Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2005, Volume 8, Issue 15+16

Candu Station Tritium Removal Facility Optimal Design and Utilization

Abstract

To date there are two industrial-sized tritium removal facilities (TRF) dedicated to detritiating CANDU reactors; the Darlington TRF in Canada and the, currently under construction. Wolsong TRF in Korea (WTRF). Both these plants have been designed for a detruiation factor of 30-40 and built with sufficient capacity to deintiate the moderator of a CANDU reactor to a steady-state tritium concentration of approximately 370 GBq/kg D₂O. A simultaneous detritiation scheme, which simultaneously detritiates both the moderator and the heat transport system (HTS), makes the most effective use of the TRF to reduce the tritium levels in the station. However, there are limitations to the amount of heavy water that can be recirculated between the moderator and HTS since the movement of heavy water between the two systems must both meet the upgrading requirements for both systems and not exceed the capacity of the upgrader. A detntiarion factor of 30-40 is sufficient to detritiate a single pool (i.e. moderator or HTS) and further increasing the detritiatton factors will not lower the final steady-state tritium concentration. However, when employing simultaneous detritiation of the moderator and HTS, a higher detritiation factor can significantly further reduce the final steady-state tritium concentration in the HTS. The benefit of a lower HTS tritium concentration is balanced against the increased cost of constructing the TRF with a higher detritiaton factor. This paper outlines the benefits of simultaneous detritiation in terms of maximizing the tritium reduction in both the moderator and HTS and demonstrates how such a recirculating scheme meets both the moderator and HTS deuterium upgrading requirements. The paper also assesses the benefit of designing for a higher detritiatmon factor in terms of reducing the station tritium levels and estimates the incremental costs of increasing the detritiation factor in the leading candidate TRF processes.