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Post-remediation action radiological report for Surface Impoundments C (3539) and D (3540) at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: During August and September 1998, Bechtel Jacobs Company LLC performed a remedial action within Impoundments 3539 and 3540 (Impoundments C and D, respectively) in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision (ROD) for the Surface Impoundments Operable Unit. The remedial action included removal of sediments and 0.1 ft of subimpoundment soil. A post-remedial action radiological survey was conducted to provide data to support the Bethel Valley ROD. Data was obtained from (1) a walkover survey for residual gamma radiation on the base of the impoundments, (2) smear surveys for transferable contamination on remaining riprap, and (3) representative sampling of subimpoundment soils. Walkover surveys identified no locations outside the impoundments with gamma exposure levels greater than three times background levels. Smear surveys detected no removable contamination above release limits as specified in 10 CFR 835, Appendix D. Subimpoundment soil samples quantified low levels of residual contamination.
Date: December 1, 1998
Partner: UNT Libraries Government Documents Department

Annual evaluation of routine radiological survey/monitoring frequencies for the High Ranking Facilities Deactivating Project at Oak Ridge, Tennessee

Description: The Bethel Valley Watershed at the Oak Ridge National Laboratory (ORNL) has several Environmental Management (EM) facilities that are designated for deactivation and subsequent decontamination and decommissioning (D and D). The Surplus Facilities Program at ORNL provides surveillance and maintenance support for these facilities as deactivation objectives are completed to reduce the risks associated with radioactive material inventories, etc. The Bechtel Jacobs Company LLC Radiological Control (RADCON) Program has established requirements for radiological monitoring and surveying radiological conditions in these facilities. These requirements include an annual evaluation of routine radiation survey and monitoring frequencies. Radiological survey/monitoring frequencies were evaluated for two High Ranking Facilities Deactivation Project facilities, the Bulk Shielding Facility and Tower Shielding Facility. Considerable progress has been made toward accomplishing deactivation objectives, thus the routine radiological survey/monitoring frequencies are being reduced for 1999. This report identifies the survey/monitoring frequency adjustments and provides justification that the applicable RADCON Program requirements are also satisfied.
Date: December 1, 1998
Partner: UNT Libraries Government Documents Department

Evaluation of the Molten Salt Reactor Experiment drain tanks for reuse in salt disposal, Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: This report was prepared to identify the source documentation used to evaluate the drain tanks in the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory (ORNL). The evaluation considered the original quality of the tanks, their service history, and their intended use during the removal of fluoride salts. It also includes recommendations for a quality verification plan. The estimates of corrosion damage to the salt containing system at the MSRE are low enough to lend optimism that the system will be fit for its intended use, which is disposal of the salt by transferring it to transport containers. The expected corrosion to date is estimated between 10 and 50 mil, or 2 to 10% of the shell wall. The expected corrosion rate when the tanks are used to remove the salt at 110 F is estimated to be .025 to 0.1 mil per hour of exposure to HF and molten salt. To provide additional assurance that the estimates of corrosion damage are accurate, cost effective nondestructive examination (NDE) has been recommended. The NDE procedures are compared with industry standards and give a perspective for the extent of additional measures taken in the recommendation. A methodology for establishing the remaining life has been recommended, and work is progressing towards providing an engineering evaluation based upon thickness and design conditions for the future use of the tanks. These extra measures and the code based analysis will serve to define the risk of salt or radioactive gases leaking during processing and transfer of the salt as acceptable.
Date: May 1, 1998
Partner: UNT Libraries Government Documents Department

Radiological benchmarks for screening contaminants of potential concern for effects on aquatic biota at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: A hazardous waste site may contain hundreds of contaminants; therefore, it is important to screen contaminants of potential concern for the ecological risk assessment. Often this screening is done as part of a screening assessment, the purpose of which is to evaluate the available data, identify data gaps, and screen contaminants of potential concern. Screening may be accomplished by using a set of toxicological benchmarks. These benchmarks are helpful in determining whether contaminants warrant further assessment or are at a level that requires no further attention. Unlike exposures to chemicals, which are expressed as the concentration in water or sediment, exposures to radionuclides are expressed as the dose rate received by the organism. The recommended acceptable dose rate to natural populations of aquatic biota is 1 rad d{sup {minus}1}. Blaylock, Frank, and O`Neal provide formulas and exposure factors for estimating the dose rates to representative aquatic organisms. Those formulas were used herein to calculate the water and sediment concentrations that result in a total dose rate of 1 rad d{sup {minus}1} to fish for selected radionuclides. These radiological benchmarks are intended for use at the US Department of Energy`s (DOE`s) Oak Ridge Reservation and at the Portsmouth and Paducah gaseous diffusion plants as screening values only to show the nature and extent of contamination and identify the need for additional site-specific investigation.
Date: July 1, 1998
Partner: UNT Libraries Government Documents Department

Guidance for treatment of variability and uncertainty in ecological risk assessments of contaminated sites

Description: Uncertainty is a seemingly simple concept that has caused great confusion and conflict in the field of risk assessment. This report offers guidance for the analysis and presentation of variability and uncertainty in ecological risk assessments, an important issue in the remedial investigation and feasibility study processes. This report discusses concepts of probability in terms of variance and uncertainty, describes how these concepts differ in ecological risk assessment from human health risk assessment, and describes probabilistic aspects of specific ecological risk assessment techniques. The report ends with 17 points to consider in performing an uncertainty analysis for an ecological risk assessment of a contaminated site.
Date: June 1, 1998
Partner: UNT Libraries Government Documents Department

Gunite and associated tanks dry well conductivity monitoring report, Oak Ridge National Laboratory, Oak Ridge, Tennessee, February 1998--December 1998

Description: A waste removal program is being implemented for the Gunite and Associated Tanks Operable Unit at Oak Ridge National Laboratory, Oak Ridge, Tennessee. The waste is being removed by means of remotely operated, in-tank, confined sluicing equipment. During sluicing operations the dry wells adjacent to each of the tanks are instrumented so that potential releases can be detected by means external to the tank. The method of detection is by monitoring the electrical conductivity of the water in the dry well associated with each tank. This report documents the dry well conductivity monitoring data for the period from February 1998 through December 1998. The dry wells monitored during this period include DW-5, DW-6, DW-7, DW-8, DW-9 and DW-10. The conductivity of the water passing through Pump Station 1 (PS1) was also monitored. During this period the sluicing activities at Tank W-6 were initiated and successfully completed. In addition, flight mixers were used to remove wastes from Tank W-5, and sluicing operations were initiated on Tank W-7. Presented in this report are the dry well conductivity, rainfall, tank level, and other appropriate information relevant to the analysis and interpretation of the monitoring data for the reporting period. A thorough analysis of the monitoring results from the six dry wells in the STF and PS1 for the period between February 1998 and December 1998 indicates that no releases have occurred from the gunite tanks being monitored. Overall, the dry well conductivity monitoring continues to provide a robust and sensitive method for detecting potential releases from the gunite tanks and for monitoring seasonal and construction-related changes in the dry well and drain system.
Date: April 1, 1999
Partner: UNT Libraries Government Documents Department

In-Process Analysis Program for the Isolock sampler at the Gunite and Associated Tanks, Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: The In-Process Analysis Program documents the requirements for handling, transporting, and analyzing waste slurry samples gathered by the Bristol Isolock slurry sampler from the Gunite and Associated Tanks at Oak Ridge National Laboratory in Oak Ridge, Tennessee. Composite samples will be gathered during sludge retrieval operations, labeled, transported to the appropriate laboratory, and analyzed for physical and radiological characteristics. Analysis results will be used to support occupational exposure issues, basic process control management issues, and prediction of radionuclide flow.
Date: May 1, 1998
Partner: UNT Libraries Government Documents Department

Health and safety plan for the removal action at the former YS-860 Firing Ranges, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

Description: This health and safety plan sets forth the requirements and procedures to protect the personnel involved in the Lead Source Removal Project at the Former YS-86O Firing Ranges. This project will be conducted in a manner that ensures the protection of the safety and health of workers, the public, and the environment. The purpose of this removal action is to address lead contaminated soil and reduce a potential risk to human health and the environment. This site is an operable unit within the Upper East Fork Poplar Creek watershed. The removal action will contribute to early source actions within the watershed. The project will accomplish this through the removal of lead-contaminated soil in the target areas of the two small arms firing ranges. This plan covers the removal actions at the Former YS-86O Firing Ranges. These actions involve the excavation of lead-contaminated soils, the removal of the concrete trench and macadam (asphalt) paths, verification/confirmation sampling, grading and revegetation. The primary hazards include temperature extremes, equipment operation, noise, potential lead exposure, uneven and slippery working surfaces, and insects.
Date: April 28, 1998
Partner: UNT Libraries Government Documents Department