Safety Analysis of the Compact Ignition Tokamak Radiation Shield^a

The baseline design of the Compact Ignition Tokamak (CIT) includes a center cell which acts as a radiation shield around the CIT machine. The safety aspects of this shield have been examined. Production of activated gas during machine operation has been investigated and the resulting doses for release under normal operation and accident conditions have been calculated. Helium, nitrogen, carbon dioxide and air have been considered for use as the CIT cover gas. Helium has several safety advantages; however, due to its relatively high cost, other gases are being considered. Nitrogen and carbon dioxide are candidates since they have a lower cost and produce short-lived activation products. Other safety aspects of the shield are also considered. The shield is found to be beneficial to CIT.

^a Work supported by the U. S. Department of Energy, Assistant Secretary for Energy Research, Office of Fusion Energy, under DOE Contract No. DE-AC07-76ID01570.