ML112590431: Difference between revisions

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The licensee meets the intent of the GDC-4 as stated in the DBNPS UFSAR, Appendix 3D.1.0, "NRC General Design Criteria." The methods for meeting GDC-4 are found in UFSAR Section 5.2.4, "RCPB Leak Detection System": It The Reactor Coolant System leakage detection system includes the following:  
The licensee meets the intent of the GDC-4 as stated in the DBNPS UFSAR, Appendix 3D.1.0, "NRC General Design Criteria." The methods for meeting GDC-4 are found in UFSAR Section 5.2.4, "RCPB Leak Detection System": It The Reactor Coolant System leakage detection system includes the following:  
: a. The containment atmosphere particulate radioactivity monitoring system. b. The containment sump level/flow monitoring system. c. The containment atmosphere gaseous radioactivity monitoring system ... The DBNPS, Unit 1, RCS leak detection systems meet the intent of the regulatory positions provided in Regulatory Guide 1.45 and therefore the prerequisites for applying GDC-4 are satisfied.
: a. The containment atmosphere particulate radioactivity monitoring system. b. The containment sump level/flow monitoring system. c. The containment atmosphere gaseous radioactivity monitoring system ... The DBNPS, Unit 1, RCS leak detection systems meet the intent of the regulatory positions provided in Regulatory Guide 1.45 and therefore the prerequisites for applying GDC-4 are satisfied.
A public version of the DBNPS UFSAR is available in the NRC Public Document Room (PDR). Documents may be examined, and/or copied for a fee, at the NRC's PDR, located at One White Flint North, Public File Area 01 F21, 11555 Rockville Pike (first floor), Rockville, Maryland, or you can contact the NRC PDR Reference staff by telephone at 1-800-397-4209 or 4737, or send an e-mail to pdr.resource@nrc.gov.
A public version of the DBNPS UFSAR is available in the NRC Public Document Room (PDR). Documents may be examined, and/or copied for a fee, at the NRC's PDR, located at One White Flint North, Public File Area 01 F21, 11555 Rockville Pike (first floor), Rockville, Maryland, or you can contact the NRC PDR Reference staff by telephone at 1-800-397-4209 or 4737, or send an e-mail to pdr.resource@nrc.gov.  
3.0 TECHNICAL EVALUATION In adopting the changes to TSs included in TSTF-513, Revision 3, the licensee proposed to revise TS 3.4.15, "RCS Leakage Detection Instrumentation" Conditions and Required Actions. The licensee proposed adding new Condition C to TS 3.4.15. New Condition C would be applicable 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 plant's containment atmosphere gaseous radioactivity monitor to a greater extent than other monitors.
 
===3.0 TECHNICAL===
 
EVALUATION In adopting the changes to TSs included in TSTF-513, Revision 3, the licensee proposed to revise TS 3.4.15, "RCS Leakage Detection Instrumentation" Conditions and Required Actions. The licensee proposed adding new Condition C to TS 3.4.15. New Condition C would be applicable 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 plant's containment atmosphere gaseous radioactivity monitor to a greater extent than other monitors.
The proposed Required Actions for new Condition C require the licensee to analyze grab samples of the containment atmosphere once every 12 hours and restore the required containment sump monitor to operable status within seven days. These actions are in addition to the Required Actions of Conditions A and B which require performing an RCS mass balance once every 24 hours. The NRC staff determined that the proposed Condition C is more restrictive than the current requirement, because the current Condition that would apply to the situation when the containment atmosphere gaseous radioactivity monitor is the only operable RCS leakage detection monitor would allow the licensee 30 days to restore the inoperable monitors to operable status. The proposed Actions and Completion Times are adequate because the grab samples combined with the more frequent RCS mass balances 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 seven 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 C is conservative relative to the STS, sufficiently alerts the operating staff, provides a comparable ability to detect RCS leakage, and provides time intervals that are reasonable.
The proposed Required Actions for new Condition C require the licensee to analyze grab samples of the containment atmosphere once every 12 hours and restore the required containment sump monitor to operable status within seven days. These actions are in addition to the Required Actions of Conditions A and B which require performing an RCS mass balance once every 24 hours. The NRC staff determined that the proposed Condition C is more restrictive than the current requirement, because the current Condition that would apply to the situation when the containment atmosphere gaseous radioactivity monitor is the only operable RCS leakage detection monitor would allow the licensee 30 days to restore the inoperable monitors to operable status. The proposed Actions and Completion Times are adequate because the grab samples combined with the more frequent RCS mass balances 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 seven 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 C is conservative relative to the STS, 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 C provides an adequate assurance of safety when judged against current regulatory standards.
Therefore, the NRC staff determined that proposed Condition C provides an adequate assurance of safety when judged against current regulatory standards.
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In accordance with the Commission's regulations, the Ohio State official was notified of the proposed issuance of the amendment.
In accordance with the Commission's regulations, the Ohio State official was notified of the proposed issuance of the amendment.
The State official had no comments.
The State official had no comments.  
5.0 ENVIRONMENTAL CONSIDERATION This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 [or changes a surveillance requirement].
 
===5.0 ENVIRONMENTAL===
 
CONSIDERATION This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 [or changes a surveillance requirement].
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent 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 and there has been no public comment on such finding (76 FR 40940; July 12, 2011). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (76 FR 40940; July 12, 2011). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Revision as of 17:31, 13 October 2018

Davis-Besse Nuclear Power Station, Unit No. 1 - Issuance of Amendment Adoption of Technical Specifications Task Force Change Traveler 513, Revision to Technical Specification 3.4.14
ML112590431
Person / Time
Site: Davis Besse Cleveland Electric icon.png
Issue date: 12/09/2011
From: Michael Mahoney
Plant Licensing Branch III
To: Allen B S
FirstEnergy Nuclear Operating Co
mahoney, m NRR/DORL/LPLIII-2 415-3867
References
TAC ME6153
Download: ML112590431 (16)


Text

UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-0001 December 9, 2011 Mr. Barry S. Allen Site Vice President FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station Mail Stop A-DB-3080 5501 North State Route 2 Oak Harbor, OH 43449-9760 DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO.1-ISSUANCE OF AMENDMENT RE: ADOPTION OF TECHNICAL SPECIFICATIONS TASK FORCE CHANGE TRAVELER 513, REVISION TO TECHNICAL SPECIFICATION 3.4.14, "[REACTOR COOLANT SYSTEM] LEAKAGE DETECTION INSTRUMENTATION" (TAC NO. ME6153)

Dear Mr. Allen:

The U.S. Nuclear Regulatory Commission (NRC, the Commission) has issued the enclosed Amendment No. 284 to Facility Operating License No. NPF-3 for the Davis-Besse Nuclear Power Station, Unit No.1 (DBNPS). The amendment revises the Technical Specifications (TS) for DBNPS in response to FirstEnergy Nuclear Operating Company's (FENOC's) application dated April 29, 2011. This amendment revises the DBNPS TSs to define a new time limit for restoring inoperable Reactor Coolant System (RCS) leakage detection instrumentation to operable status and establish alternate methods of monitoring RCS leakage when one or more required monitors are inoperable.

The amendment also makes TS Bases changes which reflect the proposed TS changes and more accurately reflect the contents of the facility design basis related to operability of the RCS leakage detection instrumentation.

The licensee's request is consistent with the guidance contained in NRC-approved Technical Specifications Task Force, Change Traveler 513 (TSTF-513), Revision 3. TSTF-513, Revision 3 was made available by the NRC on January 3, 2011 (76 FR 189) as part of the consolidated line item improvement process.

B.Allen A copy of the Safety Evaluation is also enclosed.

The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice. sftJ Michael Mahoney, Project anager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346

Enclosures:

1. Amendment No. 284 to NPF-3 2. Safety Evaluation cc w/encls: Distribution via Listserv UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-0001 FIRSTENERGY NUCLEAR OPERATING COMPANY AND FIRSTENERGY NUCLEAR GENERATION CORP. DOCKET NO. 50-346 DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO.1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 284 License No. NPF-3 The U.S. Nuclear Regulatory Commission (the Commission) has found that: The application for amendment filed by FirstEnergy Nuclear Operating Company et al. (the licensee), dated April 29, 2011, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; 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 Commission's regulations; 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 The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied. 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-3 is hereby amended to read as follows:

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 284 ,are hereby incorporated in the license. FENOC shall operate the facility in accordance with the Technical Specifications. This license amendment is effective as of its date of issuance and shall be implemented within 90 days of the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

'\::=-Ja b I.

J PILicensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications and Facility Operating License Date of Issuance:

December 9, 2011 ATTACHMENT TO LICENSE AMENDMENT NO. FACILITY OPERATING LICENSE NO. DOCKET NO. Replace the following pages of the Facility Operating License (FOL) 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. Remove Insert FOL NPF-3 FOL NPF-3 Page 4 Page 4 TSs TSs 3.4.15-1 3.4.15-1 3.4.15-2 3.4.15-2 3.4.15-3 3.4.15-3 2.C. This license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I: Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; 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: Maximum Power Level FENOC is authorized to operate the facility at steady state reactor core power levels not in excess of 2817 megawatts (thermal).

Prior to attaining the power level, Toledo Edison Company shall comply with the conditions identified in Paragraph (3) (0) below and complete the preoperational tests, startup tests and other items identified in Attachment 2 to this license in the sequence specified.

Attachment 2 is an integral part of this license. Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 284, are hereby incorporated in the license. FENOC shall operate the facility in accordance with the Technical Specifications. Additional Conditions The matters specified in the following conditions shall be completed to the satisfaction of the Commission within the stated time periods following the issuance of the license or within the operational restrictions indicated.

The removal of these conditions shall be made by an amendment to the license supported by a favorable evaluation by the Commission: FENOC shall not operate the reactor in operational Modes 1 and 2 with less than three reactor coolant pumps in operation. (b) Deleted per Amendment 6 (c) Deleted per Amendment 5 Amendment No. 284 RCS Leakage Detection Instrumentation 3.4.15 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.15 RCS Leakage Detection Instrumentation LCO The following RCS leakage detection instrumentation shall be OPERABLE: One containment sump monitor; and One containment atmosphere radioactivity monitor (gaseous or particulate).

MODES 1, 2, 3, and 4. ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Containment sump monitor inoperable.

A.i AND A.2 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.

Restore containment sump monitor to OPERABLE status. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 30 days B. Required containment atmosphere radioactivity monitor inoperable.

B.1.1 Analyze grab samples of the containment atmosphere.

OR Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 3.4.15-1 Amendment 284 3.4.15 RCS Leakage Detection Instrumentation ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. (continued)

B.1.2 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 Restore required containment atmosphere radioactivity monitor to OPERABLE status. 30 days

-NOTE-Only applicable when the containment atmosphere gaseous radiation monitor is the only OPERABLE monitor.

C. Required containment sump monitor inoperable.

C.1 AND 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 /> C.2 Restore containment sump monitor to OPERABLE status. 7 days D. Required Action and associated Completion Time of Condition A, B, or C not met. D.1 AND D.2 Be in MODE 3. Be in MODE 5. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 36 hours Both required monitors inoperable.

E.1 Enter LCO 3.0.3. Immediately Davis-Besse 3.4.15-2 Amendment 284 3.4.15 RCS Leakage Detection Instrumentation SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.15.1 Perform CHANNEL CHECK of required containment atmosphere radioactivity monitor. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> SR 3.4.15.2 Perform CHANNEL FUNCTIONAL TEST of required containment atmosphere radioactivity monitor. 31 days SR 3.4.15.3 Perform CHANNEL CALIBRATION of required containment atmosphere radioactivity monitor. 18 months SR 3.4.15.4 Perform CHANNEL CALIBRATION of containment sump monitor. 24 months Davis-Besse 3.4.15-3 Amendment 284 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 284 TO FACILITY OPERATING LICENSE NO. NPF-3 FIRSTENERGY NUCLEAR OPERATING COMPANY FIRSTENERGY NUCLEAR GENERATION CORP. DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO.1 DOCKET NO. 50-346

1.0 INTRODUCTION

By letter to the U.S. Nuclear Regulatory Commission (NRC, Commission) dated April 29, (Agencywide Document Access and Management System (ADAMS) Accession ML 11126A014), FirstEnergy Nuclear Operating Company (the licensee, FENOC) changes to the Technical Specifications (TS) for the Davis-Besse Nuclear Power Unit No.1 (DBNPS). The proposed changes revise TS 3.4.15, "RCS [Reactor Coolant Leakage Detection Instrumentation," and include TS Bases changes that summarize and the purpose of the TS and the specified safety function of the leakage detection monitors. April 29, 2011, letter included changes for DBNPS and Beaver Valley Power Station Unit Nos. 1 and 2. This amendment is only for DBNPS and an amendment for BVPS has processed by other correspondence (ADAMS Accession No. ML 11284A This amendment revises DBNPS TSs to define a new time limit for restoring inoperable leakage detection instrumentation to operable status and establish alternate methods monitoring RCS leakage when one or more required monitors are inoperable.

The also makes TS Bases changes which reflect the proposed TS changes and more reflect the contents of the facility design basis related to operability of the RCS leakage The licensee's request is consistent with the guidance contained in NRC-approved SpeCifications Task Force (TSTF) Standard Technical Specification (STS), Change TSTF-513, Revision 3, "Revise [pressurized-water reactor] PWR Operability Requirements Actions for RCS Leakage Instrumentation" (ADAMS Accession No. ML 102360355).

Revision 3, was made available by the NRC on January 3, 2011, (76 FR 189), as part of consolidated line item improvement

2.0 REGULATORY EVALUATION

The NRC's regulatory requirements related to the content of TSs are contained in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36. Paragraph (c)(2)(i) of 10 CFR 50.36 states that limiting conditions for operation (LCOs) are the lowest functional capability or performance levels of equipment required for safe operation of the facility.

Paragraph (c)(2)(ii) of 10 CFR 50.36 lists four criteria for determining whether particular items are required to be included in the TS LCOs. The first criterion 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 (RCPB). As described in the Federal Register notice associated with this regulation (60 FR 36953; July 16, 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 TS. As specified in Paragraph (c)(2)(i) of 10 CFR 50.36, when an LCO of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by TS until the condition can be met. The NRC's guidance for the format and content of PWR TSs can be found in NUREG-1430, Revision 3.0, "Standard Technical Specifications Babcock and Wilcox Plants." STS 3.4.15, "RCS Leakage Detection Instrumentation," 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 TS Bases for STS 3.4.15 contained in NUREG-1430, Revision 3.0, 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.

The TS Bases provide the purpose or reason for the TSs, which are derived from the analyses and evaluation included in the safety analysis report, including 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" (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 one gallon per minute (gpm) leak within one hour 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 revise 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.

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, describes acceptable methods of implementing the GDC-30 requirements with regard to the selection of leakage detection systems for the RCPB.

In RG 1.4S, Revision 0, Regulatory Position C.2, it states that "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 1.4S, 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) airbome 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 airbome gaseous radioactivity.

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

In RG 1.4S, Revision 0, Regulatory Position C.S, it 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 1.4S, Revision 0, further states, "In analyzing the sensitivity of leak detection systems using airbome 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 plant's containment atmosphere gaseous radioactivity monitors is dependent on the design assumptions and the plant-speCifiC licensing basis as described in the plant's updated final safety analysis report (UFSAR). The NRC staff's 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 1.4S, Revision 1, "Guidance on Monitoring and Responding to Reactor Coolant System Leakage," was issued in May 2008. RG 1.4S, Revision 1, describes methods for implementing GDC-30 requirements that are different from those in RG 1.4S, Revision 0, and was developed and issued to support new reactor licensing.

Revision 1 allows that having two TS leakage detection methods capable of detecting a one gpm leak within one hour 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 depth. The regulation in GDC-4 of Appendix A to to 10 CFR Part SO, "Environmental and dynamic effects design bases," requires structures, systems, and components important to safety to 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 NRC to demonstrate that the probability of fluid system piping rupture is extremely low under conditions consistent with the design basis for the piping.

The licensee meets the intent of the GDC-4 as stated in the DBNPS UFSAR, Appendix 3D.1.0, "NRC General Design Criteria." The methods for meeting GDC-4 are found in UFSAR Section 5.2.4, "RCPB Leak Detection System": It The Reactor Coolant System leakage detection system includes the following:

a. The containment atmosphere particulate radioactivity monitoring system. b. The containment sump level/flow monitoring system. c. The containment atmosphere gaseous radioactivity monitoring system ... The DBNPS, Unit 1, RCS leak detection systems meet the intent of the regulatory positions provided in Regulatory Guide 1.45 and therefore the prerequisites for applying GDC-4 are satisfied.

A public version of the DBNPS UFSAR is available in the NRC Public Document Room (PDR). Documents may be examined, and/or copied for a fee, at the NRC's PDR, located at One White Flint North, Public File Area 01 F21, 11555 Rockville Pike (first floor), Rockville, Maryland, or you can contact the NRC PDR Reference staff by telephone at 1-800-397-4209 or 4737, or send an e-mail to pdr.resource@nrc.gov.

3.0 TECHNICAL

EVALUATION In adopting the changes to TSs included in TSTF-513, Revision 3, the licensee proposed to revise TS 3.4.15, "RCS Leakage Detection Instrumentation" Conditions and Required Actions. The licensee proposed adding new Condition C to TS 3.4.15. New Condition C would be applicable 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 plant's containment atmosphere gaseous radioactivity monitor to a greater extent than other monitors.

The proposed Required Actions for new Condition C require the licensee to analyze grab samples of the containment atmosphere once every 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 seven days. These actions are in addition to the Required Actions of Conditions A and B which require performing an RCS mass balance once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The NRC staff determined that the proposed Condition C is more restrictive than the current requirement, because the current Condition that would apply to the situation when the containment atmosphere gaseous radioactivity monitor is the only operable RCS leakage detection monitor would allow the licensee 30 days to restore the inoperable monitors to operable status. The proposed Actions and Completion Times are adequate because the grab samples combined with the more frequent RCS mass balances 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 seven 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 C is conservative relative to the STS, 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 C provides an adequate assurance of safety when judged against current regulatory standards.

Certain American Society of Mechanical Engineers Code Class 1 piping systems in DBNPS have been approved by the NRC for LBB. The basic concept of LBB is that certain piping material has sufficient fracture toughness (Le., 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.

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 rule making for use of LBB technology.

In addressing the concerns, "10 CFR Part 50, Modification of General Design Criterion 4 Requirements for Protection Against Dynamic Effects of Postulated Pipe Ruptures," (51 FR 12502-12504; April 11, 1986), it states that: The NRC staff recognizes that the measurement or determination of leakage rates from a pressurized system involves uncertainties.

For this reason, 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 proposes minor changes to ensure continuity of the TS format. These changes re-Ietter current Condition C, which applies when the required action and the associated completion time of Condition A, B, or C are not satisfied, to Condition D, and current Condition D, which applies when both required monitors are inoperable, to Condition E. Similar changes were made to the associated Required Actions. The NRC staff determined that these changes are editorial in nature, and therefore acceptable.

The associated TS Bases submitted with the licensee's proposed revision for TS 3.4.15 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 and reflect the proposed TS changes. The proposed TS Bases changes related to the operability of the RCS leakage detection instrumentation are acceptable because they provide background information, the applicable safety analyses, a description of the limiting condition for operation, and the applicability for the RCS leakage detection instrumentation TS and are consistent with the design basis of the facility.

These instruments satisfy Criterion 1 of 10 CFR 50.36(c)(2)(ii) in that they are installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the RCPB. The NRC staff evaluated the licensee's proposed changes against the applicable regulatory requirements listed in Section 2.0 of this safety evaluation.

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 Commission's regulations, the Ohio State official was notified of the proposed issuance of the amendment.

The State official had no comments.

5.0 ENVIRONMENTAL

CONSIDERATION This amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 [or changes a surveillance requirement].

The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent 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 and there has been no public comment on such finding (76 FR 40940; July 12, 2011). 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 NRC staff 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) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public. Principal Contributors:

K. Hemphill, NRR M. Hamm, NRR Date of issuance:

December 9, 2011 B.Allen A copy of the Safety Evaluation is also enclosed.

The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice. Sincerely.

IRA! Michael Mahoney, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346

Enclosures:

1. Amendment No. 284 to NPF-3 2. Safety Evaluation cc w/encls: Distribution via Listserv DISTRIBUTION:

PUBLIC LPL3-2 RtF RidsNrrPMDavis-Besse Resource RidsNrrDirsltsb Resource RidsOgcRp Resource RidsRgn3MailCenter Resource RidsNrrLASRohrer Resource RidsNrrDorlLpl3-2 Resource RidsNrrDorlDpr Resource RidsAcrsAcnw_MailCTR Resource Amendment Accession No. ML 112590431 NRR-058 *B'y M emo D ae t d OFFICE LPL3-2/PM LPL3-2/LA DIRSIITSB OGC(NLO w/comments LPL3-2/BC NAME MMahoney SRohrer REIliott BHarris JZimmerman DATE 12/05/11 12/05/11 *8/23/11 9127111 12/09/11 OFFICIAL RECORD