SAFETY AND DETERMINISTIC FAILURE ANALYSES IN HIGH-BETA D-D TOKAMAK REACTORS (FUSION SAFETY, ADVANCED FUSION, FUELS-SAFETY).

摘要

Safety and deterministic failure analyses were performed to compare major component failure characteristics for different high-beta D-D tokamak reactors. The primary focus was on evaluating damage to the reactor facility. The analyses also considered potential hazards to the general public and operational personnel.;Issues examined using these designs were radiation induced failures, radiation safety, first wall failure from plasma disruptions, and toroidal field magnet coil failure.;The radiation issues analyzed for the first wall were radiation damage, loss-of coolant-accident (LOCA), and disposal of waste. The most critical of these for high-beta D-D systems is the possible reduction in first wall lifetime due to the enhanced radiation damage on the outboard first wall system. Possible first wall melting from the decay afterheat following a first wall LOCA does not represent a major safety concern.;Plasma disruptions in high-beta D-D tokamaks must be controlled if operation is to be feasible. Analysis has shown that first wall design modifications to increase the electrical conductivity may mitigate the damaging effects of a disruption.;Parametric designs of high-beta D-D tokamak reactors were developed, using WILDCAT as the reference. The size, and toroidal field strength were reduced, and the fusion power increased in an independent manner. These changes were expected to improve the economics of D-D tokamaks.;Toroidal field magnet coil failure, from either a loss of cryogenic helium coolant or a shorted turn, was analyzed. The times for the stored energy to be released and for damage to occur were considered. It was found that the low field coil is the most vulnerable to severe damage in the loss of helium coolant accident. Increase in the amount of copper used in the low field designs would reduce damaging effects. Coil damage from a shorted turn is weakly dependent on field strength.;Overall, from the point of view of both economics and safety, compact systems represent the optimum utilization of high-beta operation.