ML19233A270
| ML19233A270 | |
| Person / Time | |
|---|---|
| Site: | WM-00058 |
| Issue date: | 09/03/2019 |
| From: | Dennise Orlando Office of Nuclear Material Safety and Safeguards |
| To: | Kautsky M US Dept of Energy, Office of Legacy Management |
| Orlando D | |
| References | |
| Download: ML19233A270 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 3, 2019 Mark Kautsky, Site Manager U.S. Department of Energy Office of Legacy Management 2597 Legacy Way Grand Junction, CO 81503
SUBJECT:
U.S. NUCLEAR REGULATORY COMMISSION STAFF REVIEW OF THE U.S.
DEPARTMENT OF ENERGY REPORT ENTITLED INVESTIGATION OF NON-MILL RELATED WATER INPUTS TO THE TERRACE ALLUVIUM AT SHIPROCK NEW MEXICO (Docket No. WM-00058)
Dear Mr. Kautsky:
I am writing in response to the U.S. Department of Energys (DOEs) report dated April 2019, entitled Investigation of Non-Mill-Related Water Inputs to the Terrace Alluvium at Shiprock, New Mexico (Agencywide Documents Access and Management System (ADAMS) Accession Number ML19143A277). The intent of the DOEs investigation was to identify and differentiate potential non-mill-related water inputs to the shallow terrace groundwater system through the use of aqueous chemical and isotopic tracers at the Shiprock site and this report provides results and interpretation of data collected during the investigation The report identifies several sources of groundwater at the site and concludes that sources of groundwater include water related to the operation of the uranium mill and domestic water use on the terrace. The report also concludes that irrigation water, groundwater present on the terrace prior to the mill being in operation, the infiltration of meteoric water, and groundwater from flowing artesian well 0648 are unlikely or minimal sources of groundwater. The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the report and have the following comments:
1.) Figure 9 in Section 5 shows mill and non-mill-affected groundwater areas.
- a. After comparing these designated areas with all sampling locations, NRC staff concludes that the parts of the area designated as non-mill-affected are incorrectly labeled. The area between the sampling wells 835 and 833 in the west and the sampling wells 725 and 728 in the east is not represented by any well other than the artesian well 648. However, the source of the water from well 648 is considerably deeper than the water from the alluvium and weathered Mancos Shale of interest and is not a good representative sample for that water.
To determine if groundwater in the area between the sampling wells 835 and 833 in the west and the sampling wells 725 and 728 in the east has been impacted by mill activities, additional wells could be sampled, for example, wells 844, 832, 816, 815, 814, or 730. Since there are no data on uranium activity ratios from the area between the wells listed above, this area should not be listed as non-mill-affected.
M. Kautsky b. Although the area between the disposal cell and the mouth of the Many Devils Wash is not mislabeled in Figure 9 and is neither designated as mill-affected nor as non-mill-affected, NRC staff has concluded that this area would provide useful information as to how far the mill-related contaminants may have traveled.
Figure 7 in Section 4.3 shows that the gradient was downward from the disposal cell to the mouth of Many Devils Wash and that it was possible for contaminants to have moved in this direction. To determine if groundwater in the area between the disposal cell and the mouth of the Many Devils Wash has been impacted by mill activities, additional wells could be sampled, for example, wells 830, 603, 731, 1049, 1048, or 1059.
- c. Figure 9 should clearly indicate that the mill- and non-mill-affected areas were designated by using data exclusively from the uranium activity study and that an activity ratio of 1.2 was used to designate between the two areas.
2.) Section 4.2 states that the Mancos Shale has highly negative values of S-34 (<-10);
however, it also states that the Mancos Shale water from well 648 has a very positive value of 12. Gypsum dissolution is given as the cause for the high positive value in the water sample from well 648. It is unclear if gypsum dissolution effects the S-34 values from other Mancos Shale water locations and unless well 648 is an anomaly, the original statement that water from the Mancos Shale has highly negative values appears to be incorrect.
3.) Section 4.2 lists sulfate sources at the Shiprock site as either sulfuric acid used in ore processing, dissolution of sulfide minerals in the tailings, Mancos Shale groundwater, San Juan River water, Animas River water, or a combination of these sources.
Infiltration of meteoric water is mentioned in Section 5 as an additional source. All potential sources of water are briefly discussed in the report with the exception of river waters from the two rivers. Apparently, water from the Animas River is piped in for domestic use by Shiprock residents; however, this is not discussed in the report. A brief description in the report on how and where the river waters of the Animas and San Juan Rivers are used in the Shiprock area would provide better context and put some of the reports findings in perspective.
In accordance with Title 10 of Code of Federal Regulation (10 CFR) 2.390 of the NRCs Agency Rules of Practice and Procedure, a copy of this letter will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of NRCs ADAMS. ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
M. Kautsky If you have any questions concerning the NRC comments, please feel free to contact me at 301-415-6749 or at Dominick.Orlando@nrc.gov.
Sincerely,
//RA//
Dominick Orlando, Senior Project Manager Uranium Recovery and Materials Decommissioning Branch Division of Decommissioning, Uranium Recovery and Waste Programs Docket No.: WM-00058
M. Kautsky
SUBJECT:
U.S. NUCLEAR REGULATORY COMMISSION STAFF REVIEW OF THE U.S.
DEPARTMENT OF ENERGY REPORT ENTITLED INVESTIGATION OF NON-MILL RELATED WATER INPUTS TO THE TERRACE ALLUVIUM AT SHIPROCK NEW MEXICO (Docket No. WM-00058) DATE: September 3, 2019 R. Evans RIV H.Grepford, RIV, M. Posten-Brown, RIV Adams Accession No ML19233A270 *via email OFFICE NMSS NMSS NMSS NMSS NMSS NAME NOrlando SAchten HArlt RvonTill NOrlando DATE 8/21/19 8/21/19 8/26/19 8/28/19 09/03/19 OFFICIAL RECORD COPY