ML043640141

License Amendment, Request to Use Yield Strength Determined from Measured Material Properties for Reinforcing Bar in Structural Calculations for Control Rod Drive Missile Shields

ML043640141
Person / Time
Site:	Cook
Issue date:	03/11/2005
From:	Lyon C NRC/NRR/DLPM/LPD3
To:	Nazar M American Electric Power Co, Indiana Michigan Power Co
Lyon C, NRR/DLPM, 415-2296
References
TAC MC2698, TAC MC2699
Download: ML043640141 (10)

Text

March 11, 2005 Mr. Mano K. Nazar American Electric Power Senior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group 500 Circle Drive Buchanan, MI 49107

SUBJECT:

DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 - ISSUANCE OF AMENDMENTS RE: REQUEST TO USE YIELD STRENGTH DETERMINED FROM MEASURED MATERIAL PROPERTIES FOR REINFORCING BAR IN STRUCTURAL CALCULATIONS FOR CONTROL ROD DRIVE MISSILE SHIELDS (TAC NOS. MC2698 AND MC2699)

Dear Mr. Nazar:

The U.S. Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment No. 286 to Facility Operating License No. DPR-58 and Amendment No. 268 to Facility Operating License No. DPR-74 for the Donald C. Cook Nuclear Plant, Units 1 and 2.

The amendments consist of changes to the design basis in response to your application dated April 13, 2004, pursuant to Title 10 of the Code of Federal Regulations Part 50.59.

The amendments change the design basis as described in the Updated Final Safety Analysis Report to allow the use in control rod drive missile shield structural calculations of a reinforcing bar (rebar) yield strength value based on measured material properties, as documented in the licensee rebar acceptance tests.

A copy of our related safety evaluation is also enclosed. A Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.

Sincerely,

/RA/

Carl F. Lyon, Project Manager, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316

Enclosures:

1. Amendment No. 286 to DPR-58

2. Amendment No. 268 to DPR-74

3. Safety Evaluation cc w/encls: See next page

ML043640141 (Letter)

• SE dated 12/21/04 ***Previously concurred OFFICE PM:PD3-1 LA:PD3-1 SC:EMEB OCFO/DPBA OGC SC:PD3-1 NAME FLyon THarris*** KManoly* DLurie*** RWeisman*** LRaghavan DATE 3/10/05 1/4/05 12/21/04 3/9/05 3/4/05 3/10/05 Donald C. Cook Nuclear Plant, Units 1 and 2 cc:

Regional Administrator, Region III Michigan Department of Environmental U.S. Nuclear Regulatory Commission Quality 2443 Warrenville Road, Suite 210 Waste and Hazardous Materials Div.

Lisle, IL 60532-4352 Hazardous Waste & Radiological Protection Section Attorney General Nuclear Facilities Unit Department of Attorney General Constitution Hall, Lower-Level North 525 West Ottawa Street 525 West Allegan Street Lansing, MI 48913 P. O. Box 30241 Lansing, MI 48909-7741 Township Supervisor Lake Township Hall Michael J. Finissi, Plant Manager P.O. Box 818 Indiana Michigan Power Company Bridgman, MI 49106 Nuclear Generation Group One Cook Place U.S. Nuclear Regulatory Commission Bridgman, MI 49106 Resident Inspector's Office 7700 Red Arrow Highway Mr. Joseph N. Jensen, Site Vice President Stevensville, MI 49127 Indiana Michigan Power Company Nuclear Generation Group James M. Petro, Jr., Esquire One Cook Place Indiana Michigan Power Company Bridgman, MI 49106 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 Mr. John A. Zwolinski Safety Assurance Director Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106

INDIANA MICHIGAN POWER COMPANY DOCKET NO. 50-315 DONALD C. COOK NUCLEAR PLANT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 286 License No. DPR-58

1. The U.S. Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Indiana Michigan Power Company (the licensee) dated April 13, 2004, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),

and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the licensing basis as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. DPR-58 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 286, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance and shall be implemented within 45 days. In addition, the licensee shall include the revised information as described in the licensee's application dated April 13, 2004, and evaluated in the staff's safety evaluation dated March 11, 2005, in the next scheduled update of the Updated Final Safety Analysis Report submitted to the NRC pursuant to 10 CFR 50.71(e).

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

L. Raghavan, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Date of Issuance: March 11, 2005

INDIANA MICHIGAN POWER COMPANY DOCKET NO. 50-316 DONALD C. COOK NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 268 License No. DPR-74

1. The U.S. Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Indiana Michigan Power Company (the licensee) dated April 13, 2004, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),

and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the licensing basis as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. DPR-74 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 268, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance and shall be implemented within 45 days. In addition, the licensee shall include the revised information as described in the licensee's application dated April 13, 2004, and evaluated in the staff's safety evaluation dated March 11, 2005, in the next scheduled update of the Updated Final Safety Analysis Report submitted to the NRC pursuant to 10 CFR 50.71(e).

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

L. Raghavan, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Date of Issuance: March 11, 2005

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 286 TO FACILITY OPERATING LICENSE NO. DPR-58 AND AMENDMENT NO. 268 TO FACILITY OPERATING LICENSE NO. DPR-74 INDIANA MICHIGAN POWER COMPANY DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-315 AND 50-316

1.0 INTRODUCTION

By application dated April 13, 2004, the Indiana Michigan Power Company (IM, or the licensee) requested amendments pursuant to Title 10 of the Code of Federal Regulations Part 50.59 to the design basis for the Donald C. Cook Nuclear Plant, Units 1 and 2. The proposed amendments would change the design basis as described in the Updated Final Safety Analysis Report (UFSAR) to allow the use in control rod drive missile shield structural calculations of a reinforcing bar (rebar) yield strength value based on measured material properties, as documented in the licensee rebar acceptance tests.

2.0 EVALUATION

2.1 Background

During the period between September 1997, and December 2000, the licensee performed a re-analysis of the Donald C. Cook Nuclear Plant (CNP) containment structures. The U.S.

Nuclear Regulatory Commission (NRC) reviewed the re-analysis and concluded that, with the exception of the missile shields, IM used acceptable methods and appropriate assumptions and design parameters in the re-analysis activity. In a letter to the NRC, dated July 16, 2002, the licensee informed the NRC that structural calculations for the missile shields had used yield strength values based on measured material properties as documented in certified mill test reports (CMTR). In a letter to the licensee dated March 21, 2003, the NRC staff stated that there was reasonable assurance that the missile shields will perform their intended function, but the use of the CMTR reinforcing steel yield strength, in lieu of code specified material properties, in the structural calculations for the missile shields, was not an acceptable method for design basis analyses and margins.

The licensee requests NRC review, and approval of, a change to the design basis as described in the UFSAR in accordance with 10 CFR 50.59 to allow the use of a rebar yield strength value in control rod drive missile shield structural calculations, based on measured material properties as documented in IM reinforcing steel acceptance tests performed when the steel was delivered to the site.

2.2 Technical Evaluation IM calculated that the capability of the missile shields to withstand the bending moment imposed by a bounding 50 pounds per square inch (psi) loss-of-coolant pressure differential, with a load factor (multiplier on pressure) of 1.5, can be achieved with a reinforcing steel yield strength of 46,500 psi. The bending moment is resisted by #8 and #11 reinforcing steel bars in the missile shield walls. These reinforcing steel bars have been traced to their respective heats. IM took two specimens for each heat of the steel bars when they were delivered to the site, and tested them for yield, and tensile strengths. The IM Concrete Reinforcement Bar Test Reports recorded two yield strengths and two tensile strengths for each heat of the reinforcing steel bars delivered for missile shield wall construction.

Table 1, Summary of Testing for Rebar Used in Control Rod Drive Missile Shields, of the licensees April 13, 2004, submittal, lists four tests of yield strength for #11 bars for Unit 1, eight tests of yield strength for #11 bars for Unit 2, and two tests of yield strength for #8 bars for both Units 1 and 2. The lowest yield strength is 49,487 psi for #11 bars, and 50,759 psi for #8 bars.

All other yield strength values are greater than 50,000 psi. Since all the yield strength values of field tests on the steel bars are greater than the acceptance criterion of 46,500 psi, the licensee concluded that the missile shields possess greater strength than that needed to satisfy the design basis criteria. The staff finds that the use of yield strength of reinforcing steel, based on field test values, to analyze the capability of missile shields by the licensee is acceptable. This is based on the fact that the licensee has demonstrated that the lowest yield strength recorded was 49,487 psi, which exceeds the minimum design basis value of 46,500 psi.

It should be recognized that, although the CNP rebar procurement specification is American Society of Testing and Materials (ASTM) A615, which sets a minimum yield strength of 40,000 psi, the average yield strength based on actual rebar testing is about 51,000 psi. The revised magnitude of compartment pressure as a result of the transient mass distribution analysis necessitated an average rebar yield strength of 46,500 psi. The lowest measured rebar yield strength was 49,487 psi, and the variance in actual rebar yield strength test values is very low.

The licensee also performed a statistical evaluation using NUREG-1475, "Applying Statistics,"

to determine the lower limit rebar yield strength for 95 percent of the population with 95 percent confidence. Thus, it is highly unlikely that any rebars in the compartment wall have a yield strength less than the minimum value of 46,500 psi. Considering a postulated scenario in which a rebar with a yield strength below 46,500 psi might exist in the compartment wall, the actual resulting strain in this rebar would be determined based on the overall deformation of the wall under postulated applied loads, which is dependent on the average rebar yield strength in the sections considered in the design. Therefore, the presence of a rebar with a yield strength below 46,500 psi would have an insignificant effect on the overall load carrying characteristic of the compartment wall. Accordingly, the staff concurs with the licensee's determination regarding the overall structural adequacy of the compartment wall, and concludes that the wall design conforms to the original design basis for the plant.

2.3 Conclusion Based on its review of Enclosure 2 of the licensee's submittal dated April 13, 2004, the NRC staff has concluded that it is acceptable to use the field acceptance test values of yield strength for reinforcing steel bars to analyze the capability of the control rod drive missile shields. The test demonstrated that the minimum test value exceeds the minimum design basis yield

strength and, therefore, the reinforcing steel bars have adequate strength to ensure that the integrity of the control rod drive missile shields is maintained. The staff, therefore, approves the proposed changes to the design basis as described in the CNP UFSAR.

3.0 STATE CONSULTATION

In accordance with the NRC's regulations, the Michigan State official was notified of the proposed issuance of the amendments. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20, or change a surveillance requirement. The staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The NRC has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (69 FR 60682). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement, or environmental assessment need be prepared in connection with the issuance of the amendments.

5.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: J. Ma Date: March 11, 2005