ML20023D462
| ML20023D462 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/03/1983 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | Norelius C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20023D448 | List: |
| References | |
| 1-320, NUDOCS 8305200520 | |
| Download: ML20023D462 (2) | |
Text
ic a ;u q
..b e
Docket No. 50-346 ungoo License No. NPF-3 Acumo R CRNu Serial No. 1-320 Vce Prescer.L Nxwe
" m a s se2i February 3, 1983 Mr. C. E. Norelius, Director Division of Engineeritig and Techt.ical Programs United States Nuclear Regulatory CcTeission Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Norelius:
Toledo Edison achnewledges receipt of ycur December 21, 1982, letcar (Log No. 1-718 Inspecticn Report Ko. 50-346/87-25) summarizing the inapection activities at the Davis-Besee Huclear Paver Station Urit 1.
The Inspection Report contained a Notice of Violar.icn concerning the acccunting for cross-core shuffling of the fuel for Cycle. 3 in our safety evaluation to determine whether an unreviewed safety questien was involved. Toleda Ediscn believes that tha reload pattern did not entail an unreviewed safety question for the reasons givea in the following tesponse.
Violation:
As a result of the inspection conducted on Sentember 15, 29-30, 1982, and in accordance with NRC Enforcement ?clicyz 47 FR 9987 (March 9, 1982), the following violation was identified:
Technical Specification 6.5.2.7.a states in part that "The Company Nuclear Review Board shall review the safety evaluations for changes to procedures, equipment or systems completed under the provision of Section 50.59, 10 CFR, to verify that such actions did not constitute an unreviewed safety question."
10 CFR 50.59(a)(1) states in part that, "The holder of a license authorizing operation of a production or utilization facility may (i) make changes in the facility as described in the safety analysis report, without prior Commission approval, unless the proposed change involves a change in the technical specifications incorporated in the license or an unreviewed safety question."
Contrary to the above, the licensee did not account for cross-core shuffling of fuel for Cycle 3 in its safety evaluation to determine whether an unreviewed safety question was involved.
The fuel shuffle resulted in a core power tilt in excess of that predicted by design.
THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652 8305200520 830517 PDR ADOCK 05000346 pEB 1 1 gg3 C
=
Docket No. 50-346 License No. NPF-3 Serial No. 1-320 February 3, 1983 Page 2
Response
The driving force for the quadrant power tilt in the reactor core need not be fuel related as demonstrated by the existence of tilt during the Beginning of Cycle 1 (B0C-1) when all fuel was non-irradiated. Although this perturb-ation may be accentuated due to the reload shuffling scheme, this does not constitute an unreviewed safety question.
In the case of Davis-Besse the quadrant power tilt was caused by a feedwater flow and temperature mismatch between loops 1 and 2, which eccurced through both Cycles 1 and 2 and resulted in a positive tilt in the WX quadrant ranging from.5 to 1% through both cycles. The safety evaluation for Cycle 3 reload analyets nodeled the cross core shuffle that was used la Cycle 3.
The safety evaluation assumed that Cycles 1 and 2 had been ran with symmetric core power distributions and that any carry-evet effect of burnup mismatches between cora quadrants would be small and would be within the technical specification limits.
The Davis-Besse Technical Specifications, Section 3.2.4, provides a Quadrant Power Tilt Sready State Lirit. This limit accommodates tilt induced by any mechaniss. The shuffling schetTen are designed to mininire hot channel factors and power peaking problems such that the tilt limit becomes bounding. The steady state cuadraut power tilt limit in Cycle 3 Technical Specificettons w&o evalutted against the Cycle 3 reload pretern and was found to be acceptable.
Even though this limit was exceeded at BOC-3, appropriate actions stipulated in Davis-Besse Technical Specifications were undertaken to restore the tilt within i
limits. At no time was operation of the core conducted outside the safety limits and the Technical Specification
x actions were adequate to restore the tilt within limits.
Pursuant to this we have concluded that an unreviewed safety question was never involved. Also, since the cross-core shuffle reload pattern was modeled in the Cycle 3 reload analysis, the safety evaluation thereof did consider this care configuration to ensure core operation within the safety limits.
Very truly yours, RPC:SCJ:JAE ej c/2 cc: DB-1 NRC Resident Inspector I
-.