ML20211P869
| ML20211P869 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 07/21/1986 |
| From: | Sears P Office of Nuclear Reactor Regulation |
| To: | Randazza J Maine Yankee |
| References | |
| NUDOCS 8607230398 | |
| Download: ML20211P869 (3) | |
Text
o July 21,1986 f Doc'ke U o.L5'0-309 Mr. J. B. Randazza Executive Vice President Maine Yankee Atomic Power Company 83 Edison Drive Augusta, Maine 04336
Dear Mr. Randazza:
REQUEST FOR ADDITIONAL INFORMATION - MAINE YANKEE RESPONSE TO THE 10 CFR 50.54(f) LETTER RELATED TO REACTOR COOLANT PUMP INTEGRITY The staff has reviewed your response to our 10 CFR 50.54(f) letter related to the integrity of your reactor coolant pumps in light of the sheared shaft event at Crystal River 3 on January 1,1986.
The staff has determined that the results of your analyses indicate that the radiological consequences of the locked rotor event coincident with the loss of offsite power and a limiting single failure are within 10 CFR 100 limits.
The staff also believes that the sheared shaft event is bounded by the locked rotor event.
However, as stated in our previous letter, the Crystal River event indicates that a significantly high probability may exist for cracks in your Reactor Coolant Pump (RCP) shafts, cap bolts, and pins, which could propagate to failure.
Your response did not address completely our concerns regarding the impeller bolting and drive pin issue.
The cracking of the cap bolts at Davis Besse and failures at Crystal River 3 have been attributed to Intergranular Stress Corrosion Cracking (IGSCC).
Florida Power Corporation's corrective action was to redesign the bolts including changing the materials.
You have not addressed the issues of IGSCC.
In addition, while referring to plans for inspecting RCP shafts at your next refueling outage, you did not provide a firm commitment as to inspections of RCP shafts, bolts, and drive pins.
Therefore, to enable us to complete our evaluation, the following additional information will be required.
In light cf failure of bolts and drive pins at Crystal River 3 and cracks found in these same components at Davis Besse, provide your plans for inspection and any corrective action which might be required including replacement with a different material as proposed by Florida Power Corporation for Crystal River 3.
In addition, provide more definitive information describing your plans to inspect your reactor coolant pump shafts at your next refueling outage.
You are requested to submit the above information within 45 days from the date of this letter.
%"f 8607230398 860721 PDR ADOCK 05000309 P
J The information requested by this letter affects fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.
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Sincerely,
/S/
Patrick M. Sears, Project Manager i
PWR Project Directorate #8 Division of PWR Licensing-B cc: See next page Distribution:
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Mr. J. B. Randazza Maine Yankee Atomic Power Company Maine Yankee Atomic Power Station cc:
Charles E. Monty, President Mr. P. L. Anderson, Project Manager Maine Yankee Atomic Power Company Yankee Atomic Electric Company 83 Edison Drive 1671 Worchester Road Augusta, Maine 04336 Framingham, Massachusetts 07101 Mr. Charles B. Brir.kman Mr. G. D. Whittier Manager - Washington Nuclear Licensing Section Head Operations Maine Yankee Atomic Power Company Combustion Engineering, Inc.
83 Edison Drive 7910 Woodmont Avenue Augusta, Maine 04336 Bethesda, Maryland 20814 John A. Ritsher, Esquire Ropes & Gray 225 Franklin Street Boston, Massachusetts 02110 State Planning Officer Executive Department 189 State Street Augusta, Maine 04330 Mr. John H. Garrity, Plant Manager Maine Yankee Atomic Power Company P. O. Box 808 Wiscasset, Maine 04578 Regional Administrator, Region I U.S. Nuclear Regulatory Comission 631 Park Avenue King of Prussia, Pennsylvania 19406 First Selectman of Wiscasset Municipal Building U.S. Route 1 Wiscasset, Maine 04578 Mr. Cornelius F. Holden Resident Inspector c/o U.S. Nuclear Regulatory Commission P. O. Box E Wiscasset, Maine 04578 i
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