Characterisation of a multitube PERMCAT reactor in view of a technical facility for highly tritiated water processing at the Tritium Laboratory Karlsruhe

Development of a technical scale PERMCAT reactor for processing of highly tritiated water

“…As described in the previous paper [1] large quantities of tritiated water of low (0.4·10 12 Bq kg −1 ) to medium (11.1·10 12 Bq kg −1 ) activity concentration is inevitably produced in a future fusion plant using tritium in its fuel cycle. Options currently under investigation such as the Combined Electrolysis Catalytic Exchange (CECE) process chosen for ITER are able to process tritiated water of a mean specific activity of 0.4·10 12 Bq kg −1 [2] with a decontamination factor (DF) of 2.5·10 5 [2,3].…”

“…The key process parameters (swamping gas ratio, total water vapor flow rate, water vapor pressure) for operating a PERMCAT were already thoroughly investigated in the last paper presented [1], resulting in a proposal of a three stage PERMCAT cascade to decontaminate HTW. Therefore, to further optimise the PERMCAT performance before starting the design of a three stage cascade it was necessary to improve the geometry of the technical scale PERMCAT reactor.…”

“…The experimental setup used to perform isotope exchange experiments between D 2 O vapor and H 2 is identical as reported in the previous paper [1]. D 2 O vapor produced by an evaporator and He carrier gas from a gas bottle is fed at a 1:1 ratio into the PERMCAT while being processed counter current to H 2 at a fixed swamping ratio of 1:4.…”

“…The additional amount of very highly tritiated water (HTW) of up to 5.2·10 16 Bq kg −1 (expected from torus cleaning and accidental tritium release into a glove box [4]) are to be processed in a short period of time down to an activity concentration compatible with the CECE process. The high radiotoxicity [5], the characteristic radiochemical decomposition (self radiolysis) [6][7][8] and the corrosive nature of HTW [9] inevitably require a fast and safe decontamination with a robust and reliable process [1]. Therefore, the TLK has proposed the PERMCAT process to decontaminate HTW [10].…”

Inactive commissioning of a micro channel catalytic reactor for highly tritiated water production in the CAPER facility of TLK

“…Although the amount of such HTW will be small, a suitable detritiation process has to be identified both for safety and economic reasons [1]. From a safety point of view, HTO is very dangerous not only for its high radiotoxicity but also because its self radiolysis leads to the formation of explosive mixture of HT and O 2 [2]. Moreover, as reported by Bellanger [3], tritiated water causes corrosion of stainless steel by pitting and crevice attack.…”