ML032460784

License Amendment, Issuance of Amendment, Addition of Required Actions for Scram Discharge Volume Vent and Drain Valve Operability

ML032460784
Person / Time
Site:	Limerick
Issue date:	11/26/2003
From:	Scott Wall NRC/NRR/DLPM/LPD1
To:	Skolds J Exelon Generation Co, Exelon Nuclear
Wall, S. NRR/DLPM 415-2855
Shared Package
ML033300362	List: ML032460784
References
TAC MB6885, TAC MB6886
Download: ML032460784 (19)

Text

November 26, 2003 Mr. John L. Skolds, President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - ISSUANCE OF AMENDMENT RE: ADDITION OF REQUIRED ACTIONS FOR SCRAM DISCHARGE VOLUME VENT AND DRAIN VALVE OPERABILITY (TAC NOS. MB6885 AND MB6886)

Dear Mr. Skolds:

The Commission has issued the enclosed Amendment No. 168 to Facility Operating License No. NPF-39 and Amendment No. 131 to Facility Operating License No. NPF-85 for the Limerick Generating Station, Units 1 and 2. These amendments consist of changes to the Technical Specifications (TSs) in response to your application dated November 26, 2002.

These amendments revise TS 3.1.3.1, Control Rod Operability, by adding new Limiting Condition of Operation criteria and applicable ACTION requirements for scram discharge volume (SDV) vent and drain valves. The changes also modify TS 3.6.3, Primary Containment Isolation Valves, to clarify the relationship between TS 3.1.3.1 and TS 3.6.3 regarding SDV vent and drain valves.

A copy of our safety evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely,

/RA/

Scott P. Wall, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosures:

1. Amendment No. 168 to License No. NPF-39

2. Amendment No. 131 to License No. NPF-85

3. Safety Evaluation cc w/encls: See next page

Limerick Generating Station, Units 1 & 2 cc:

Chief Operating Officer Director Licensing Exelon Generation Company, LLC Exelon Generation Company, LLC 4300 Winfield Road Nuclear Group Headquarters Warrenville, IL 60555 Correspondence Control P. O. Box 160 Site Vice President Kennett Square, PA 19348 Limerick Generating Station Exelon Generation Company, LLC Manager Licensing P.O. Box 2300 Limerick and Peach Bottom Sanatoga, PA 19464 Exelon Generation Company, LLC Nuclear Group Headquarters Plant Manager Correspondence Control Limerick Generating Station P.O. Box 160 Exelon Generation Company, LLC Kennett Square, PA 19348 P.O. Box 2300 Sanatoga, PA 19464 Vice President General Counsel and Secretary Regulatory Assurance Manager - Limerick Exelon Generation Company, LLC Exelon Generation Company, LLC 2301 Market Street, S23-1 P.O. Box 2300 Philadelphia, PA 19101 Sanatoga, PA 19464 Correspondence Control Desk Senior Vice President - Nuclear Services Exelon Generation Company, LLC Exelon Generation Company, LLC 200 Exelon Way, KSA 1-N-1 4300 Winfield Road Kennett Square, PA 19348 Warrenville, IL 60555 Regional Administrator, Region I Vice President - Mid-Atlantic Operations U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC 475 Allendale Road 200 Exelon Way, KSA 3-N King of Prussia, PA 19406 Kennett Square, PA 19348 Senior Resident Inspector Vice President - Operations Support U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC Limerick Generating Station 4300 Winfield Road P.O. Box 596 Warrenville, IL 60555 Pottstown, PA 19464 Vice President Library Licensing and Regulatory Affairs U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC Region I 4300 Winfield Road 475 Allendale Road Warrenville, IL 60555 King of Prussia, PA 19406

Limerick Generating Station, Units 1 & 2 cc:

Chief-Division of Nuclear Safety PA Dept. of Environmental Resources P.O. Box 8469 Harrisburg, PA 17105-8469 Chairman Board of Supervisors of Limerick Township 646 West Ridge Pike Linfield, PA 19468 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803

November 26, 2003 Mr. John L. Skolds, President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - ISSUANCE OF AMENDMENT RE: ADDITION OF REQUIRED ACTIONS FOR SCRAM DISCHARGE VOLUME VENT AND DRAIN VALVE OPERABILITY (TAC NOS. MB6885 AND MB6886)

Dear Mr. Skolds:

The Commission has issued the enclosed Amendment No. 168 to Facility Operating License No. NPF-39 and Amendment No. 131 to Facility Operating License No. NPF-85 for the Limerick Generating Station, Units 1 and 2. These amendments consist of changes to the Technical Specifications (TSs) in response to your application dated November 26, 2002.

These amendments revise TS 3.1.3.1, Control Rod Operability, by adding new Limiting Condition of Operation criteria and applicable ACTION requirements for scram discharge volume (SDV) vent and drain valves. The changes also modify TS 3.6.3, Primary Containment Isolation Valves, to clarify the relationship between TS 3.1.3.1 and TS 3.6.3 regarding SDV vent and drain valves.

A copy of our safety evaluation is also enclosed. Notice of Issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely,

/RA/

Scott P. Wall, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosures:

1. Amendment No. 168 to License No. NPF-39

2. Amendment No. 131 to License No. NPF-85

3. Safety Evaluation cc w/encls: See next page DISTRIBUTION:

PUBLIC PDI-2 R/F JClifford SWall MOBrien SMagruder ACRS RGiardina MRubin CDoutt GThomas FAkstulewicz OGC GHill (4) CBixler, RGN-I Package Number: ML033300362 ADAMS Accession Number: ML032460784 TS(s) Accession Number: ML

• see previous concurrence OFFICE PDI-2/PM PDI-2/LA SRXB/SC* IROB/SC* OGC PDI-2/SC NAME SWall MOBrien FAkstulewicz TBoyce KKannler JClifford DATE 10/30/03 10/31/03 11/04/03 11/05/03 11/12/03 11/26/03 Official Record Copy

EXELON GENERATION COMPANY, LLC DOCKET NO. 50-352 LIMERICK GENERATING STATION, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 168 License No. NPF-39

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

A. The application for amendment by Exelon Generation Company, LLC (the licensee) dated November 26, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is also 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-39 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No. 168, are hereby incorporated in the license. Exelon Generation Company 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.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

James W. Clifford, Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: November 26, 2003

ATTACHMENT TO LICENSE AMENDMENT NO. 168 FACILITY OPERATING LICENSE NO. NPF-39 DOCKET NO. 50-352 Replace the following pages of the 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 3/4 1-3 3/4 1-3 3/4 1-4 3/4 1-4 3/4 1-5 3/4 1-5 3/4 6-17 3/4 6-17 B 3/4 1-2 B 3/4 1-2

- B 3/4 1-2a B 3/4 6-4 B 3/4 6-4

EXELON GENERATION COMPANY, LLC DOCKET NO. 50-353 LIMERICK GENERATING STATION, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 131 License No. NPF-85

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

A. The application for amendment by Exelon Generation Company, LLC (the licensee) dated November 26, 2002, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is also 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-85 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No. 131, are hereby incorporated in the license. Exelon Generation Company 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.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

James W. Clifford, Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: November 26, 2003

ATTACHMENT TO LICENSE AMENDMENT NO. 131 FACILITY OPERATING LICENSE NO. NPF-85 DOCKET NO. 50-353 Replace the following pages of the 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 3/4 1-3 3/4 1-3 3/4 1-4 3/4 1-4 3/4 1-5 3/4 1-5 3/4 6-17 3/4 6-17 B 3/4 1-2 B 3/4 1-2

- B 3/4 1-2a B 3/4 6-4 B 3/4 6-4

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 168 AND 131 TO FACILITY OPERATING LICENSE NOS. NPF-39 AND NPF-85 EXELON GENERATION COMPANY, LLC LIMERICK GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-352 AND 50-353

1.0 INTRODUCTION

By letter dated November 26, 2002, Exelon Generation Company, LLC (Exelon or the licensee),

submitted a request to modify the Technical Specifications (TSs) for Limerick Generating Station, Units 1 and 2 (LGS-1 and 2), by adding new Limiting Condition for Operation (LCO) criteria and applicable ACTION requirements for scram discharge volume (SDV) vent and drain valves to TS 3.1.3.1, Control Rod Operability. The changes also modify TS 3.6.3, Primary Containment Isolation Valves, to clarify the relationship between TS 3.1.3.1 and TS 3.6.3 regarding SDV vent and drain valves. These changes will more closely align the LGS-1 and 2 TSs with NUREG-1433, Standard Technical Specifications [STSs], General Electric Plants,

[Boiling Water Reactor] BWR/4, Revision 2. The licensee also proposed to modify the associated Bases as a result of the changes.

2.0 REGULATORY EVALUATION

Pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.36 (10 CFR 50.36), each licensee authorizing operation of a production or utilization facility must include TSs. Section 50.36 requires that the TSs include items in eight specific categories: 1) safety limits, limiting safety system settings, and limiting control settings; 2) LCOs; 3) surveillance requirements (SRs); 4) design features; 5) administrative controls; 6) decommissioning; 7) initial notification; and 8) written reports. Section 50.36(c)(2)(ii) gives four criteria to be used to determine if an LCO is required to be established in the TSs for a particular item. An LCO must be established for any item meeting one or more of the following four criteria:

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

Criterion 2: A process variable, design feature, or operating restriction that is an initial condition of a design-basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

Criterion 3: A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

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

In April 2001, the Nuclear Regulatory Commission (NRC) issued NUREG-1433, Standard Technical Specifications, General Electric Plants, BWR/4, Revision 2. The STSs were developed based on the criteria outlined in 10 CFR 50.36. NUREG-1433 was established as a general model for developing potential TSs for General Electric BWR/4 plants. The generic Bases presented in NUREG-1433 provide information regarding the application of the TS criteria and reflect detailed system configurations and operating characteristics for all reactor designs. Licensees adopting portions of NUREG-1433 to existing TSs should adopt all related requirements, as applicable, to achieve a high degree of standardization and consistency.

STS 3.1.8, Scram Discharge Volume (SDV) Vent and Drain Valves, in NUREG-1433, Revision 2, applies to the proposed LGS-1 and 2 amendments.

3.0 TECHNICAL EVALUATION

The November 26, 2002, application was not based on the risk-informed process delineated in Regulatory Guide 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis." Nevertheless, the licensee submitted the results of a probabilistic risk analysis for the proposed 7-day allowed outage time (AOT), and included estimates for incremental conditional core damage probability and incremental conditional large early release probability. However, because the licensees request was not risk-informed, the NRC staff based its review on the deterministic methodology employed by the licensee and conformance to current regulations. Therefore, the NRC staff has reviewed the licensees proposed changes for compliance with 10 CFR 50.36 and agreement with the precedent established in NUREG-1433, Revision 2.

3.1 System Description The purpose of the SDV is to serve as a collection volume for reactor coolant displaced by the control rod drive (CRD) pistons during a scram. The design and functions of the SDV are described in Section 4.6.1.2.4.2.6 of the LGS-1 and 2 Updated Final Safety Analysis Report (UFSAR). During normal operation, the SDV vent and drain valves remain open to allow operational leakage from the CRDs to the SDV to drain. This ensures that a sufficient air volume is available in the SDV at all times to allow a complete scram. The SDV vent lines are open to reactor building atmosphere to assure proper drainage of the SDV.

The SDV consists of header piping that connects to each control rod hydraulic control unit and drains into an instrument volume. The header piping is sized to receive and contain all the water discharged by the CRDs during a scram. There are two headers and two instrument volumes. The two instrument volumes are connected to a common drain line, which has two

redundant air operated isolation valves in series. Similarly, the two headers are connected to a common vent line having two redundant air-operated isolation valves in series. The valves close automatically upon receipt of a scram signal to isolate the SDV to prevent leakage of reactor coolant past the CRD seals following a scram. The valves also close automatically upon loss of air to the valves or electrical power to the associated solenoid pilot valves.

Following a scram, the valves will reopen automatically when the scram signal is reset.

In order to permit control rods to insert completely during a scram, an adequate free volume must exist in the SDV to accommodate the water displaced by the CRD pistons as the control rods are inserted into the reactor. As a precautionary measure, the reactor will automatically scram if the water level in the SDV instrument volume exceeds the high level setpoint. This assures that the reactor will shut down while an adequate air volume remains in the SDV to support full insertion of the control rods. The SDV high level scram can be manually blocked only when the reactor mode switch is in the Shutdown or Refuel positions. This permits the control room operators to reset the scram signal, which automatically reopens the SDV vent and drain valves to drain the SDVs. Water level in the SDV is detected by both float-sensing and pressure-sensing instrumentation. This gives operators time to take corrective action before the scram occurs.

During normal operation, the only expected source of leakage into the SDV is from CRD seal leakage past the scram outlet valves. This leakage is typically maintained at very small values because excessive leakage past the scram outlet valves would cause the control rods to drift.

A drifting control rod can initiate a rod block, as well as a scram, if the associated trip setpoints are exceeded. If the SDV drain lines were isolated, SDV level would increase due to normal scram outlet valve leakage.

3.2 Applicability of Technical Specification Requirements The design-basis accident (DBA) and transient analysis assumes all of the control rods are capable of scramming. The SDV vent and drain valves operate automatically to:

(b) Close during a scram to limit the amount of reactor coolant discharged so that adequate core cooling is maintained and offsite doses remain within the limits of 10 CFR Part 100; and (c) Open on a scram reset to maintain the SDV vent and drain paths open so that there is sufficient volume to accept the reactor coolant discharged during a scram.

Accordingly, SDV vent and drain valves satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii). Therefore, the NRC staff concludes that establishing LCOs with applicable ACTION requirements specifically for the SDV vent and drain valves is acceptable.

3.3 TS 3/4.1.3.1, Control Rod Operability, and TS 3/4.6.3, Primary Containment Isolation Valves The licensee proposed to revise the current TS 3.1.3.1 by:

1. Modifying the LCO to add operability requirements for the SDV vent and drain valves.

2. Modifying the APPLICABILITY to reflect the addition of OPERATIONAL CONDITION 3 with a note that OPERATIONAL CONDITION 3 is only applicable to the SDV vent and drain valves.

3. Adding the following ACTION statements and associated footnotes:

d. With one or more scram discharge volume (SDV) vent or drain lines with one valve inoperable, restore the inoperable valve(s) to OPERABLE status within 7 days or be in at least HOT SHUTDOWN within the next 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s*** and in COLD SHUTDOWN with the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

e. With one or more SDV vent or drain lines with both valves inoperable, isolate the associated line with 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s**** or be in at least HOT SHUTDOWN within the next 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s*** and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

• • • Separate Action entry is allowed for each SDV vent and drain line.

• • • • An isolated line may be unisolated under administrative control to allow draining and venting of the SDV.

The licensee also proposed to revise TS 3/4.6.3 to reflect that ACTION requirements and AOTs for inoperable SDV vent and drain valves are contained in TS 3.1.3.1. TS 3.6.3 ACTION (a) will be modified by adding the following ** note:

• • Except for the scram discharge volume vent and drain valves In addition, the following new ACTION (c) will be added:

c. With one or more scram discharge volume vent or drain valves inoperable, perform the applicable actions specified in TS 3.1.3.1.

3.4 Primary Containment Isolation Valve Requirements Since SDV vent and drain valves are primary containment isolation valves (PCIVs) at LGS-1 and 2, they form part of the containment boundary. The PCIV safety function is to minimize the loss of reactor coolant inventory and establish the primary containment boundary during a DBA.

Currently, with one valve in a SDV line inoperable, TS 3.6.3 requires that the remaining valve in the affected line be operable and the penetration be isolated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. If both valves in a SDV line are inoperable, TS 3.6.3 requires that the facility be in at least HOT SHUTDOWN

within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Under the proposed changes, isolation of the SDV vent and drain line will be required within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if both valves in the line are inoperable and, with only one inoperable valve in a line, continued operation would be permitted for up to 7 days. Additionally, as outlined in Section 3.3 above, the proposed changes would modify TS 3.6.3 to reflect that action requirements and AOTs for SDV vent and drain valves are contained in TS 3.1.3.1.

The two redundant automatic isolation valves in each SDV vent and drain line provide assurance that the SDV will be isolated during a scram, thereby limiting the amount of reactor coolant discharge. The NRC staff review of the consequences of a structural failure of the SDV following a scram is discussed in NUREG-0803, Generic Safety Evaluation Report Regarding Integrity of BWR Scram System Piping, dated August 1981. In the NUREG-0803 safety evaluation, the NRC staff concluded that, for a bounding leakage case corresponding to a rupture of the SDV, offsite doses would be well within the 10 CFR Part 100 reference values, and that adequate core cooling would be maintained. The failure to isolate one or more SDV vent or drain lines is bounded by the NUREG-0803 evaluation. The NRC staff concluded in NUREG-0991, Safety Evaluation related to the Operation of Limerick Generating Station Units 1 and 2, that the design of the SDV fully meets the requirements of the NRC generic report.

The proposed changes do not impact the design basis of the system, nor do they result in a physical change to LGS-1 and 2. With regards to containment isolation requirements, the NRC staff finds that the proposed changes are bounded by the NUREG-0803 evaluation and, therefore, are acceptable. Furthermore, the NRC staff finds that reflecting TS 3.6.3 requirements for SDV vent and drain valves within TS 3.1.3.1 is editorial in nature and, therefore, is acceptable.

3.5 Control Rod Operability Requirements As described in Section 3.1 above, during normal operation, the SDV vent and drain valves remain open to allow operational leakage from the CRDs to the SDV to drain. This ensures that a sufficient air volume is available in the SDV at all times to allow a complete scram. The SDV vent lines are open to reactor building atmosphere to assure proper drainage of the SDV.

Currently, the TSs for LGS-1 and 2 do not provide a specific LCO for the SDV vent and drain valves. Furthermore, while TS 3.1.3.1 does include SRs associated with the SDV vent and drain valves, the existing TS does not provide a specific AOT to allow time for restoration should one of these valves become inoperable with respect to the CRD system safety function.

Therefore, if one or more of the SDV valves were discovered to be inoperable, the condition of more than 8 control rods being inoperable would result in a 12-hour AOT. As outlined in Section 3.3 above, the proposed changes would add new TS requirements specifically for the SDV vent and drain valves. As discussed in Section 3.2 above, SDV vent and drain valves satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii), and establishing LCOs with applicable ACTION requirements specifically for the SDV vent and drain valves is acceptable.

3.5.1 OPERABILITY and OPERATIONAL CONDITIONS To be consistent with NUREG-1433, Revision 2, the licensee has proposed to modify the TS 3.1.3.1 LCO by including operability requirements for the SDV vent and drain valves during OPERATIONAL CONDITIONS 1 and 2. To reflect current TS 3.6.3 requirements, the licensee proposed to extend TS 3.1.3.1 operability requirements for the SDV vent and drain valves to OPERATIONAL CONDITION 3.

In OPERATIONAL CONDITIONS 1 and 2, a scram may be required; therefore, the SDV vent and drain valves must be OPERABLE. In OPERATIONAL CONDITIONS 3 and 4, control rods are not able to be withdrawn since the reactor mode switch is in shutdown and a control rod block is applied. This provides adequate controls to ensure that only a single control rod can be withdrawn. Also, during OPERATIONAL CONDITION 5, only a single control rod can be withdrawn from a core cell containing fuel assemblies. Therefore, for the safety function associated with scramming the reactor, the SDV vent and drain valves are not required to be OPERABLE in OPERATIONAL CONDITIONS 3, 4, and 5 since the reactor is subcritical. The NRC staff finds that the proposed changes are applicable to OPERATIONAL CONDITIONS 1 and 2, consistent with NUREG-1433, Revision 2, and, therefore, are acceptable.

Since SDV vent and drain valves are also classified as PCIVs, they are required to be OPERABLE in OPERATIONAL CONDITIONS 1, 2, and 3 for containment isolation requirements. In OPERATIONAL CONDITIONS 1, 2, and 3, a DBA could cause a release of radioactive material to primary containment. In OPERATIONAL CONDITIONS 4 and 5, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these OPERATIONAL CONDITIONS. Therefore, PCIVs are not required to be OPERABLE in OPERATIONAL CONDITIONS 4 and 5. The NRC staff finds that applying TS 3.1.3.1 operability requirements for the SDV vent and drain valves to OPERATIONAL CONDITION 3 is consistent with current TS 3.6.3 requirements, editorial in nature and, therefore, is acceptable.

3.5.2 One Valve Inoperable To be consistent with NUREG-1433, Revision 2, the licensee proposed the addition of TS 3.1.3.1.d for one or more SDV vent or drain lines with one valve inoperable. The proposed ACTION statement would allow 7 days to repair the inoperable valve. If the affected valve is not restored to operable status within the 7-day time period, the licensee would then be required to proceed to HOT SHUTDOWN in the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. With only one valve inoperable, the isolation function would be maintained since the redundant valve in the affected line would perform its safety function of isolating the SDV. The NRC staff has previously evaluated the 7-day AOT with NUREG-1433, Revision 2, and determined the time to be reasonable given the level of redundancy in the lines and the low probability of a scram occurring while the valve(s) are inoperable. The NRC staff finds the proposed ACTION statement to be acceptable because of the redundant SDV design, the low likelihood of a scram, and its consistency with NUREG-1433, Revision 2.

3.5.3 Two Valves Inoperable and Administrative Controls To be consistent with NUREG-1433, Revision 2, the licensee proposed the addition of TS 3.1.3.1.e for one or more SDV vent or drain lines with both valves inoperable. The proposed ACTION statement would permit the licensee to take up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to repair two inoperable valves on the same vent or drain line, or to manually isolate the affected line. If this requirement is not met, the licensee would then be required to be in HOT SHUTDOWN within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The NRC staff has previously evaluated the 8-hour AOT with NUREG-1433, Revision 2, and determined the time to be reasonable given the low probability of a scram occurring while the line is not isolated and the unlikelihood of significant CRD leakage. The NRC staff finds the proposed ACTION statement acceptable because the likelihood of a scram is low, the NUREG-0803 evaluation bounds the 8-hour AOT, and it is consistent with NUREG-1433, Revision 2.

To be consistent with NUREG-1433, Revision 2, the licensee proposed that TS 3.1.3.1.e have a footnote that would permit the SDV to be unisolated under administrative control to allow draining and venting of accumulated water to avoid a reactor scram on high SDV level. The administrative controls ensure that the valves can be closed if a scram occurs with the valves open. The licensee has stated that these administrative controls would be conducted by a dedicated operator. In situations where the SDV vent and drain valves are isolated per TSs there is a possibility that over time leakage from the CRDs could fill the SDV with reactor coolant, thereby limiting the volume available for a reactor scram. As described in Section 3.1 above, the SDV instrumentation is designed to alarm on increasing SDV water level and initiate a reactor scram on high SDV level (before the scram headers begin to fill). While this arrangement ensures that the scram headers can accept the scram reactor coolant discharge, it increases the probability of a spurious scram with the SDV isolated. Allowing any accumulated water in the line to be drained precludes an inadvertent scram due to high SDV level. The NRC staff finds the proposed footnote to the ACTION statement to be acceptable because the valves can be quickly closed by a dedicated operator, it reduces the likelihood of a scram on high SDV level, and it is consistent with NUREG-1433, Revision 2.

3.5.4 Separate Action Entries To be consistent with NUREG-1433, Revision 2, the licensee proposed that TS 3.1.3.1.d and TS 3.1.3.1.e have a footnote that would permit entry into separate ACTION statements for each SDV vent and drain line. Complying with the required actions would allow for continued operation during the AOT, and subsequent inoperable SDV lines would be governed by subsequent ACTION statement entry and application of associated required actions. The NRC staff finds the proposed footnote to the ACTION statements acceptable because the required actions for each condition provide appropriate compensatory actions for each inoperable SDV line, and it is consistent with NUREG-1433, Revision 2.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to installation or use of a facility component 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 and there has been no public comment on such finding (68 FR 803). 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) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: R. Giardina S. Wall Date: November 26, 2003