ML23159A266
| ML23159A266 | |
| Person / Time | |
|---|---|
| Site: | WM-00065 |
| Issue date: | 06/12/2023 |
| From: | Mary Johnson NRC/RGN-IV/DRSS/DIOR |
| To: | |
| Johnson M | |
| References | |
| Download: ML23159A266 (10) | |
Text
June 12, 2023 MEMORANDUM TO:
Docket File WM-00065 THROUGH:
Gregory G. Warnick, Chief Decommissioning, ISFSI, and Operating Reactor Branch Division of Radiological Safety and Security FROM:
M. Troy Johnson, Health Physicist Decommissioning, ISFSI, and Operating Reactor Branch Division of Radiological Safety and Security
SUBJECT:
OBSERVATIONAL SITE VISIT AT FALLS CITY DISPOSAL SITE On May 23, 2023, the U.S. Nuclear Regulatory Commissions (NRC) Region IV Office conducted an observational site visit at the U.S. Department of Energys (DOE) Falls City Disposal Site in Karnes County, Texas. This site visit was conducted in accordance with Inspection Procedure 89060 Department of Energy Observational Site Visits. The purpose of the site visit was to observe DOEs routine, annual inspection of the Falls City disposal site.
Enclosed to this memorandum is the NRCs trip report for this site visit.
In summary, DOE conducted the annual inspection in accordance with the requirements specified in the updated NRC-accepted Long-Term Surveillance Plan dated March 2008 (ML082050099). The disposal cell and surrounding area observed by the inspectors appeared to be in acceptable condition. No significant regulatory issues or safety concerns were identified during the site visit.
Docket No. WM-00065 License No. General License under 10 CFR 40.27
Enclosure:
NRC Trip Report cc: Charlee A. Boger, Site Manager, DOE CONTACT: M. Troy Johnson, DRSS/DIOR (817)-200-1596 Signed by Warnick, Gregory on 06/12/23
Enclosure U.S. NUCLEAR REGULATORY COMMISSION REGION IV Docket:
WM-00065 License:
General license under 10 CFR 40.27 Report:
WM-00065/2023-001 Licensee:
U.S. Department of Energy Facility:
Falls City Disposal Site Location:
Karnes County, Texas Date:
May 23, 2023 Inspectors:
Approved By:
M. Troy Johnson Health Physicist Decommissioning, ISFSI, and Operating Reactor Branch Division of Radiological Safety and Security Stephanie G. Anderson Senior Health Physicist Decommissioning, ISFSI, and Operating Reactor Branch Division of Radiological Safety and Security Gregory G. Warnick, Chief Decommissioning, ISFSI, and Operating Reactor Branch Division of Radiological Safety and Security
Attachment:
Photographs Taken at the Falls City Disposal Site
2 NRC Report 1
Background
The Falls City Uranium Mill Tailings Disposal Site is classified as a Title I site under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 and is located in Karnes County, Texas, approximately 8 miles southwest of the town of Falls City and 46 miles southeast of San Antonio. The site comprises 231.15 acres, of which 127 acres are occupied by the disposal cell, including the apron. The disposal cell contains 7,143,000 dry tons of residual radioactive materials. These materials consist of tailings, mill site debris, vicinity property materials, and collected windblown contamination. Total activity within the cell is 1,277 curies of radium-226.
The Falls City mill site was operated from 1961 to 1982. By Susquehanna Western, Incorporated, Tepcore, Incorporated, and Solution Engineering, Incorporated. In 1982, the Falls City mill site was designated for cleanup under Title I of UMTRCA. Remedial action started in 1992 was completed in 1994.
The DOE maintains long-term custody of the site under the U.S. Nuclear Regulatory Commissions (NRCs) general license requirements of 10 CFR 40.27. The Long-Term Surveillance Plan (LTSP) explains how DOE will fulfill the general license requirements specified in 10 CFR 40.27. The NRC accepted the LTSP for the Falls City Uranium Mill Tailings Disposal Site by letter dated July 8,1997 (ML20149A760).
2 Site Status Site features include two boundary monuments, three survey monuments, two site markers, sixty-four perimeter warning signs, one site entrance sign, an access gate, a vehicle gate, and five monitoring wells. The LTSP requires DOE to inspect the Falls City Uranium Mill Tailings Disposal Site once every calendar year. The DOE inspectors observe the status of these site features during each annual inspection.
The DOE conducted the last site inspection on May 10, 2022. In this inspection, the fence on the southwest side, between perimeter sign P18 and survey monument SM-3, showed signs of rust as well as damage from cattle encroaching on the site and was scheduled to be replaced. Additionally, the need for replacement of perimeter sign P62 was identified.
Ground water in the uppermost aquifer in the vicinity of the Falls City site is not suitable for use for any purpose because of naturally elevated levels of uranium. In accordance with the LTSP, the ground water monitoring network consists of five monitor wells located downgradient from the Conquista/Deweesville aquifer and the underlying Dilworth aquifer as well as to the south in the Conquista/Deweesville aquifer. These monitor ground water to demonstrate that legacy ground water contamination is not degrading downgradient ground water. The sample locations were selected based on ground water flow direction. Ground water samples are collected annually from these five wells and analyzed for total uranium. Sampling includes field measurements of pH, ground water temperature, conductivity, dissolved oxygen, oxidation-reduction potential, turbidity, and water levels. The most recent samples were taken in February of 2023.
3 3
Site Observations and Findings The DOE staff conducted the annual inspection on May 23, 2023. The purposes of the annual inspection was to confirm the integrity of the visible features of the site, to identify changes in conditions that may affect site integrity, and to determine the need for maintenance or additional inspection and monitoring.
The LTSP section 3.3.2 divides the site into three areas called transects. The transects are the disposal cell (top, side slopes, and apron of the disposal cell, apron outfall, and rock drains), the site perimeter (area between the disposal cell and boundary of the site, including the boundary fence), and the outlying area (area within 0.25 mile of the site).
Each transect inside the site is visually inspected by walking a series of random traverses across each transect so that the entire transect surface is inspected. Within each transect, inspectors examine specific site surveillance features, such as survey and boundary monuments, signs, site markers, rock drains, previously identified items from former inspections, as well as other items (success of previous maintenance, erosion, settling, slumping, plant or animal encroachment, human intrusion or vandalism, and other activity or phenomenon that might affect the safety, integrity, long-term performance, or institutional control of the site).
The inspectors walked the site with DOE inspectors and Texas Commission of Environmental Quality (TCEQ) personnel. The inspectors observed the fence identified from the previous inspection between perimeter sign P18 and survey monument SM-3 had been replaced and that the sign P62 had also been replaced. Areas of new wild hog (Sus scrofa) encroachment were noted along the fence line and the DOE inspectors made note of this so areas dug under the fence could be filled. Evidence of previous filling of areas dug under the fence line from wild hog encroachment were noted by the inspectors. The remainder of the fence line observed by the inspectors, while still functional, showed obvious signs of decay from various factors. The lead DOE inspector indicated that the year 2025 budget included funding to replace the fence entirety. The areas of the cell and drainage observed by the inspectors showed no sign of erosion and regular maintenance of the vegetation in the area was evident by the presence of multiple grass bails present on the property and the short height of the mesquite (glandulosa) trees.
The inspectors conducted a radiological survey using a Thermo Scientific RadEye G survey meter (serial number 30932, calibrated to cesium-137 with a calibration due date of November 9, 2023). With a background of about 10 microRoentgen per hour (R/hr),
as measured on the access road to the site, measurements within the property ranged from 8-15 R/hr. In summary, the ambient gamma radiation measurements across the site were indistinguishable from background levels, indicating that no residual radioactivity or naturally occurring radioactivity was identified at the site.
4 Conclusions The DOE inspectors conducted the site inspection in accordance with the site-specific checklist, LTSP, and 10 CFR 40.27 requirements. Maintenance items are being identified and corrected in accordance with the LTSP with a focus on safety, integrity, long-term performance, or institutional control of the site.
4 5
Meeting Summary The NRC inspectors participated in a pre-planning meeting with the DOE site manager, DOE representatives, and TCEQ personnel prior to the site inspection. During this meeting, the NRC, DOE, and TCEQ representatives discussed topics such as site status, inspection plan, and potential physical hazards. The inspectors discussed the final site observations with DOE staff at the conclusion of the onsite visit.
6 Persons Contacted Charlee Boger, Site Manager Jennifer Graham, Site Lead/Inspector Larry Martin, Falls City Site Lead Danika Marshall, Lead Inspector
Attachment Figure 1: Falls City Disposal Site arial view Figure 2: Vehicle gate entrance
2 Figure 3: Perimeter sign Figure 4: Cell apron slope north looking southwest
3 Figure 5: site marker, center top of cell Figure 6: Survey monument 3 (south corner)
4 Figure 7: Wild hog encroachment under fence Figure 8: Previous wild hog encroachment repair
5 Figure 9: Drainage looking north from south corner Figure 10: Monitoring well 0708