ML20206N025
| ML20206N025 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 04/16/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20206N009 | List: |
| References | |
| NUDOCS 8704200346 | |
| Download: ML20206N025 (6) | |
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^t NUCLEAR REGULATORY COMMISSION UNITED STATES h
WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NtICLEAR REACTOR REGULATION SUPPORTINC AMENDMENT NO. 32 TO FACILITY OPERATING LICENSE NO. NPF-18 COMMONWEALTH EDISON COMPANY LA SALLE COUNTY STATION, UNIT 2 l
l DOCKET NO. 50-374
1.0 INTRODUCTION
By letter from C. P. Allen, Comonwealth Edison (CE), to H. R. Denton, NRC, dated December 9,1986 (Reference 1), Technical Specification changes were roposed for the operation of La Salle County Station Unit 2 for Cycle ?
p(LS2C2) with a reload using General Electric (GE) manufactured fuel assemblies and GE analyses and methodologies,. The requested Technical Specification changes and reports (including Reference 2) discussing the reload and analyses done to support and justify the second cycle operation were included with the submittal. There was also an attachment B to Reference I proposing Technical Specification changes related to single loop operation.
2.0 EVALUATION 2.1 RELOAD DESCRIPTION The LS2C2 reload will retain 108 8CRB176 and 432 8CRB219 fuel assemblies from the first cycle and add 224 new BP8CRB299L GE fuel assemblies. The reload is based on the Cycle 1 exposure of 10.016 to 10.216 Giga Watt Days /Short Ton (GWD/ST) and a Cycle 2 exposure of 6.775 GWD/ST. The loading will be a conventional scatter pattern with low reactivity fuel on the periphery.
2.2 FUEL DESIGN The new fuel assembly to be used for LS2C2, BP8CRR299L, has been generically approved structually in the staff's review of NEDE-24011, GESTAR II (Amendment 13). This fuel type has been analyzed for generic application with approved methods and meets the approved litrits of GESTAR II (Reference 5). Therefore, the new fuel is acceptable for LS2C2.
2.3 NUCLEAR DESIGN The nuclear design for LS?C2 has been perfomed with the methodology des-cribed in GESTAR II (Reference 3). The results of these analyses are given in Reference 2.
The shutdown margin is 2 percent Delta K at the beginning of cycle and 1.4 percent Delta K at the exposure of minimum shutdown margin.
Therefore, it meets the required 0.38 percent Delta K shutdown margin. The Standby Liquid Control system also meets the shutdown requirements with a 8704200346 870416 PDR ADOCK 05000374 p
. shutdown margin of 3.9 percent Delta K.
Since these and other LS2C2 nuclear design parameters have been obtained with previously approved methods and fall within expected ranges, the nuclear design is acceptable.
2.4 THERMAL-FYDRAULIC DESIGN The thermal-hydraulic design for LS2CP has been performed with the method-ology described in GESTAR II (Reference 31, and the results are given in Reference 2.
The para;neters used for the analyses are those approved in Reference 3 for the La Salle class BWR-5.
The Safety Limit Minimum Critical Power Ratio (SLMCPR) values are increased by 0.01 to reflect the approved limits when going from first cycle to reload cores. These SLMCPR values are 1.07 and 1.08 for two and one loop operation, respectively. The Operating Limit MCPR (OLMCPR) values are determined by the limiting transients, Rod Withdrawal Error (RWE), Feedwater Controller Failure (FWCF) and Load Rejection Without Bypass (LRWBP). The analysis of these events for LS2C2, via the ODYN Option B approach, provides new Cycle 2 Technical Specification values of OLMCPR as a function of f.
At (and belowl a T of 0.736, RWE provides the limit at a MCPR of 1.?5.
FWCF is limiting above 0.736 until above a Tof 0.754, where LRWBP is the limiting event.
i Approved methods (Reference 3) were used to analyze these events land others I
which could be limiting), and the analyses and results are acceptable and fall within expected ranges.
The changes in MCPR limits, Maximum Average Planar Linear Heat Generation Rate (PAPLHGR) limits, and the Average Power Range Monitor (APRM) setpoints, when going from two to one (recirculation) loop operation, remain the same for Cycle 2 as they were for Cycle 1.
These changes for one loop operation, which have been approved previously, continue to be acceptable.
The thermal-hydraulic stability of the Cycle 2 core has been analyzed using the approved methods (Reference 3). The result is a decay ratio of 0.60 at the intersection of the natural circulation line and the 105 percent rod line. Existing Technical Specifications do not allow continued operation in natural circulation. Operation at the combination of low flow and high power sufficient to produce high decay ratia is thus limited. Although the cycle specific analysis predicts adequate ato sility, proposed Technical Specification changes to assure stabiMt dn -ng single loop operation (SLO) have been included in Attachment B cf 'pm
- e 1.
These changes are in general accord with the specificatior. apprcmd recently for other reactors (e.g., Duane Arnold 50-3311. These specifications provide for the establishment of regions above the 80 percent rod line where: (a) below 39 percent flow, action must be taken to leave the region; and (b) above 39 percent flow and below 45 percent flow, action must be taken to monitor Average Power Hange Monitor (APRM1 - Local Power Range Monitor (LPRM1 noise and to reduce the noise or leave the region if the noise is greater than 3
)
times the baseline. These specifications also provide for the establish-ment of baseline noise levels when entering the surveillance region fif
. not previously accomplished in the cycle). These action and surveillance requirements (including the LPRM specificationiand the times for accomp-lishing them are comparable to other recently approved specifications and meet the objectives of GE Service Information Letter 380 (Reference 4); ano are, therefore, acceptable. Thus one loop operation is, generally, accept-able for la Salle without restrictions other than those presented in Specification 3/4.4.1.
2.5 TRANSIENT AND ACCIDENT ANALYSES The transient and accident analysis methodologies used for LS2C2 are des-cribed in GESTAR II (Reference 3).
Generally, the ODYN Option B approach, was used for transient analyses. The loss of Feedwater Heating event was analyzed with the GE BWR Simulator Code, approved in Reference 3.
The limiting MCPR events have been previously indicated in Section 2.4 The core wide transient analyses methodologies and results are acceptable and fall within expected ranges.
The RWE was analyzed on a plant and cycle specific basis (as opposed to the statistical approach), and a rod block setpoint of 1.07 was selected to provide an OLMCPR of 1.25. The fuel assembly misloading and misorientation events were not analyzed for LS2C2. As approved via Reference 3, the mislocated assembly is not analyzed for reload cores on the basis of studies indicating the small probability of an event exceeding MCPR limits. The l
misoriectation event is not of concern to C lattice cores (i.e., La Salle) because of the symmetry of the fuel bundle, gaps and power distribution.
These local event analyses are, thus, acceptable.
The limiting pressurization event, the Main Steam Isolation Valve closure with flux scram, was analyzed with standard GESTAR II methods. The results for peak steam dome and vessel pressures were well under required limits.
These are acceptable methodologies and results.
Loss of Coolant Accident (LOCA) analyses, using approved methodologies and parameters (Reference 3), were performed to provide MAPLHGR values for the new reload fuel assemblies (BP8CRB299L). These analyses and results are acceptable.
The Rod Drop Accident (RDA) was not specifically analyzed for LS2C2.
La Salle uses a Banked Position Withdrawal Sequence for control rod with-drawal.
For plants using this system, the RDA event has been statistically analyzed generically; and it was found, with a high degree of' confidence, that the peak fuel enthalpy would not approach the NRC required limit of 280 cal /gm for this event. This approach and analysis have been approved by the NRC (Reference 3) and are acceptable for LS2C2.
2.6 TECHNICAL SPECIFICATIONS The Techn.ical Specification changes are for the most part minor and provide for MCPR changes due to second cycle parameter changes, MAPLHGR limits for
- t..
a new fuel type, elimination of End of Cycle - Recirculation Pump-Trip (E0C-RPT) inoperable provision for the cycle, and for a change in k.
In f
addition, a Technical Specification providing for extended operation in the SLO mode has been added. Details of the specification changes follow:
II) Specification 2.1 and Bases and Tables B2.1.2-1 through B2.1.2-4:
The SLMCPR for two and one (recirculationi loop operations were increased by 0.01 to 1.07 and 1.08.
This is standard practice for second cycles and is based on parameter changes for reload cores given in the changes in the Bases Tables. These changes are taken from Reference 3.
These various changes are acceptable.
(2) Specification 3/4.2.1 and Figures 3.2.1.1 and 3.2.1-2:
A new MAPLHGR curve is provided for the new fuel and a fuel assembly designation change is made. These are acceptable.
1 (3) Specification 3/4.2.3 and Figures 3.2.2-1 and 3.2.3-2:
The provision for the EOC-RPT inoperable condition in Specification 3/4.2.3 was removed. This is acceptable.
The MCPR vs < curve is changed to reflect the new transient analyses as previously discussed. The change is acceptable.
The k factor curve was changed to be compatible with the standard LaSafiepowerandflowvaluesasgiveninReference3. This is acceptable.
(4) Actions d and e of Specification 3.3.4.2:
Changes were made to make this specification compatible with the elimination of EOC-RPT inoperable provision of Specification 3.2.3.
These changes, including the indicated power reduction, are reason-able and acceptable.
(5) Specification 3/4.4.1 and Bases for 3/4.4.1:
These changes are to assure thermal-hydraulic stability for single loop operation. They have been discussed in Section 2.4 of this evaluation and are acceptable.
(6) Table 3.3.6-2:
Table 3.3.6-2 is revised to incorporate the required RBM setroint change (RBM setpoint of 107 percent). This revision is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change in the installation and use of a. facility component located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements. The staff has determined that this 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 cumula-tive occupational radiation exposure. The Comission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accord-ingly, this 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 this amendment.
4.0 CONCLUSI0_N The Commission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Register (52 FR 2877) on January 28, 1987, and censulted with the state of Illinois. No public comments were received, and the state of Illinois did not have any comments.
The staff 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, and (2) such i
activities will be conducted in compliance with the Comission's regula-tions and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
5.0 REFERENCES
1.
Letter from C. M. Allen, to H. R. Denton, NRC, "La Salle County Station Unit 2, Proposed Amendment to Technical Specification for 1
Facility Operating License NPF-18-Reload Licensing Package for Cycle 2," December 9, 1986.
2.
General Electric Report - 23A4735, June 1986, " Supplemental Reload Licensino Submittal for La Salle County Station, Unit 2, Reload 1 (Cycle 2)."
3.
NEDE-24011-PA-8, May 1986 " General Electric Standard Application for Reactor Fuel," (GESTAR II.
4.
General Electric Service Information Letter No. 380, Revision 1 February 10, 1984
. 5.
Letter, G. Lainas, NRC, to J. S. Charnley, GE, dated March 26, 1986, Acceptance for Referencing of Licensing Topical Report NEDE-24011-P-A Amendment 13, Rev. 6, " General Electric Standard Application for Reactor Fuel."
Principal Contributor:
T. Huang, NRR Dated: April 16,1987 4
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AMENDMENT N0. 32 T0 FACILITY OPERATING LICENSE N0. NPF LA SALLE, UNIT.2' DISTRIBUTION:
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NRC PDR Local PDR-PRC System NSIC
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EHylton EAdensam Attorney, DELD i
CMiles RDiggs JPartlow '
BGrimes EJordan LHannon
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