The presence of tritium in tokamaks is a key issue associated with the materials that are most likely to be used for the type of equipment in the plant and for tritiated waste management. This chapter deals with the peculiarities requested for the tritium process in the different forms in which it exists in fusion devices. Tritium can easily interact with the materials and create chemical, mechanical and aging problems. Those materials that are exposed to tritium frequently have problems related to hydrogen embrittlement, or may undergo tritium permeation if the gas temperature is too high. Also, the equipment which handles tritium has to be especially designed in order to support the tritium peculiarities such as the difficulty to be safely contained. The technological problems connected with the fuel cycle are treated by referring to the solutions that are adopted in the existing fusion devices. From the radwaste point of view, a distinction should be made between activated and tritium-contaminated solid materials generated from the tokamak machine itself, which comprise the largest fraction, and wastes generated from the fuel cycle systems. The former is an activated metal solid which, in some cases, is also contaminated by tritium; the latter is solid, liquid or gaseous waste, mainly contaminated by tritium. Other types of radioactive waste generated in tokamaks are the usual low- or intermediate-level wastes which can be found in any nuclear facility and might be slightly contaminated by tritium (e.g., contaminated filter materials from off-gas systems, lightly contaminated trash, and residues from recycling or recovery operations, staff clothes, plastics, etc.). ©2013 Nova Science Publishers, Inc. All rights reserved.
Tritium in tokamak devices: Technological issues
Di Pace, L.;Porfiri, M.T.
2013-01-01
Abstract
The presence of tritium in tokamaks is a key issue associated with the materials that are most likely to be used for the type of equipment in the plant and for tritiated waste management. This chapter deals with the peculiarities requested for the tritium process in the different forms in which it exists in fusion devices. Tritium can easily interact with the materials and create chemical, mechanical and aging problems. Those materials that are exposed to tritium frequently have problems related to hydrogen embrittlement, or may undergo tritium permeation if the gas temperature is too high. Also, the equipment which handles tritium has to be especially designed in order to support the tritium peculiarities such as the difficulty to be safely contained. The technological problems connected with the fuel cycle are treated by referring to the solutions that are adopted in the existing fusion devices. From the radwaste point of view, a distinction should be made between activated and tritium-contaminated solid materials generated from the tokamak machine itself, which comprise the largest fraction, and wastes generated from the fuel cycle systems. The former is an activated metal solid which, in some cases, is also contaminated by tritium; the latter is solid, liquid or gaseous waste, mainly contaminated by tritium. Other types of radioactive waste generated in tokamaks are the usual low- or intermediate-level wastes which can be found in any nuclear facility and might be slightly contaminated by tritium (e.g., contaminated filter materials from off-gas systems, lightly contaminated trash, and residues from recycling or recovery operations, staff clothes, plastics, etc.). ©2013 Nova Science Publishers, Inc. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
