High Power Equipment in Confined Spaces.

DOE-HDBK-6004-99

In some off normal excursions it is not expected that remote equipment always continue to be

operable, but in all cases it should not contribute to problems through its failure mode and should be

recoverable to a safe area.

High Power Equipment in Confined Spaces.

The physical hazards of high power and/or automated systems in restrictive spaces should be

addressed. Very high capacity and rigid systems (typical of high precision) will be present, with

possibly multiple systems in a common workspace. The hazards associated with this should be

addressed.

Plasma Energy

Plasma energy will be present within the fusion facility during normal operation. During off normal

excursions the plasma energy will be dissipated into its surroundings, in an extremely short period of

time. The rapid collapse of a plasma field will create very large electromagnetic transients and

runaway electrons.

Remote equipment either operating or stored within range of the plasma energy must be able to

withstand any off normal event that equipment is intended to address. From other off normal events,

all critical equipment should be safely recoverable.

Cryogenic

Cryogenic materials in large quantities (e.g. liquid nitrogen, and liquid helium) will be present many

areas around the fusion facility. Remote equipment intended to work near or service cryogenic

facilities should provide appropriate materials of construction. Seals, wire insulation, etc. should be

appropriately chosen or protected.

Radiological Fields

Radiological fields will be normally present at high levels during operation and at decaying levels

during outages. During the life of a fusion facility, the outage levels of ionizing radiation are expected

to be continually increasing, due to activation of metals.

The primary hazards to the remote handling equipment are high energy ionizing radiation (gamma and

some beta), and neutrons. The expected results to the equipment are activation of materials,

degradation of non-metallics, and destruction of electronics. The latter is expected to have the most

severe effect on the operability of the remote systems.

Electronic systems will be most vulnerable to the direct gamma attack, and, to a lesser extent, damage

due to neutrons and runaway electrons. Shielding or remote placement of electronics appropriately

should be designed into all systems. Cameras for remote maintenance will require radiation-resistant

optics and shielding of electronics.