CMSR CANDU LLW Source Term Characterization

Operational and legacy CANDU generated low-level radioactive waste (LLW) is monitored, inventoried, and segregated at the Clean-Energy Materials Sorting and Recycling (CMSR) laboratory, a joint project between Laurentis Energy Partners (Laurentis) and McMaster University. At the CMSR laboratory, swipes and large area wipes (LAWs) of contaminated LLW material and solid LLW samples were collected for analysis. Considering the LLW volume sample size of the research initiative, this is believed to be the most statistically significant source term characterization performed to date on CANDU generated LLW.

This research initiative has demonstrated the value in sorting and segregation as it relates to LLW volume minimization. This extends to enhanced segregation techniques, waste container space optimization, as well as the identification of non-contaminated materials in CANDU LLW. Industry standard isotopes of interest (eg. Cs-137 and Co-60) were confirmed to be present and in relatively high abundance across all waste streams and LLW vintages sampled, as expected. However, the distribution of other radionuclides associated with LLW was highly variable, and generally at much lower abundances than anticipated (if present at all). Application of dose-rate to radioactivity estimate, though efficient and technically sound, has been shown to generally overestimate and over-characterize CANDU generated LLW.

As expected, the standard for LLW bin radioactivity quantification remains conservative in nature, measuring higher when compared to the individually measured contents within (gamma signature to radioactivity correction). Although a significant number of samples were taken throughout this project, supplemental sample collection is recommended to increase the sample size of LLW vintages that were infrequently or not available throughout the duration of this study.