ML19066A167
| ML19066A167 | |
| Person / Time | |
|---|---|
| Site: | WM-00063 |
| Issue date: | 03/18/2019 |
| From: | Dennise Orlando Division of Decommissioning, Uranium Recovery and Waste Programs |
| To: | Denny A US Dept of Energy (DOE) |
| N ORLANDO DUWP | |
| References | |
| Download: ML19066A167 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 18, 2019 Angelita Denny, 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 REPORT ENTITLED FINAL MEXICAN HAT UMTRCA DISPOSAL CELL SLOPE COVER DEPRESSIONS EVALUATION REPORT, MEXICAN HAT, UTAH (DOCKET NO. WM-63 DATED JANUARY 2019 (Docket No. WM-00063)
Dear Ms. Denny:
I am writing to in response to the U.S. Department of Energy (DOE) report entitled Final Mexican Hat [UMTRCA] Disposal Cell Side Slope Cover Depressions Evaluation Report, Mexican Hat, Utah (Docket No. WM-63) dated January 2019 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML19023A388).
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the report and believes that DOE is following a reasonable course of action at the site. However, it is important to understand if the depressions are the result of something that happened at the site (rain or subsidence), or are an artifact of construction of the cover system. To that end, it is not clear if the photo that was provided to DOE by the International Atomic Energy Agency in November 2018 showing the northeast portion of the site was evaluated as part of the report. This could be useful in understanding the conditions during construction and if these depressions are a remnant/artifact of the construction itself. We have the following additional comments that DOE may wish to consider as it moves forward with the project:
- DOE may find it helpful to understand where the edge of the tailings are on the northeast slope as this was not identified on any of the figures or drawings.
- The report discusses how 2015 was a large rain year - one of the wettest years on record. Based on what has been observed at other sites, wet years may have some connection to cover performance and it is not clear if this is related to the formation of the depressions. DOE may want to further evaluate this potential contributing factor to the formation of the depressions.
- The bedding material in the area where the depressions exist is showing signs of segregation and DOE may find it helpful to understand if the segregation resulted from the rain events, or if this was an artifact of construction (i.e., was mixing or placing the bedding material performed improperly).
A. Denny
- Although we did not review their original or revised bedding material calculations in detail, DOE stated the design was consistent with the guidance. However, if the design was consistent with the guidance, it is not clear if the depressions are a construction related issue, or if the guidance is not completely correct. DOE may want to evaluate this possibility.
- The report discusses a break in the remedial action between November 1990 and March 1993 and that a soil sealer was placed on the contaminated fill. It is not clear if the soil sealer was residual radioactive material and if the radon barrier or bedding material or bedding layer was in place at that time. DOE may want to evaluate if the soil sealer may have impacted the cover.
- One of the recommendations in the report is to do additional sampling and testing in the area of the depressions, but it is not clear what types of tests DOE is considering. It would be helpful if this was determined prior to commencing site operations.
- Another recommendation discusses installing a System Operation and Analysis at Remote Sites (SOARS) based weather system with a camera and precipitation monitoring would be useful for evaluating precipitation at the site. It is not clear if this system will be able to detect rain events similar to what occurred in 2015 and DOE may want to determine this prior to installation of the SOARS system.
In accordance with 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.
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 Materials Decommissioning Branch Division of Decommissioning, Uranium Recovery and Waste Programs Office of Nuclear Material Safety and Safeguards Docket No.: WM-00063 Mexican Hat dist. List
A. Denny
SUBJECT:
U.S. NUCLEAR REGULATORY COMMISSION STAFF REVIEW OF THE REPORT ENTITLED FINAL MEXICAN HAT UMTRCA DISPOSAL CELL SLOPE COVER DEPRESSIONS EVALUATION REPORT, MEXICAN HAT, UTAH (DOCKET NO. WM-63 DATED JANUARY 2019 (Docket No. WM-00063)
DATE March 18, 2019 R. Evans RIV T. Pruett, RIV ADAMS Acession No.: ML19066A167 *via email OFFICE NMSS NMSS NMSS NMSS NMSS NAME NOrlando SAchten DMandeville RvonTill NOrlando DATE 3/12/19 3/12/19 3/15/19 3/18/19 3/18/19 OFFICIAL RECORD COPY