ML053120095

Letter, Correction to Safety Evaluation for Amendment No. 196 Regarding Extension of Reactor Coolant System Pressure and Temperature Curves

ML053120095
Person / Time
Site:	Saint Lucie
Issue date:	11/23/2005
From:	Moroney B NRC/NRR/ADRO/DORL/LPLD
To:	Stall J Florida Power & Light Co
Moroney B, NRR/DLPM, 415-3974
Shared Package
ML053130370	List: ML053120095
References
TAC MC5580
Download: ML053120095 (6)

Text

November 23, 2005 Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420

SUBJECT:

ST. LUCIE, UNIT 1 - CORRECTION TO SAFETY EVALUATION FOR AMENDMENT NO. 196 REGARDING EXTENSION OF REACTOR COOLANT SYSTEM PRESSURE AND TEMPERATURE CURVES (TAC NO. MC5580)

Dear Mr. Stall:

On September 21, 2005, the U.S. Nuclear Regulatory Commission issued Amendment No. 196 to Renewed Facility Operating License No. DPR-67 for the St. Lucie Plant, Unit No. 1. The amendment revised applicability of the Reactor Coolant System Pressure and Temperature curves from 23.6 Effective Full Power Years (EFPY) to 35 EFPY. Due to an administrative error, the 23.6 EFPY number was incorrectly stated as 26 EFPY on 2 pages of the safety evaluation (SE). The error did not affect the conclusions of the safety evaluation.

Enclosed are revised Pages 2 and 3 of the SE with the revisions noted by a bar in the right margin. Please substitute the revised pages for those originally provided. We are sorry for any inconvenience this may have caused.

Sincerely, Brendan T. Moroney, Project Manager Plant Licensing Branch D Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-335

Enclosures:

Revised SE pages cc w/enclosures: See next page

ML053120095 NRR-106 OFFICE LPLII-2/PM LPLII-2/LA LPLII-2/BC NAME BMoroney BClayton MMarshall DATE 11/14/05 11/14/05 11/23/05 The method to predict the reactor vessel material irradiation damage is provided in Regulatory Guide (RG) 1.99, Rev. 2, Radiation Embrittlement of Reactor Vessel Materials.

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 pressure vessel neutron fluence, and is intended to ensure the accuracy and reliability of the fluence determination required by GDC 14, 30, and 31.

3.0 TECHNICAL EVALUATION

The purpose of this review and the following evaluation is to establish the validity of the fluence value and the correctness of the 35 EFPY estimate.

Westinghouse Commercial Atomic Power report, WCAP-15446, Revision 1, Analysis of Capsule 284E from the Florida Power and Light St. Lucie Unit 1 Reactor Vessel Radiation Surveillance Program, dated January 2002, includes updates that reflect data from two additional surveillance capsules that were removed since the original fluence evaluation.

Review of WCAP-15446, Revision 1, by the NRC staff indicated that the calculations were carried out using the correct methodology, correct approximations and correct cross sections.

The original Adjusted Reference Temperature (ART) is 191EF at 1/4T (reactor vessel wall thickness) and 137EF at 3/4T for the lower shell axial welds. The licensee calculated projected values of vessel fluence for the lower shell axial welds utilizing the maximum fluence value for Operating Cycle 15 as the benchmark, a conservative assumption for future fuel loadings, and a 10 percent increase to cover unforseen variations. These calculations are conservative with respect to the guidance in RG 1.190 and are acceptable. The new critical weld fluence for 35 EFPY is 1.88x1019 neutrons per square centimeter (n/cm2), which was reduced from the maximum value of 2.85x1019 n/cm2 in the original assessment.

WCAP-15446, Revision 1, provides materials information regarding the critical lower shell axial weld based on limiting weld heat No. 305424, which is part of the Beaver Valley surveillance capsule test program. The licensee examined all of the materials in the belt zone and concluded that the lower shell axial weld remains the critical element.

This material was then used to back-calculate the fluence for which the 1/4T ART is 191EF and this resulted in the proposed value of 35 EFPY. The maximum value of 2.85x1019 n/cm2 was applied to all circumferential welds to assure that the lower shell axial weld is the critical element. The calculation is straight forward and the equations used are in accordance with RG 1.99. The NRC staff verified that the calculations were performed correctly. Therefore, the proposed extension of applicability of the P/T limit curves to 35 EFPY is acceptable. The limiting values in the P/T limit curves, which include the lowest service temperature, minimum boltup temperature, and minimum pressure limits, do not change from the previously approved values, since these limits are not based on fluence.

St. Lucie Unit 1 TS 3.4.9.1 establishes a limiting condition for operation based on the RCS P/T limits, as shown in Figures 3.4-2a, 3.4-2b and 3.4-3. The proposed amendment revises the title of each figure to indicate a change in applicability from 23.6 EFPY to 35 EFPY. The curves are not changed. This is acceptable based on the preceding evaluation. Figures 3.4-2a and 3.4-2b

also have a note added to indicate the limiting material and limiting ART value used in the analysis. The information is consistent with the analysis and has no operational impact and, therefore, the change is acceptable.

The LTOP setpoints are also based on the existing P/T limit analysis and, therefore, do not change. TS Figure 3.1-1b provides limits on maximum allowable RCS heatup and cooldown rates for a single high head safety injection pump in operation during LTOP conditions, The proposed amendment revises the title of Figure 3.1-1b to indicate a change in applicability from 23.6 EFPY to 35 EFPY. Since the curve is not changed and is based on the P/T curves, the proposed change is acceptable.

The licensee proposes to continue the practice of not applying instrument uncertainties to the P/T limit curves. However, as indicated on page 10 of Attachment 1 of the submittal, the licensee accounts for instrument uncertainties in the LTOP analysis for the relief valve enable and pressure lift setpoints. Therefore, they do not need to be accounted for in the P/T limit curves.

In summary, the NRC staff reviewed the submitted information and the request to extend the applicability of the P/T limit curves and the LTOP setpoints for St. Lucie Unit 1. The request is based on vessel fluence conservatism in the existing P/T curves. This was demonstrated by recalculation of the fluence with methods that adhere to the guidance in RG 1.190, and therefore, are acceptable. The ART value for 35 EFPY was calculated to match the existing 1/4T value of 191EF of the current P/T curves. The staff finds this acceptable, because it assures that the proposed extension of the P/T curves is valid. The LTOP setpoints remain unchanged because they are based on the P/T curves.

4.0 STATE CONSULTATION

Based upon a letter dated May 2, 2003, from Michael N. Stephens of the Florida Department of Health, Bureau of Radiation Control, to Brenda L. Mozafari, Senior Project Manager, U.S. Nuclear Regulatory Commission, the State of Florida does not desire notification of issuance of license amendments.

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. 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 (70 FR 9993, dated March 1, 2005). Accordingly, this amendment 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 this amendment.

Mr. J. A. Stall ST. LUCIE PLANT Florida Power and Light Company cc:

Senior Resident Inspector Mr. G. L. Johnston St. Lucie Plant Plant General Manager U.S. Nuclear Regulatory Commission St. Lucie Nuclear Plant P.O. Box 6090 6351 South Ocean Drive Jensen Beach, Florida 34957 Jensen Beach, Florida 34957 Craig Fugate, Director Mr. Terry Patterson Division of Emergency Preparedness Licensing Manager Department of Community Affairs St. Lucie Nuclear Plant 2740 Centerview Drive 6351 South Ocean Drive Tallahassee, Florida 32399-2100 Jensen Beach, Florida 34957 M. S. Ross, Managing Attorney Mark Warner, Vice President Florida Power & Light Company Nuclear Operations Support P.O. Box 14000 Florida Power and Light Company Juno Beach, FL 33408-0420 P.O. Box 14000 Juno Beach, FL 33408-0420 Marjan Mashhadi, Senior Attorney Florida Power & Light Company Mr. Rajiv S. Kundalkar 801 Pennsylvania Avenue, NW. Vice President - Nuclear Engineering Suite 220 Florida Power & Light Company Washington, DC 20004 P.O. Box 14000 Juno Beach, FL 33408-0420 Mr. Douglas Anderson County Administrator Mr. J. Kammel St. Lucie County Radiological Emergency 2300 Virginia Avenue Planning Administrator Fort Pierce, Florida 34982 Department of Public Safety 6000 Southeast Tower Drive Mr. William A. Passetti, Chief Stuart, Florida 34997 Department of Health Bureau of Radiation Control 2020 Capital Circle, SE, Bin #C21 Tallahassee, Florida 32399-1741 Mr. William Jefferson, Jr.

Site Vice President St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957-2000