A Solution to Memory Effect Problem in Solid Polymer Electrolysis for Tritium Enrichment

The solid polymer electrolysis apparatus for tritium enrichment requires the enrichment factor to calculate the tritium concentration in sample water measured. Standard tritium water, with the initial concentration of approximately 10Bq kg-1, was thus used twice a year to determine the enrichment factor. We found a tritium memory effect of 50-80mBq, which was much than the detection limit (20mBq), after enrichment of the standard water. The observed memory effect corresponded to the level explained by the residue of enriched standard water restrained in the polymer electrolyte membrane. We found that the restrained tritium water is diluted by filling the apparatus with distilled water (