ML13018A312
| ML13018A312 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/24/2013 |
| From: | Mahesh Chawla Plant Licensing Branch III |
| To: | Entergy Nuclear Operations |
| Chawla M | |
| References | |
| TAC ME5806 | |
| Download: ML13018A312 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 24, 2013 Vice President, Operations Entergy Nuclear Operations, Inc.
Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530
SUBJECT:
PALISADES NUCLEAR PLANT - CORRECTION TO AMENDMENT NO. 245 REGARDING PRIMARY COOLANT SYSTEM PRESSURE-TEMPERATURE LIMITS (TAC NO. ME5806)
Dear Sir or Madam:
On January 19, 2012 (Agencywide Documents Access and Management System Accession (ADAMS) Accession No. ML113480303), the U.S. Nuclear Regulatory Commission (NRC) issued Amendment No. 245 to Renewed Facility Operating License No. DPR-20 for the Palisades Nuclear Plant (PNP). This amendment consisted of a change to the technical specifications (TSs) in response to your application dated March 7, 2011. The amendment revised facility's TSs to add an applicability period of 42.1 effective full-power years to the existing pressure-temperature limit curves and low temperature overpressure protection setpoint limit curve for PNP.
Following issuance of the amendment, the NRC staff was informed by the Palisades licensee that the following sections of the Safety Evaluation (SE) had incorrect information:
- 1. Section 3.3.2 on page 6 - Value of 185.5F ART is in error. The correct value is 185.8F.
- 2. Section 3.3.3 on page 7 - LTOP value is incorrectly shown as a fixed value of 315 psia.
LTOP setpoint is a variable, depending on reactor vessel inlet pressure, as shown in TS Figure 3.4.12-1, "LTOP Setpoint Limit,".
The NRC staff determined that these errors were entirely administrative in nature, and were inadvertently introduced, and were not the subject of the amendment or the associated notice to the public. Thus, according to the NRC's policy established by SECY-96-238 (ADAMS Accession No. 9611250030 (Legacy Library)), these errors can be corrected by a letter.
Enclosed, please find the replacement pages 6 and 7 of the SE.
-2 These corrections do not change any of the conclusions in the safety evaluation associated with the amendment. We regret any inconvenience this may have caused. If you have any questions regarding this matter, please call me at (301) 415-4037.
Sincerely, Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
Corrected SE pages 6 and 7 cc w/encl: Distribution via ListServ
ENCLOSURE PALISADES NUCLEAR PLANT DOCKET NO. 50-255 REPLACEMENT SAFETY EVALUATION PAGE FOR AMENDMENT NO. 245
-6 The above-referenced supplement to WCAP-15353 describes the fluence calculations performed in support of the present request. The report stated that the neutron transport calculations were carried out using the Discrete Ordinates Radial Transport (DORT) code, and performing a three dimensional flux synthesis. The DORT code used nuclear data from the BUGLE-96 wide-group cross section library. The code also treats anisotropic scattering with a P5 legendre expansion, and models the vessel geometry using an S16 order of angular quadrature. RG 1.190 recommends that, at a minimum, fluence calculations be based on BUGLE-96 nuclear data, using P3 and S8 approximations. The methods used in the licensee calculations are consistent with the nuclear data suggested by RG 1.190, and exceed the minimum calculational rigor suggested by RG 1.190. On this basis, the NRC staff finds the fluence calculations acceptable. The licensee-reported surveillance capsule dosimetry analysis results agree within the 20 percent uncertainty specified in RG 1.190, and on this basis the NRC staff finds that the fluence calculations are acceptably qualified.
3.3.2 ART Value and TS Curves To assess the validity of the licensee's proposed curves, the staff first performed an independent calculation of the CF and ART values for the circumferential weld #27204 and the axial weld heat #W5214 using the methodology in RG 1.99, Revision 2. Based on these calculations, the NRC staff verified that the licensee's limiting material is axial weld heat
- W5214. The staff's calculated ART values were in agreement with the licensee's calculated ART values of 252.7°F and 185.8°F for the 1/4T location and the 3/4T location, respectively, for intermediate shell axial weld heat #5214.
The staff then evaluated the new calculated TS curves in WCAP-17341-NP for acceptability by performing a limited number of independent calculations. The licensee stated that the new calculated TS curves were based on the methodologies of Appendix G of Section XI of the ASME Code, 1998 Edition with the 2000 Addenda and Code Case N-641.1 NRC Regulatory Issue Summary 2004-04, dated April 5, 2004 [ADAMS Accession No. ML040920323], states that the ASME Section XI, Appendix G, 1998 Edition with the 2000 Addenda may be used without the need for exemption. The use of the K1c fracture toughness curve is appropriate for evaluating the potential for crack initiation without imposing unnecessary conservatism in the controlled heatup and cooldown process of a RPV. The staff evaluated selected points on the cooldown and heatup curves, and the results were in agreement with the licensee's values shown in Tables 5-1 and 5-2 from WCAP-17341-NP.
The staff examined the comparisons in Figures 6-1 through 6-4 ofWCAP-17341-NP between the new calculated P-T curves (including a margin to account for delta pressure correction of 35 psi when the temperature is below 300°F and 54 psi for higher temperatures), but with no margin for instrument errors, and the existing TS curves. The staff's comparison showed that the existing curves are more conservative because the allowable pressure for each temperature for the current P-T curves is less than or equal to the allowable pressure for the new P-T curves.
Since the new P-T limits are equally or more conservative to P-T limits generated using the 1998 edition through 2000 addenda of the ASME Code,Section XI, Appendix G, which is incorporated by reference in 10 CFR 50.55a, these P-T limits would be acceptable per 1 Code Case N-641 allows an LTOP enable temperature of RTNDT + 40°F for assumed axial surface flaws in axial welds and plates, and RTNDT -_85°F for assumed circumferential flaws in circumferential welds.
-7 10 CFR 50, Appendix G. However, since the licensee elected to continue to use its existing TS P-T limits, which are more conservative than the new P-T curves, the existing TS limits are, by definition, more conservative than the limits that would be generated using the ASME Code,Section XI, Appendix G, and are therefore acceptable. The additional conservatism of the existing curves relative to the new P-T curves is mainly due to the fact that the use of K1c was not allowed in the edition of the ASME Code used to generate the existing curves. The staff also found that the minimum temperature requirements of Table 1 of Appendix G to 10 CFR Part 50 were properly implemented in the P-T limit curves. Therefore, the staff verified that the licensee's proposed P-T limits are in accordance with Appendix G to Section XI of the ASIVIE Code and satisfy the requirements of Appendix G to 10 CFR Part 50.
3.3.3 Low Temperature Overpressure Protection (LTOP)
The LTOP system, provided by the power operated relief valves and also by the shut down cooling relief valves, prevents RCS overpressurization below certain temperatures, thus maintaining reactor coolant pressure boundary integrity. The LTOP analysis determines the Limiting Conditions for Operation that ensures the low-temperature structural integrity for the period of applicability.
The NRC staff reviewed the LTOP analysis contained in Appendix B of WCAP-17341-NP using the guidance in ASME Code Case N-641, "Alternative Pressure-Temperature Relationship and Low Temperature Overpressurization Protection System RequirementsSection XI Division 1."
The new, calculated LTOP enabling temperature is 313.2°F based on the criteria specified in Code Case N-641. The current LTOP enabling temperature is applicable when any system cold leg temperature is below 430°F, i.e., more conservative than the new value that is calculated in WCAP-17341-NP. The LTOP setpoint limit curve is unaffected by this proposed license amendment, and Figure 3.4.12-1 in the Technical Specifications is amended to include the curve applicability period. Therefore, the NRC staff agrees that the current LTOP enabling temperature is more conservative and concludes that the requested addition of the 42.1 EFPY applicability period to the LTOP curve is acceptable.
4.0
SUMMARY
The staff concludes that the licensee's current TS P-T limits, are acceptable with the proposed addition of an applicability period of 42.1 EFPY, because the current P-T limits are equally or more conservative than the P-T limits that would be generated using an edition and addenda of the ASME Code,Section XI, that is acceptable to the NRC staff, thus meeting the requirements of 10 CFR 50, Appendix G. Hence, the proposed additions to the TS may be incorporated into the PNP TS and are valid through 42.1 EFPY.
5.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Michigan State official was notified of the proposed issuance of the amendment. The Michigan 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 or change the
-2 These corrections do not change any of the conclusions in the safety evaluation associated with the amendment. We regret any inconvenience this may have caused. If you have any questions regarding this matter, please call me at (301) 415-4037.
Sincerely, IRAJ Mahesh Chawla, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
Corrected SE pages 6 and 7 cc w/encl: Distribution via ListServ DISTRIBUTION:
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