ML073310416
| ML073310416 | |
| Person / Time | |
|---|---|
| Site: | Three Mile Island  |
| Issue date: | 11/27/2007 |
| From: | Peter Bamford NRC/NRR/ADRO/DORL/LPLI-2 |
| To: | Pardee C AmerGen Energy Co |
| Bamford, Peter J., NRR/DORL 415-2833 | |
| References | |
| TAC MD5963 | |
| Download: ML073310416 (6) | |
Text
November 27, 2007
Mr. Charles Pardee Chief Nuclear Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
THREE MILE ISLAND NUCLEAR STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED REACTOR BUILDING EMERGENCY SUMP SYSTEM BUFFER CHANGE (TAC NO. MD5963)
Dear Mr. Pardee:
By letter dated June 29, 2007 (Agencywide Documents Access and Management System Accession Number ML072070257), AmerGen Energy Company, LLC, submitted an amendment request for the Three Mile Island Nuclear Station, Unit 1. The proposed amendment would revise the technical specifications to accommodate a change in the reactor building emergency sump pH control system buffer from sodium hydroxide to trisodium phosphate dodecahydrate.
The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information. The questions were sent via electronic transmission on October 31, 2007, to Mr. David Distel of your staff and substantially restate information requested previously by letter dated October 4, 2007 (ADAMS Accession Number ML072670549). The draft questions were sent to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. The questions were discussed with your staff in a teleconference on November 5, 2007, and no further clarifications to the questions were deemed necessary. During a telephone call with Mr. Distel on November 26, 2007, it was agreed that your response would be provided by November 30, 2007.
Please contact me at 301-415-2833, if you have any questions.
Sincerely, /ra/ Peter J. 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 November 27, 2007
Mr. Charles Pardee Chief Nuclear Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
THREE MILE ISLAND NUCLEAR STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED REACTOR BUILDING EMERGENCY SUMP SYSTEM BUFFER CHANGE (TAC NO. MD5963)
Dear Mr. Pardee:
By letter dated June 29, 2007 (Agencywide Documents Access and Management System Accession Number ML072070257), AmerGen Energy Company, LLC, submitted an amendment request for the Three Mile Island Nuclear Station, Unit 1. The proposed amendment would revise the technical specifications to accommodate a change in the reactor building emergency sump pH control system buffer from sodium hydroxide to trisodium phosphate dodecahydrate.
The Nuclear Regulatory Commission staff has been reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information. The questions were sent via electronic transmission on October 31, 2007, to Mr. David Distel of your staff and substantially restate information requested previously by letter dated October 4, 2007 (ADAMS Accession Number ML072670549). The draft questions were sent to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. The questions were discussed with your staff in a teleconference on November 5, 2007, and no further clarifications to the questions were deemed necessary. During a telephone call with Mr. Distel on November 26, 2007, it was agreed that your response would be provided by November 30, 2007.
Please contact me at 301-415-2833, if you have any questions.
Sincerely, /ra/ Peter J. 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 RidsRgn1MailCenter RidsNrrDorlDpr RidsNrrLAABaxter RidsNrrDorlLpl1-2 MYoder, NRR
ADAMS Accession Number: ML073310416
- by email OFFICE LPL1-2/PM LPL1-2/LA CSGB/BC* LPL1-2/BC NAME PBamford ABaxter AHiser HChernoff DATE 11/27/07 11/27/07 10/31/2007 11/27/07 OFFICIAL RECORD COPY
Three Mile Island Nuclear Station, Unit 1
cc:
Site Vice President - Three Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC P. O. Box 480 Middletown, PA 17057
Vice President - Operations, Mid-Atlantic AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348
Vice President - Licensing and Regulatory Affairs AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555
Regional Administrator Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406
Chairman Board of County Commissioners of Dauphin County Dauphin County Courthouse Harrisburg, PA 17120
Chairman Board of Supervisors of Londonderry Township R.D. #1, Geyers Church Road Middletown, PA 17057
Senior Resident Inspector (TMI-1)
U.S. Nuclear Regulatory Commission P.O. Box 219 Middletown, PA 17057
Director - Licensing and Regulatory Affairs AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348
Director Bureau of Radiation Protection Pennsylvania Department of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469
Plant Manager - Three Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC P. O. Box 480 Middletown, PA 17057
Regulatory Assurance Manager - Three Mile Island Nuclear Station, Unit 1 AmerGen Energy Company, LLC P.O. Box 480 Middletown, PA 17057
Ronald Bellamy, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406
Michael A. Schoppman Framatome ANP Suite 705 1911 North Ft. Myer Drive Rosslyn, VA 22209
Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803
Eric Epstein TMI Alert
4100 Hills dale Road Harrisburg, PA 17112
Correspondence Control Desk 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. Charles G. Pardee Chief Nuclear Officer AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348
Assistant General Counsel AmerGen Energy Company, LLC 200 Exelon Way Kennett Square, PA 19348
Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
Enclosure REQUEST FOR ADDITIONAL INFORMATION REGARDING REACTOR BUILDING SUMP PH CONTROL SYSTEM BUFFER CHANGE THREE MILE ISLAND UNIT 1 DOCKET NO. 50-289
By letter dated June 29, 2007, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072070257), AmerGen Energy Company, LLC, the licensee, submitted a license amendment request pertaining to the replacement of the containment sump buffer at Three Mile Island (TMI), Unit 1. By letter dated October 4, 2007, ADAMS Accession No. ML072670549, additional information was requested by the Nuclear Regulatory Commission (NRC) staff. The TMI response dated October 19, 2007, ADAMS Accession No.
ML072980699, was incomplete regarding question number nine. Therefore, a response to the supplemental question below is requested.
Original Question #9
TMI is proposing to switch to TSP [trisodium phosphate] as a buffering chemical. Testing indicates that TSP in the presence of dissolved calcium can result in rapid precipitation of calcium phosphate, which can create significant head loss across a sump strainer covered with a debris bed. Provide a list of all potential sources and amounts of calcium within the TMI containment and provide the calculated dissolved calcium concentration in a post-LOCA [loss of coolant accident] pool. Provide the relative chemical precipitate loading predicted by the WCAP-16530-NP model for TMI with TSP and at the maximum projected pH value (8) for the pool.
Supplemental Question
Your response to the NRC staff's question in letter dated October 19, 2007, regarding calcium sources and dissolved calcium concentration in the post-LOCA pool (Question #9) did not contain sufficient detail for the staff to complete its review. Testing has shown that TSP, in the presence of dissolved calcium, can result in rapid formation of calcium phosphate precipitates that can be
detrimental to Emergency Core Cooling System operability. Licensees who use TSP need to ensure that their plant-specific calcium loading will not create a precip itate load that challenges the operability of their strainers. Al though calcium silicate in sulation is the most significant source of calcium in most containments, there are many other sources that must be considered. Calcium may be dissolved from other insulation materials such as mineral wool, marinate board, and other micro-porous insulation materials. Calcium leached from concrete can contribute to chemical effects, especially in containments with large areas of uncoated concrete, or containments in which concrete may be eroded by direct jet impingement. Because of the concerns listed above, the staff requested in letter dated October 4, 2007, that TMI provide the potential calcium sources and provide the dissolved calcium level following a LOCA. The staff specifically requests a response to the following information from the previous Request for Additional Information, question #9 in order to complete our review of this amendment request:
A.) Provide a complete list of potential calcium sources in the TMI-1 containment, including their expected contribution to calcium loading and the basis for the estimated contribution from each source.
B.) Provide the calculated dissolved calcium level in the post-LOCA sump pool.
C.) Provide a comparison of post-LOCA precipitate loading under existing buffer and proposed buffer at the maximum projected pH value (8) for the pool. This may be done using the WCAP-16530 model or other means.