ML20217E961
| ML20217E961 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 04/20/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20217E940 | List: |
| References | |
| NUDOCS 9804280013 | |
| Download: ML20217E961 (3) | |
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UNITED STATES p
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NUCLEAR REGULATORY COMMISSION l
o WASHINGTON, D.C. 30606 4 001
+9.....,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.100 TO FACILITY OPERATING LICENSE NO. DPR-22 NORTHERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263
1.0 INTRODUCTION
By letter dated March 13,1998, as supplemented March 25,1998, the Northem States Power Company (the licensee) requested an amendment to the Technical Specifications (TS) appended 1
to Facility Operating License No. DPR-22 for the Monticello Nuclear Generating Plant (MNGP).
The proposed amendment would revise the Minimum Critical Power Ratio (MCPR) safety limits based on the cyde-specific analysis of the current mixed core of GE [ General Electric] 11, GE10, 4
four GE12 lead use assemblies, and eight Siemens Power Company (SPC) ATRIUM-9B fuel parameters. The proposed amendment would also change the footnotes on TS pages 6 and 249b which will make the safety limit MCPR values applicable to cycle 19 only. In addition, the proposed amendment makes administrative corrections of previously introduced errors on TS pages 6 and 249b. The March 25,1998, letter provided clarifying information in response to the staff's request for additionalinformation. This information was within the scope of the original application and did not change the staff's initial proposed no significant hazards considerations determination. Therefore, renoticing was not warranted.
2.0 EVALUATION in accordance with 10 CFR 50.90, the licensee requested a change to the MNGP TS to revise the MCPR safety limits based on the cycle-specific analysis, and also to make administrative corrections of previously introduced errors in the TS. The MCPR safety limits are the lowest MCPR values that will ensure that at least 99.9 percent of the fuel rods in the core would not be expected to experience boiling transition during either normal operation or anticipated operational occurances as specified in the Standard Review Plan (NUREG-0800), Section 4.4, " Thermal and Hydraulic Design." The proposed revision of TS 2.1.A. 2.3, and TS 6.7 is described below.
2.1 Revision to TS 2.1.A The licensee has proposed to change the Safety Limit MCPR (SLMCPR) in TS 2.1.A from 1.08 to
.1.10 for two recirculation loop operation, and from 1.09 to 1.11 for single recirculation loop operation, when the reactor steam dome pressure is greater than 800 psia [ pounds per square inch absolute), and core flow is greater than 10 percent rated core flow. This proposed TS change also involves changing the footnote on page 6 from cycle "18" to cycle "19."
9804280013 900420 PDR ADOCK 05000263 P
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2-Although cycles 18 and 19 use the same fuel types, the cycle-specific SLMCPR for cycle 19 is higher primarily because: (1) cycle 19 has a slightly flatter core MCPR distribution and much flatter in-bundle power distribution than cycle 18; and (2) cycle 19 is loaded with a higher reload average batch weight percent enrichment than cycle 18.
The proposed changes to SLMCPR values in TS 2.1.A for cycle 19 are based on the analyses performed using MNGP cycle 19 cycle-specific inputs and approved methodologies including GESTAR ll (NEDE-24011-P-A-13, Sections 1.1.5 and 1.2.5 [ proprietary information-not publicly available]) and a revised R-factor methodology described in NEDC-32505P, "R-Factor Calculation Method for GE11, GE12 and GE13 Fuel," [ proprietary information-not publicly available]
November 1995. The revised R-factor calculation method uses the same NRC-approved equation
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stated in GESTAR ll (NEDE-24011-P-A) with the correction factors that substitute rod-integrated powers for the lattice peaking factors to account for the effects of the part-length-rod design.
The staff has reviewed the R-factor calculation method for GE11 fuel, the relevant information provided in the proposed Amendment 25 to GESTAR 11, NEDE-24011 (which is under staff review), and the supplemental information dated March 25,1998, in response to the staff request for additionalinformation during a teleconference on March 24,1998, on the MNGP cycle 19 SLMCPR calculation with respect to modeling of the eight SPC ATRIUM-9B assemblies and their impact on the SLMCPR calculation. The ATRIUM-9B assemblies are loaded in the core locations such that they have significant CPR margin relative to the limiting MCPR assemblies in the core.
In addition, an administrative adder of 0.02 wi!! be incorporated in the operating limit MCPR in the MNGP cycle 19 3D-Monicore core monitoring databank for the ATRIUM-9B assemblies.
Based on its review of the above information. the staff has concluded that the proposed change of the SLMCPR in TS 2.1.A from 1.08 to 1.10 for two recirculation loop operation, and from 1.09 to 1.11 for single recirculation loop operation for MNGP cycle 19 is acceptable since the revised l
l SLMCPR will ensure that at least 99.9 percent of the fuel rods in the core would not be expected l
to experience boiling transition during either normal operation or anticipated operational occurrences as specified in the Standard Review Plan (NUREG-0800), Section 4.4.
The proposed change to the footnote on TS page 6 from cycle "18" to cycle "19" is acceptable since it clarifies the fact that the revised SLMCPR values are for cycle 19 only.
2.2 Revision to TS 2.3.A l
j The proposed administrative change on TS page 6 from "MWT" to "MWt" is acceptable since the change does not alter the intent of the TS while ensuring consistency with the remainder of the TS.
2.3 Revision to TS 6.7 l
The proposed administrative change to TS 6.7.a. on page 249b from " Linear Heat Generation i
l Ratio Limits" to " Linear Heat Generation Rate Limits" is acceptable since the change does not alter the intent of the TS while correcting a previously introduced error.
Also, the proposed change to the footnote on TS page 249b from "* For cycle 18 only as approved in SE dated October 1997" to "* For cycle 19 only as approved in SE dated April 20, I
. 1998is acceptable since it clarifies the fact that the revised SLMCPR values are for cycle 19 only and it reflects the approved use of the revised R-factor calculation method and will ensure that values for cycle-specific parameters are determined such that applicable limits (i.e., nuclear limits, transient analysis limits, and accident analysis limits) are met.
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Minnesota State official was notified of the l
proposed issuance of the amendment. The State official had no comments.
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4.0 ENVIRONMENTAL CONSIDERATION
j The amendment changes a requirement with respect to the installation or use of a facility l
component located within the restricted area as defined in 10 CFR Part 20. The 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 (63 FR 13704).
Accordingly, the amendment meets the eligibility enteria 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, i
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5.0 CONCLUSION
l 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.
t Principal Contributor: T. Huang Date: April 20, 1998 l,'
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