TRU (transuranic) population control by sorting waste at the source

Sorting waste at the source (SWATS) of its generation is under investigation at the Rocky Flats plant as a method to decrease the fraction of transuranic (TRU) waste in the plant waste population. Low-level waste (LLW) is defined to have <100 nCi of alpha-particle emissions per gram of waste, and TRU waste is at or above that level. The LLW definition implies detectability of slightly <1 mg of plutonium per kilogram of waste. The goal of this work is to develop and test instruments that are capable of distinguishing LLW from TRU waste at the package or bagout stage. To meet the sorting challenge, and to better quantify the LLW fraction, the authors built a prototype gamma-ray counter with three plastic scintillators, each 305 mm wide {times} 915 mm long {times} 51 mm thick. While the authors anticipate a favorable benefit-to-cost ratio from waste sorting, its noted that today's environmental laws and regulations provide powerful incentives to minimize all wastes, particularly the more radioactive and hazardous varieties. Economics may become less influential compared to the ability to characterize, certify, and otherwise comply with applicable laws and regulations with state-of-the-art technical ability. It is believed that instruments similar to these couldmore » be especially useful if they were designed into any new facilities built in the future.« less