The extended storage of radioactive ion-exchange resins in polyethylene high-integrity containers. Final report

This research and development program was carried out by Brookhaven National Laboratory (BNL) for the Empire State Electric Energy Research Corporation to evaluate the use of high-density polyethylene (HDPE) as a container material for the extended storage of waste ion-exchange resins at nuclear reactor sites. The resins are produced as a consequence of reactor coolant and liquid waste stream cleanup. Resin storage for periods of less than 5 years does not add significant additional regulatory burdens on the generator. However, for longer storage times, extra information will be required to demonstrate that the containers maintain their integrity. At this time, HDPE is the material of choice for storage at many nuclear power plants. It was selected because it combines low cost compared with high-integrity containers fabricated from metallic or composite, materials, and superior resistance to corrosion from a very wide range of environments. In addition, HDPE high-integrity containers have been developed for the disposal of low-level wastes under shallow-land burial environments for which a 300-year minimum lifetime is expected. Thus, many of the technical considerations for storage have already been addressed during container licensing activities for disposal. From a detailed analysis of the expected types of resin wastes and themore » expected storage conditions, it is concluded from the current research effort that HDPE containers may be used to store the majority of resins for many decades without incurring failure if the container is left undisturbed. During storage, radiation-induced losses in ductility were determined to be the principal degradation mode. The severity depended on both the dose rate and the dose level achieved. The major potential for container failure will occur during times when container transport is carried out. During these periods, lifting stresses will be applied and accidental dropping is also a possibility.« less