Radionuclide characterization of reactor decommissioning waste and spent fuel assembly hardware

The US Nuclear Regulatory Commission (NRC) has recently enacted rules setting forth technical, safety, and financial criteria for decommissioning of licensed nuclear facilities, including commercial nuclear power stations. These rules have addressed six major issues, including decommissioning alternatives, timing, planning, financial assurance, residual radioactivity, and environmental review. Also, the rules governing disposal of low-level radioactive wastes in commercial shallow land burial facilities will be applicable to most of the wastes generated during reactor decommissioning. This study has been implemented to provide the NRC and licensees with a more comprehensive and defensible data base and regulatory assessment of the radiological factors associated with reactor decommissioning and disposal of wastes generated during these activities. The objectives of this study are being accomplished during a two-phase sampling, measurement, and appraisal program utilizing: (1) the decommissioning of Shippingport Atomic Power Station, and (2) neutron activated materials from commercial reactors. Radioactive materials obtained from Shippingport Station and from a number of commercial stations for comprehensive radionuclide and stable element analyses are being utilized to assess the following important aspects of reactor decommissioning and radioactive waste characterization: (1) radiological safety and technology assessment from an actual reactor decommissioning (Shippingport); (2) radiological characterization of intensely radioactive materials (greater than Class-C) associated with the reactor pressure vessel and spent fuel assembly hardware from commercial nuclear power plants; (3) evaluation of the accuracy of computer codes for predicting radionuclide inventories in retired reactors and neutron activated components; and (4) assessment of waste disposal options associated with reactor decommissioning