ML091240074

Electronic Transmission, Draft Request for Additional Information Regarding License Amendment Request to Adopt TSTF-490-A, Deletion of E Bar Definition and Revision to Reactor Coolant System Specific Activity

ML091240074
Person / Time
Site:	Three Mile Island
Issue date:	05/04/2009
From:	Peter Bamford Plant Licensing Branch 1
To:	Chernoff H Plant Licensing Branch 1
Bamford, Peter J., NRR/DORL 415-2833
References
Download: ML091240074 (5)

Text

May 4, 2009 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Peter Bamford, Project Manager /RA/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

THREE MILE ISLAND, UNIT NO. 1 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT TSTF-490-A, DELETION OF E BAR DEFINITION AND REVISION TO REACTOR COOLANT SYSTEM SPECIFIC ACTIVITY TECHNICAL SPECIFICATON The attached draft request for additional information (RAI) was transmitted by electronic transmission on May 1, 2009 to Ms. Wendi Croft, at Exelon Generation Company, LLC (Exelon, the licensee). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees amendment request regarding the proposed deletion of the E Bar definition and a revision to Reactor Coolant System Activity technical specifications. The draft RAI is related to the licensees submittal dated November 6, 2008.

The draft questions were sent to ensure that they were understandable, the regulatory basis was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI.

This memorandum and the attachment do not represent an NRC staff position.

Docket Nos. 50-289

Enclosure:

As stated

May 4, 2009 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Peter Bamford, Project Manager /RA/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

THREE MILE ISLAND, UNIT NO. 1 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT TSTF-490-A, DELETION OF E BAR DEFINITION AND REVISION TO REACTOR COOLANT SYSTEM SPECIFIC ACTIVITY TECHNICAL SPECIFICATON The attached draft request for additional information (RAI) was transmitted by electronic transmission on May 1, 2009 to Ms. Wendi Croft, at Exelon Generation Company, LLC (Exelon, the licensee). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees amendment request regarding the proposed deletion of the E Bar definition and a revision to Reactor Coolant System Activity technical specifications. The draft RAI is related to the licensees submittal dated November 6, 2008.

The draft questions were sent to ensure that they were understandable, the regulatory basis was clear, and to determine if the information was previously docketed. Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI.

This memorandum and the attachment do not represent an NRC staff position.

Docket Nos. 50-289

Enclosure:

As stated DISTRIBUTION:

Public RidsNrrPMPBamford LPL1-2 R/F Accession No.: ML091240074 OFFICE LPL1-2/PM NAME PBamford DATE 5/4/09 OFFICIAL RECORD COPY

DRAFT REQUEST FOR ADDITIONAL INFORMATION THREE MILE ISLAND NUCLEAR STATION, UNIT 1 LICENSE AMENDMENT REQUEST TO ADOPT TSTF-490-A DELETION OF E BAR DEFINITION AND REVISION TO REACTOR COOLANT SYSTEM SPECIFIC ACTIVITY TECHNICAL SPECIFICATON DOCKET NO. 50-289 By letter dated November 6, 2008, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML083120122), supplemented by letter dated December 11, 2008, (ADAMS Accession No. ML083470249), AmerGen Energy Company, LLC (the licensee, now Exelon Generation Company, LLC) submitted a license amendment request regarding proposed changes to the technical specifications (TSs) for Three Mile Island, Unit 1 (TMI-1). The proposed amendment would replace the current TMI-1 TS limit on Reactor Coolant System (RCS) gross specific activity with a new limit on RCS noble gas specific activity. The noble gas specific activity limit would be based on a new dose equivalent Xenon-133 (DEX) definition that would replace the current E Bar average disintegration energy definition. In addition, the current dose equivalent Iodine-131 (DEI) definition would be revised. The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review.

1.) The proposed Inserts 1 and 2 contained in the letter dated November 6, 2008, provide definitions for DEI and DEX, respectively.

These definitions indicate that DEI and DEX may be determined using several references for dose conversion factors (DCFs). However, the purpose of the limiting condition for operation (LCO) for DEI and DEX is to satisfy Title 10 of the Code of Federal Regulations (10 CFR),

Section 50.36, criterion 2, which establishes an operating restriction that is an initial condition of a design basis accident (DBA). When surveillance of the reactor coolant system radionuclides is performed, each acceptable set of DCFs will yield a different DEI and DEX. As approved by the NRC staff, the intent of Technical Specification Task Force Traveler (TSTF)-490 was to allow the licensee to select, from the acceptable list, one DCF reference for the calculation of DEI, and one DCF reference for the calculation of DEX. Therefore, consistent with 10 CFR 50.36 and TSTF-490, the licensee should specify one DCF reference for each definition, which will be consistent with the specified LCO and DBA analysis, or justify why a list of several DCFs is consistent with the specified LCO and DBA analysis. Therefore, please justify how the use of multiple DCFs maintains consistency with the specified LCO values and DBA analyses or provide revised definitions for DEI and DEX that specify one DCF reference for each definition.

2.) Consistent with the safety evaluation for TSTF-490, please confirm that the site-specific limits for both DEI and DEX, and the DCFs used for the determination of DEI and DEX surveillances, are consistent with the current design bases radiological dose consequence analyses (for example, steam generator tube rupture and main steam line break). For DEX, please provide the information necessary (dose conversion factors and reactor coolant system radioisotopic concentrations) for the NRC staff to verify the proposed value in the LCO.

3.) The proposed TS Table 4.1-3, item 1(a) requires a verification that DEX is less than or equal to 797 microcuries/gram. The TS bases submitted with the application letter dated November 6, 2008 (Insert 6), state that Due to the inherent difficulty in detecting [Krypton] Kr-85 in a reactor coolant sample due to masking from radioisotopes with similar decay energies, such as [Fluorine] F-18 and I-134, that it is acceptable to include the minimum detectable activity of Kr-85 in the [surveillance requirement] SR Table 4.1-3 calculation.

If no or little masking occurs, the use of the minimum detectible activity of Kr-85 would underestimate the amount of Kr-85 present in the reactor coolant sample.

Therefore, please justify why use of the minimum detectable Kr-85 is an acceptable and conservative approach for performing this surveillance.

4.) Inserts 4 and 5, contained in the letter dated November 6, 2008, refer to REFUELING as a mode in capital letters, indicating that REFUELING is defined in the TS Definition section. However, the current TMI-1 TS Definition section contains references to REFUELING SHUTDOWN, REFUELING OPERATION, and REFUELING INTERVAL, but not REFUELING. Please clarify the intended mode of applicability relating to inserts 4 and 5.