Remedial actions are taken to identify and contain or remove soil and ground water contamination to prevent it from spreading. Remedial actions are conducted at inactive waste sites or facilities where releases or spills have occurred and contamination has been released into the environment.
Remedial actions involve four primary tasks:
site discovery, preliminary assessment, and site inspection;
site assessment, including characterization, evaluation of cleanup alternatives, and selection of remedy;
site cleanup; and
site closure and compliance monitoring.
A site discovery, preliminary assessment, or site inspection is conducted to quickly determine if there is a contamination problem. This involves taking samples, analyzing them for contaminants, reviewing historical records on plant operations, interviewing past and present operations personnel, and preparing a plan for in-depth characterization of the site.
Site assessment is a methodical scientific process that determines the type and extent of contamination. Contamination detection is achieved through analyzing soil, biota, flora, fauna, and water samples. These analyses are evaluated to determine potential environmental and human health risks. Cleanup alternatives are then developed and evaluated. Final cleanup remedies are selected based on the type and extent of contamination, environmental, physical, and geologic site characteristics, available technology, resource requirements, and compliance with federal and state laws.
Site cleanup activities include the physical containment and/or removal and disposal of existing contamination.
Site closure and compliance monitoring, the final steps, ensure that the identified contamination problems have been adequately addressed and that any unanticipated problems are detected.
Decommissioning involves the decontamination and/or dismantlement and removal of nuclear facilities that are no longer active and pose a risk to public health or the environment. Many government-owned facilities that supported early nuclear weapons production and energy research have no current use and have been retired and declared surplus. In many cases, facilities such as reactors, hot cells, processing plants, and chemical or waste storage tanks have contamination present and must be monitored. DOE maintains surplus facilities in a safe and secure condition until decontamination and/or dismantlement activities have been completed.
Decommissioning tasks include:
surveillance and maintenance,
facility assessment and characterization,
waste disposal, and
Surveillance and maintenance activities involve the monitoring and inspection of inactive facilities awaiting decommissioning to prevent worker, public, and environmental exposure to potential hazards. Facility assessment and characterization activities determine the extent of these hazards and the type, extent, and nature of existing contamination. Chemical and radiological sensors can be used for facility characterization to help select appropriate decommissioning cleanup techniques. In addition, automated and robotic samplers help characterize facilities where entry would be hazardous to workers. DOE conducts an environmental review to assure viable decommissioning alternatives are evaluated and that selected options comply with approved health and safety standards and environmental laws.
Decommissioning operations range from minimal cleanup activities to complete structural dismantlement. Contaminated materials must be removed using methods that minimize the generation of additional waste. For example, in situ (in place) decommissioning has the significant advantage of reducing personnel exposure to hazards, avoiding transportation expenses, and deferring the need to develop new waste disposal areas. DOE works with its stakeholders to seek the most effective and cost efficient decontamination processes. When necessary, demolition of existing structures follows decontamination.
DOE disposes of waste found or generated during the decommissioning process according to its form and toxicity.