ML20168A924

Issuance of Amendment Nos. 176 and 176 Regarding Revision to Technical Specification 3.4.15, RCS Leakage Detection Instrumentation

ML20168A924
Person / Time
Site:	Comanche Peak
Issue date:	11/16/2020
From:	Dennis Galvin Plant Licensing Branch IV
To:	Peters K Vistra Operations Company
Galvin D
References
EPID L-2019-LLA-0259
Download: ML20168A924 (27)

Text

November 16, 2020 Mr. Ken J. Peters Senior Vice President and Chief Nuclear Officer Attention: Regulatory Affairs Vistra Operations Company LLC Comanche Peak Nuclear Power Plant 6322 N FM 56 P.O. Box 1002 Glen Rose, TX 76043

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 -

ISSUANCE OF AMENDMENT NOS. 176 AND 176 REGARDING REVISION TO TECHNICAL SPECIFICATION 3.4.15, RCS LEAKAGE DETECTION INSTRUMENTATION (EPID L-2019-LLA-0259)

Dear Mr. Peters:

The U.S. Nuclear Regulatory Commission (NRC, the Commission) has issued the enclosed Amendment No. 176 to Facility Operating License No. NPF-87 and Amendment No. 176 to Facility Operating License No. NPF-89 for Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2, respectively. The amendments consist of changes to the technical specifications (TSs) in response to your application dated November 7, 2019.

The amendments revise TS 3.4.15, RCS [Reactor Coolant System] Leakage Detection Instrumentation, to align with the Standard Technical Specifications for Westinghouse Plants and to incorporate the changes made by Technical Specifications Task Force (TSTF) Traveler TSTF-513, Revision 3, Revise PWR [Pressurized-Water Reactor] Operability Requirements and Actions for RCS Leakage Instrumentation.

K. Peters A copy of the related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commissions monthly Federal Register notice.

Sincerely,

/RA/

Dennis J. Galvin, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446

Enclosures:

1. Amendment No. 176 to NPF-87

2. Amendment No. 176 to NPF-89

3. Safety Evaluation cc: Listserv

COMANCHE PEAK POWER COMPANY LLC AND VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-445 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 176 License No. NPF-87

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Vistra Operations Company LLC (Vistra OpCo) dated November 7, 2019, 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 license 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.

Enclosure 1

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 Facility Operating License No. NPF-87 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. 176 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated into this license. Vistra OpCo 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. Digitally signed by Jennifer L. Dixon-Herrity Dixon-Herrity Date: 2020.11.16 14:40:40 -05'00' Jennifer L. Dixon-Herrity, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Facility Operating License and Technical Specifications Date of Issuance: November 16, 2020

COMANCHE PEAK POWER COMPANY LLC AND VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 2 DOCKET NO. 50-446 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 176 License No. NPF-89

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Vistra Operations Company LLC (Vistra OpCo) dated November 7, 2019, 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 license 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.

Enclosure 2

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 Facility Operating License No. NPF-89 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. 176, and the Environmental Protection Plan contained in Appendix B, are hereby incorporated into this license. Vistra OpCo shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3. This 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 Digitally signed by Jennifer L. Jennifer L. Dixon-Herrity Dixon-Herrity Date: 2020.11.16 14:41:27 -05'00' Jennifer L. Dixon-Herrity, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Facility Operating License and Technical Specifications Date of Issuance: November 16, 2020

ATTACHMENT TO LICENSE AMENDMENT NO. 176 TO FACILITY OPERATING LICENSE NO. NPF-87 AND AMENDMENT NO. 176 TO FACILITY OPERATING LICENSE NO. NPF-89 COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-445 AND 50-446 Replace the following pages of the Facility Operating License Nos. NPF-87 and NPF-89, and Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Facility Operating License No. NPF-87 REMOVE INSERT 3 3 Facility Operating License No. NPF-89 REMOVE INSERT 3 3 Technical Specifications REMOVE INSERT 3.4-37 3.4-37 3.4-38 3.4-38 3.4-39 3.4-39

(3) Vistra OpCo, pursuant to the Act and 10 CFR Part 70, to receive, possess, and use at any time, special nuclear material as reactor fuel, in accordance with the limitations for storage and amounts required for reactor operation, and described in the Final Safety Analysis Report, as supplemented and amended; (4) Vistra OpCo, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use, at any time, any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (5) Vistra OpCo, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required, any byproduct, source, and special nuclear material without restriction to chemical or physical form, for sample analysis or instrument calibration or associated with radioactive apparatus or components; and (6) Vistra OpCo, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C. This license shall be deemed to contain and is subject to the conditions specified in the Commissions regulations set forth in 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1) Maximum Power Level Vistra OpCo is authorized to operate the facility at reactor core power levels not in excess of 3458 megawatts thermal through Cycle 13 and 3612 megawatts thermal starting with Cycle 14 in accordance with the conditions specified herein.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 176 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated into this license. Vistra OpCo shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

Unit 1 Amendment No. 176

(3) Vistra OpCo, pursuant to the Act and 10 CFR Part 70, to receive, possess, and use at any time, special nuclear material as reactor fuel, in accordance with the limitations for storage and amounts required for reactor operation, and described in the Final Safety Analysis Report, as supplemented and amended; (4) Vistra OpCo, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use, at any time, any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (5) Vistra OpCo, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required, any byproduct, source, and special nuclear material without restriction to chemical or physical form, for sample analysis or instrument calibration or associated with radioactive apparatus or components; and (6) Vistra OpCo, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C. This license shall be deemed to contain and is subject to the conditions specified in the Commissions regulations set forth in 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1) Maximum Power Level Vistra OpCo is authorized to operate the facility at reactor core power levels not in excess of 3458 megawatts thermal through Cycle 11 and 3612 megawatts thermal starting with Cycle 12 in accordance with the conditions specified herein.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 176 and the Environmental Protection Plan contained in Appendix B, are hereby incorporated into this license. Vistra OpCo shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

(3) Antitrust Conditions DELETED Unit 2 Amendment No. 176

RCS Leakage Detection Instrumentation 3.4.15 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.15 RCS Leakage Detection Instrumentation LCO 3.4.15 The following RCS leakage detection instrumentation shall be OPERABLE:

a. One containment sump (level or discharge flow) monitor,

b. One containment atmosphere radioactivity monitor (gaseous or particulate), and

c. One containment air cooler condensate flow rate monitor.

APPLICABILITY: MODES 1, 2, 3, and 4 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Required containment A.1 -------------------NOTE-------------------

sump monitor inoperable. Not required until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishment of steady state operation.

Perform SR 3.4.13.1. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AND A.2 Restore required containment sump 30 days monitor to OPERABLE status.

COMANCHE PEAK - UNITS 1 AND 2 3.4-37 Amendment No. 150, 156, 176

RCS Leakage Detection Instrumentation 3.4.15 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required containment B.1.1 Analyze grab samples of the Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> atmosphere radioactivity containment atmosphere.

monitor inoperable.

OR B.1.2 ------------------NOTE------------------

Not required until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishment of steady state operation.

Perform SR 3.4.13.1. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> AND B.2.1 Restore required containment 30 days atmosphere radioactivity monitor to OPERABLE status.

OR B.2.2 Verify containment air cooler 30 days condensate flow rate monitor is OPERABLE.

C. Containment air cooler C.1 Perform SR 3.4.15.1. Once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> condensate flow rate monitor inoperable. OR C.2 ------------------NOTE------------------

Not required until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishment of steady state operation.

Perform SR 3.4.13.1. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> COMANCHE PEAK - UNITS 1 AND 2 3.4-38 Amendment No. 150, 156, 176

RCS Leakage Detection Instrumentation 3.4.15 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

---

NOTE---------------- D.1 Analyze grab samples of the Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Only applicable when the containment atmosphere.

containment atmosphere gaseous radiation monitor is AND the only OPERABLE monitor.

---

D.2.1 Restore required containment 7 days sump monitor to OPERABLE D. Required containment status.

sump monitor inoperable.

OR AND D.2.2 Restore containment air cooler 7 days Containment air cooler condensate flow rate monitor to condensate flow rate OPERABLE status.

monitor inoperable.

E. Required containment E.1 Restore required containment 30 days atmosphere radioactivity atmosphere radioactivity monitor to monitor inoperable. OPERABLE status.

AND OR Containment air cooler E.2 Restore containment air cooler 30 days condensate flow rate condensate flow rate monitor to monitor inoperable. OPERABLE status.

F. Required Action and F.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met. AND F.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> G. All required monitors G.1 Enter LCO 3.0.3. Immediately inoperable.

COMANCHE PEAK - UNITS 1 AND 2 3.4-39 Amendment No. 150, 156, 176

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 176 TO FACILITY OPERATING LICENSE NO. NPF-87 AND AMENDMENT NO. 176 TO FACILITY OPERATING LICENSE NO. NPF-89 COMANCHE PEAK POWER COMPANY LLC AND VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-445 AND 50-446

1.0 INTRODUCTION

By [[letter::CP-201900393, License Amendment Request (LAR)19-001, Application to Adopt TSTF-513-A, Revision 3, PWR Operability Requirements and Actions for RCS Leakage Instrumentation|letter dated November 7, 2019]] (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19325C593), Vistra Operations Company LLC (the licensee) proposed changes to the technical specifications (TSs) for Comanche Peak Nuclear Power Plant (Comanche Peak), Unit Nos. 1 and 2.

The proposed changes would revise TS 3.4.15, RCS [Reactor Coolant System] Leakage Detection Instrumentation. For information, the application also included TS Bases changes that summarize and clarify the purpose of the TSs and the specified safety function of the leakage detection monitors.

The licensee stated that the license amendment request seeks to adopt U.S. Nuclear Regulatory Commission (NRC)-approved Technical Specifications Task Force (TSTF) Standard Technical Specification (STS) Change Traveler, TSTF-513, Revision 3, Revise PWR

[Pressurized-Water Reactor] Operability Requirements and Actions for RCS Leakage Instrumentation, to clarify operability, add a new Condition when the containment atmosphere gaseous radioactivity monitor is the only operable monitor, and correct usage of the term required with regard to containment air cooler condensate flow rate monitor, with the licensees end goal to have Comanche Peak Limiting Condition for Operation (LCO) 3.4.15 final TS in full alignment with TSTF-513, Revision 3. The availability of TSTF-513 was announced in the Federal Register on January 3, 2011 (76 FR 189) as part of the consolidated line item improvement process (ADAMS Accession No. ML101340267).

Enclosure 3

2.0 REGULATORY EVALUATION

2.1 Description of System

The RCS leakage detection system is composed of four independent detection systems: the containment sump level and discharge flow monitoring system, the containment air particulate radioactivity monitoring system, the containment gas radioactivity monitoring system, and the specific humidity monitors that measure condensate flow rate from the containment air cooling coils.

Containment sump level and discharge flow monitoring is provided for three sumps consisting of two containment sumps and one reactor cavity sump. For containment sump level monitoring, each of the three sumps have a separate high level audible/visual alarm in the control room.

For containment discharge flow monitoring, after collection in any of the three sumps, leakage is pumped via a common header to floor drain tank 1 or to the waste holdup tank. In this common discharge header is a flow totalizer/indicator that measures flow and facilitates the recording of this total flow in the control room. The two containment sumps also have an additional level switch arranged with a time delay and appropriate logic so that an increase by 1 gallon per minute (gpm) or greater flow into a sump will actuate an audible/visual alarm in the control room.

The containment air particulate monitor takes continuous air samples from the containment atmosphere and measures the particulate activity collected on a filter paper system. After passing through an iodine and noble gas monitor downstream of the particulate monitor, the air returns to the containment. The sensitivity of the containment air particulate monitor to an increase in reactor coolant leak rate is dependent upon the magnitude of the normal baseline leakage into the containment. Sensitivity is greatest where baseline leakage is lowest.

The radioactive gas monitor indicates the presence of containment gaseous activity originating from RCS leakage provided reactor coolant gaseous activity exists as a result of fuel-cladding defects. It measures the gaseous beta radioactivity by continuously sampling the containment atmosphere. The radioactive gas monitor is less sensitive to an increase in reactor coolant leak rate than the containment particulate monitor.

The specific humidity monitors measure RCS leakage by measuring the condensate flow rate from the containment air cooling coils. The containment specific humidity increases proportionately with time and leakage until the dewpoint is reached at the containment recirculation unit cooling coils. If the specific humidity increases above this point, the heat removal needed to cool the air-steam mixture to its dewpoint temperature increases above this point. Therefore, since the cooling coils are designed to remove heat at a constant rate, an increase in specific humidity results in increased condensate flow. The containment air cooler condensate flow rate measuring system consists of a vertical standpipe with an internal self-siphoning device, which empties the condensate in the standpipe to the sump when the standpipe is nearly full. The condensate measuring system permits measurement of the condensate flow rate from each containment recirculation unit by means of a derivative unit, which measures the rate of change in the standpipe level. Should the RCS leakage inside the containment increase, the condensate flow also increases, thereby increasing the rate of change of the standpipe level. The rate of level change in the standpipe is continuously recorded on strip chart recorders in the control room. An alarm for high rate of level change is provided to warn control room personnel of an increase in the condensate flow rate. An alarm

is also provided if condensate flow is greater than the amount of flow that the siphon can discharge to the sump.

2.2 Proposed Changes to the Technical Specifications Current Comanche Peak TS 3.4.15 is different than STS 3.4.15, RCS Leakage Detection Instrumentation, in NUREG-1431, Standard Technical Specifications, Westinghouse Plants, Volume 1, Specifications, Revision 4.0, dated April 2012 (ADAMS Accession No. ML12100A222), which reflects the changes in TSTF-513, Revision 3. The licensee proposes to align the current Comanche Peak TS 3.4.15 with NUREG-1431 STS 3.4.15 and to adopt the STS changes proposed in TSTF-513, Revision 3. A full description of the TS changes is presented in Section 3.0 of this safety evaluation.

2.3 Applicable Regulatory Requirements and Guidance The NRC regulatory requirements related to the content of the TSs are contained in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36, Technical specifications. The regulation in 10 CFR 50.36(c)(2)(i) states, in part, that Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. The regulations in 10 CFR 50.36(c)(2)(ii) lists four criteria for determining whether particular items are required to be included in the TS LCOs. The first criterion (Criterion 1) applies to Installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary. As described in the Federal Register notice regarding this regulation (60 FR 36953; July 19, 1995), the scope of TSs includes two general classes of technical matters: (1) those related to prevention of accidents, and (2) those related to mitigation of the consequences of accidents. Criterion 1 addresses systems and process variables that alert the operator to a situation when accident initiation is more likely, and supports the first of these two general classes of technical matters which are included in TSs. As stated, in part, in 10 CFR 50.36(c)(2)(i), When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.

The NRCs guidance for the format and content of PWR TSs can be found in NUREG-1431, Revision 4.0. STS 3.4.15 contains the guidance specific to the RCS leakage detection instrumentation for PWRs. The STS Bases provide a summary statement of the reasons for the STS.

The Bases for STS 3.4.15 contained in NUREG-1431, Standard Technical Specifications, Westinghouse Plants, Volume 2, Bases, Revision 4.0, dated April 2012 (ADAMS Accession No. ML12100A228), provide background information, the applicable safety analyses, a description of the LCO, the applicability for the RCS leakage detection instrumentation TS, and describe the actions and surveillance requirements (SRs). The TS Bases provide the purpose or reason for the TSs that are derived from the analyses and evaluation included in the safety analysis report, and for these Specifications, the RCS leakage detection instrumentation design assumptions and licensing basis for the plant.

As stated in NRC Information Notice (IN) 2005-24, Nonconservatism in Leakage Detection Sensitivity, dated August 3, 2005 (ADAMS Accession No. ML051780073), the reactor coolant activity assumptions for containment atmosphere gaseous radioactivity monitors may be

nonconservative. This means the monitors may not be able to detect a 1 gpm leak within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> under all likely operating conditions.

The issue described in IN 2005-24 has raised questions regarding the operability requirements for containment atmosphere gaseous radioactivity monitors. TSTF-513, Revision 3, revises the TS Bases to reflect the proposed TS changes and more accurately describe the contents of the facility design basis related to operability of the RCS leakage detection instrumentation. Part of the TS Bases changes revises the specified safety function of the RCS leakage detection monitors to specify the required instrument sensitivity level. In addition, TSTF-513, Revision 3, includes revisions to TS Actions for RCS leakage detection instrumentation to establish limits for operation during conditions of reduced monitoring sensitivity because of inoperable RCS leakage detection instrumentation.

The regulation in 10 CFR Part 50, Appendix A, General Design Criterion (GDC) 30, Quality of reactor coolant pressure boundary, requires means for detecting and, to the extent practical, identifying the location of the source of RCS leakage.

Regulatory Guide (RG) 1.45, Revision 0, Reactor Coolant Pressure Boundary Leakage Detection Systems, dated May 1973 (ADAMS Accession No. ML003740113), describes acceptable methods of implementing the GDC 30 requirements with regard to the selection of leakage detection systems for the reactor coolant pressure boundary (RCPB).

RG 1.45, Revision 0, Regulatory Position C.2, states:

Leakage to the primary reactor containment from unidentified sources should be collected and the flow rate monitored with an accuracy of one gallon per minute (gpm) or better.

RG 1.45, Revision 0, Regulatory Position C.3 states:

At least three separate detection methods should be employed and two of these methods should be (1) sump level and flow monitoring and (2) airborne particulate radioactivity monitoring. The third method may be selected from the following:

a. monitoring of condensate flow rate from air coolers [or]

b. monitoring of airborne gaseous radioactivity.

Humidity, temperature, or pressure monitoring of the containment atmosphere should be considered as alarms or indirect indication of leakage to the containment.

RG 1.45, Revision 0, Regulatory Position C.5 states:

The sensitivity and response time of each leakage detection system in regulatory position 3. above employed for unidentified leakage should be adequate to detect a leakage rate, or its equivalent, of one gpm in less than one hour.

RG 1.45, Revision 0, states, in part:

In analyzing the sensitivity of leak detection systems using airborne particulate or gaseous radioactivity, a realistic primary coolant radioactivity concentration assumption should be used. The expected values used in the plant environmental report would be acceptable.

The appropriate sensitivity of a plants containment atmosphere gaseous radioactivity monitors is dependent on the design assumptions and the plant-specific licensing basis as described in the plants final safety analysis report (FSAR). The NRC staffs approval of the use of expected primary coolant radioactivity concentration values used in the environmental report creates a potential licensing conflict when a licensee is able to achieve and maintain primary coolant radioactivity concentration values lower than the value assumed in the environmental report.

RG 1.45, Revision 1, Guidance on Monitoring and Responding to Reactor Coolant System Leakage, was issued in May 2008 (ADAMS Accession No. ML073200271). RG 1.45, Revision 1, describes methods for implementing GDC 30 requirements that are different from those in RG 1.45, Revision 0, and was developed and issued to support new reactor licensing.

RG 1.45, Revision 1, allows that having two TS leakage detection methods capable of detecting a 1 gpm leak within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> provides adequate leakage detection capability from a safety perspective. It recommends that other potential indicators (including the gaseous radiation monitors) be maintained even though they may not have the same detection capability. These indicators, in effect, provide additional defense-in-depth.

The regulation, 10 CFR Part 50, Appendix A, GDC 4, Environmental and dynamic effects design bases, requires, in part, Structures, systems, and components important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents. GDC 4 allows the use of leak-before-break (LBB) technology to exclude dynamic effects of pipe ruptures in the design bases when analyses reviewed and approved by the Commission demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping.

Comanche Peaks compliance with GDC 30 is discussed in its updated FSAR (UFSAR)

(ADAMS Package Accession No. ML17226A045) Section 3.1.4.1, Criterion 30 - Quality of Reactor Coolant Pressure Boundary. With respect to RCS leakage detection, Comanche Peak UFSAR Section 3.1.4.1 states:

Leakage from components is detected by an increase in the amount of makeup of water required to maintain a normal level in the pressurizer.

The reactor vessel closure joint is provided with a temperature-monitored leakoff between double gaskets. Leakage into the containment is drained to the Containment Building Sump.

Leakage is also detected by measuring the airborne activity and the rate at which condensate drained from the Containment Building recirculation units.

Monitoring the inventory of reactor coolant in the system at the pressurizer, volume control tank, and coolant drain collection tanks makes available an accurate indication of integrated leakage. The RCPB leakage detection system is discussed in Section 5.2.5.

Comanche Peaks UFSAR Section 5.2.5, Detection of Leakage Through Reactor Coolant Pressure Boundary, states, in part:

The leakage detection systems provide information which permits the plant operators to take immediate corrective action should a leak be evaluated as detrimental to the safety of the plant. Leakage detection system design objectives are in accordance with the requirements of 10 CFR Part 50, GDC 30, and NRC RG 1.45 [, Revision 0].

3.0 TECHNICAL EVALUATION

3.1 Proposed Changes to Align with NUREG-1431 Current Comanche Peak TS 3.4.15 differs from STS 3.4.15 in NUREG-1431, Volume 1, Revision 4.0, which reflects the changes in TSTF-513, Revision 3. The licensee proposed to align the current Comanche Peak TS 3.4.15 with NUREG-1431 STS 3.4.15. This section addresses the differences between Comanche Peak current TS 3.4.15 and NUREG-1431, STS 3.4.15.

TS 3.4.15 LCO The current Comanche Peak TS LCO 3.4.15 states:

The following RCS leakage detection instrumentation shall be OPERABLE:

a. One Containment Sump Level and Flow Monitoring System;

b. One containment atmosphere particulate radioactivity monitor; and

c. One containment air cooler condensate flow rate monitor or one containment atmosphere radioactivity monitor (gaseous).

The licensee proposed to re-align the LCO requirements to be consistent with NUREG-1431, STS 3.4.15. The proposed Comanche Peak TS LCO 3.4.15 would state:

The following RCS leakage detection instrumentation shall be OPERABLE:

a. One containment sump (level or discharge flow) monitor,

b. One containment atmosphere radioactivity monitor (gaseous or particulate), and

c. One containment air cooler condensate flow rate monitor.

STS LCO 3.4.15 requires three instruments to be operable, one for the containment sump, one for the containment radioactivity, and one for containment humidity. The Westinghouse design represented in the STS is as follows:

The containment sump is used to collect unidentified leakage and consists of the normal sump and the emergency sump. The monitor on the containment sump detects level or flow rate or the operating frequency of a pump and is instrumented to detect when there is an increase above the normal valve by 1 gpm.

The reactor coolant contains radioactivity that when released to the containment can be detected by the gaseous or particulate containment atmosphere radioactivity monitor.

An increase in humidity of the containment atmosphere could indicate the release of water vapor to the containment. Condensate flow from air coolers is instrumented to detect when there is an increase above the normal value by 1 gpm.

The NRC staff reviewed Comanche Peaks RCS leakage detection instrumentation described in TS 3.4.15 and found that it matches that of the representative Westinghouse Plant in NUREG-1431, STS 3.4.15. The NRC staff concludes that the proposed changes to Comanche Peak TS LCO 3.4.15 require instruments of diverse monitoring principles to be operable to provide confidence that small amounts of unidentified leakage are detected in time to allow operator actions to place the plant in a safe condition when RCS leakage indicates possible RCPB degradation, and that the requirements of 10 CFR 50.36(c)(2)(i) are met because the LCO is the lowest functional capability or performance level of equipment required for safe operation of the facility. Therefore, the NRC staff finds that proposed changes are acceptable.

TS 3.4.15 Actions Comanche Peak TS 3.4.15, Actions A through E, address inoperability of the current LCO requirements. The remedial actions (i.e., Actions) associated with an LCO contain Conditions that typically describe the ways in which the requirements of the LCO can fail to be met. Each stated Condition has Required Action(s) and Completion Time(s) (CT). For certain Conditions, the TS requires exiting the Mode of Applicability of an LCO (i.e., shutdown the reactor).

TS 3.4.15 Action A Proposed TS LCO 3.4.15.a requires one containment sump monitor (level or discharge flow) to be operable compared to the current TS LCO 3.4.15.a, which requires one containment sump level and flow monitoring system to be operable. The proposed Condition A, Required containment sump monitor inoperable, addresses the condition when sump monitoring required in the proposed TS LCO 3.4.15.a is inoperable, which is comparable to the current Condition A, which addresses the condition when sump monitoring required in the current TS LCO 3.4.15.a is inoperable. In addition, the revision aligns proposed Condition A with the STS 3.4.15 Condition A. Condition A in both the proposed and current TS address the inoperability of the sump monitoring while two diverse leakage detection instrumentation remain operable. Since the revision to Condition A is comparable to Condition A in the current TS and aligns Condition A with the STS, the NRC staff finds the revision to Condition A acceptable.

The licensee retained Required Action A.1, which requires for the condition of an inoperable required containment sump monitor the performance of an RCS water inventory balance once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The proposed Required Action A.2, Restore required containment sump monitor to OPERABLE status, requires the restoration of the proposed TS LCO 3.4.15.a in 30 days, which is comparable to the current Required Action A.2, which requires the restoration of the sump monitoring required in the current TS LCO 3.4.15.a in 30 days. In addition, the revision aligns proposed Required Action A.2 with the STS 3.4.15 Required Action A.2. Since the revision to Required Action A.2 is comparable to Required Action A.2 in the current TS and aligns Required Action A.2 with the STS, the NRC staff finds the revision to Required Action A.2 acceptable.

TS 3.4.15 Action B Proposed TS LCO 3.4.15.b requires one containment atmosphere radioactivity monitor (gaseous or particulate) to be operable compared to the current TS LCO 3.4.15.b, which requires one containment atmosphere particulate radioactivity monitor. The proposed TS LCO 3.4.15.b includes the relocated containment atmosphere gaseous radioactivity monitor from current TS LCO 3.4.15.c. The proposed grouping of gaseous and particulate monitors in TS LCO 3.4.15.b enhances the LCO since it requires the monitoring of containment atmosphere radioactivity, which may be subject to the potential limitation of low coolant radioactivity, while requiring the diverse leakage detection instrumentation of the containment air cooler condensate flow rate monitor. The proposed Condition B, Required containment atmosphere radioactivity monitor inoperable, addresses the condition when containment atmosphere radioactivity monitoring required in the proposed TS LCO 3.4.15.b is inoperable, which is comparable to the current Condition B (considering the proposed change to TS LCO 3.4.15.b),

which addresses the condition when containment atmosphere particulate radioactivity monitoring required in the current TS LCO 3.4.15.b is inoperable. In addition, the revision aligns proposed Condition B with the STS 3.4.15 Condition B. Condition B in both the proposed and current TS address the inoperability of the containment atmosphere radioactivity monitoring while two diverse leakage detection instrumentation remain operable. Since the revision to Condition B is comparable to Condition B in the current TS and aligns Condition B with the STS, the NRC staff finds the revision to Condition B acceptable.

The licensee proposed to add new Required Action B.2.2 to TS 3.4.15 Condition B as an alternative to current Required Action B.2. New Required Action B.2.2 would require verifying the containment air cooler condensate flow rate monitor is operable within 30 days. In order to add new Required Action B.2.2 to TS 3.4.15 Condition B, current Required Action B.2 is renumbered from B.2 to B.2.1 and a logic connector or is used to connect Required Action B.2 (renumbered as B.2.1) to new Required Action B.2.2.

The proposed Required Action B.2.1, Restore required containment atmosphere radioactivity monitor to OPERABLE status, requires the restoration of the proposed TS LCO 3.4.15.b in 30 days, which is comparable to the current Required Action B.2 (considering the proposed change to TS LCO 3.4.15.b), which requires the restoration of the containment atmosphere particulate radioactivity monitor required in the current TS LCO 3.4.15.b in 30 days. The proposed Required Action B.2.2, Verify containment air cooler condensate flow rate monitor is OPERABLE, permits reactor operation to continue if the containment air cooler condensate flow rate monitoring system is operable, provided grab samples are taken and analyzed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or a water inventory balance is performed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, because the containment air cooler condensate flow rate monitor is adequate to detect RCS leakage and at least one other form of leakage detection is available (e.g., containment sump level or discharge flow monitor). The remedial actions (grab samples, water inventory balance), unchanged from the current TS, provide alternate periodic information that is adequate to detect leakage, in addition to the information provided by the containment air cooler condensate flow rate monitor and containment sump level or discharge flow monitor to detect leakage. In addition, the revision aligns proposed Required Actions B.2.1 and B.2.2 with the STS 3.4.15 Required Actions B.2.1 and B.2.2. Since (1) the revision to Required Action B.2.1 is comparable to Required Action B.2 in the current TS, (2) the new Required Action B.2.2 ensures two diverse leakage detection instrumentation remain available with existing remedial actions, and (3) the revision aligns Required Actions B.2.1 and B.2.2 with the STS, the NRC staff finds the revision to Required Actions B.2.1 and B.2.2 acceptable.

TS 3.4.15 Actions C and E The current Action C addresses the condition when current TS LCO 3.4.15.c is not met. The current TS LCO 3.4.15.c requires either one containment air cooler condensate flow rate monitor or one containment atmosphere gaseous radioactivity monitor; therefore, the current Action C addresses the condition when neither of these alternative monitors is operable. As discussed above, to align proposed Condition C with STS 3.4.15 Condition C, the licensee has proposed to relocate the containment atmosphere gaseous radioactivity monitor from current TS LCO 3.4.15.c to proposed TS LCO 3.4.15.b (which would require one containment atmosphere radioactivity monitor, gaseous or particulate), leaving only the requirement for one containment air cooler condensate flow rate monitor in the proposed TS LCO 3.4.15.c.

Reflecting the proposed TS LCO 3.4.15.b (containment atmosphere radioactivity monitor, gaseous or particulate) and the proposed TS LCO 3.4.15.c (containment air cooler condensate flow rate monitor), the licensee proposed to split and revise the current Action C into proposed Action C and Action E. The proposed Action C addresses the condition when the proposed TS LC 3.4.15.c is not met, and the proposed Action E addresses the condition when the proposed TS LCO 3.4.15.b and the proposed TS LCO 3.4.15.c are both not met.

Specifically, the licensee proposed the following changes to TS 3.4.15 Action C:

Revise the current TS 3.4.15 Condition C to address the inoperability of just the containment air cooler condensate flow rate monitor.

Replace TS 3.4.15 Required Action C.1.1 with Required Action C.1, Perform SR 3.4.15.1.

Relocate and revise TS 3.4.15 Required Action C.2.1 to TS 3.4.15 Required Action E.1.

Relocate and revise TS 3.4.15 Required Action C.2.2 to TS 3.4.15 Required Action E.2.

Renumber TS 3.4.15 Required Actions C.1.1 and C.1.2 as TS 3.4.15 Required Actions C.1 and C.2, respectively.

Revise and partially relocate TS 3.4.15 Condition C to TS 3.4.15 Condition E.

The proposed TS LCO 3.4.15.c requires one containment air cooler condensate flow rate monitor to be operable. The proposed Condition C, Containment air cooler condensate flow rate monitor inoperable, addresses the condition when the containment air cooler condensate flow rate monitor in the proposed TS LCO 3.4.15.c is inoperable. In addition, the revision aligns proposed Condition C with the STS 3.4.15 Condition C. Since the revision to Condition C is comparable to Condition C in the current TS, accounting for the relocation of the containment atmospheric gaseous radioactivity monitor from LCO 3.4.15.c to LCO 3.4.15.b, and aligns Condition C with the STS, the NRC staff finds the revision to Condition C acceptable.

The licensee proposed to revise the current Required Actions for Condition C to align them with those in the STS. The current Required Actions for Condition C requires that grab samples of the containment atmosphere be analyzed with a CT of once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Required Action C.1.1) or that a water inventory balance, in accordance with SR 3.4.13.1 (Required Action C.1.2), be performed to provide alternate periodic information. In addition, the current Required Actions for Condition C require that containment atmospheric gaseous radioactivity monitor (Required Action C.2.1) or the containment air cooler condensate flow rate monitor (Required Action C.2.2) be restored with 30 days. With the relocation of the containment atmosphere gaseous radioactivity monitor from current TS LCO 3.4.15.c to proposed TS LCO 3.4.15.b, and the corresponding change to Condition C, the grab samples of the

containment atmosphere (Required Action C.1.1) and the restoration of the containment atmospheric gaseous radioactivity monitor (Required Action C.2.1) are no longer applicable.

Consistent with STS Required Action C.1.1, the licensee proposed to replace the current Required Action C.1.1 with Perform SR 3.4.15.1, with a CT of once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. SR 3.4.15.1 requires the performance of a channel check of the required containment atmosphere particulate and gaseous radioactivity monitors in accordance with the Surveillance Frequency Control Program. The channel check provides reasonable confidence that the required containment atmosphere radioactivity monitor is operating properly. The restoration of the containment air cooler condensate flow rate monitor in 30 days (the current Required Action C.2.2) is not necessary since at least two diverse leakage detection instrumentation, a containment sump monitor, and a containment atmosphere radioactivity monitor, remain operable, along with the periodic channel check of the containment atmosphere radioactivity monitor or the water inventory balance. With the removal of current Required Actions C.2.1 and C.2.2, the current Required Actions C.1.1 and C.1.2 are renumbered to C.1 and C.2 respectively. Based on (1) two diverse leakage detection instrumentation remaining operable, (2) the Required Actions to either confirm the operation of the containment atmosphere radioactivity monitor or provide alternate periodic information that is adequate to detect leakage (water inventory balance), and given that (3) the proposed Required Actions aligns the Required Actions with the STS, the NRC staff finds the revision to Condition C Required Actions acceptable.

The licensee proposed to revise and partially relocate the current Action C into proposed Action E to address the condition when the proposed TS LCO 3.4.15.b and TS LCO 3.4.15.c are both not met and to align with STS Condition E.

Current Comanche Peak TS 3.4.15 Condition C states:

Required containment atmosphere gaseous radioactivity monitor inoperable.

AND Required containment air cooler condensate flow rate monitor inoperable.

The licensee proposed to revise and partially relocate TS 3.4.15 Condition C to TS 3.4.15 Condition E. TS 3.4.15 Condition C (renumbered as TS 3.4.15 Condition E) would be revised to state:

Required containment atmosphere radioactivity monitor inoperable.

AND Containment air cooler condensate flow rate monitor inoperable.

The two parts of proposed Condition E reflect the relocation of the containment atmosphere gaseous radioactivity monitor to proposed LCO 3.4.15.b and the corresponding changes to Condition B and Condition C. The deletion of required from the second part of proposed Condition E is acceptable because the LCO does not provide for more than one containment air cooler condensate flow rate monitor. The term required is reserved for situations in which there are multiple ways to meet the LCO, such as the requirement for either a gaseous or particulate containment atmosphere radioactivity monitor. Given that the proposed Condition E

(1) is comparable to current Condition C, accounting for the relocation of the containment atmospheric gaseous radioactivity monitor from LCO 3.4.15.c to LCO 3.4.15.b, (2) addresses the condition when TS LCO 3.4.15.b and TS LCO 3.4.15.c are both not met, and (2) aligns Condition E with the STS, the NRC staff finds the proposed Condition E acceptable.

The licensee proposed to revise and partially relocate the current Required Actions for Condition C to Condition E to align them with those in the STS. Specifically, the licensee proposed to relocate and revise the current Required Action C.2.1 and its associated CT to Required Action E.1, and to relocate the current Required Action C.2.2 to Required Action E.2.

In proposed Condition E, the only operable leakage detection instrumentation would be the containment sump monitor. The proposed Required Actions, to be completed within 30 days, would be to restore the required containment atmosphere radioactivity monitor to OPERABLE status (proposed Required Action E.1), or to restore the containment cooler condensate flow rate monitor to OPERABLE status (proposed Required Action E.2). In addition, in proposed Condition E (effectively, proposed Conditions B and C together), the additional remedial actions for an inoperable containment atmosphere radioactivity monitor (Required Actions B.1.1 and B.1.2) and for an inoperable containment air cooler condensate flow rate monitor (proposed Required Actions C.1 and C.2) would apply. The 30-day CT to restore either of the inoperable monitors ensures that the plant would not be operated for an extended period without diverse monitors for detecting leakage; the containment sump monitor would still be available for leakage detection, and additional information would be available, as applicable, from the alternative periodic remedial actions (e.g., the periodic water inventory balance in accordance with SR 3.4.13.1, in Required Action B.1.2 and proposed Required Action C.2). Given that the proposed Condition E Required Actions are (1) comparable to those of the current Condition C Required Actions, accounting for the relocation of the containment atmospheric gaseous radioactivity monitor from LCO 3.4.15.c to LCO 3.4.15.b, (2) reflect the implementation of the applicable proposed Condition B and proposed Condition C Required Actions, and (3) align the TS with the STS, the NRC staff finds the proposed Condition E Required Actions acceptable.

3.2 Proposed Changes to Adopt TSTF-513 In adopting the changes to the TSs included in TSTF-513, Revision 3, the licensee proposed to revise TS 3.4.15 Conditions and Required Actions. The licensee proposed adding new Condition D to TS 3.4.15. As indicated by the addition of a new note, New Condition D would be applicable only when the containment atmosphere gaseous radioactivity monitor is the only operable RCS leakage detection monitor. This new Condition is necessary because improved fuel integrity and the resulting lower primary coolant radioactivity concentration affects a plants containment atmosphere gaseous radioactivity monitor to a greater extent than other monitors.

The proposed Required Actions for new Condition D require the licensee to analyze grab samples of the containment atmosphere once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and restore the required containment sump monitor to operable status within 7 days, or analyze grab samples of the containment atmosphere once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and restore the containment air cooler condensate flow rate monitor to OPERABLE status within 7 days. These actions are in addition to the Required Actions of Conditions A and C, which require performing a water inventory balance in accordance with SR 3.4.13.1 once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and a CHANNEL CHECK of the containment atmosphere radioactivity monitor once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

The NRC staff determined that the proposed Condition D Required Actions and CTs are adequate because the grab samples combined with the more frequent RCS mass balances and Channel Checks will provide an alternate method of monitoring RCS leakage when the containment atmosphere gaseous radioactivity monitor is the only operable RCS leakage

detection monitor, and the 12-hour interval is sufficient to detect increasing RCS leakage long before a piping flaw could progress to a catastrophic failure of the primary RCPB. Allowing 7 days to restore another RCS leakage monitor to operable status is reasonable given the diverse methods employed in the Required Actions to detect an RCS leak and the low probability of a large RCS leak during this period. Proposed Condition D sufficiently alerts the operating staff, provides a comparable ability to detect RCS leakage, and provides time intervals that are reasonable. Therefore, the NRC staff determined that proposed Condition D provides an adequate assurance of safety when judged against current regulatory standards.

Certain American Society of Mechanical Engineers Code Class 1 piping systems in Comanche Peak have been approved by the NRC for LBB. The basic concept of LBB is that certain piping material has sufficient fracture toughness (i.e., ductility) to resist rapid flaw propagation, thereby minimizing the probability of a pipe rupture. The licensee has evaluated postulated flaws in RCS loop piping and determined the piping has sufficient fracture toughness that the postulated flaw would not lead to pipe rupture and potential damage to adjacent safety-related systems, structures and components before the plant could be placed in a safe, shutdown condition. The NRC staff has previously reviewed and approved these plant-specific LBB analyses (ADAMS Package Accession No. ML081510157). Before remotely approaching a pipe rupture, the postulated flaw would lead to limited but detectable leakage, which would be identified by the leak detection systems in time for the operator to take action. The NRC staff previously addressed concerns that LBB depends on erroneous leak rate measurements in the final rulemaking for use of LBB technology. In addressing the concerns, it was noted (in 51 FR 12502; April 11, 1986) that:

. . . one criterion for application of leak-before-break is that postulated flaw sizes be large enough so that the leakage is about ten times the leak detection capability, and that this flaw be stable even if earthquake loads are applied to the pipe in addition to the normal operating loads. This margin of a factor of ten is more than ample to account for uncertainties in both leakage rate calculations and [leak] detection capabilities.

Additional sensitivity studies reported by Lawrence Livermore National Laboratory in NUREG/CR-2189, dated September 1981, entitled Probability of Pipe Fracture in the Primary Coolant Loop of a PWR Plant indicate that even in the absence of leak detection, the probability of pipe ruptures in PWR primary coolant loop piping is sufficiently low to warrant exclusion of these events from the design basis.

The proposed actions for inoperable RCS leakage detection instrumentation maintain sufficient continuity, redundancy, and diversity of leakage detection capability that an extremely low probability of undetected leakage leading to pipe rupture is maintained. This extremely low probability of pipe rupture continues to satisfy the basis for acceptability of LBB in GDC 4.

The licensee also proposed minor changes to ensure continuity of the TS format. These changes re-designate current Condition D, which applies when the required action and the associated completion time are not satisfied, as Condition F, and current Condition E, which applies when there are no operable monitors, as Condition G. Similar changes were made to the associated Required Actions. The NRC staff determined that these editorial changes are appropriate to reflect the insertion of a new Condition D, and therefore are acceptable.

As described above, the licensee proposed changes to TS 3.4.15 to align with STS 3.4.15, to clarify the operability requirements for RCS leakage detection instrumentation, and to allow a limited time to repair one or more of the inoperable monitors. The licensee did not propose any changes that would affect the design capability, function, operation, or method of testing the RCS leakage detection instrumentation. Therefore, the NRC staff finds that there is no change to conformance to GDC 30 and RG 1.45, Revision 0 and thus, the requirements of GDC 30 and the guidelines of RG 1.45, Revision 0 will continue to be met.

3.3 Technical Evaluation Conclusion

The NRC staff evaluated the licensees proposed changes against the applicable regulatory requirements listed in Section 2.0 of this safety evaluation. The NRC confirmed that the regulatory requirements of 50.36(c)(2)(i) will continue to be met because the LCO, as amended by the proposed change, will continue to require the lowest functional capability or performance levels of equipment required for safe operation of the facility. When one on more required containment leakage detection instrumentation is not operable, the proposed change includes acceptable remedial actions to ensure continued leakage monitoring either through the remaining operable containment leakage detection instrumentation or through periodic alternative leakage detection, and identifies conditions requiring the shutdown of the reactor.

The NRC also confirmed that the Comanche Peak RCS leakage detection instrumentation matches that of the representative Westinghouse Plant in NUREG-1431 and that the Comanche Peak TS 3.4.15 has been acceptably aligned to STS 3.4.15. The NRC staff also compared the proposed changes to the changes made to STS by TSTF-513, Revision 3. The NRC staff determined that all the proposed changes afford adequate assurance of safety when judged against current regulatory standards. Therefore, the NRC staff finds the proposed changes acceptable.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Texas State official was notified of the proposed issuance of the amendments on June 16, 2020. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve 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 amendments involve no significant hazards consideration, published in the Federal Register on February 20, 2020 (85 FR 9813), and there has been no public comment on such finding. Accordingly, the amendments meet 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 amendments.

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 amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: K. Bucholtz, NRR D. Galvin, NRR Date: November 16, 2020

ML20168A924 *by e-mail OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA* NRR/DSS/STSB/BC*

NAME DGalvin PBlechman VCusumano DATE 11/10/2020 11/12/2020 2/14/2020 OFFICE OGC* NLO NRR/DORL/LPL4/BC* NRR/DORL/LPL4/PM*

NAME CCarson JDixon-Herrity DGalvin DATE 11/10/2020 11/16/2020 11/16/2020