Tritium inventory in fusion machine and air detritiation after accidental release.

Abstract

The effects of operational modes of the R-project fusion machine on the total tritium inventory are discussed by the use of which has been originally developed at ANL. The effects of the dwell time, the burn time, and the fractional burnup on the tritium inventory are elucidated . Air detritiations in the R-project fusion machine building are shown graphically as a function of elapsed time after the accidental release of tritium by the use of TSOAK code developed at ANL. The effects of air flow rate on the d~tritiation, the formation of TH and THO, and the amount of tritiated species soaked into the building surface of the R-project fusion machine are also evaluated . I l. Introduction If a large fusion machine in which much more tritium is used is developed, tritium will have to be handled at each own site. In other words, it is no use to refer to other areas where we have a lot of experience. The natures of the problem that fall within the frame of fusion fuel handling in fusion machine are not yet well recognized, it is neverthless of great importance to keep the inventory of tritium in fusion machine as low as possible and to prevent positively the accidental release of tritium from the fusion machine. Although the total tritium inventory for proposed various fusion reactors have been estimated 1) no paper concerning the dependence of total tritium inventory on the operational modes of fusion machine is published. On the other hand, a time-dependent air detritiation, i. e., the clean up characteristics, that could occur in a typically-sized reactor building following a range of tritiurn releases has been elucidated for the selected fusion reactor 1) It is the purpo.se of the present paper to predict the effect of operational modes of fusion machine on the total tritium inventory and to show the air detritiation in the fusion machine building, the concentration of TH .and/or THO formed in building atmosphere, and the tritium soaked on building inner surface in terms of the time elapsed after the accidental release of tritium. In order to evaluate quantitatively, a set of representative parameters are selected on current projection for the R -project fusion machine which has been designed at Institute of Plasma Physics, Nagoya Universify. 2. Simple Description of Computer Code 2. l. TCODE2) The computer code which is c~lled TCODE and has originally been developed at ANL2) was revised and used to the present work. A comprehensive package of performs detailed parametric analysis of tritium and vacuum systems. In order to determine