Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 16
Book Description
Completion of the Transuranic Greater Confinement Disposal Borehole Performance Assessment for the Nevada Test Site
Author: COMPLETION OF THE TRANSURANIC GREATER CONFINEMENT DISPOSAL BOREHOLE PERFORMANCE ASSESSMENT FOR THE NEVADA TEST SITE.
Author: Angela ColarussoPublisher:
ISBN:
Category :
Languages : en
Pages : 15
Book Description
Classified transuranic material that cannot be shipped to the Waste Isolation Pilot Plant in New Mexico is stored in Greater Confinement Disposal boreholes in the Area 5 Radioactive Waste Management Site on the Nevada Test Site. A performance assessment was completed for the transuranic inventory in the boreholes and submitted to the Transuranic Waste Disposal Federal Review Group. The performance assessment was prepared by Sandia National Laboratories on behalf of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office using an iterative methodology that assessed radiological releases from the intermediate depth disposal configuration against the regulatory requirements of the 1985 version of 40 CFR 191 of the U.S. Environmental Protection Agency. The transuranic materials are stored at 21 to 37 m depth (70 to 120 ft) in large diameter boreholes constructed in the unsaturated alluvial deposits of Frenchman Flat. Hydrologic processes that affect long- term isolation of the radionuclides are dominated by extremely slow upward rates of liquid/vapor advection and diffusion; there is no downward pathway under current climatic conditions and there is no recharge to groundwater under future ''glacial'' climatic conditions. A Federal Review Team appointed by the Transuranic Waste Disposal Federal Review Group reviewed the Greater Confinement Disposal performance assessment and found that the site met the majority of the regulatory criteria of the 1985 and portions of the 1993 versions of 40 CFR 191. A number of technical and procedural issues required development of supplemental information that was incorporated into a final revision of the performance assessment. These issues include inclusion of radiological releases into the complementary cumulative distribution function for the containment requirements associated with drill cuttings from inadvertent human intrusion, verification of mathematical models used in the performance assessment, inclusion of dose calculations from collocated low-level waste in the boreholes for the individual protection requirements, further assessments of engineered barriers and conditions associated with the assurance requirements, and expansion of documentation provided for assessing the groundwater protection requirements. The Transuranic Waste Disposal Federal Review Group approved the performance assessment for Greater Confinement Disposal boreholes in 2001 and did not approve the Application of the Assurance Requirements. Remaining issues concerned with engineered barriers and the multiple aspects of the Assurance Requirements will be resolved at the time of closure of the Area 5 Radioactive Waste Management Site. This is the first completion and acceptance of a performance assessment for transuranic materials under the U.S. Department of Energy self-regulation. The Greater Confinement Disposal boreholes are only the second waste disposal configuration to meet the safety regulatory requirements of 40 CFR 191.
Use of a Scenario-development Procedure to Identify Potentially Disruptive Scenarios, Greater Confinement Disposal Facility, Area 5, Nevada Test Site
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 9
Book Description
The Greater Confinement Disposal (GCD) facility includes four boreholes that contain transuranic (TRLT) waste. Presence of the TRU waste means that this facility must comply with the US Environmental Protection Agency's Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Waste-Final Rule 40 CFR Part 191. To comply with the Containment Requirements of this rule, all potentially disruptive events and processes, and by implication all potentially disruptive combinations of events and processes (scenarios), must be identified for possible inclusion in performance assessments. Screening of the FEPs identified four events for scenario development: exploratory drilling for natural resources, drilling withdrawal wells, irrigation, and subsidence. Recent environmental-isotope analyses of the vadose zone suggest that radionuclide transport from the boreholes to the water table by infiltration is not a feasible transport mechanism within the time frame of regulatory concern. For this reason, the event of drilling withdrawal wells was merged with exploratory drilling for resources. The descriptions of the remaining three events were modified slightly to aid in estimation of event probabilities and consequence analyses. The three events are: exploratory drilling for resources penetrates a TRU borehole, irrigation occurs at the Radioactive Waste Management Site (RWMS), and subsidence occurs at the RWMS. Use of a logic diagram with these three events resulted in the construction of eight scenarios, including base-case (undisturbed) conditions. Screening these scenarios at this stage of scenario development was beyond the scope of this task. Based on the implementation assumptions, this scenario-development procedure produced a comprehensive set of mutually exclusive scenarios that are reproducible and auditable for use in GCD performance assessments.
RESULTS OF THE PERFORMANCE ASSESSMENT FOR THE CLASSIFIED TRANSURANIC WASTES DISPOSED AT THE NEVADA TEST SITE.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Most transuranic (TRU) wastes are destined for the Waste Isolation Pilot Plant (WIPP). However, the TRU wastes from the cleanup of US nuclear weapons accidents are classified for national security reasons and cannot be disposed in WIPP. The US Department of Energy (DOE) sought an alternative disposal method for these ''special case'' TRU wastes and from 1984 to 1987, four Greater Confinement Disposal (GCD) boreholes were used to place these special case TRU wastes a minimum of 21 m (70 ft) below the land surface and a minimum of 200 m (650 ft) above the water table. The GCD boreholes are located in arid alluvium at the DOE's Nevada Test Site (NTS). Because of state regulatory concerns, the GCD boreholes have not been used for waste disposal since 1989. DOE requires that TRU waste disposal facilities meet the US Environmental Protection Agency's (EPA's) requirements for disposal of TRU wastes, which are contained in 40 CFR 191. This EPA standard sets a number of requirements, including probabilistic limits on the cumulative releases of radionuclides to the accessible environment for 10,000 years. The DOE Nevada Operations Office (DOE/NV) has contracted with Sandia National Laboratories (Sandia) to conduct a performance assessment (PA) to determine if the TRU waste emplaced in the GCD boreholes complies with the EPA's requirements. Sandia has completed the PA using all available information and an iterative PA methodology. This paper overviews the PA of the TRU wastes in the GCD boreholes [1]. As such, there are few cited references in this paper and the reader is referred to [1] and [2] for references. The results of the PA are that disposal of TRU wastes in the GCD boreholes easily complies with the EPA's 40 CFR 191 safety standards for disposal of TRU wastes. The PA is undergoing a DOE Headquarters (DOE/HQ) peer review, and the final PA will be released in FY2001 or FY2002.
Nevada Test Site (NTS) and Off-site Locations in the State of Nevada, Tonopah Test Range, Portions of the Nellis AFB Range (NAFR) Complex, the Central Nevada Test Area, and Shoal Area, Nye County
Author: Disposal of Low Activity Radioactive Waste
Author: International Atomic Energy AgencyPublisher:
ISBN:
Category : Business & Economics
Languages : en
Pages : 506
Book Description
Contains the proceedings of an international symposium on Disposal of Low Activity Radioactive Waste held in Córdoba, Spain, in December 2004. Issues addressed included policies and strategies for low activity radioactive waste; very low activity radioactive waste; and low activity radioactive waste from decommissioning.
Radioactive Waste Management
Author: Publisher:
ISBN:
Category : Radioactive waste disposal
Languages : en
Pages : 536
Book Description
Nevada Test Site Experience with Greater Confinement Disposal
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
At the NTS, we consider Greater Confinement Disposal (GCD) to be a good waste management practice rather than a disposal technology. This is an important distinction because it redefines the nature of GCD. All disposal facilities operate under the principal of ''as low as reasonably achievable'' (ALARA) in reducing personnel and public exposures. ALARA is not a technology or method but a principal put into practice. We view GCD in the same manner.
Author: 
Author: R. V. Guzowski