Title: Radiation damage effects on hydrogen permeation in fusion reactors

The present investigation considers possible effects due to the radiation fields expected in INTOR and their impact in tritium permeation and retention. After a short review of those suspected effects, a review of literature available on the subject and a discussion of the way in which they have been modelled, results of a parametric analysis to evaluate the sensitivity of permeation and retention to these parameters is presented. This study used a 316 stainless steel first wall as a medium for investigation but similar effects should be seen on limiters, divertor plates, etc. Nonmetals such as graphite and carbides couldmore » exhibit exaggerated response to radiation compared with these results.« less

FY 1983 has been a very productive year with respect to obtaining results and educating students in the field of Fusion Materials. We have analyzed the results of 14 MeV irradiated copper and have correlated the information with previous work done at HEDL. The 750 keV light ion accelerator has been used to preimplant samples with He as well as to study blistering in nickel. A collaborative effort with ORNL was completed on helium-irradiated Cu-Ni alloys. The effects of injected interstitials on void nucleation were studied and a theory developed to explain some past discrepancies in ion irradiated specimens. Initialmore » ion irradiations have been performed on 316 SS and HT-9 alloys. New techniques for plating type 316 stainless steel, ferritic steels and aluminum have been developed as well as intense beams of Fe, Ti and Al for ion bombardment studies. Two new electron microscopy facilities have been installed; a JELCO-200CX with EDX capabilities a high resolution Vacuum Generator HB501 for very precise microchemical analysis.« less

Tritium permeation through the first wall of advanced fusion reactors is examined. A fraction of the D-T which bombards the first wall as charge exchange neutral particles will permeate through the first wall and enter the coolant. Calculations of the steady state permeation rate for the US INTOR Tokamak design result in values of less than or equal to 0.002 grams of tritium per day under the most favorable conditions. For unfavorable surface conditions the rate is greater than or equal to 0.1 g/day. The magnitude of these permeation rates is critically dependent on the temperatures and surface conditions ofmore » the wall. The introduction of permeation barriers at the wall-coolant interface can significantly reduce permeation rates and hence may be desirable for reactor applications.« less