Laserfiche WebLink
Umetco-Uravan Radioactive Materials License 660-02. See copy of Decision Analysis attached <br />hereto as Attachment C. A portion of that analysis states: <br />Geochemical attenuation of potential leachate would occur as liquid is transmitted <br />through the bedrock formations. The Salt Wash Member is about 120 feet thick with <br />sandstones totaling about 90 feet in thickness and containing calcium carbonate cement. <br />Geochemically, this calcium carbonate would buffer any solutions exiting the repository. <br />The Salt Wash member also contains about 30 feet of shale. Tests on Salt Wash shales <br />indicate Cation Exchange Capacity (CEC) values ruiging from 9.9 meq/100 g to 32 <br />meq/100 g and a pH of approximately 8.4. These tests indicate that the Salt Wash <br />shales could attenuate coutaminants contained in repository seepage. [See page 15 <br />of Decision Analysis. Emphasis added.] <br />Of course, the same Salt Wash formation underlies the JD-6 and JD-8 mines and will <br />provide the same attenuation of contaminants wluch could be released from the mines' waste <br />piles. <br />F. Cotter Answered the Division's Ouestions. <br />After more meetings with the Division, Cotter asked GeoScience to respond to the issues <br />raised by the staff. The report prepared on behalf of Cotter by GeoScience dated February 7, <br />2006 responds to the Division's January 17, 2006 letter review. After a detailed review of the <br />questions raised by the Division related to the PORFLOW Multiphase Transport Model, the <br />GeoScience report concludes in part, "The implications of this analysis suggest that <br />infiltrating water would actually dilute groundwater concentrations of species of concern. <br />Realistically, the impact from the waste rock piles on the underlying groundwater quality <br />would be `negligible'." <br />The GeoSeiences' report also states, "The modeling simulations used in the Cotter Mine <br />reports used a zero value for sorption that is wrrealistic but still results in contaminant migration <br />rates that failed to reach the water table," <br />11 <br />