ML051090159

License Amendment, Revision to the Licensing Basis to Define a New Hydraulic Analysis Methodology

ML051090159
Person / Time
Site:	Prairie Island
Issue date:	05/10/2005
From:	Mahesh Chawla NRC/NRR/DLPM/LPD3
To:	Solymossy J Nuclear Management Co
Chawla M, NRR/.DLPM, 415-8371
References
TAC MC3043, TAC MC3044
Download: ML051090159 (16)

Text

May 10, 2005 Mr. Joseph M. Solymossy Site Vice President Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC 1717 Wakonade Drive East Welch, MN 55089

SUBJECT:

PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 -

ISSUANCE OF AMENDMENTS (TAC NOS. MC3043 AND MC3044)

Dear Mr. Solymossy:

The U.S. Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment No. 169 to Facility Operating License No. DPR-42 and Amendment No. 159 to Facility Operating License No. DPR-60 for the Prairie Island Nuclear Generating Plant (PINGP),

Units 1 and 2, respectively. The amendments consist of changes to the Technical Specifications in response to your application dated May 3, 2004, as supplemented by letters dated February 4, and March 28, 2005.

The amendments revise the licensing basis to define a new hydraulic analysis methodology for demonstrating functionality of the cooling water (CL) system following a design basis seismic event. The seismic analysis methodology for the CL system is revised to include 1) evaluation of CL system performance following a seismic event assuming a rupture of a non-seismic pipe at the worst case location, and 2) application of acceptance criteria from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section lll, to demonstrate that the CL system non-seismic piping will maintain pressure boundary integrity with design basis seismic loads.

J. Solymossy The following commitment was established by the licensee in its letter dated March 28, 2005.

NMC will include in the scope of the PINGP Generic Letter 89-13 program CL non-seismic piping on which stress analysis are performed to change the assumed pipe rupture location as proposed in the LAR dated May 3, 2004. NMC has not revised any Nuclear Regulatory Commission commitments.

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

Sincerely,

/RA/

Mahesh L. Chawla, Project Manager, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-282 and 50-306

Enclosures:

1. Amendment No. 169 to DPR-42

2. Amendment No. 159 to DPR-60

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

ML051090159 OFFICE PDIII-1/PM PDIII-1/LA SC:SPLB SC:EMEB SC:IROB OGC PDIII-1/SC NAME MChawla THarris SJones KManoly DTrimble AFernandez LRaghava n

DATE 04/20/05 04/20/05 04/22/05 04/22/05 04/21/05 05/02/05 5/10/05

Prairie Island Nuclear Generating Plant, Units 1 and 2 cc:

Jonathan Rogoff, Esquire Vice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Manager, Regulatory Affairs Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC 1717 Wakonade Drive East Welch, MN 55089 Manager - Environmental Protection Division Minnesota Attorney Generals Office 445 Minnesota St., Suite 900 St. Paul, MN 55101-2127 U.S. Nuclear Regulatory Commission Resident Inspector's Office 1719 Wakonade Drive East Welch, MN 55089-9642 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60532-4351 Administrator Goodhue County Courthouse Box 408 Red Wing, MN 55066-0408 Commissioner Minnesota Department of Commerce 85 7th Place East, Suite 500 St. Paul, MN 55101-2198 Tribal Council Prairie Island Indian Community ATTN: Environmental Department 5636 Sturgeon Lake Road Welch, MN 55089 Nuclear Asset Manager Xcel Energy, Inc.

414 Nicollet Mall, R.S. 8 Minneapolis, MN 55401 John Paul Cowan Executive Vice President & Chief Nuclear Officer Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Craig G. Anderson Senior Vice President, Group Operations Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 November 2004

NUCLEAR MANAGEMENT COMPANY, LLC DOCKET NO. 50-282 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 169 License No. DPR-42 1.

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

A.

The application for amendment by Nuclear Management Company, LLC (the licensee), dated May 3, 2004, as supplemented by letters dated February 4, and March 28, 2005, 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; 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 Commission's 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 Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, by Amendment 169, Facility Operating License No. DPR-42 is hereby amended to authorize revision to the Updated Safety Analysis Report (USAR), as set forth in the license amendment application dated May 3, 2004, as supplemented by letters dated February 4, and March 28, 2005. The license shall update the USAR to incorporate the change in the licensing basis which allows to define a new hydraulic analysis methodology for demonstrating functionality of the cooling water (CL) system following a design basis seismic event. The seismic analysis methodology for the CL system is revised to include 1) evaluation of CL system performance following a seismic event assuming a rupture of a non-seismic pipe at the worst case location, and 2) application of acceptance criteria from the ASME Code, Section lll, to demonstrate that the CL system non-seismic piping will maintain pressure boundary integrity with design basis seismic loads. The licensee shall submit the revised description authorized by this amendment with the next update of the USAR.

3.

This license amendment is effective as of its date of its issuance and shall be implemented within 30 days. The USAR changes shall be implemented in the next periodic update of the USAR in accordance with 10 CFR 50.71(e).

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

L. Raghavan, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Date of Issuance: May 10, 2005

NUCLEAR MANAGEMENT COMPANY, LLC DOCKET NO. 50-306 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 159 License No. DPR-60 1.

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

A.

The application for amendment by Nuclear Management Company, LLC (the licensee), dated May 3, 2004, as supplemented by letters dated February 4, and March 28, 2005, 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; 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 Commission's 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 Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, by Amendment 159, Facility Operating License No. DPR-60 is hereby amended to authorize revision to the Updated Safety Analysis Report (USAR), as set forth in the license amendment application dated May 3, 2004, as supplemented by letters dated February 4, and March 28, 2005. The license shall update the USAR to incorporate the change in the licensing basis which allows to define a new hydraulic analysis methodology for demonstrating functionality of the cooling water (CL) system following a design basis seismic event. The seismic analysis methodology for the CL system is revised to include 1) evaluation of CL system performance following a seismic event assuming a rupture of a non-seismic pipe at the worst case location, and 2) application of acceptance criteria from the ASME Code, Section lll, to demonstrate that the CL system non-seismic piping will maintain pressure boundary integrity with design basis seismic loads. The licensee shall submit the revised description authorized by this amendment with the next update of the USAR.

3.

This license amendment is effective as of its date of its issuance and shall be implemented within 30 days. The USAR changes shall be implemented in the next periodic update of the USAR in accordance with 10 CFR 50.71(e).

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

L. Raghavan, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Date of Issuance: May 10, 2005

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 169 TO FACILITY OPERATING LICENSE NO. DPR-42 AND AMENDMENT NO. 159 TO FACILITY OPERATION LICENSE NO. DPR-60 NUCLEAR MANAGEMENT COMPANY, LLC PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-282 AND 50-306

1.0 INTRODUCTION

By letter dated May 3, 2004, as supplemented by letters dated February 4, and March 28, 2005, the Nuclear Management Company, LLC (the licensee), requested an amendment to Facility Operating Licenses DPR-42 and DPR-60 for the Prairie Island Nuclear Generating Plant, Units 1 and 2 (PINGP), respectively. The license amendment request (LAR) would change the licensing basis to define a new hydraulic analysis methodology for demonstrating functionality of the cooling water (CL) system, following a design basis seismic event. The LAR will change the seismic analysis methodology for the CL system to include 1) evaluation of CL system performance following a seismic event assuming a rupture of a non-seismic pipe at the worst case location, and 2) application of acceptance criteria from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code), Section lll, Subsection ND, to demonstrate that the CL system non-seismic piping will maintain pressure boundary integrity with design basis seismic loads.

The supplemental letters contained clarifying information and did not change the initial no significant hazards consideration determination and did not expand the scope of the original Federal Register notice.

U.S. Nuclear Regulatory Commission (NRC) Inspection Report 50-282/00-13 and 50-306/00-13, dated December 20, 2000, questioned the methods used by the licensee to evaluate the capabilities of the CL system during a seismic event at PINGP. At that time (and currently), the licensing basis for the CL system assumed that during a seismic event, through-wall cracks of a specified size would develop in each non-safety-related cooling water pipe that connects off the main header. By memorandum dated March 27, 2001, NRC Region III submitted Task Interface Agreement (TIA) requesting assistance from the NRCs Office of Nuclear Reactor Regulation (NRR) in resolving these issues. In the response to TIA 2001-02, dated August 29, 2003, NRR stated, in part:

In demonstrating functional capability of a system, it is acceptable to perform a system hydraulic analysis, assuming a complete failure of a single pipe (worst case - i.e., the largest line connected to a header) at a time; the intent here is to bound possible cases where partial failures (cracks) may occur in multiple lines following a seismic event.

However, credit cannot be given for any non-seismic piping remaining intact following a seismic event, unless the piping has been analyzed to specific criteria (proposed by the licensee and approved by the staff) for demonstrating the seismic adequacy of that piping.

To address the issues contained in NRRs response to TIA 2001-02, the licensee submitted the aforementioned LAR and supplemental letters. The NRC staff reviewed the LAR with respect to the licensees evaluation of CL system performance following a seismic event and the proposed criteria for establishing the integrity of the CL system non-seismic piping with design basis seismic loads.

2.0 REGULATORY EVALUATION

In revising the seismic analysis methodology for the CL system, the licensee is departing from the current evaluation method used in their Updated Safety Analysis Report (USAR) for establishing the design bases of the CL system, and proposes to implement the NRC staffs position that was stated in response to TIA 2001-2. Consistent with Title 10 of the Code of Federal Regulations (10 CFR ) Section 50.59(c)(2)(viii), this change in analysis methodology requires a license amendment in accordance with 10 CFR 50.90. The acceptability of the licensees LAR will be determined based upon an adequate demonstration of the CL system to perform its design function consistent with the existing plant licensing basis and the NRC staffs position stated in response to TIA 2001-02.

The NRC staff evaluation included the structural and functional integrity of piping systems, components and their supports, including core support structures, which are designed in accordance with the rules of the ASME Code,Section III, Division 1, United States of America Standards B31.1 Power Piping Code, and General Design Criteria 1, 2 and 4. The NRC staff review focused on verifying that the licensee has provided reasonable assurance of the structural and functional integrity of piping systems, components, component internals, and their supports under normal and vibratory loadings, including those due to fluid flow, postulated accidents and natural phenomena such as earthquakes.

3.0 TECHNICAL EVALUATION

3.1 System Description The CL system provides a heat sink for removal of process and operating heat from safety-related components during a design-basis accident or transient. During normal operation, and a normal shutdown, the CL system provides this function for various safety-related and non-safety-related components. Examples of safety-related components supplied by the CL system include Unit 1 emergency diesel generators, component cooling heat exchangers, and back-up water supply to the auxiliary feedwater pumps.

The CL system is shared between the two PINGP units. It consists of two trains that are automatically separated by a safety injection (SI) signal in either unit. In addition to supplying the above safety-related loads, there are several piping connections to the headers that supply water to cool non-safety-related loads. The single largest non-safety-related supply line (one per unit), which supplies the turbine building loads, can be isolated by closing a safety-related motor-operated valve. The isolation valve on each of these lines closes automatically on a SI signal coincident with a low pressure condition in the safety-related supply header or can be remotely closed from the control room. The other valves that could be used to isolate the non-safety-related lines from the safety-related supply headers are manual valves. During a seismic event, without a SI signal, all of the valves (both the motor-operated turbine building isolation valves and the manual valves) would remain open unless closed by operator action.

3.2 Proposed Method for Evaluating CL System Post-Seismic Performance The safety-related portions of the CL system are designed to withstand a seismic event (Class I piping). Consistent with the plant design requirements, portions of non-Class I piping connected to Class I piping up to the first anchor point are included in the analysis of the Design Class I piping subject to seismic loads. The other areas of the non-Class I piping are not typically analyzed for seismic loads. However, there are non-Class I CL system piping connecting to the Class I piping, beyond the location of system classification change, that were not designed for design-basis seismic loads. In the following discussion, both the Class I and the non-Class I piping within the first anchor will be referred to as "seismic" and all other CL system piping will be referred to as "non-seismic". The use of design approach for non-seismic issues was raised in NRC Inspection Report 50-282/00-13 (Unit 1) and 5-306/00-13 (Unit 2).

The LAR proposes to change the facility licensing basis to specifically define a hydraulic analysis methodology for demonstrating functionality of the CL system following a seismic event and to define acceptable analytical methods for demonstrating the seismic capability of the CL system non-seismic piping.

The licensee proposes to change the licensing basis for the CL system by adopting the method for demonstrating functional capability discussed in the NRR response to TIA 2001-02. In its response (Reference 2) to the NRC staffs request for additional information, the licensee indicated that since the hydraulic analyses have not been finalized and PINGP does not have approved acceptance criteria, the stress analyses have not yet been performed. The licensee also indicated that it would be able to prevent the non-seismic CL system piping from rupture at the worst case location through the performance of seismic analysis (and addition of supports, as necessary) for the limiting piping run(s). In addition, the licensee also indicated that for the analyses of these piping run(s), the methodology, load combinations, input response spectra, and damping factors would be consistent with the current licensing basis. The proposed acceptance criteria for the non-seismic CL system piping is based on requirements of ASME Section Ill, Subsection ND, Class 3 Components, 1986 Edition, Service Level D stress limit which is considered acceptable.

In Reference 2, the licensee also indicated that the use of these acceptance criteria were identified during a phone conversation with the NRC staff in March of 2004. Use of similar criteria were approved for another facility to demonstrate that non-safety-related piping will not rupture during a seismic event; refer to NRC Safety Evaluation for Three Mile Island, TMI-1 Amendment No. 221, Revised Seismic Verification Methodology for Auxiliary Steam System Piping (TAC No. MA561 7), dated March 10, 2000. In response to a seismic event, the function of the CL system is to support achieving and maintaining safe shutdown.

As described in the PINGP proposed USAR Section 10.4.1.2.3, a hydraulic analysis is used to verify that certain safety-related components receive adequate CL system flow under a variety of system configurations following a design basis event. The licensee has proposed expanding the use of this analysis to evaluate the effect of bounding failures of CL system non-seismic piping segments. The staffs acceptance of the LAR will be based on the licensees demonstration of this analysis to evaluate the effect of bounding failures of CL system non-seismic piping segments. The NRC staffs acceptance of the LAR will be based on the licensees demonstration of the capability of the CL system to perform its design function consistent with the existing plant licensing basis and the NRC staffs position as stated in response to TIA 2001-02.

By letter dated January 31, 2005, the NRC staff requested additional information pertaining to the Regulatory Guide 1.29(c)(2) regulatory position on the failure of non-class 1 portions of structures, systems, or components over the Class 1 components, such as CL system piping.

The NRC staff requested the licensee to confirm that CL system non-seismic piping will continue to be protected from the failure of non-seismic structures, systems, and components (SSCs) in accordance with the existing plant licensing basis. By letter dated February 4, 2005, the licensee responded that this LAR does not request NRC approval of criteria that will be used to assure that the piping will not be adversely affected by the failure of nonseismic SSCs.

The licensee recognizes that the potential effects from seismically induced failure of non-seismic SSCs need to be considered for the evaluation of these non-seismic branch lines. For example, if failure of a non-safety-related structure could occur, there is the potential that more than one non-seismic branch line may be affected. Consideration of such non-seismic SSC failure effects on the non-seismic CL branch lines (should they occur) will be consistent with the plant licensing basis for evaluation of damage to safety-related SSCs which could result from the failure of non-seismic SSCs during a seismic event.

As discussed in the LAR, the licensee may choose to increase the CL system operating margin by changing the worst case location of the assumed pipe rupture. One of the options mentioned is to provide automatic isolation capability for the CL system supply lines to the non-safety-related containment chilled water system. By letter dated January 31, 2005, the NRC staff also requested that where the licensee proposes to credit automatic isolation valves for excluding CL system non-seismic piping from consideration, the licensee confirm that these valves are seismic Category l, safety-related valves, which will automatically actuate to close during a seismic event, and that the single-failure criterion will be satisfied. By letter dated February 4, 2005, the licensee further responded that they agree that the automatic isolation valve(s) would need to be safety-related, seismically qualified, actuate to close on a signal induced by a seismic event, satisfy single-failure criterion, and so forth; consistent with the plant licensing basis as reflected in the UFSAR. The licensee stated that consideration of these inputs is consistent with normal design practices at PINGP. The NRC staff finds the February 4, 2005, response to be acceptable.

The LAR includes a provision to change the worst case location of assumed pipe rupture to a smaller, less limiting, location through performance of stress analysis of currently unanalyzed non-seismic CL branch line piping. By teleconference on March 8, 2005, the NRC staff requested that the licensee clarify how long-term piping integrity will be assured following application of the provision to change the worst case location. By letter dated March 28, 2005, the licensee responded that in order to provide assurance that the piping is not significantly degrading with time, they will include piping that is analyzed in accordance with this provision in the scope of the PINGP Generic Letter 89-13 program. The licensee further stated that in accordance with the Generic Letter 89-13 program, pipe wall thinning inspections are currently performed for safety-related piping of the CL system. Accordingly, as stated in their letter dated March 28, 2005, the licensee has established the following commitment:

NMC will include in the scope of the PINGP Generic Letter 89-13 program CL non-seismic piping on which stress analysis are performed to change the assumed pipe rupture location as proposed in the LAR dated May 3, 2004. NMC has not revised any Nuclear Regulatory Commission commitments.

The NRC staff finds the licensees March 28, 2005, response to be acceptable.

3.3 Operator Actions Considerations The licensees LAR only requests approval from the NRC to change the seismic analysis methodology for the CL system. The effects on operator actions or action times from this revised analysis methodology are unknown at this time. However, the potentially changed CL system response and affected operator actions or action times include:

1. The water supply source to the CL system during a seismic event is limited in capacity.

During a seismic event, it is expected that the intake canal will pump down, at which point CL system flow is limited to the capacity of the emergency intake line (15,000 gpm). The CL system flow rate during a seismic event (to be determined by the revised analysis) will determine when this limitation in flow capacity will occur (i.e., how long it takes for the intake canal to pump down), and when operators will be required to reduce CL system flow to within the capacity of the emergency intake line. In the current licensing basis, the licensee has determined that:

(a) The volume in the intake canal provides an approximately 4.8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> supply of water, and; (b) The intake canal contains two to three times the minimum water volume for operator action.

Under the revised analysis methodology, the licensee will need to re-determine and obtain follow-on NRC approval for both of these items, i.e., the number of hours that the intake canal is available as a supply, and to confirm the two to three times operator action operating margin.

2. Operator action may be required to isolate a ruptured pipe.

Preliminary discussions with the licensee indicate that operator action may not be required to isolate any pipe break. However, with the revised analysis still pending, there is the possibility that the licensee may need to credit operator action to isolate a pipe break, in order to demonstrate that the CL system can establish and maintain safe shutdown during a seismic event. Should the licensee determine that operator action is required to isolate any pipe break, the licensee will need to submit the details of the required actions to the NRC for follow-on approval.

3. Operator action may be required to reduce CL pump flow rates.

It is unclear if the current licensing basis includes the potential for run out of the CL pumps (i.e.,

CL pump flow/head beyond the manufacturers recommendations) during a seismic event. In the revised analysis, the licensee shall consider the potential for CL system pump run out during a seismic event. Should the licensee determine in the revised analysis that during a seismic event pump run out will occur, and that operators will be required to reduce CL pump flow rates, then the licensee will need to submit the details of the required actions to the NRC for follow-on approval.

4. Operator Actions Considerations As discussed above, if, as a result of the revised hydraulic analysis, the licensee determines any changes from the current USAR in the required operator actions or action times, then the licensee shall submit the details supporting these changes in actions/times to the NRC for follow-on approval. In general, the details needed to support a significant change in operator action times or a change in the required operator actions include (from NRC Information Notice 97-78, Crediting of Operator Actions in Place of Automatic Actions and Modifications of Operator Actions, Including Response Times):

1. The need for the operator action or need for the change in action times.

2. What the proposed operator actions are.

3. What are the postulated scenarios for which the operator actions will be required.

4. What are the assumed times for the actions, and how these times are justified (either in accordance with American National Standard (ANSI/ANS) 58.8, Time Response Design Criteria for Nuclear Safety-Related Operator Actions, or by live demonstration runs).

5. Who will perform the actions, and will these actions occur in the control room or locally.

6. Provide copies of the procedures which direct the operator actions to the NRC for review.

7. What indicators or alarms will be used to prompt operator action, and are the indicators/alarms safety grade and with a safety grade power source.

8. What equipment will be used to take the actions, and is the equipment safety grade with a safety grade power source.

9. Describe the training received, both initial and continuing, for the operator actions.

The NRC staff will use the regulatory guidance contained in NUREG-1764, Guidance for the Review of Changes to Human Actions, in any subsequent review of changes in operator actions/action times from the current USAR.

4.0

SUMMARY

The licensees LAR would change the licensing basis to define a new hydraulic analysis methodology for demonstrating functionality of the CL system following a design basis seismic event. In part, the licensee proposes to change the seismic analysis methodology for the CL system to include an evaluation of CL system performance. The NRC staff reviewed the LAR with respect the licensees evaluation of CL system performance following a seismic event, and finds that given the licensees proposed hydraulic analysis methodology and its application, the licensee has satisfactorily shown the capability of the CL system to perform its design function consistent with the existing plant licensing basis and the NRC staffs position as stated in response to TIA 2001-02.

The NRC staff finds that the licensees proposal is acceptable pertaining to the acceptance criteria of upgrading the portion of non-Class 1 CL piping to a seismic grade, in accordance with ASME Section Ill, Subsection ND, Class 3 Components, 1986 Edition, Service Level D stress limit, provided that the analysis of CL system piping should be performed using appropriate load combinations, input response spectra, and damping factors consistent with the licensing basis for Class 1 piping at PINGP and that the pipe wall thinning inspections will include the non-seismic CL system piping.

In their LAR, the licensee has not requested any change in the operator action. In case of a seismic event, the operator actions to be taken are based on plant procedures established on existing licensing basis. The licensee has requested to revise the PINGP licensing basis and change the seismic analysis methodology for the CL system. In revising the seismic analysis methodology for the CL system, if the operator actions and/or action times required to ensure the capability of the CL system are affected, licensee shall submit the details supporting these changes in actions/times to the NRC for follow-on approval. The staff finds this approach to be acceptable.

6.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Minnesota State official was notified of the proposed issuance of the amendment. The State official had no comments.

7.0 ENVIRONMENTAL CONSIDERATION

The amendment changes the requirements with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or change the surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (69 FR 40677). 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.

8.0 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 Commission's 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.

9.0 REFERENCES

1. Nuclear Management Company, LLC letter (L-PI-04-016) to NRC, License Amendment Request For Resolution of Unresolved Items Related to Methods For Evaluation of Cooling Water System, Prairie Island Nuclear Generating Plant, dated May 3, 2004.

2. Nuclear Management Company, LLC letter (L-PI-05-007) to NRC, Supplement to License Amendment Request (LAR) For Resolution of Unresolved Items Related to Methods For Evaluation of Cooling Water System TAC Nos. MC3043 and MC3044, dated February 4, 2005.

3. Nuclear Management Company, LLC letter (L-PI-05-022) to NRC, Supplement to License Amendment Request (LAR) For Resolution of Unresolved Items Related to Methods For Evaluation of Cooling Water System TAC Nos. MC3043 and MC3044, dated March 28, 2005.

Principal Contributor: R. Young, D. Muller, C. Wu Date: May 10, 2005