ML061530295

Request for Additional Information, Ultimate Heat Sink License Amendment Request

ML061530295
Person / Time
Site:	LaSalle
Issue date:	06/15/2006
From:	Sands S Plant Licensing Branch III-2
To:	Crane C Exelon Generation Co
Sands S,NRR/DORL, 415-3154
References
TAC MC0336, TAC MC0337
Download: ML061530295 (7)

Text

June 15, 2006 Mr. Christopher M. Crane, President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO ULTIMATE HEAT SINK LICENSE AMENDMENT REQUEST (TAC NOS. MD0336 AND MD0337)

Dear Mr. Crane:

By letter to the Nuclear Regulatory Commission (NRC) dated March 13, 2006 (Agencywide Documents Access and Management System Accession No. ML060720507), Exelon Generation Company, LLC submitted a request to change the technical specifications (TS) related to TS 3.7.3, Ultimate Heat Sink, for the LaSalle County Station, Units 1 and 2.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on June 1, 2006, it was agreed that LaSalle County Station would provide a response within 30 days of the date of this letter.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3154.

Sincerely,

/RA/

Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosure:

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

June 15, 2006 Mr. Christopher M. Crane, President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO ULTIMATE HEAT SINK LICENSE AMENDMENT REQUEST (TAC NOS. MD0336 AND MD0337)

Dear Mr. Crane:

By letter to the Nuclear Regulatory Commission (NRC) dated March 13, 2006 (Agencywide Documents Access and Management System Accession No. ML060720507), Exelon Generation Company, LLC submitted a request to change the technical specifications (TS) related to TS 3.7.3, Ultimate Heat Sink, for the LaSalle County Station, Units 1 and 2.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on June 1, 2006, it was agreed that LaSalle County Station would provide a response within 30 days of the date of this letter.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3154.

Sincerely,

/RA/

Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosure:

Request for Additional Information DISTRIBUTION:

PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsNrrPMSSands RidsNrrLADClarke RidsAcrsAcnwMailCenter RidsOgcRp RidsRgn3MailCenter RidsNrrDorlDpr RidsNrrDeEicb ADAMS Accession Number: ML061530295 OFFICE LPL3-2/PM LPL3-2/LA EICB/BC LPL3-2/BC NAME SSands:mw DClarke AHowe* DCollins DATE 06/15/2006 06/15/2006 06/2/2006 06/15/2006 OFFICIAL RECORD COPY

LaSalle County Station Units 1 and 2 cc:

Site Vice President - LaSalle County Station Robert Cushing, Chief, Public Utilities Division Exelon Generation Company, LLC Illinois Attorney General's Office 2601 North 21st Road 100 W. Randolph Street Marseilles, IL 61341-9757 Chicago, IL 60601 LaSalle County Station Plant Manager Regional Administrator Exelon Generation Company, LLC U.S. NRC, Region III 2601 North 21st Road 801 Warrenville Road Marseilles, IL 61341-9757 Lisle, IL 60532-4351 Regulatory Assurance Manager - LaSalle Illinois Emergency Management Exelon Generation Company, LLC Agency 2601 North 21st Road Division of Disaster Assistance &

Marseilles, IL 61341-9757 Preparedness 110 East Adams Street U.S. Nuclear Regulatory Commission Springfield, IL 62701-1109 LaSalle Resident Inspectors Office 2605 North 21st Road Document Control Desk - Licensing Marseilles, IL 61341-9756 Exelon Generation Company, LLC 4300 Winfield Road Phillip P. Steptoe, Esquire Warrenville, IL 60555 Sidley and Austin One First National Plaza Senior Vice President of Operations Chicago, IL 60603 Exelon Generation Company, LLC 4300 Winfield Road Assistant Attorney General Warrenville, IL 60555 100 W. Randolph St. Suite 12 Chicago, IL 60601 Vice President - Licensing and Regulatory Affairs Chairman Exelon Generation Company, LLC LaSalle County Board 4300 Winfield Road 707 Etna Road Warrenville, IL 60555 Ottawa, IL 61350 Attorney General 500 S. Second Street Springfield, IL 62701 Chairman Illinois Commerce Commission 527 E. Capitol Avenue, Leland Building Springfield, IL 62706

LaSalle County Station Units 1 and 2 Director - Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Assistant General Counsel Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348 Manager Licensing - Dresden, Quad Cities and Clinton Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

REQUEST FOR ADDITIONAL INFORMATION LASALLE COUNTY STATION, UNITS 1 AND 2 DOCKET NOS. 50-373 AND 50-374 In reviewing the Exelon Generation Companys (Exelons) license amendment request submittal dated March 13, 2006, related to ultimate heat sink (UHS) for the LaSalle County Station, Units 1 and 2 (LaSalle), the NRC staff has determined that the following information is needed in order to complete its review:

1. Show that the temperatures in the two circulating water intake canals are sufficiently representative of each other and of the UHS temperature as assumed in the safety analysis to support the use of the averaged temperature at both units. Show how these relationships remain valid when one unit is out of service, or explain how this will be accommodated in the technical specification (TS) for the other unit. (Category 2.a)

2. Describe any thermowell modifications or adaptors required for the installation of the resistance temperature detectors (RTDs). Confirm that the RTD insertion length is compatible with the thermowells. Identify any seismic requirements applicable to this installation; for example, if safety-related cooling water is extracted from these canals, there may be seismic II/I considerations. (Category 2.a)

3. The request indicates that the existing thermocouple wires will be used for the RTDs, and that temperature compensator modules will be used to correct any signal effects.

Where will these temperature compensator modules be located? What is the specific compensation provided, and how does this account for: (Category 2.a)

(a) thermocouple wire resistence, especially considering that the RTDs are using a 2-wire, rather than 3- or 4-wire configuration, and (b) dissimilar metallic junction at both ends of the thermocouple cables. Please explain how these effects are addressed in the uncertainty evaluation.

4. Provide the detailed uncertainty evaluation, showing the source of all input information and the full derivation of all results and conclusions. (Category 2.a)

5. Describe the configuration (in regard to the acquisition and exchange of these temperature measurement data) of the Data Acquisition System, Plant Process Computer for each unit, and the data communications in each unit and between units as they presently exist and as they would exist following the implementation of the requested change. (Category 2.a)

6. What method or procedures for determining the UHS temperature reading, used to satisfy the TS requirement, will be used after all four new RTDs are installed? Include details on handling failed inputs (if one RTD fails in one unit, if one RTD fails in each unit, if two fail in one unit, if two fail in one unit and one fails in the other unit).

(Category 2.a)

ENCLOSURE

7. How are the temperature values presented to the operators and system engineer including any alarms, warnings, or other identification of status or failures?

(Category 2.a)

8. Describe the type of RTD to be used, and the calibrated range of the temperature measurement. (Category 2.a)

9. How frequently will the new RTD readings be sampled and how frequently are the associated calculations performed? (Category 2.a)

10. The statistical theory upon which the assumed accuracy improvement is partly based requires statistical independence among the measurements. How are the common-mode uncertainty elements, such as environmental effects and common maintenance and test equipment, accounted for in the analysis? (Category 2.a)

11. How were any aging effects on RTD and component accuracy accounted for in the uncertainty calculations? (Category 2.a)

12. Describe the calibration and surveillance procedures to be implemented to maintain the accuracy of the individual temperature measurements. (Category 2.a)

RAI CATEGORIES (Select only one, most dominant category for each RAI question)

1. More information is needed because of:

a. complexity of request

b. first-of-a-kind nature of request

c. NRC change in regulatory significance or focus

d. NRC questions on previously used methodology or guidance

e. licensee change to previously used methodology

f. licensee reduction in current safety margin

2. The review can not be completed without additional explanation or clarification of:

a. input variables or analytical assumptions

b. methodology used or results obtained

c. applicability or bounding nature of third party analyses or data correlations

d. differences from NRC guidance documents (SRP, RG, etc.)

e. no significant hazards consideration discussion

f. environmental considerations discussion

g. applicable regulatory requirements discussion

h. information that appears to be incorrect and needs to be corrected

i. response to previous RAI appears inadequate

3. Reviewer requesting information even though the question is, or the question asks for:

a. not directly related to the request

b. inconsistent with applicable codes, standards, RGs, or SRP sections

c. information accessible from readily available sources and was explicitly referenced

d. information does not appear needed given the precedent cases discussed in the request

e. information that is not safety significant or pertinent to the regulatory finding

f. information that is known to engineers who work in the general technical area

g. going beyond the current licensing basis and doesnt need to be asked

h. a formal commitment

4. Other (please specify)