Safe Handling Of Tritium

The use of tritium as a basic fuel material in a thermonuclear fusion reactor raises particular safety issues due to the combined effects of its physico chemical properties and radioactive nature. Furthermore the possibility of attaining further significant progresses in developing and demonstrating the feasibility of tritium burning devices relies on the handling of tritium macroquantities, say ten grammes, in a safe and reliable manner. It is also undoubted that, apart from technological constraints, any validation and exploitation of thermonuclear fusion as a source of energy will be strongly conditioned by the application of stringent operational and environmental safety criteria as it derives from norms of the modern legislation and public acceptance considerations. Even if the safe handling of tritium has already been demonstrated to be feasible on a full fuel cycle scale, it is unanimously recognized that further efforts are still to be concentrated on the improvement of current concepts and development of advanced technologies. Some of the areas requiring substantial additional efforts are plasma exhaust fuel c1ean-up, tritium pellet injection, processing of inert carrier gas, development of large free-oil pumps,tritlUm process analytics, development of large detritiation systems, beryllium-tritium interaction studies, tritium hold-up studies in getter beds, adsorbers and structural materials, tritium recovery from first wall, structural and breeder materials for minimizing tritiated waste arising,tritium storage technology, tritiated waste disposal technolo~y, methodology for routine tritium accountancy,etc . . Most of them are intrinsically related to the safety requirement of tritium technology.

This publication contains information on the dosimetry and monitoring of tritium, the use of protective clothing for work with tritium, safe practices in tritium handling laboratories and details of tritium compatible materials. The information has been compiled from experience in the various applications of tritium and should represent valuable source material to all users of tritium, including those involved in fusion R&D.

The data presented demonstrate substantial nonvolatile transfer of tritium from contaminated surfaces to skin by direct contact. Since radioactivity on the contaminated surfaces is not necessarily detectable by gas-flow monitoring methods, this route of entry of tritium into body tissue must be considered an unrecognized, potential hazard, where the handling of apparatus exposed to high levels of tritium is concerned. The liability of contact-transferred tritium in skin, its chemical form and location within the skin, and the exact radioactivity content of the contaminated surfaces are particular problems remaining to be established by exact methods. The demonstration of non-volatile contact transfer is reported here because of its significance to health safety practice.

This book focuses on tritium as a fuel for fusion reactors and a next-generation energy source. Following an introduction of tritium as a hydrogen radioisotope, important issues involved in establishing safe and economical tritium fuel cycles including breeding for a fusion reactor are summarized; these include the handling of large amounts of tritium: confinement, leakage, contamination, permeation, regulation and tritium accountancy, and impacts on surrounding areas. Targeting and encouraging the students and technicians who will design and operate fusion reactors in the near future, this book offers a valuable resource on tritium science and technology.