ML19256G238
| ML19256G238 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 12/24/1979 |
| From: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19256G237 | List: |
| References | |
| TAC-12649, NUDOCS 7912280525 | |
| Download: ML19256G238 (3) | |
Text
PORTLAND GENERAL ELECTRIC COMPANY EUGENE WATER & ELECTRIC BOARD AND PACIFIC POWER & LIGHT COMPANY TROJAN NL* CLEAR PLANT Operating License NPF-1 Docket 50-344 License Change Application 56 This License Change Application is submitted in support of Licensee's request to revise a certain Limiting Condition for Operation, Surveillance Requirement and appropriate Bases in the Trojan Technical Specification (Appendix A to Operating License NPF-1) regarding power distribution limits (Fxy, FAH) and control rod insertion limits.
PORTLAND GENERAL ELECTRIC COMPANY
~
By
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C. Goodwin, Jf.
Assistant Vice President Thermal Plant Operation and Maintenance Subscribed and sworn to before me this 24th day of December 1979.
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Notary Public of Q/egon My Commission Expires:
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LCA 56 Page 1 of 2 LICENSE CHANGE APPLICATION 56 1.
On Page 3/4 2-6a of Appendix A to the Trojan Operating License, Technical Specification Surveillance Requirement 4.2.2.2 should of <1.65 over the entire height of be changed to permit an F Anevaluationhfthe'coreloadingdesignforTrojan the core.
Cycle 3 fuel has revealed that the existing Fxy(Z) Technical Specification would not permit unrestricted operation during the fuel cycle.
2.
On Page 3/4 2-8 of Appendix A to the Trojan Operating License, Technical Specification 3.2.3, the interim burnup-dependent FAH penalty should be eliminated. Trojan is presently being operated with an interim FaH Technical Specification pending completion of the NRC review of the Westinghouse partial rod bow test data. This NRC review has been completed and is consistent with this modification.
3.
On Page B3/4 2-5 of Appendix A to the Trojan Operation License Technical Specification under Bases 3/4.2.2 and 3/4.2.3, control rod insertion limits must be raised in order to permit unre-stricted operation in Cycle 3.
This is due to peaking factor limitations associated with the Cycle 3 loading patterns.
REASON FOR CHANGE This LCA proposes revisions to the Fxy, FAH and rod insertion limit Technical Specifications which will permit unrestricted operation of Trojan during Cycle 3.
SAFETY EVALUATION 1.
F Technical Specification change:
Calcult' ions of the total ry peaking factor, Fq x (relative power) that would result during expected power maneuvers in Cycle 3, have demonstrated that the current total peaking factor limit (Technical Specification 3.2.2 and Figure 3.2.2) would not be exceeded during Cycle 3 provided F$TP f,1.65 over the entire height of the core with all rods fuflywithdrawn. The design of the Cycle 2 core loading is based en the current requirement that Fxy shallremainf,1.55.in the top 4 ft of the core. Nevertheless, additioaal analyses have been done to verify that even if F in the top 4 ft of xy core elevation were to be in the range from 1.55 to 1.65, the total peaking factor F (Z) would still be maintained within the Q
current Technical Specification limits during the remainder of Cycle 2 operations. Therefore, it is acceptable to change the F
Technical Specifiestion at any tire prior to the start of xy Cycle 3.
This would assure that the reiised Technical Specifi-cation is in place during the early portion of Cycle 3 which is when operational restrictions would be most likely to occur.
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LCA 56 Page 2 of 2 LICENSE CHANGE APPLICATION 56 2.
FAH Technical Specification Change: The conclusions of the NRC review of the Westinghouse partial rod bow test data and analy-ses are documented in an April 5, 1979 letter from J. F. Stolz (NRC) to T. M. Anderson (Westinghouse). The NRC-approved relationship for bow penalty as a function of gap closure is as follows:
No DNB effect for closures of less than 50 percent and linear interpolation to determine the DNB effect for closures between 50 and 85 percent and between 85 percent and contact (100 percent). The bow effect at 85 percent closure is ll.4 per-cent DNBR for N-loop analysis and 14 percent for the loss of flow accident and N-1 loop analysis. Comparison of this bow penalty relationship with the Trojan design demonstrates that sufficient margin presently exists to accommodate this DNB penalty without the need of imposing a penalty on the FAH Technical Specification. Most of this margin is due to conser-vatisms that are generically incorporated in DNB analyses and a small amount is due to the fact that Trojan has a higher measured Reactor Coolant System flow rate than was assumed in the safety analyses. Furthermore, while this available margin accommodates the rod bow DNB penalty for region average burnups up to 33,000 mwd /MTU, the peaking factor (FAH) burnup further precludes the possibility of exceeding DNB limits at region average burnups greater than 33,000 MWJ/MTU.
These considerations are applicable only to 4-loop operations; the acceptability of the proposed FAH limit for 3-loop operation has not been addressed in view of the fact that Section 2.3 of the Trojan Operating License prohibits such operation.
3.
Rod Insertion Limit Technical Specification Change: All acci-dent analyses for Cycle 2 and Cycle 3 have been made assuming deeper insertion limits and since more shallow insertion limits are less limiting, the proposed Technical Specification is a change in the conservative direction.
SCHEDULE CONSIDERATION The proposed changes are needed to permit unrestricted operation during Cycle 3.
The most limiting portion of Cycle 3 is at the beginning-of-life when peaking factors are the greatest. Therefore, it is important that these changes be incorporated prior to startup of Cycle 3.
It is hoped that prompt action can be taken and a license amendment received prior to Plant startup following refueling (by April 1, 1980).
BASIS FOR DETERMINATION OF AMENDMENT CLASS This License Change Application has been reviewed and determined to result in a Class III amendment. This evaluation is based on the test that the methodology of this License Change Application has been pre-viously reviewed and approved by the NRC, involves a single safety issue, and does not involve a significant hazard consideration.
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