ML071700177

Request for Additional Information Regarding the High Thermal Performance (Htp) Fuel Reactor Coolant System Pressure-Temperature Safety Limit Technical Specification Amendment

ML071700177
Person / Time
Site:	Three Mile Island
Issue date:	07/11/2007
From:	Peter Bamford NRC/NRR/ADRO/DORL/LPLI-2
To:	Crane C AmerGen Energy Co
Bamford, Peter J., NRR/DORL 415-2833
References
TAC MD4910
Download: ML071700177 (5)

Text

July 11, 2007 Mr. Christopher M. Crane President and Chief Executive Officer AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

THREE MILE ISLAND, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE HIGH THERMAL PERFORMANCE (HTP) FUEL REACTOR COOLANT SYSTEM PRESSURE-TEMPERATURE SAFETY LIMIT TECHNICAL SPECIFICATION AMENDMENT (TAC NO. MD4910)

Dear Mr. Crane:

By letter dated March 22, 2007 (Agencywide Documents Access and Management System Accession Number ML070860968), AmerGen Energy Company, LLC submitted a license amendment request (LAR) for a technical specification change regarding the Three Mile Island (TMI), Unit 1 Reactor Coolant System Pressure-Temperature Safety Limit. This change will support the introduction of AREVA NPs Mark-B-HTP fuel design during the TMI, Unit 1 Cycle 17 reload (Fall 2007). The proposed amendment would revise various technical specification figures and tables associated with the variable low pressure trip setpoint to reflect more restrictive Safety Limits and more restrictive Limiting Safety System Settings for the Reactor Protection System.

The NRC staff has reviewed the information provided in the LAR and has identified the enclosed request for additional information (RAI). This RAI was also emailed to Mr. David Distel of your staff on June 7, 2007. The draft questions were sent to ensure that they were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. During a subsequent telephone discussion with members of your staff on June 18, 2007, it was agreed that your response would be provided within 30 days of the date of this letter.

Please contact me at 301-415-2833, if you have any questions.

Sincerely,

/ra/

Peter Bamford, Project Manager Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-289

Enclosure:

As stated cc w/encl: See next page

July 11, 2007 Mr. Christopher M. Crane President and Chief Executive Officer AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

THREE MILE ISLAND, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE HIGH THERMAL PERFORMANCE (HTP) FUEL REACTOR COOLANT SYSTEM PRESSURE-TEMPERATURE SAFETY LIMIT TECHNICAL SPECIFICATION AMENDMENT (TAC NO. MD4910)

Dear Mr. Crane:

By letter dated March 22, 2007 (Agencywide Documents Access and Management System Accession Number ML070860968), AmerGen Energy Company, LLC submitted a license amendment request (LAR) for a technical specification change regarding the Three Mile Island (TMI), Unit 1 Reactor Coolant System Pressure-Temperature Safety Limit. This change will support the introduction of AREVA NPs Mark-B-HTP fuel design during the TMI, Unit 1 Cycle 17 reload (Fall 2007). The proposed amendment would revise various technical specification figures and tables associated with the variable low pressure trip setpoint to reflect more restrictive Safety Limits and more restrictive Limiting Safety System Settings for the Reactor Protection System.

The NRC staff has reviewed the information provided in the LAR and has identified the enclosed request for additional information (RAI). This RAI was also emailed to Mr. David Distel of your staff on June 7, 2007. The draft questions were sent to ensure that they were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. During a subsequent telephone discussion with members of your staff on June 18, 2007, it was agreed that your response would be provided within 30 days of the date of this letter.

Please contact me at 301-415-2833, if you have any questions.

Sincerely,

/ra/

Peter Bamford, Project Manager Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-289

Enclosure:

As stated cc w/encl: See next page DISTRIBUTION:

PUBLIC RidsOgcRp LPLI-2 R/F RidsAcrsAcnwMailCenter RidsNrrPMPBamford RidsNrrLACSola RidsRgn1MailCenter RidsNrrDorlDpr RidsNrrDorlLpl1-2 BMarcus SSun ADAMS Accession Number: ML071700177

• by letter ** by email OFFICE LPLI-2/PM LPLI-2/PM LPLI-2/LA EICB/BC SRXB/BC LPLI-2/BC NAME PBamford EMiller CSola AHowe* GCranston** HChernoff DATE 06/27/2007 06/27/2007 06/27/2007 05/21/2007 05/22/2007 07/11/2007 OFFICIAL RECORD COPY

Three Mile Island Nuclear Station, Unit 1 cc:

Site Vice President - Three Mile Island Nuclear Director Station, Unit 1 Bureau of Radiation Protection AmerGen Energy Company, LLC Pennsylvania Department of P. O. Box 480 Environmental Protection Middletown, PA 17057 Rachel Carson State Office Building P.O. Box 8469 Vice President - Operations, Mid-Atlantic Harrisburg, PA 17105-8469 AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-N Plant Manager - Three Mile Island Nuclear Kennett Square, PA 19348 Station, Unit 1 AmerGen Energy Company, LLC Vice President - Licensing and Regulatory P. O. Box 480 Affairs Middletown, PA 17057 AmerGen Energy Company, LLC 4300 Winfield Road Regulatory Assurance Manager - Three Warrenville, IL 60555 Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC Regional Administrator P.O. Box 480 Region I Middletown, PA 17057 U.S. Nuclear Regulatory Commission 475 Allendale Road Ronald Bellamy, Region I King of Prussia, PA 19406 U.S. Nuclear Regulatory Commission 475 Allendale Road Chairman King of Prussia, PA 19406 Board of County Commissioners of Dauphin County Michael A. Schoppman Dauphin County Courthouse Framatome ANP Harrisburg, PA 17120 Suite 705 1911 North Ft. Myer Drive Chairman Rosslyn, VA 22209 Board of Supervisors of Londonderry Township Dr. Judith Johnsrud R.D. #1, Geyers Church Road National Energy Committee Middletown, PA 17057 Sierra Club 433 Orlando Avenue Senior Resident Inspector (TMI-1) State College, PA 16803 U.S. Nuclear Regulatory Commission P.O. Box 219 Eric Epstein Middletown, PA 17057 TMI Alert 4100 Hillsdale Road Director - Licensing and Regulatory Affairs Harrisburg, PA 17112 AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-E Correspondence Control Desk Kennett Square, PA 19348 AmerGen Energy Company, LLC P.O. Box 160 Kennett Square, PA 19348

Three Mile Island Nuclear Station, Unit 1 cc:

Manager Licensing - Three Mile Island Nuclear Station, Unit 1 Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348 Mr. Christopher M. Crane President and Chief Executive Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Assistant General Counsel AmerGen Energy Company, LLC 200 Exelon Way Kennett Square, PA 19348

REQUEST FOR ADDITIONAL INFORMATION HTP FUEL REACTOR COOLANT SYSTEM PRESSURE-TEMPERATURE SAFETY LIMIT TECHNICAL SPECIFICATION AMENDMENT REQUEST TAC NO. MD4910 DOCKET NO. 50-289 By letter dated March 22, 2007 (Agencywide Documents Access and Management System Accession Number ML070860968), AmerGen Energy Company, LLC (the licensee) submitted a license amendment request (LAR) regarding Three Mile Island, Unit 1 technical specifications (TSs). The proposed amendment would involve changes associated with instrument setpoints for the reactor coolant system (RCS) pressure-temperature safety limit associated with the use of AREVA NPs Mark-B-HP fuel design. Based on the review of the information provided by the licensee, the staff has the following additional questions.

1. The licensee indicated that the transient core penalty for a specific transient core model was calculated based on the largest departure from nucleate boiling (DNB) ratio difference between the limiting Mark-B-HTP fuel rod in a full core model of the Mark-B-HTP fuel and specific transient core model for all of the statepoints, condition I/II DNB transients, and axial power shapes.

Discuss the results of the transient core penalty analyses for condition I/II DNB transients with associated axial power shapes, and demonstrate that (1) the analysis scope in terms of the applicable condition I/II DNB transients and the allowable axial power shapes is adequate, and (2) the calculated value of the transient core penalty is a bounding value and acceptable for determining the thermal design limit that is used to calculate the reactor core safety limit.

2. Provide the basis for your determination that no setpoint changes to reactor trip functions, other than the variable low RCS pressure trip, are needed to assure that the analyses of record remain bounding, or new analyses meet the applicable acceptance criteria for design-basis events.

3. Identify the reactor coolant pressure and reactor outlet temperature at the end points and mid point of proposed TS Figure 2.1-1.

4. Identify the low reactor coolant pressure and high reactor outlet temperature intercept points of proposed TS Figure 2.3-1.

5. Demonstrate that, for operation with measured values at the limits of the Acceptable Operation region of proposed TS Figure 2.3-1, there would be adequate assurance that the actual operating point will be conservative relative to the indicated Safety Limit line, given measurement errors consistent with the instrument channel uncertainties.

Enclosure

6. Identify the normal operating point for the reactor coolant pressure and reactor outlet temperature.

7. Identify the low reactor coolant pressure and high reactor outlet temperature intercept points for:

(a) TS Variable Low Pressure Trip (VLPT) Limiting Safety System Setting Setpoint (b) Adjusted TS VLPT (c) VLPT Nominal Setpoint (NSP)

(d) VLPT As-Left Tolerance Band (e) VLPT Pre-Defined As-Found Tolerance Band

8. Provide additional details concerning the methodology used to develop the VLPT 10 pounds per square inch gauge additional margin. Confirm that this additional margin has not been used in determining the VLPT Pre-Defined As-Found Tolerance Band.

9. The licensee has stated that the VLPT setpoint calculation is prepared in accordance with American National Standards Institute (ANSI) / Instrument Society of America (ISA)

Standard 67.04.01-2000, Setpoints for Nuclear Safety-Related Instrumentation, and Recommended Practice ISA-RP67.04.02-2000, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation. In order to assess the adequacy of this methodology please provide a description of:

(a) the criteria (not just the methods) used for combining uncertainties in determining trip setpoints and allowable values.

(b) the relationship of the allowable value to the setpoint methodology and testing requirements. Also, describe the method of documentation of this relationship.

Providing a description of how the regulatory positions of RG 1.105, Revision 3 are incorporated into the VLPT setpoint calculations would constitute an acceptable way to address questions 9(a) and 9(b) above.

10. The Summary of AmerGen Commitments includes a commitment to determine the predefined limits for the VLPT NSP As-Found Tolerance on a programmatic basis. The licensee should clarify this commitment. Arent the predefined limits for the VLPT NSP As-Found Tolerance Band determined and included in March 22, 2007 submittal? Why would the limits of the VLPT NSP As-Found Tolerance Band need to be recalculated on a programmatic basis? What are the periodicity or events that would trigger a recalculation of the VLPT NSP As-Found Tolerance Band? Would a recalculation of the VLPT NSP As-Found Tolerance Band be the cause for a revision to any of the VLPT related items in question 7 (a) - (d) above?