Determination of14C in spent HTGR fuel elements

Spent HTGR-fuel spheres were analysed chemically to determine their¹⁴C content.¹⁴C is mainly (∼96%) produced in the graphite matrix of the fuel. About 75% of the¹⁴C is derived from¹⁴N. More than 99% of¹⁴C is released as CO₂ during the combustion of the fuel elements. Assuming no¹⁴C retention, the maximum body burden at the critical region of a 50000 MW HTGR reprocessing plant will be ∼ 70 mrem/a. Paper presented at the 9th Radiochemical Conference, Piestany, CSSR.