A model has allowed us to perform the analysis of the tritium inventory and
permeation in the international thermonuclear experimental reactor (ITER)
breeding blanket under the hypothesis of steady state conditions. Li2ZrO3 (
reference) and Li2TiO3 (alternative) have been studied as breeding material
s. The total breeder inventory assessed is 7.64 g for the Li2ZrO3 at refere
nce temperature. The model has also been used for a parametric analysis of
the tritium permeation. At reference temperature and purge helium velocity
of 0.01 m/s, the HT partial pressure is ranging from 10 to 30 Pa in the bre
eder and 1.5 x 10(-3) Pa in the beryllium. At 0.1 mis of purge helium veloc
ity, the HT partial pressure is reduced of one order by magnitude in the br
eeder and becomes 5 x 10(-5) Pa in the beryllium. The tritium permeation in
to the coolant for the whole blanket is ranging from 100 to 250 mCi per day
for purge helium velocity of 0.01 mis. The analysis of the tritium invento
ry and permeation for the alternative Li2TiO3 breeding material has been ca
rried out too;The tritium inventory in the breeder is in the range from 6 t
o 375 g larger than in Li2ZrO3 by about a factor 5; the tritium permeation
into coolant is comparable to the Li2ZrO3 one. This analysis provides indic
ations on the influence of the operating parameters on the tritium control
in the ITER breeding blanket; particularly the control of the tritium inven
tory by the temperature and the tritium permeation by the purge gas velocit
y. (C) 2000 Elsevier Science B.V. All rights reserved.