ML071070594

Request for Additional Information Regarding Proposed Amendment Regarding Turbine Control Fluid Oil System Modification

ML071070594
Person / Time
Site:	Cook
Issue date:	04/20/2007
From:	Tam P NRC/NRR/ADRO/DORL/LPLIII-1
To:	Nazar M Indiana Michigan Power Co
References
TAC MD3161
Download: ML071070594 (4)

Text

April 20, 2007 Mr. Mano K. Nazar Senior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106

SUBJECT:

D. C. COOK NUCLEAR PLANT, UNIT 2 (DCCNP-2) - REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED AMENDMENT INVOLVING TURBINE CONTROL SYSTEM FLUID OIL PRESSURE (TAC NO. MD3161)

Dear Mr. Nazar:

In a letter dated September 15, 2006, Indiana Michigan Power Company (I&M) requested an amendment to the Technical Specifications (TS) of DCCNP-2 to reflect a plant modification that will replace the current turbine control system, leading to a change of the nominal control fluid oil operating pressure from 114 psig to 1600 psig. I&M proposed to revise the allowable low fluid oil pressure value in the TS from greater than or equal to 57 psig to greater than or equal to 750 psig. The Nuclear Regulatory Commission (NRC) staff determined that additional information is needed to complete its review. Accordingly, by e-mail dated January 3, 2007 (Accession No. ML070040188), the NRC staff provided draft questions to I&M personnel.

On January 11, 2007, the NRC staff discussed the draft questions with I&M personnel by telephone, and agreed to revise the questions where appropriate. The enclosed Request for Additional Information (RAI) conveys the revised questions. Please respond by June 30, 2007.

Feel free to contact me if you need clarification of this RAI.

Sincerely,

/RA/

Peter S. Tam, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-316

Enclosure:

Request for Additional Information cc w/encl: See next page

ML071070594 OFFICE LPL3-1\PM LPL3-1/LA BOPB/BC LPL3-1/BC NAME PTam THarris JSegala LRaghavan DATE 4/19/07 4/19/07 4/12/07 4/20/07

• Questions transmitted by memo of 4/12/07.

REQUEST FOR ADDITIONAL INFORMATION D.C. COOK NUCLEAR PLANT, UNIT 2 (DCCNP-2)

AMENDMENT REGARDING TURBINE CONTROL SYSTEM FLUID OIL PRESSURE (1) As indicated in the licensees submittal, the replacement of the turbine control system will increase the normal control oil fluid operating pressure from 114 psig to 1600 psig and will revise the allowable low fluid oil pressure value for turbine trip from greater than or equal to 57 psig to greater than or equal to 750 psig. Please provide the following information:

(i) Discuss to what extent this change involves any associated piping design changes that are necessary to accommodate the increased pressure; (ii) Discuss whether or not pipe failures associated with this change need to be considered due to the large increase in turbine oil operating pressure; and if so (iii) Discuss to what extent any safety-related equipment needs to be protected from the effects of these postulated pipe failures.

(2) There is insufficient information in the application regarding the replacement of the existing mechanical-hydraulic control system for the main turbine and the east and west main feed-pump turbines with a Triconex TS3000 triple modular redundant control system. Please describe:

(i) The system design and how it operates, and how oil pressure varies with time during normal plant operation and following a turbine trip; and (ii) The basis for how the 750 psig trip set point was established to assure that spurious trips will not occur and safety functions will not be challenged, including uncertainty considerations.

Donald C. Cook Nuclear Plant, Units 1 and 2 cc:

Regional Administrator, Region III Michigan Department of Environmental U.S. Nuclear Regulatory Commission Quality Suite 210 Waste and Hazardous Materials Div.

2443 Warrenville Road Hazardous Waste & Radiological Lisle, IL 60532-4351 Protection Section Nuclear Facilities Unit Attorney General Constitution Hall, Lower-Level North Department of Attorney General 525 West Allegan Street 525 West Ottawa Street P. O. Box 30241 Lansing, MI 48913 Lansing, MI 48909-7741 Township Supervisor Lawrence J. Weber, Plant Manager Lake Township Hall Indiana Michigan Power Company P.O. Box 818 Nuclear Generation Group Bridgman, MI 49106 One Cook Place Bridgman, MI 49106 U.S. Nuclear Regulatory Commission Resident Inspector's Office Mark A. Peifer, Site Vice President 7700 Red Arrow Highway Indiana Michigan Power Company Stevensville, MI 49127 Nuclear Generation Group One Cook Place Kimberly Harshaw, Esquire Bridgman, MI 49106 Indiana Michigan Power Company One Cook Place Bridgman, MI 49106 Mayor, City of Bridgman P.O. Box 366 Bridgman, MI 49106 Special Assistant to the Governor Room 1 - State Capitol Lansing, MI 48909 Susan D. Simpson Regulatory Affairs Manager Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106