evaluated to ensure that the proposed changes meet the following key principles:
The proposed change meets the current regulations, unless it explicitly relates to a requested exemption or rule change.
The proposed change is consistent with the defense-in-depth philosophy.
The proposed change maintains sufficient safety margins.
When proposed changes result in an increase in risk associated with core damage frequency or large early release frequency, the increase(s) should be small and consistent with the intent of the Commissions Safety Goal Policy Statement.
The impact of the proposed change should be monitored using performance measurement strategies.
The STS applicable to the proposed changes are provided in NUREG-1433, Revision 4.0, Volume 1 and Volume 2, dated April 2012.
3.0 TECHNICAL EVALUATION
Revising the frequency of a channel calibration and channel functional test instrument channel under the SFCP requires assurance that component performance characteristics, such as drift between each test, will not result in undetected instrument errors that exceed the assumptions of the safety analysis and supporting instrument loop uncertainty calculations. These requirements are consistent with the methodology described in TR NEI 04-10, which is required by the SFCP. The SFCP does not permit changes to the TS allowable values or nominal trip setpoints; but allows only the surveillance frequency to be changed when determined permissible by TR NEI 04-10. Therefore, prior to extending the test intervals for an instrument channel component or components associated with a given calibration step, the component performance characteristics must be evaluated to verify the allowable value or nominal trip setpoint will still be valid and to establish a firm technical basis supporting the extension. In addition, each change must be reviewed by the licensee to ensure the applicable uncertainty allowances are conservative (bounding) (e.g., sensor drift, rack drift, indicator drift).
Documentation to support the changes shall be retained per the guidance in TR NEI 04-10.
Five key safety principles that must be evaluated before changing any surveillance frequency are identified in Section 3.0 of TR NEI 04-10. Principle 3, The proposed change maintains sufficient safety margins, requires confirmation of the maintenance of safety margins, which, in this case, includes performance of deterministic evaluations to verify preservation of instrumentation trip setpoint and indication safety margins.
The evaluation methodology specified in TR NEI 04-10 also requires consideration of common cause failure effects and monitoring of the instrument channel component performance following the frequency change, to ensure that channel performance is consistent with the analysis to support an extended frequency.
The method of evaluating a proposed surveillance frequency change is not dependent on the number of components in the channel. Each step needs to be evaluated to determine the acceptable surveillance frequency for that step. The proposed change to permit changing the surveillance frequency of channel component(s) does not affect the test method or evaluation method. The requirement to perform a channel calibration or channel functional test on the entire channel is not changed.
For example, an evaluation in accordance with TR NEI 04-10 may determine that a field sensor (e.g., a transmitter) should be calibrated every 48 months, that the rack modules should be calibrated every 30 months, and that the indicators should be calibrated every 24 months.
Under the current TS requirements, all devices in the channel must be calibrated every 24 months. However, under the proposed change, sensors, rack modules, and indicators would be calibrated at the appropriate frequency for the tested devices. As required by the channel
calibration definition, the test would still encompass all devices in the channel required for channel operability.
Per TS 5.5.15, NEI 04-10 methodology must be used to evaluate surveillance frequency changes to determine if such SR extensions could be applied. Process elements are used to determine the cumulative risk impact of changes, update the PRA, and impose corrective actions, if needed, following implementation. Several steps are required by TR NEI 04-10, Section 4.0, Step 7, to be evaluated prior to determining the acceptability of changes. These steps include history of surveillance tests, industry and plant specific history, impact on defense-in-depth, vendor recommendations, required test frequencies for the applicable codes and standards, ensuring that plant licensing basis would not be invalidated and other factors. The NRC staff finds these measures acceptable in determining the SR extensions.
In addition, TR NEI 04-10, Section 4.0, Step 16 requires an independent decisionmaking panel to review the cumulative impact of all STI changes over a period of time. This is also specified by RGs 1.174 and 1.177. The independent decisionmaking panel is composed of the site Maintenance Rule expert panel, surveillance test coordinator, and subject matter expert, who is a cognizant system manager or component engineer. Based on the above information, the NRC staff finds that the setpoint changes will be tracked in an acceptable manner.
Licensees with an SFCP may currently revise the surveillance frequency of instrumentation channels. The testing of these channels may be performed by means of any series, sequential, overlapping, or total channel steps. However, all required components in the instrumentation channel must be tested in order for the entire channel to be considered operable.
The NRC staff notes that industry practice is to perform instrument channel surveillances, such as channel calibrations and channel functional tests, using separate procedures based on the location of the components. Each of these procedures may be considered a step. The results of all these procedures are used to satisfy the SRs using the existing allowance to perform it by means of any series of sequential, overlapping, or total channel steps. The proposed changes would allow for determining an acceptable surveillance frequency for each step.
The NRC staff notes that the NEI 04-10 methodology includes the determination of whether the structure, system, and components (SSCs) affected by a proposed change to a surveillance frequency are modeled in the PRA. Where the SSC is directly or implicitly modeled, a quantitative evaluation of the risk impact may be carried out. The methodology adjusts the failure probability of the impacted SSCs based on the proposed change to the surveillance frequency. Where the SSC is not modeled in the PRA, bounding analyses are performed to characterize the impact of the proposed change to the surveillance frequency. Potential impacts on the risk analyses due to screening criteria and truncation levels are addressed by the requirements for PRA technical adequacy, consistent with the guidance contained in RG 1.200, and by sensitivity studies identified in TR NEI 04-10. The licensee is not proposing to change the methodology, or the acceptance criteria for extending STIs, and licensee will need to evaluate changes in the frequency for performing each of the steps in the instrumentation surveillance test per the methodology in TR NEI 04-10.
Therefore, the NRC staff concludes that the proposed change determines an acceptable test frequency for individual steps within instrumentation channel surveillance tests is acceptable because any extended STIs will be developed within the established constraints of the SFCP and TR NEI 04-10.
The regulatory requirements in 10 CFR 50.36 are not specific regarding the frequency of performing surveillance tests. The proposed change only affects the frequency of performance and does not affect the surveillance testing method or acceptance criteria. Therefore, the proposed change is consistent with the surveillance testing requirements of 10 CFR 50.36.
PRA Acceptability The guidance in RG 1.200 states that the quality of a licensees PRA should be commensurate with the safety significance of the proposed TS change and the role the PRA plays in justifying the change. That is, the greater the change in risk or the greater the uncertainty in that risk as a result of the requested TS change, or both, the more rigor that should go into ensuring the quality of the PRA.
The NRC staff has performed an assessment of the PRA models used to support the approved SFCP that uses TR NEI 04-10, using the guidance of RG 1.200 to assure that the PRA models are capable of determining the change in risk due to changes to surveillance frequencies of SSCs, using plant-specific data and models. Capability Category II of the NRC-endorsed PRA standard is the target capability level for supporting requirements for the internal events PRA for this application. Any identified deficiencies to those requirements are assessed further to determine any impacts to proposed decreases to surveillance frequencies, including the use of sensitivity studies, where appropriate, in accordance with TR NEI 04-10.
The SFCP permits revising of the surveillance frequency for instrumentation channels. The NRC staff evaluated whether TR NEI 04-10 can be applied to subsets in an instrument channel when the SFCP currently specifies a surveillance interval that is applied to the entire channel.
The NRC staff notes that the current channel surveillance may be performed by means of any series of sequential, overlapping, or total channel steps. In practice, this means that a channel is divided into subsets and each subset is tested separately. Therefore, the current instrument channel testing is already composed of a sequence of individual tests.
The instrument function may be modeled in the PRA differently depending on the site and the function (e.g., channel may be modeled individually, subsets may be modeled, or the channel function may be modeled as a single entity). There are different steps through the evaluation methodology in TR NEI 04-10 that could be used based on the different PRA modeling approaches. The appropriate modeling of these different approaches is included in the NRC staffs review of the PRA modeling during the review of the application to implement an SFCP that uses TR NEI 04-10.
The PRA in use at Columbia is the same as that used to support the license amendment that authorized the SFCP and follows TR NEI 04-10. Currently, the TSs allow the licensee to change the surveillance frequency of an entire channel under the SFCP. The proposed amendment would allow the licensee to change the surveillance frequency of each subset of the channel. The NRC staff finds that changes to the surveillance frequency caused by defining and using individual, testable component subsets can be appropriately evaluated with the current SFCP and the current PRAs. The NRC staff also finds that the risk-informed methodology review and the PRA acceptability review that were performed during the review of the application for an amendment authorizing the SFCP that uses TR NEI 04-10 is adequate.
The regulations at 10 CFR 50.36(c)(3) require that TSs include items in specified categories, including SRs. The proposed changes modify the definitions applicable to instrumentation channel components but do not alter the previously approved technical approach in TR NEI 04-10. Thus, the TSs, as revised, continue to specify the appropriate SRs for tests and inspections to ensure the necessary quality of affected SSCs is maintained, ensure facility operation within safety limits, and ensure LCOs are met.
Additionally, the NRC staff finds the proposed TS changes to be technically clear and consistent with customary terminology and format in accordance with SRP Chapter 16.0. The NRC staff reviewed the proposed changes against the regulations and concludes that the changes continue to meet the requirements of Section 50.36(c)(3) of 10 CFR, for the reasons discussed above, and thus provide reasonable assurance that the revised TSs provide the requisite requirements and controls for the facility to operate safely. Therefore, the NRC staff concludes that the proposed TS changes are acceptable.
3.1 VARIATIONS FROM TSTF-563 Channel Calibration Definition Columbias Channel Calibration definition states,... The CHANNEL CALIBRATION shall encompass the entire channel, including the required sensor, alarm, display, and trip functions, and shall include the CHANNEL FUNCTIONAL TEST... The CHANNEL CALIBRATION may be performed by means of any series of sequential, overlapping, or total channel steps, so that the entire channel is calibrated. The licensee proposes to delete, so that the entire channel is calibrated from Columbias Channel Calibration definition. The NRC staff has determined that this language is repetitive to the language earlier in the definition stating the Channel Calibration shall encompass the entire channel. The NRC staff concludes that the deleted language is acceptable because the requirement to perform a Channel Calibration on the entire channel has not changed and this variation does not affect the applicability of TSTF-563 or the NRC staffs SE to the proposed LAR.
Channel Functional Test Definition Currently, Columbias Channel Functional Test definition in TS 1.1 states:
A CHANNEL FUNCTIONAL TEST shall be the injection of a simulated or actual signal into the channel as close to the sensor as practicable to verify OPERABILITY, including required alarm, interlock, display, and trip functions, and channel failure trips. The CHANNEL FUNCTIONAL TEST may be performed by means of any series of sequential, overlapping, or total channel steps so that the entire channel is tested.
Columbias Channel Functional Test definition differs from that in the STS on which TSTF-563 is based. The licensee proposes to revise Channel Functional Test definition so that it aligns with the language in NUREG-1433, Revision 4.0. The following paragraph denotes the revised Channel Functional Test. Deletions are shown in strikeout and additions in bold italics.
The CHANNEL FUNCTIONAL TEST shall be the injection of a simulated or actual signal into the channel as close to the sensor as practicable to verify OPERABILITY, including required alarm, interlock, display, and trip functions, and channel failure trips of all devices in the channel required for channel
OPERABILITY. The CHANNEL FUNCTIONAL TEST may be performed by means of any series of sequential, overlapping, or total channel steps, and each step must be performed within the Frequency in the Surveillance Frequency Control Program for the devices included in the step so that the entire channel is tested.
The licensee proposes to delete the list of devices along with the statement that the entire channel is tested in the channel functional test definition and replace it with language that would require testing all the devices in the channel required for channel operability. In addition, in its supplemental letter dated February 19, 2020, the licensee stated that Columbia will continue to test all the devices in the channel (i.e. required alarm, interlock, display, and trip functions, and channel trips). The NRC staff finds that the proposed language would continue to require that all the channel devices downstream of the signal are to be tested and that the test would still encompass all devices in the channel required for channel operability, therefore the proposed revision of the Channel Functional Test definition is consistent with the language in NUREG-1433, Revision 4.0. The NRC staff further finds that the revised language is acceptable because the requirement to perform a Channel Functional Test on the entire channel has not changed, and this variation does not affect the applicability of TSTF-563, as approved by the NRC staffs SE, to the proposed LAR.
4.0 STATE CONSULTATION
In accordance with the Commissions regulations, the Washington State official was notified of the proposed issuance of the amendment on May 13, 2020. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and changes SRs.
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, as published in the Federal Register on November 5, 2019 (84 FR 59658), and there has been no public comment on such finding.
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: K. Bucholtz, NRR T. Sweat, NRR Date: June 29, 2020
- by e-mail OFFICE NRR/DORL/LPL4/PM*
NRR/DORL/LPL4/LA*
NRR/DSS/STSB/BC*
NAME JKlos (SLingam for)
PBlechman VCusumano DATE 5/19/2020 5/19/2020 2/21/2020 OFFICE OGC* (NLO)
NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME MYoung JDixon-Herrity MChawla (SLingam for)
DATE 6/25/2020 6/29/2020 6/29/2020