[en] The 216-A-29 ditch is located in the central portion of the Hanford Site within Operable Unit 200-PO-5. The ditch is classified under the Resource Conservation and Recovery Act of 1976 as a Treatment, Storage, and Disposal (TSD) Facility and as such, is to be removed from service in support of the Hanford Federal Facility Agreement and Consent Order Tri-Party Agreement (1) Milestone M-17-10, which states open-quotes cease all liquid discharges to hazardous land disposal units unless such units have been clean closed in accordance with the Resource Conservation and Recovery Act of 1976.close quotes (2) The 216-A-29 ditch is one stream feeding the 216-B-3 Pond system, and its removal from service was necessary to support the closure strategy for the 216-B-3 Pond system. Interim stabilization of the 216-A-29 ditch is the first step required to comply with the Tri-Party Agreement (2) and the eventual decommissioning of the entire B Pond system. Interim stabilization was required to maintain the 216-A-29 ditch in a stable conformation until closure actions have been determined and initiated

[en] The process of decommissioning a facility such as a nuclear reactor or reprocessing plant presents many waste management options and concerns. Waste minimization is a primary consideration, along with protecting personnel and the environment. Waste management is complicated in that both radioactive and chemical hazardous wastes must be dealt with. This paper presents the general decommissioning approach of a recent project at Los Alamos. Included are the following technical objectives: site characterization work that provided a thorough physical, chemical, and radiological assessment of the contamination at the site; demonstration of the safe and cost-effective dismantlement of a highly contaminated and activated nuclear-fueled reactor; and techniques used in minimizing radioactive and hazardous waste

[en] When conducting its environmental restoration, waste management, and decontamination and decommissioning activities, the US Department of Energy (DOE) must comply with a myriad of regulatory procedures and environmental standards. An assessment of the status of existing federal standards that may be applied to chemical and radioactive substances on DOE sites found substantial gaps and inconsistencies among the existing standards, and technical issues associated with the application of those standards. Of 271 chemical and radioactive substances found to be important across environmental media at the Hanford, Savannah River, and Oak Ridge Sites, 96 (35%) are unregulated by federal regulations and are not covered by DOE guidelines, 48 (18%) are covered by single federal standards or DOE guidelines, and 127 (47%) are covered by multiple regulations or DOE guidelines. Inconsistencies and technical issues among standards include the promulgation of different standards under different regulations for a given substance in an environmental medium, the application of standards for purposes other than originally intended, and the inability to meet standards because of technical limitations. Given the lack of a complete, consistent set of standards or generic procedures for determining applicable standards, and given the existence of inconsistencies and technical issues among the existing set of standards, DOE may be faced with lengthy negotiations of standards on a case-by-case basis. Such negotiations could result in inconsistent cleanup levels, high costs, potential delays, and missed regulatory milestones

[en] The field of environmental engineering and environmental science is so new that many colleges and universities have only begun the process of bringing academic program, into their areas. Many professional personnel don't need full degree programs but may need only certain courses to enhance their skills in the environmental area. This article discusses the partnership between the Hanford contractors, DOE-RL, and Washington State University in an innovative way in solving a portion of the remediation work force problems

[en] In July of 1987 the Weldon Spring quarry was listed on the Environmental Protection Agency National Priority List as the highest priority Federal facility site. The Weldon Spring Site Remedial Action Project applied the principles and techniques of Value Engineering (VE) and the Observational Method to remedial planning efforts at the quarry. VE sessions resulted in modifications of the scenarios developed during the Remedial Investigation/Feasibility Study (RM) process in preparation for conceptual design activities for the removal of waste from the quarry. The Observational Method, a technique developed to manage uncertainties, was used to guide both environmental and engineering planning to ensure that the waste removal activities win be carried out in a safe and environmentally responsible manner

[en] This paper examines and defines the thermodynamic conditions conducive to the spontaneous separation of an initially homogeneous silicate melt generated during vitrification of contaminated soil or other wastes into immiscible phases. Immiscible phase development win be shown to have potentially important implications regarding melter operation and contaminant immobilization. Development of a molten immiscible iron phase will be shown to be dependent upon the oxidation/reduction chemistry of iron and the presence of electrochemically reducing constituents, specifically organic carbon. Immiscible molten iron can concentrate other selected native phase metallic contaminants drastically impacting their long-term immobilization and impact optimal melter selection. Depending upon melt redox conditions, an immiscible sulfate or sulfide melt may also develop during vitrification of sulfur-rich wastes. Although potentially minimal melter operational impacts result from immiscible sulfur phase formation, contaminants partitioned into the immiscible sulfur phase may be very poorly attenuated, potentially resulting in failure for various leach test criteria. Potential mitigative measures are discussed

[en] In situ vitrification (ISV) has been identified as a potential treatment technology for stabilizing underground tanks at Hanford and other US Department of Energy (DOE) sites. A key requirement for this application is an electrical system that can supply the power needed to vitrify a tank in a single setting. This paper describes an engineering-scale test conducted at the Pacific Northwest Laboratory (PNL) to assess the efficiency of a six-electrode, six-phase energy supply system in melting soil. The test was conducted with a 30-kW six-phase system. Based on the test results, a six-electrode, six-phase system shows potential for scaleup to larger systems

[en] The purpose of this paper is to convey the logic of the CERCLA document flow including Work Plans, Characterization Studies, Risk Assessments, Remedial Investigations, Feasibility Studies, proposed plans, and Records of Decision. The intent is to show how schedules at the Savannah River Site are being formulated to accomplish work using an observational approach where carefully planned tasks can be initiated early and carried out in parallel. This paper will share specific proactive experience in working with the EPA to expedite projects, begin removal actions, take interim actions, speed document flow, and eliminate unnecessary documents from the review cycle

[en] Nuclear weapons materials production is no longer the mission of the Hanford Site, a 560-square-mile area in southeastern Washington's Columbia Basin. Environmental remediation, including removal of radioactive and hazardous contaminants, waste management and disposal decommissioning of old facilities, and restoration of land and groundwater, has become the site's major mission. The mission is conducted within the framework of the Tri-Party Agreement between USDOE, USEPA, and the State of Washington. There is broad public interest in cleanup and the future of the Hanford Site. A facilitated process to develop alternative future use and cleanup scenarios is about to begin. The process will introduce some traditional tools of land use planning alongside environmental regulations and cleanup technologies in order to develop an integrated vision. Many interests, including local governments, Indian Tribes, state and federal agencies, business, agriculture, labor, environmental, and recreational groups will be involved. It is hoped a widely shared vision of the site's future will both guide and sustain support for cleanup and restoration

[en] This paper summarizes the policy of DOE's Office of Environmental Restoration for accepting new facilities into the Environmental Restoration Program. Facilities that are eligible for acceptance include DOE buildings, structures, and sites that are currently the responsibility of operating program, of the Office of Nuclear Energy, the Office of Defense Programs, and the Office of Energy Research. The policy states that the Office of Environmental Restoration, under DOE's Office of Environmental Restoration and Waste Management (EM), will accept DOE-contaminated facilities that are surplus to DOE needs and have no future intended use. The facilities will be turned over to EM for remediation or decommissioning when they are completely shutdown and when stored nuclear and hazardous materials have been removed