Speaker
Description
Regulatory requirements set by the radioactive waste repository operator and the waste processor necessitate verifying that waste intended for disposal does not contain materials exempt from regulation under applicable legislation or radionuclides with only short half lives. At the LVR 15 research reactor facility, the dominant contaminant in compressible waste is activated water from the primary cooling circuit. Until 2024, the activity of this waste was estimated using a single gamma spectrometric measurement of a contaminated bag performed in 2015.
Starting in fall 2024, the methodology was expanded to include quarterly radiochemical analyses of primary circuit water, incorporating alpha emitting and pure beta emitting radionuclides. The calculation model was further refined by introducing experimentally validated coefficients that account for evaporation effects across different waste materials.
These analyses showed that approximately 96% of the total activity in compressible waste originates from tritium, which had previously neither been measured nor reported. The remaining activity consists of roughly 3.7% gamma emitting radionuclides and a small fraction of pure beta emitters.
Based on these findings, quarterly coefficients are now derived from water sample characterization to determine the activity of each individual waste bag. Threshold values are also updated quarterly to evaluate whether the waste, after one or five years of decay, may be released as conventional waste. Waste meeting these criteria is designated for temporary storage by the radioactive waste processor.
Based on these findings, quarterly coefficients are calculated to determine the activity of each individual waste bag. Additionally, threshold values are updated each quarter to assess whether the waste, after one or five years of decay, may be released into the environment as conventional waste. Such waste is designated for temporary storage by the radioactive waste processor.