ML060460417

Correction to Amendments Deletion of the Power Range Neutron Flux High Negative Rate Function

ML060460417
Person / Time
Site:	Cook
Issue date:	02/28/2006
From:	Tam P NRC/NRR/ADRO/DORL/LPLE
To:	Nazar M Indiana Michigan Power Co
References
TAC MC8805, TAC MC8806
Download: ML060460417 (5)

Text

February 28, 2006Mr. Mano K. NazarSenior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106

SUBJECT:

DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 - CORRECTION TO AMENDMENTS RE: DELETION OF THE POWER RANGE NEUTRON FLUX HIGH NEGATIVE RATE TRIP FUNCTION (TAC NOS. MC8805 AND MC8806)

Dear Mr. Nazar:

On February 10, 2006, the Nuclear Regulatory Commission (NRC) issued Amendment No. 293to Renewed Facility Operating License No. DPR-58 and Amendment No. 275 to RenewedFacility Operating License No. DPR-74 for Donald C. Cook Nuclear Plant, Units 1 and 2. Theamendments deleted the power range neutron flux high negative rate trip function from Table 3.3.1-1, "Reactor Trip System Instrumentation" of the units' Technical Specifications.Subsequent to issuance, the NRC staff noted that the safety evaluation (SE) supporting theamendments references General Design Criterion 10, despite the fact that both units wereconstructed before Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50 was promulgated. Accordingly, referencing GDC 10 in the SE is an error.

Enclosed please find corrected pages 1 and 2 of the SE, deleting all references to GDC 10, with marginal lines indicating the areas corrected. Please use these pages to replace corresponding pages in the SE. The corrections on pages 1 and 2 of the SE do not change the NRC staff's conclusion in the SE. The NRC staff regrets any inconvenience this error may have caused you.

Sincerely,/RA/Peter S. Tam, Senior Project ManagerPlant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-315 and 50-316

Enclosures:

As stated cc w/encls: See next page February 28, 2006Mr. Mano K. NazarSenior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106

SUBJECT:

DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 - CORRECTION TO AMENDMENTS RE: DELETION OF THE POWER RANGE NEUTRON FLUX HIGH NEGATIVE RATE TRIP FUNCTION (TAC NOS. MC8805 AND MC8806)

Dear Mr. Nazar:

On February 10, 2006, the Nuclear Regulatory Commission (NRC) issued Amendment No. 293to Renewed Facility Operating License No. DPR-58 and Amendment No. 275 to RenewedFacility Operating License No. DPR-74 for Donald C. Cook Nuclear Plant, Units 1 and 2. Theamendments deleted the power range neutron flux high negative rate trip function from Table 3.3.1-1, "Reactor Trip System Instrumentation" of the units' Technical Specifications.Subsequent to issuance, the NRC staff noted that the safety evaluation (SE) supporting theamendments references General Design Criterion 10, despite the fact that both units wereconstructed before Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50 was promulgated. Accordingly, referencing GDC 10 in the SE is an error.

Enclosed please find corrected pages 1 and 2 of the SE, deleting all references to GDC 10, with marginal lines indicating the areas corrected. Please use these pages to replace corresponding pages in the SE. The corrections on pages 1 and 2 of the SE do not change the NRC staff's conclusion in the SE. The NRC staff regrets any inconvenience this error may have caused you.

Sincerely,/RA/

Peter S. Tam, Senior Project ManagerPlant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket Nos. 50-315 and 50-316

Enclosures:

As stated cc w/encls: See next pageDISTRIBUTIONPUBLICLPLIII-1 R/F RidsNrrPMPTamRidsNrrLATHarrisRidsOgcRpGHill(2)RidsAcrsAcnwMailCenterRidsNrrDorlLple RidsRgn3MailCenterRidsNrrDirsItsbRidsNrrDorlSSunADAMS Accession Number: ML060460417 OFFICENRR/LPL3-1/PMNRR/LPL3-1/LANRR/SPWBNRR/SPWB/BCNRR/LPL3-1/BC(A)NAMEPTam THarrisSSunJNakoskiTKobetzDATE2/28/062/24/062/28/062/28/062/28/06OFFICIAL RECORD COPY SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIONRELATED TO AMENDMENT NO. 293 TORENEWED FACILITY OPERATING LICENSE NO. DPR-58AND AMENDMENT NO. 275 TO RENEWED FACILITY OPERATING LICENSE NO. DPR-74INDIANA MICHIGAN POWER COMPANYDONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2DOCKET NOS. 50-315 AND 50-31

61.0INTRODUCTION

By application dated August 10, 2005 (Agencywide Documents Access and ManagementSystem (ADAMS) Accession No. ML052300238), Indiana Michigan Power Company (the licensee) requested amendments to the Technical Specifications (TSs) for the Donald C. Cook (D. C. Cook) Nuclear Plant, Units 1 and 2. The proposed amendments would delete the power range neutron flux high negative rate trip function from Table 3.3.1-1, "Reactor Trip System Instrumentation." The licensee stated that the proposed change would allow elimination of an unnecessary tripfunction and thereby reduce the potential for a transient due to reactor shutdown in meeting TSrequirements for a limiting condition for operation (LCO) of the trip function. The Nuclear Regulatory Commission (NRC) staff's review of the application is set forth below.

2.0REGULATORY EVALUATION

ll l

l l

l l

lThe NRC's regulatory requirements related to the content of TSs are set forth in l10 CFR 50.36, "Technical Specifications." Specifically, 10 CFR 50.36(c)(2)(ii) specifies four screening criteria to be used in determining whether an LCO is required to be included in the TSs:Revised by letter dated 2/28/06l Criterion 1 - Installed instrumentation that is used to detect, and indicate in the controlroom, a significant abnormal degradation of the reactor coolant pressure boundary (RCPB); Criterion 2 - A process variable, design feature, or operating restriction that is an initialcondition of a design-basis accident (DBA) or transient analysis that either assumes the failure of, or presents a challenge to, the integrity of a fission product barrier;Criterion 3 - A structure, system or component (SSC) that is part of the primary successpath, and which functions or actuates to mitigate a DBA or transient that either assumesthe failure of, or presents a challenge to, the integrity of a fission product barrier; and Criterion 4 - An SSC which operating experience or probabilistic risk assessment hasshown to be significant to public health and safety. The licensee proposed to delete the power range neutron flux high negative rate trip functionfrom the D. C. Cook TSs. The NRC staff evaluation of the licensee's proposed change waspredicated upon continued compliance with the screening criteria specified in 10 CFR 50.36.l

3.0TECHNICAL EVALUATION

The power range neutron flux high negative rate trip function was designed as part of thereactor protecti on system (RPS) to mitigate the consequences of one or more dropped rodcluster control assemblies (RCCAs) event. The dr opped RCCAs event is an anticipatedoperational occurrence, and is caused by a single electric or mechanical failure that results in a number and combination of RCCAs from the same group of a given bank to drop to the bottomof the core. The resulting negative reactivity insertion causes nuclear power to quickly decrease and core radial peaking factors to increase. The reduced power and continued steam generation cause the reactor coolant temperature to decrease. In the manual control mode, thepositive reactivity feedback due to dropping temperature causes the reactor power to rise to initial power level at a reduced reactor vessel inlet temperature with no power overshoot. In the automatic control mode, the plant control system detects the reduction in core power andinitiates control bank withdrawal in order to restore core power. As a result, power overshoot occurs, resulting in lower calculated departure from nucleate boiling ratios (DNBRs). At higherpower levels, in the event of a dropped RCCA event, the RPS will detect the rapidly decreasingneutron flux due to the dropped RCCAs and trip the reactor based on the power range neutronflux high negative rate trip function, thus ending the transient and assuring that DNBR designlimits are maintained. Since the dropped RCCA event is an anticipated operational occurrence,it must be shown that the DNBR design limits are met for the combination of high nuclearl power, high radial peaking factor, and other system conditions that exist following the droppedRCCA event.In a topical report WCAP-10297-P-A, "Dropped Rod Methodology for Negative Flux Rate TripPlants" (see ADAMS Accession No. 8304140120) Westinghouse documented a methodology for the analysis of the dropped RCCA event and concluded that the high negative flux rate tripwas required only when a dropped RCCA (or RCCA bank) exceeded the threshold value ofreactivity worth. Any dropped RCCA having a worth below the threshold value would notRevised by letter dated 2/28/06l Donald C. Cook Nuclear Plant, Units 1 and 2 cc:Regional Administrator, Region IIIU.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville RoadLisle, IL 60532-4351Attorney GeneralDepartment of Attorney General 525 West Ottawa Street Lansing, MI 48913Township SupervisorLake Township Hall

P.O. Box 818 Bridgman, MI 49106U.S. Nuclear Regulatory CommissionResident Inspector's Office 7700 Red Arrow Highway Stevensville, MI 49127James M. Petro, Jr., EsquireIndiana Michigan Power Company One Cook Place Bridgman, MI 49106Mayor, City of Bridgman P.O. Box 366 Bridgman, MI 49106Special Assistant to the GovernorRoom 1 - State Capitol Lansing, MI 48909Mr. John A. ZwolinskiSafety Assurance Director Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106Michigan Department of Environmental Quality Waste and Hazardous Materials Div.

Hazardous Waste & Radiological Protection Section Nuclear Facilities Unit Constitution Hall, Lower-Level North 525 West Allegan Street P. O. Box 30241 Lansing, MI 48909-7741Lawrence J. Weber, Plant ManagerIndiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106Mr. Joseph N. Jensen, Site Vice President Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106