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 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 Affairs P. O. Box 480 AmerGen Energy Company, LLC Middletown, PA 17057 4300 Winfield Road Warrenville, IL 60555 Regulatory Assurance Manager - Three Mile Island Nuclear Station, Unit 1 Regional Administrator AmerGen Energy Company, LLC Region I P.O. Box 480 U.S. Nuclear Regulatory Commission Middletown, PA 17057 475 Allendale Road King of Prussia, PA 19406 Ronald Bellamy, Region I U.S. Nuclear Regulatory Commission Chairman 475 Allendale Road Board of County Commissioners King of Prussia, PA 19406 of Dauphin County Dauphin County Courthouse Michael A. Schoppman Harrisburg, PA 17120 Framatome ANP Suite 705 Chairman 1911 North Ft. Myer Drive Board of Supervisors Rosslyn, VA 22209 of Londonderry Township R.D. #1, Geyers Church Road Dr. Judith Johnsrud Middletown, PA 17057 National Energy Committee Sierra Club Senior Resident Inspector (TMI-1) 433 Orlando Avenue U.S. Nuclear Regulatory Commission State College, PA 16803 P.O. Box 219 Middletown, PA 17057 Eric Epstein TMI Alert Director - Licensing and Regulatory Affairs 4100 Hillsdale Road AmerGen Energy Company, LLC Harrisburg, PA 17112 200 Exelon Way, KSA 3-E Kennett Square, PA 19348 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
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 staffs 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 precipitate load that challenges the operability of their strainers. Although calcium silicate insulation 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:
Enclosure
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.