ML20002C388
| ML20002C388 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/18/1972 |
| From: | Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Bloch E US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20002C389 | List: |
| References | |
| NUDOCS 8101100235 | |
| Download: ML20002C388 (2) | |
Text
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Mr. E. J. Bloch, Director MAY 2 21972> @ae: Docket No 50-155 Directorate of Licensing U.S. mci /:C EERn
/7 License No DPR-6 US Atomic Energy Commission Qy Washington, LC 20545 4
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Dear Mr. Bloc'u By letter dated December 30, 1971, we reported preliminary results of our reanalysis of the perfomar_ce of the Emergency Core Cooling Systems (ECCS) installed at the Big Rock Point Nuclear Plant.
In responding to our submittal (Mr. Donald J. Skovholt's letter of January 17,1972), you requested that we revise our analysis to in-clude more conservative assumptions and to submit a schedule of im-provements, if they are necessary, by July 1,1972. This' letter is intended to provide such infomation for the Design Basis Accident.
Information cor.cerning intermediate-and small-break sizes will be submitted at a later date.
Reanalysis was performed in accordance with the Interim Acceptance Criteria of both the " worst" case of fuel type currently in use at the Big Rock Point Nuclear Plant as well as future fuel design concepts. Results of the analysis for the " worst" case current fuel, referred to as Type F fuel, and a new type of fuel scheduled for in* tial use at the Big Rock Point Nuclear Plant (Nuclear Fuel Services, Inc (NFS) demonstration fuel assemblies) in 1973 are de-scribed in the attached report titled " Design Basis Accident Loss-of-Coolant Analysis for NFS Demonstration Fuel Assemblies." This reanalysis shows the Type F fuel exceeds the Interim Acceptance Criteria, but the NFS demonstration fuel is well within the criteria.
The reanalysis for Type F fuel was performed assuming that the assembly operated at its licensed power limits, with the reactor operating at full power, 240 MW. The analysis of the NFS demonstra-t tion assemblies assumed that an assembly was operated at power output equal to the Type F fuel when "F" fuel is operated at itc licensed limit.
Studies of the design basis accident, and existing equipment and plant configurations, have shown plant operation within the Interim Acceptance Criteria limits is only achievable through chan[;es in fuel design from those presently in use in the Lig Rock Point Nuclear Plant.
8101100p.3f 2760 7
- Mr. E. J. Bloch 2
Docket-No-50.-155 May 18, 1972 The use of the 11 x 11 rod array and unpowered rod is one design cor-cept that will enable Big Rock Point to meet Interim Acceptance Criteria limits in future reload fuel types.
Our plans, and schedule for meeting the Interim Acceptance i
Criteria, are based on replacing the current reload fuel, Type F, as
. it reaches its design and equilibrium fuel cycle end of life with Type Reload G fuel assemblies. On a pure equilibrium fuel cycle basis, Reload G would displace all Reload F fuel by spring of 1977
- However, equilibrium fuel cycles have not been possible in the past at the Big Rock Point Nuclear Plant because of the large numbers of fuel bundles irradiated (past and present) for research and development purposes and premature failures of reload fuel types. For these two reasons, it is possible that some Reload F fuel may remain in the core through the spring of 1978. A licensing submittal is currently being prepared for Reload G and will be submitted within one month.
. Four NFS demonstration assemblies, of the type snalyzed in the attached report, are scheduled to be placed into use at the Big Rock Point Nuclear Plant during the next refueling outage, currently scheduled de for spring of 1973 A licensing submittal vill be submitted within the next two months, Reanalysis of the small-break loss-of-coolant accident is in progress. Required modification. if any, will likely have an effect on the intermediate-break analysis. The results of these reanalyses will be submitted prior to the July 1,1972 deadline.
Yours very truly, 1
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RBS/ map Ralph B. Sewell Nuclear Licensing Administrator CC: Boyce H. Crier, USAEC
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