ML050240193

ANO, Unit 2 - Issuance of Amendment Modification of ANO-2 Pressure/Temperature Cooldown Rates

ML050240193
Person / Time
Site:	Arkansas Nuclear
Issue date:	03/07/2005
From:	Holland D NRC/NRR/DLPM/LPD4
To:	Forbes J Entergy Operations
Holland D, NRR/DLPM, 415-1436
References
TAC MC2641
Download: ML050240193 (12)

Text

March 7, 2005 Mr. Jeffrey S. Forbes Site Vice President Arkansas Nuclear One Entergy Operations, Inc.

1448 S. R. 333 Russellville, AR 72801

SUBJECT:

ARKANSAS NUCLEAR ONE, UNIT NO. 2 (ANO-2) - ISSUANCE OF AMENDMENT RE: MODIFICATION OF ANO-2 PRESSURE/TEMPERATURE COOLDOWN RATES (TAC NO. MC2641)

Dear Mr. Forbes:

The Commission has issued the enclosed Amendment No. 256 to Facility Operating License No. NFP-6 for ANO-2. The amendment consists of changes to the Technical Specifications in response to your application dated April 15, 2004, as supplemented by letter dated January 20, 2005.

The amendment changes the existing cooldown curve to a single 32 effective full power years pressure/temperature limit curve that is applicable for cooldown at a rate of 100 EF/hour or 50 EF in any half-hour step. The proposed curve is applicable for reactor coolant system cold-leg temperatures ranging from 50 EF to 560 EF.

Pursuant to 10 CFR 2.390, we have determined that the enclosed Safety Evaluation (SE) does not contain proprietary information. However, we will delay placing the draft SE in the public document room for a period of ten working days from the date of this letter to provide you with the opportunity to comment on the proprietary aspects.

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

Sincerely,

/RA/

Drew Holland, Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-368

Enclosures:

1. Amendment No. 256 to NFP-6

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

March 7, 2005 Mr. Jeffrey S. Forbes Site Vice President Arkansas Nuclear One Entergy Operations, Inc.

1448 S. R. 333 Russellville, AR 72801

SUBJECT:

ARKANSAS NUCLEAR ONE, UNIT NO. 2 (ANO-2) - ISSUANCE OF AMENDMENT RE: MODIFICATION OF ANO-2 PRESSURE/TEMPERATURE COOLDOWN RATES (TAC NO. MC2641)

Dear Mr. Forbes:

The Commission has issued the enclosed Amendment No. 256 to Facility Operating License No. NFP-6 for ANO-2. The amendment consists of changes to the Technical Specifications in response to your application dated April 15, 2004, as supplemented by letter dated January 20, 2005.

The amendment changes the existing cooldown curve to a single 32 effective full power years pressure/temperature limit curve that is applicable for cooldown at a rate of 100 EF/hour or 50 EF in any half-hour step. The proposed curve is applicable for reactor coolant system cold-leg temperatures ranging from 50 EF to 560 EF.

Pursuant to 10 CFR 2.390, we have determined that the enclosed Safety Evaluation (SE) does not contain proprietary information. However, we will delay placing the draft SE in the public document room for a period of ten working days from the date of this letter to provide you with the opportunity to comment on the proprietary aspects.

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

Sincerely,

/RA/

Drew Holland, Project Manager, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-368

Enclosures:

1. Amendment No. to NFP-6

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

PUBLIC (No DPC for 10 working days) PDIV-1 Reading RidsNrrDlpmLpdiv (HBerkow)

RidsNrrDlpmLpdiv1 (AHowe) RidsNrrPMDHolland RidsNrrLADJohnson RidsAcrsAcnwMailCenter RidsOgcRp GHill (2)

RidsNrrDripIrob (TBoyce) BElliott JMedoff RidsRgn4MailCenter (AHowell)

Accession No.ML050240193 OFFICE PDIV-1/PM PDIV-1/LA IROB/BC OGC PDIV-1/SC NAME DHolland DJohnson TBoyce MHiggins AHowe DATE 3/3/05 3/2/05 2/13/05 3/2/05 3/7/05 OFFICIAL RECORD COPY

ENTERGY OPERATIONS INC.

DOCKET NO. 50-368 ARKANSAS NUCLEAR ONE, UNIT NO. 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 256 License No. NPF-6

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

A. The application for amendment by Entergy Operations, Inc. (EOI) dated April 15, 2004, as supplemented by letter dated January 20, 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 license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.c.(2) of Facility Operating License No. NFP-6 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 256, are hereby incorporated in the renewed license.

EOI shall operate the facility in accordance with the Technical Specifications.

3. The license amendment is effective as of its date of issuance and shall be implemented within 60 days from the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Allen G. Howe, Chief, Section 1 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: March 7, 2005

ATTACHMENT TO LICENSE AMENDMENT NO. 256 RENEWED FACILITY OPERATING LICENSE NO. NFP-6 DOCKET NO. 50-313 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 4-22 3/4 4-22 3/4 4-23a 3/4 4-23a

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST TO AMEND THE REACTOR COOLANT SYSTEM PRESSURE/TEMPERATURE LIMIT REQUIRMENTS FOR ARKANSAS NUCLEAR ONE, UNIT 2 ENTERGY OPERATIONS, INC.

DOCKET NO. 50-368

1.0 INTRODUCTION

1.1 Background Information By application dated April 15, 2004, as supplemented by letter dated January 20, 2005, Entergy Operations, Inc. (EOI or the licensee) submitted a license amendment request to change the pressure/temperature (P/T) limit cooldown curve in the Arkansas Nuclear One, Unit No. 2 (ANO-2) technical specifications (TS). The current P/T limit cooldown, heatup, and core critical curves in the ANO-2 TS were previously approved in ANO-2 Facility License Amendment No.

242 for up to 32 effective full power years (EFPY). The current 32 EFPY cooldown curve is based on a graded cooldown, whose cooldown rate varies based on operating temperature for the reactor coolant system (RCS). The supplemental letter dated January 20, 2005, provided additional information that clarified the application, did not change the scope of the application as originally noticed, and did not change the staff's original proposed no significant hazards consideration determination as published in the Federal Register on May 11, 2004 (69 FR 26188).

The licensee proposes to change the 32 EFPY cooldown curve to one that is based on a 100 EF/hour cooldown rate or a cooldown of 50 EF in any half-hour step. The licensees proposed curve is applicable to RCS cold-leg temperatures ranging from 50 EF to 560 EF. The license amendment request does not include any proposed changes to the current 32 EFPY heatup, core critical, or pressure test curves.

1.2 Impacted Technical Specifications EOIs license amendment request changes the following limiting condition of operation (LCO) requirements in the ANO-2 TS:

• LCO 3.4.9.1.b changes the criteria for the variable cooldown rates to a single cooldown criterion that is applicable for RCS cold-leg temperatures in the 50 EF ! 560 EF range:

A maximum cooldown rate of 100 EF per hour (constant) or 50 EF in any half hour period (step) for RCS cold leg temperatures between 50 EF and 560 EF.

• LCO Figure 3.4-2b updates the P/T limit cooldown curve, as based on the new criterion in LCO 3.4.9.1.b.

2.0 REGULATORY EVALUATION

The Nuclear Regulatory Commission (NRC) staff evaluates the acceptability of a facilitys proposed P/T limits and P/T limit report based on the following regulations and guidance.

Title 10 of Code of Federal Regulations (10 CFR) Part 50.60(a) states:

Except as provided in paragraph (b) of this section, all light-water nuclear power reactors, other than reactor facilities for which the certifications under §50.82(a)(1) have been submitted, must meet the fracture toughness and material surveillance program requirements for the reactor coolant program pressure boundary set forth in appendices G and H to this part.

Appendix H to 10 CFR Part 50, "Reactor Vessel Material Surveillance Program Requirements,"

establishes requirements related to facility reactor pressure vessel (RPV) material surveillance programs. Regulatory Guide (RG) 1.190, "Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence," describes methods and assumptions acceptable to the NRC staff for determining the RPV neutron fluence. RG 1.99, Revision 2, "Radiation Embrittlement of Reactor Vessel Materials," contains methodologies for determining the increase in transition temperature resulting from neutron radiation. Appendix G to 10 CFR Part 50, "Fracture Toughness Requirements," requires that facility P/T limit curves for the RPV be at least as conservative as those obtained by applying the methodology of Appendix G to Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code). The most recent version of Appendix G to Section XI of the ASME Code that has been endorsed in 10 CFR 50.55a and, therefore, by reference in 10 CFR Part 50, Appendix G, is the 2001 Edition through the 2003 Addenda of the ASME Code. This edition of Appendix G to Section XI incorporates the provisions of ASME Code Cases 588 and 640.

Additionally, Appendix G to 10 CFR Part 50 imposes minimum head flange temperatures when system pressure is at or above 20% of the preservice hydrostatic test pressure.

Generic Letter (GL) 92-01, Revision 1, Reactor Vessel Structural Integrity, requested that licensees submit the RPV data for their plants to the NRC staff for review, and GL 92-01, Revision 1, Supplement 1, requested that licensees provide and assess data from other licensees that could affect their RPV integrity evaluations.

NUREG-0800, "Standard Review Plan," Section 5.3.2, "Pressure-Temperature Limits and Pressurized Thermal Shock," provides guidance on using these regulations and documents in the NRC staffs review. Additionally, Section 5.3.2 provides guidance to the NRC staff in performing check calculations of the licensees submittal.

RG 1.99, Revision 2, provides the staffs methodology for calculating the adjusted reference temperature values (RTNDT values) for the RPV materials and the initial RTNDT, the RTNDT, and margin term (M) values that are used as parameters in the calculation of RTNDT values.

RG 1.190 provides the staffs recommended methodology for performing neutron fluence determinations that are used in the RTNDT value calculations.

3.0 TECHNICAL EVALUATION

3.1 Technical Bases for Calculating P-T Limits The basic parameter of the methodology in Appendix G to Section XI of the ASME Code is the stress intensity factor (KI), which is a function of the stress state and flaw configuration.

Appendix G to Section XI of the Code requires a safety factor of 2.0 on stress intensities resulting from reactor pressure during normal and transient operating conditions, and a safety factor of 1.5 on these stress intensities for hydrostatic testing curves. The flaw, as postulated in Appendix G to Section XI of the ASME Code, has a depth that is equal to 1/4 of the RPV beltline thickness and a length equal to 1.5 times the RPV beltline thickness.

The methodology of Appendix G to Section XI of the ASME Code requires licensees to calculate the critical stress intensity factors for the RPV over the entire range of operating temperatures for the RCS. For any given operating temperature analyzed, the critical stress intensity (K IC) value is required to be calculated as a function of both the specific operating temperature and the limiting RTNDT value for the materials in the RPV. The RTNDT value is a material property parameter that is used to monitor the fracture toughness of the RPV. The methods of Appendix G to Section XI of the ASME Code then apply the KIC values as the basis for calculating the maximum allowable operating pressures for the RPV over the operating temperature range for the RCS.

For any beltline material and operating temperature, the RTNDT value used in the KIC value calculation is calculated in accordance with the methodology of RG 1.99, Revision 2. In the RG methodology, the RTNDT value is calculated using the accumulated neutron fluence for the material. Thus, the RTNDT value is calculated as the sum of the initial (unirradiated) reference temperature value (initial RTNDT value), the mean value of the adjustment in reference temperature caused by irradiation (RTNDT value), and an M value. The M value is an additional safety margin in the calculations that is used to account for uncertainties in the values of the initial RTNDT, the copper and nickel alloying contents of the material, and the calculational procedures for the RTNDT value calculations.

3.2 Staff Assessment The licensees proposed 32 EFPY P/T limit cooldown curve for ANO-2 was developed using the methods of Appendix G to Section XI of the ASME Code and ASME Code Case N-640. The proposed 32 EFPY cooldown curve applies to cooldowns of the RPV at a rate of 100 EF/hour or a cooldown of 50 EF in any half-hour step. The proposed cooldown curve is applicable to RCS cold-leg temperatures ranging from 50 EF ! 560 EF.

The NRC staff performed an independent calculation of the 32 EFPY cooldown curve. For its P/T limit calculations, the NRC staff applied the requirements of 10 CFR Part 50, Appendix G, and the methodologies of Appendix G to Section XI of the Code, as modified by the methodology of the ASME Code Case. For the evaluation of the limiting RPV nozzle, the staff modified the methods of Appendix G to Section XI of the ASME Code by using the nozzle evaluation methods proposed in Appendix 5 of Welding Research Council Bulletin WRC-175, PVRC [Pressure Vessel Research Council] Recommendations on Toughness Requirements for Ferritic Materials, August 1972. The modification of the ASME Code,Section XI, Appendix

G methods by WRC-175 for RPV nozzles is allowed under the provisions of Paragraph G-2223 of Appendix G to Section XI of the ASME Code.

For cooldowns of the reactor, the inside 1/4T surface flaw is the limiting flaw location for the RPV beltline. Therefore, for its independent calculations, the staff assessed the 1/4T location of the RPV as the basis for calculating the KIC values for the RPV beltine and used these KIC values and the methods of analysis in Appendix G to Section XI of the Code to calculate the maximum allowable pressures throughout the operating temperature range. The staff assessed the 1/4T location for both 100 EF per hour transient cooldown conditions and 0 EF per hour steady state cooldown conditions. The staff applied the limiting RPV neutron fluence (E > 1.0 MeV) values at the 1/4T location of the RPV shell as the basis for calculating the limiting RTNDT value used in the KIC value calculations. The staff confirmed that the 1/4T RTNDT values were based on the methodology of RG 1.99, Revision 2, and that the methods establish Lower Shell Plate C-8010-1 (Heat No. C8161-2) as the limiting 1/4T beltline material for the ANO-2 RPV. The staff calculated a limiting 32 EFPY 1/4T RTNDT value of 113.1 EF for this material. This 1/4T RTNDT value was within 0.4 EF and, therefore, in good agreement with the value calculated by EOI (112.7 EF) for its assessment. The staff also calculated the KIC values for the RPV outlet nozzle to evaluate the impact of the RPV nozzle stress loadings on the P/T limits calculations. This nozzle is the limiting RPV nozzle in the RPV. The staff applied a limiting RTNDT value of 0 EF for its calculations of KIC values for the RPV outlet nozzle and used the methods of WRC-175 to modify the bases for calculating the maximum allowable pressures for the limiting RPV nozzle throughout the RCS operating temperature range.

For any specific temperature being assessed, the staff used the lowest calculated pressure from its 100 EF per hour transient cooldown, 0 EF per hour steady state cooldown, and limiting nozzle assessments as the basis for establishing the corresponding maximum allowable pressure value for the temperature, and compared the result to the minimum temperature requirement in Table 1 of 10 CFR Part 50, Appendix G, to determine final P/T limit point.

Based on these methods, the staff confirmed that the licensees proposed 32 EFPY cooldown curve for ANO-2 curves were at least as conservative as those required in Table 1 of 10 CFR Part 50, Appendix G, as modified by the ASME Code Case-640 methods. The staff also confirmed that the licensees proposed 32 EFPY cooldown curve to ANO-2 included the appropriate minimum temperature requirements of Table 1 of 10 CFR Part 50, Appendix G.

Therefore, the staff concludes that the licensees proposed 32 EFPY cooldown curve for ANO-2 complies with P/T limit acceptance criteria of 10 CFR Part 50, Appendix G.

4.0 REGULATORY COMMITMENTS The licensee's April 15, 2004, application contained the following regulatory commitments:

TYPE SCHEDULED (Check one) COMPLETION COMMITMENT DATE (If ONE-TIME CONTINUING Required)

ACTION COMPLIANCE The P/T curves provided in BAW-2405, X Prior to Revision 2 are adjusted for sensor implementation location but do not account for any of the TS instrument uncertainty. The P/T limit Change uncertainty will be added to the cooldown curves contained in the ANO-2 operating procedures.

The ANO-2 SAR will be modified to reflect X Within the next the reference to Revision 2 of BAW-2405. ANO-2 SAR update cycle after NRC approval.

The NRC staff finds that reasonable controls for the implementation and for subsequent evaluation of proposed changes pertaining to the above regulatory commitments are best provided by the licensees administrative processes, including its commitment management program. The above regulatory commitments do not warrant the creation of a regulatory requirement (item requiring prior NRC approval of subsequent changes).

5.0 STATE CONSULTATION

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

6.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to the 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 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 issued a proposed finding that the amendment involved no significant hazards consideration on May 11, 2004 (69 FR 26188) and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

7.0 CONCLUSION

The staff has determined that the licensees proposed 32 EFPY cooldown curve for ANO-2 was generated in accordance with the requirements in Appendix G to Section XI of the ASME

Code. The staff, therefore, concludes that the licensees proposed 32 EFPY cooldown curve is in compliance with the requirements of Section IV.B.2 of 10 CFR Part 50, Appendix G, and is acceptable for incorporation into the ANO-2 TS.

Principal Contributor: J. Medoff Date: March 7, 2005

Arkansas Nuclear One cc:

Senior Vice President Vice President, Operations Support

& Chief Operating Officer Entergy Operations, Inc.

Entergy Operations, Inc. P. O. Box 31995 P. O. Box 31995 Jackson, MS 39286-1995 Jackson, MS 39286-1995 Wise, Carter, Child & Caraway Director, Division of Radiation P. O. Box 651 Control and Emergency Management Jackson, MS 39205 Arkansas Department of Health 4815 West Markham Street, Slot 30 Little Rock, AR 72205-3867 Winston & Strawn 1400 L Street, N.W.

Washington, DC 20005-3502 Mr. Mike Schoppman Framatome ANP 3815 Old Forest Road Lynchburg, VA 24501 Senior Resident Inspector U.S. Nuclear Regulatory Commission P. O. Box 310 London, AR 72847 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 County Judge of Pope County Pope County Courthouse Russellville, AR 72801 January 2005