Draft Report for Comment: “Documentation and Applications of the Reactive Geochemical Transport Model RATEQ,” NUREG/CR-6871, 35743-35744 [E5-3200]

Download as PDF Federal Register / Vol. 70, No. 118 / Tuesday, June 21, 2005 / Notices Nuclear Management Company, LLC, Docket Nos. 50–266 and 50–301, Point Beach Nuclear Plant, Units 1 and 2, Town of Two Creeks, Manitowoc County, Wisconsin Date of application for amendments: October 15, 2004. Brief description of amendments: The amendments revised Technical Specifications related to the reactor coolant pump flywheel inspection program by increasing the inspection interval to 20 years. Date of issuance: June 6, 2005. Effective date: As of the date of issuance and shall be implemented within 45 days. Amendment Nos.: 218, 223. Facility Operating License Nos. DPR– 24 and DPR–27: Amendments revised the Technical Specifications. Date of initial notice in Federal Register: March 29, 2005 (70 FR 15945). The Commission’s related evaluation of the amendments is contained in a Safety Evaluation dated June 6, 2005. No significant hazards consideration comments received: No. Nuclear Management Company, LLC, Docket Nos. 50–282 and 50–306, Prairie Island Nuclear Generating Plant, Units 1 and 2, Goodhue County, Minnesota Date of application for amendments: October 15, 2004. Brief description of amendments: The amendments revise Technical Specifications related to the reactor coolant pump flywheel inspection program by increasing the inspection interval to 20 years. Date of issuance: June 7, 2005. Effective date: As of the date of issuance and shall be implemented within 90 days. Amendment Nos.: 170, 160. Facility Operating License Nos. DPR– 42 and DPR–60: Amendments revised the Technical Specifications. Date of initial notice in Federal Register: March 15, 2005 (70 FR 12748). The Commission’s related evaluation of the amendments is contained in a Safety Evaluation dated June 7, 2005. No significant hazards consideration comments received: No. Pacific Gas and Electric Company, Docket Nos. 50–275 and 50–323, Diablo Canyon Nuclear Power Plant, Unit Nos. 1 and 2, San Luis Obispo County, California Date of application for amendments: September 23, 2004, and its supplements dated December 21, 2004, and April 7, 2005. VerDate jul<14>2003 22:07 Jun 20, 2005 Jkt 205001 Brief description of amendments: The amendments increase the current minimum emergency diesel generator fuel oil inventory required to be maintained onsite to support the use of low-sulfur fuel oil required by California Air Resources Board. Date of issuance: May 25, 2005. Effective date: As of the date of issuance, and shall be implemented within 90 days from the date of issuance. Amendment Nos.: Unit 1—181; Unit 2—183. Facility Operating License Nos. DPR– 80 and DPR–82: The amendments revised the Technical Specifications. Date of initial notice in Federal Register: January 4, 2005 (70 FR 402). The December 21, 2004, and April 7, 2005, supplemental letters provided additional clarifying information, did not expand the scope of the application as originally noticed, and did not change the staff’s original proposed no significant hazards consideration determination. The Commission’s related evaluation of the amendments is contained in a Safety Evaluation dated May 25, 2005. No significant hazards consideration comments received: No. Tennessee Valley Authority, Docket Nos. 50–327 and 50–328, Sequoyah Nuclear Plant, Units 1 and 2, Hamilton County, Tennessee Date of application for amendments: June 5, 2003, as supplemented by letters dated June 3 and October 26, 2004. Brief description of amendments: The amendments authorize changes to the Updated Final Safety Analysis Report (UFSAR) for both units, to acknowledge credit for possible operator action to ensure that the containment design pressure is not exceeded in the event of a high energy line break inside containment with a consequential failure of the station control and service air system inside containment. Date of issuance: May 24, 2005. Effective date: As of the date of issuance and shall be implemented as part of the next UFSAR update made in accordance with 10 CFR 50.71(e). Amendment Nos.: 302 and 292. Facility Operating License Nos. DPR– 77 and DPR–79: Amendments authorize changes to the UFSAR. Date of initial notice in Federal Register: June 24, 2003 (68 FR 37584). The supplemental letters provided clarifying information that was within the scope of the initial notice and did not change the initial proposed no significant hazards consideration determination. PO 00000 Frm 00129 Fmt 4703 Sfmt 4703 35743 The Commission’s related evaluation of the amendments is contained in a Safety Evaluation dated May 24, 2005. No significant hazards consideration comments received: No. Union Electric Company, Docket No. 50–483, Callaway Plant, Unit 1, Callaway County, Missouri Date of application for amendment: October 27, 2004. Brief description of amendment: The amendment revised Technical Specification 3.7.3, ‘‘Main Feedwater Isolation Valves (MFIVs),’’ to add the main feedwater regulating valves (MFRVs) and the associated MFRV bypass valves (MFRVBVs). In addition, the allowed outage time, or completion time, for inoperable MFIVs is extended. Date of issuance: May 31, 2005. Effective date: This amendment is effective as of its date of issuance, and shall be implemented prior to entry into Mode 3 in the restart from the upcoming Refueling Outage 14 (fall 2005). Amendment No.: 167. Facility Operating License No. NPF– 30: The amendment revised the Technical Specifications. Date of initial notice in Federal Register: December 7, 2004 (69 FR 70722). The Commission’s related evaluation of the amendment is contained in a Safety Evaluation dated May 31, 2005. No significant hazards consideration comments received: No. Dated at Rockville, Maryland, this 10th day of June, 2005. For the Nuclear Regulatory Commission. Ledyard B. Marsh, Director, Division of Licensing Project Management, Office of Nuclear Reactor Regulation. [FR Doc. E5–3138 Filed 6–20–05; 8:45 am] BILLING CODE 7590–01–P NUCLEAR REGULATORY COMMISSION Draft Report for Comment: ‘‘Documentation and Applications of the Reactive Geochemical Transport Model RATEQ,’’ NUREG/CR–6871 Nuclear Regulatory Commission. ACTION: Notice of availability and request for comments. AGENCY: Background The U.S. Nuclear Regulatory Commission (NRC) uses environmental models to evaluate the potential release of radionuclides from NRC-licensed sites. In doing so, the NRC recognizes E:\FR\FM\21JNN1.SGM 21JNN1 35744 Federal Register / Vol. 70, No. 118 / Tuesday, June 21, 2005 / Notices that, at many sites, groundwater-related pathways could contribute significantly to the potential dose received by members of the public. Consequently, consistent with its mission to protect the health and safety of the public and the environment, the NRC uses contaminant transport models to predict the locations and concentrations of radionuclides in soil as a function of time. Through this notice, the NRC is seeking comment on documentation of a subsurface transport model developed for the NRC by the U.S. Geological Survey (USGS) for realistic transport modeling at sites with complex chemical environments. Because many radionuclides temporarily attach, or adsorb, to the surfaces of soil particles, their mobility is reduced compared to that of compounds that move with the groundwater without interacting with solid surfaces. As a result, most subsurface-transport models used by the NRC and its licensees estimate the effects of the anticipated interactions between radionuclides and solids in the ground. Toward that end, these subsurface-transport models use a ‘‘distribution coefficient,’’ which is assumed to be constant and reflects the proportion of radionuclide in the groundwater compared to the radionuclide associated with the solids in the ground. These distribution coefficients are widely used, and consequently, the relevant literature documents ranges of their values for various soil types and radionuclides. However, the documented ranges can be very large because the chemical reactions that cause radionuclides to attach to solids are very sensitive to water chemistry and soil mineralogy. As a result, uncertainties in the parameters used to characterize the adsorption of radionuclides in soils have been identified as a major source of uncertainty in decommissioning, uranium recovery, and radioactive waste disposal cases evaluated by the NRC. Surface-complexation and ionexchange models offer a more realistic approach to considering soilradionuclide interactions in performance-assessment models. These models can also account for variable chemical environments that might affect such interactions. The subject report, prepared for the NRC by the USGS, describes the theory, implementation, and examples of use of the RATEQ computer code, which simulates radionuclide transport in soil and allows the use of surface-complexation and ion-exchange models to calculate VerDate jul<14>2003 22:07 Jun 20, 2005 Jkt 205001 distribution coefficients based on actual site chemistry. The RATEQ code will help the NRC staff define realistic site-specific ranges of the distribution coefficient values used to evaluate NRC-licensed sites. In site-remediation cases, such as restoration of the groundwater aquifer in and around uranium in-situ leach mining facilities, the RATEQ code can aid in the estimation of restoration costs by estimating the volume of treatment water needed to restore sites to acceptable environmental conditions. Solicitation of Comments: The NRC seeks comments on the report and is especially interested in comments on the value of the report to users who run the RATEQ code and are familiar with the types of complex chemical environments that complicate many remediation projects. The NRC will consider all written comments received before September 30, 2005. Comments received after September 30, 2005, will be considered if it is practical to do so, but the NRC staff is able to ensure consideration only for comments received on or before this date. Comments should be addressed to the contact listed below. Availability: An electronic version of the report is available in Adobe Portable Document Format at http:// www.nrc.gov/reading-rm/doccollections/nuregs/contract/cr6871/ cr6871.pdf and can be read with Adobe Acrobat Reader software, available at no cost from http://www.adobe.com. The report and the computer files for the test cases discussed therein are available at http://wwwrcamnl.wr.usgs.gov/rtm. Hard and electronic copies of the report are available from the contact listed below. DATES: Dr. John D. Randall, Mail Stop T9C34, U.S. Nuclear Regulatory Commission, 11545 Rockville Pike, Rockville, MD 20852, telephone (301) 415–6192, e-mail jdr@nrc.gov. FOR FURTHER INFORMATION CONTACT: Dated at Rockville, Maryland, this 10th day of June, 2005. For the Nuclear Regulatory Commission. Cheryl A. Trottier, Chief, Radiation Protection, Environmental Risk & Waste Management Branch, Division of Systems Analysis and Regulatory Effectiveness, Office of Nuclear Regulatory Research. [FR Doc. E5–3200 Filed 6–20–05; 8:45 am] BILLING CODE 7590–01–P PO 00000 Frm 00130 Fmt 4703 Sfmt 4703 NUCLEAR REGULATORY COMMISSION Draft Report for Comment: ‘‘Consideration of Geochemical Issues in Groundwater Restoration at Uranium In-Situ Leach Mining Facilities,’’ NUREG/CR–6870 Nuclear Regulatory Commission. ACTION: Notice of availability and request for comments. AGENCY: Background Some mining processes use fluids to dissolve (or leach) a mineral without the need to remove physically the ore containing the mineral from an ore deposit in the ground. In general, these ‘‘in-situ’’ leach mining operations at uranium mines are considerably more environmentally benign than traditional mining and milling of uranium ore. Nonetheless, the use of leaching fluids to mine uranium may contaminate the groundwater aquifer in and around the region from which the uranium is extracted. The U.S. Nuclear Regulatory Commission (NRC) requires licensees to restore the aquifer to established waterquality standards following the cessation of in-situ leach mining operations. The NRC also requires licensees to ensure that sufficient funds will be available to cover the cost of decommissioning their facilities. For these uranium mines, restoration generally consists of pumping specially treated water into the affected aquifer and removing the displaced water—and thereby the undesirable contaminants— from the system. Because groundwater restoration can represent approximately 40 percent of the cost of decommissioning a uranium leach mining facility, a good estimate of the necessary volume of treatment water is important to estimate the cost of decommissioning accurately. The subject report, prepared for the NRC by the U.S. Geological Survey, summarizes the application of a geochemical model to the restoration process to estimate the degree to which a licensee has decontaminated a site where a leach mining process has been used. Toward that end, this report analyzes the respective amounts of water and chemical additives pumped into the mined regions to remove and neutralize the residual contamination using 10 different restoration strategies. The analyses show that strategies that used hydrogen sulfide in systems with low natural oxygen content provided the best results. On the basis of those findings, this report also summarizes E:\FR\FM\21JNN1.SGM 21JNN1

Agencies

[Federal Register Volume 70, Number 118 (Tuesday, June 21, 2005)]
[Notices]
[Pages 35743-35744]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E5-3200]


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NUCLEAR REGULATORY COMMISSION


Draft Report for Comment: ``Documentation and Applications of the 
Reactive Geochemical Transport Model RATEQ,'' NUREG/CR-6871

AGENCY: Nuclear Regulatory Commission.

ACTION: Notice of availability and request for comments.

-----------------------------------------------------------------------

Background

    The U.S. Nuclear Regulatory Commission (NRC) uses environmental 
models to evaluate the potential release of radionuclides from NRC-
licensed sites. In doing so, the NRC recognizes

[[Page 35744]]

that, at many sites, groundwater-related pathways could contribute 
significantly to the potential dose received by members of the public. 
Consequently, consistent with its mission to protect the health and 
safety of the public and the environment, the NRC uses contaminant 
transport models to predict the locations and concentrations of 
radionuclides in soil as a function of time. Through this notice, the 
NRC is seeking comment on documentation of a subsurface transport model 
developed for the NRC by the U.S. Geological Survey (USGS) for 
realistic transport modeling at sites with complex chemical 
environments.
    Because many radionuclides temporarily attach, or adsorb, to the 
surfaces of soil particles, their mobility is reduced compared to that 
of compounds that move with the groundwater without interacting with 
solid surfaces. As a result, most subsurface-transport models used by 
the NRC and its licensees estimate the effects of the anticipated 
interactions between radionuclides and solids in the ground. Toward 
that end, these subsurface-transport models use a ``distribution 
coefficient,'' which is assumed to be constant and reflects the 
proportion of radionuclide in the groundwater compared to the 
radionuclide associated with the solids in the ground. These 
distribution coefficients are widely used, and consequently, the 
relevant literature documents ranges of their values for various soil 
types and radionuclides. However, the documented ranges can be very 
large because the chemical reactions that cause radionuclides to attach 
to solids are very sensitive to water chemistry and soil mineralogy. As 
a result, uncertainties in the parameters used to characterize the 
adsorption of radionuclides in soils have been identified as a major 
source of uncertainty in decommissioning, uranium recovery, and 
radioactive waste disposal cases evaluated by the NRC.
    Surface-complexation and ion-exchange models offer a more realistic 
approach to considering soil-radionuclide interactions in performance-
assessment models. These models can also account for variable chemical 
environments that might affect such interactions. The subject report, 
prepared for the NRC by the USGS, describes the theory, implementation, 
and examples of use of the RATEQ computer code, which simulates 
radionuclide transport in soil and allows the use of surface-
complexation and ion-exchange models to calculate distribution 
coefficients based on actual site chemistry.
    The RATEQ code will help the NRC staff define realistic site-
specific ranges of the distribution coefficient values used to evaluate 
NRC-licensed sites. In site-remediation cases, such as restoration of 
the groundwater aquifer in and around uranium in-situ leach mining 
facilities, the RATEQ code can aid in the estimation of restoration 
costs by estimating the volume of treatment water needed to restore 
sites to acceptable environmental conditions.
    Solicitation of Comments: The NRC seeks comments on the report and 
is especially interested in comments on the value of the report to 
users who run the RATEQ code and are familiar with the types of complex 
chemical environments that complicate many remediation projects.

DATES: The NRC will consider all written comments received before 
September 30, 2005. Comments received after September 30, 2005, will be 
considered if it is practical to do so, but the NRC staff is able to 
ensure consideration only for comments received on or before this date. 
Comments should be addressed to the contact listed below.
    Availability: An electronic version of the report is available in 
Adobe Portable Document Format at http://www.nrc.gov/reading-rm/doc-
collections/nuregs/contract/cr6871/cr6871.pdf and can be read with 
Adobe Acrobat Reader software, available at no cost from http://
www.adobe.com. The report and the computer files for the test cases 
discussed therein are available at http://wwwrcamnl.wr.usgs.gov/rtm. 
Hard and electronic copies of the report are available from the contact 
listed below.

FOR FURTHER INFORMATION CONTACT: Dr. John D. Randall, Mail Stop T9C34, 
U.S. Nuclear Regulatory Commission, 11545 Rockville Pike, Rockville, MD 
20852, telephone (301) 415-6192, e-mail jdr@nrc.gov.

    Dated at Rockville, Maryland, this 10th day of June, 2005.

    For the Nuclear Regulatory Commission.
Cheryl A. Trottier,
Chief, Radiation Protection, Environmental Risk & Waste Management 
Branch, Division of Systems Analysis and Regulatory Effectiveness, 
Office of Nuclear Regulatory Research.
[FR Doc. E5-3200 Filed 6-20-05; 8:45 am]
BILLING CODE 7590-01-P