Shield cooling system failures

The cask provides the shielding, inert environment, confinement, component grappling, andl.4-kW(t) cooling capability required to handle sodium-wetted, irradiated core components. Its inside diameter isabout 8 in. The dolly provides traverse drive, cask elevation, and seismic-restraint functions. The control system provides the control consoles, motor control equipment, and all interconnecting cables. Control of the transfer cask is semiautomatic that is, key operations are automatically performed after the operator initiates a command. Interlocks are incorporated to meet safety requirements. Status lights indicate the exact machine conditions during all operations and manual overrides permit the operator to complete key operations in case of a control system failure. 

A similar diesel-driven pumping system provided emergency once-through cooling to the graphite moderator and shields. This coolant provided backup to the ECS In the event of long-term failure of the ECS (WHC 1989a). 

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