ML20106D658
| ML20106D658 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/19/1984 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| 1094, 55531, TAC-55531, NUDOCS 8410260114 | |
| Download: ML20106D658 (3) | |
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TOLEDO
%me EDISON Docket No. 50-346 AcHano P. Cnoust ll"U""
License No. NPF-3 a,2, m 32,i Serial No. 1094 October 19, 1984 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz Operating Reactor Branch 10. 4 Division of Operating Reactors United States Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Stolz:
This is in response to your letter dated October 12, 1984 (Log No. 1622) concerning Cycle 5 Reload Analysis; Request for Additional Information.
The attaciunent provides Toledo Edison's response for Davis-Besse Nuclear Power Station Unit 1.
Very truly yours, RPC: GAB se d/3 cc: DB-1 NRC Resident Inspector 8410260114 841019 PDR ADOCK 05000346
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THE TOLEDO EDIGON CrMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652
Dock;t N;. 50-346 License No. NFF-3 Serial No. 1094 October 19, 1984 Questions Concerning Davis-Besse Cycle 5 Reload QUESTION 1:
In a letter from T. C. Baldwin of B&W to Dale Powers of NRC dated January 8,1983, concerning alternate vendor's fuel pellets in reload batches, it was stated that 8 test rods with alternate vendor's fuel pellets are being used in the ANO-1 Cycle #6. This letter also stateI that B&W would provide a written description and assurance of maintenance for this fuel of material properties used in core performance codes.
In the letter from J. H. Taylor of B&7 to J. F. Stolz of NRC dated September 17, 1984 it was stated that fuel pellets manufactured by G.E. would be used in DB-1, Cycle 5 and that:
1.
There would be no impact on models or methods used in evaluating the safety of the reactor, and 2.
The material properties and dimensional requirements were established by B&W.
It is not fully cicar whether B&W intends to continue a QA check on this fuel from G.E. or whether the responsibility rests on G.E.
Please clarify.
RESPONSE
B&W intends to continue QA checks on GE fuels for all future batches.
QUESTION 2:
In the Cycle 5 reload report (B&W - 1827) in Section 4.1, Fuel Assembly Mechanical Design (Page 4-1), a description is given for the new Mark-B5 upper end fitting modifications (spider and spring).
Is this a total new end fitting? Is the surveillance on the springs going on now (cld design) and, if so, will the surveillance continue for the new design?
RESPONSE
The Mark B-5 upper end fittings is not entirely new. The old-fitting uses holddown springs made of Inconel 750 with 15/32 inch spring wire. The new holddown spring uses Inconel 718 with 1/2 inch gage wire. Toledo Edison intends to continue visual inspection programs on the new fuel holddown springs.
QUESTION 3:
In the previous Cycle 4 for DB-1, the SER stated, in regards to the thermal behavior of the fuel, that the TAFY-3 and TACO-2 codes were used and NRC raised a concern that only the newer TACO series codes were capable of correctly calculating fission gas release (and therefore rod pressure) at high burnups.
B&W responded that fuel rod
r Docket No. 50-346 Lic nsa No. NPF-3 Serial No. 1094 October 19, 1984 pressure predicted by TACO-1 is lower than that predicted by TAFY-3 for fuel rod exposures of up to 42 mwd /kgU and that the expected exposure of any fuel rod during Cycle 4 is less than this amount. What is the comparable situation for Cycle 57
RESPONSE
There is no change in analysis methodology for fuel roJ pin pressure calculations from Cycle 4 to Cycle 5.
The calculated results for Cycle 5 shows that the fuel rod pressure will be acceptable for rod exposure up to 45,000 MWD /MTU.
QUESTION 4:
Cive a comparison of the flux - A flux / flow trip setpoints for Cycle 4 and 5.
RESPONSE
The flux - A flux / flow setpoints for Cycle 4 and Cycle 5 can be found in pages 8-12 and 8-11 of the corresponding cycle reload report.
QUESTION 5:
For Cycle 4 it was stated that the most recent reactor coolant flow rate measured was 387,200 gpm.
What is the most current measured reactor coolant flow rate?
RESPONSE
The 387,200 gpm flow rate as indicated in Cycle 4 reload report is not the " measured" flow rate.
It is the flow rate corresponding to 110% of the design RCS flow rate which is the design condition for reload analysis.
The latest measurement showed that the RCS flow rate is at 404,308 gpm.
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