Laserfiche WebLink
~l <br />MEMO to Bruce H./James :~. <br />November 15, 1996 - DMO Exemption <br />Page 2 <br />into the existing mine openings and portals, and C) cover the disturbed areas with any <br />immediately available topsoil. <br />After several meetings and discussions with the Division, the operator agreed to complete a field <br />investigation to characterize the average uranium content of waste rock and low-grade ore at <br />both mine sites. The operator proposed, and the Division agreed, that a calibrated probe (which <br />measures beta and gamma emissions) would be used to take measurements at 100-foot grid <br />spacings on the Sunday and West Sunday mine dumps. The probe would be field-calibrated <br />to a known ore standard so measurements would be convertible to ore percent uranium values. <br />In addition, the operator agreed to collect five (5) random QA/verification samples which would <br />be sent to an independent lat~oratory for analysis of uranium content (volumetric). <br />The 100-foot grid pattern provided thirty (30) stations at the Sunday mine and ten (10) stations <br />at the West Sunday mine. Two probes were calibrated, using a known quantity of uranium <br />(.19%), prior to taking measurements at the Sunday mine and re-calibrated prior to moving to <br />the West Sunday mine site. The five (5) QA/verification sample sites were randomly selected <br />from a sample sack which contained 40 pieces of paper: each mazked with a grid station <br />number. <br />The probes were inserted as far into the waste material as possible (usually just a few inches) <br />then, after the meters stabilized, a measurement was recorded. A shovel full of waste material <br />was collected at each of the ~QA/verification stations. <br />As noted in EFN's report, at three stations (D-15, G-2 and B-4) the probes and the lab tests are <br />in complete agreement. However, at grid stations F-15 and D-3 the sample analysis show a <br />much higher uranium content than the probes. Ms Rehmann adequately explains the reason for <br />the discrepancies on page 2, last paragraph, of the report. <br />Overall, the average uranium content at the Sunday mine waste dumps amounu to .04%. The <br />average uranium content at the West Sunday waste dump is .03%. These are well below the <br />.OS% uranium value that the Division decided would determine DMO status. Even though the <br />overall averages are below .OS% there were two areas that exceeded .OS% (H-2 and D-3). <br />Based on the available data it is my opinion that the operator adequately demonstrated that the <br />waste dtrmps at the referenced mines do not contain quantities of uranium that would adversely <br />affect human health, property or the environment. The waste dumps do contain "hot spots" <br />(where the uranium content t;xceeds .OS%) but these will be taken care of during fuia] closure <br />pursuant to BI1vI and DOE reclamation requirements or pursuant to the requirements of Rule <br />3.1.5(5). <br />The operator should be aware: that this exemption only applies to the existing site conditions and <br />that nothing in the exemptions shall exempt the operator where site conditions or circumstances <br />change. <br />M:1oss\jrt\urutium.jd <br />