Instrumentation and Controls

DOE-HDBK-6004-99

and, where applicable, accident conditions) should be considered and materials selected so there will

be no loss in function for the design life of the equipment.

The surface finish of all external materials should allow for ease of radiological decontamination.

Highly polished, non oxidizing, and non painted surfaces should be used so as to not entrap

radiological material or produce mobile dust.

The potential for hydrogen embrittlement and weakening of structural members should be considered

in all locations where exposure to hydrogen, deuterium, or tritium is anticipated.

The radiological activation of materials in areas of high gamma and neutron fluxes should be

considered in the choice of materials. This includes metals, greases, fluids, and elastomers.

Instrumentation and Controls

The following instrumentation and control features should be provided in the design of the remote

handling equipment as necessary to prevent damage to the handling equipment, to nearby safety-class

or safety-related SSCs, and to the handled components; to provide for personnel safety; and to

remotely recover equipment (to prevent the necessity of personnel recovery of equipment):

1. Underload - An interlock actuated upon a reduction in load, while lowering with grapple

attached, at other than full down position, to prevent any further downward travel.

2. Overload - An interlock actuated upon an unacceptable increase in hoisting force to prevent

upward travel.

3. Up-Position - An interlock set at a predetermined operational limit to prevent any further upward

travel.

4. Down-Position - An interlock set at the predetermined operational limit to prevent any further

down travel.

5. End-Travel (hardstop) - Physical limit to translation.

6. Up-Limit (hardstop) - Physical limit to hoisting.

7. Slow Zone - Region of travel where a reduction in hoist speed is mandatory and automatic.

8. Non-Simultaneous Motion - Automatic restriction against simultaneous hoisting and translating

motions.

9. Grapple Release - An interlock to prevent opening a grapple under load.

10. Bridge Travel - An interlock at a predetermined operational bridge travel limit.

11. Trolley Travel - An interlock at a predetermined operational trolley travel limit.

12. Slack Cable - An interlock actuated at a loss of cable load to prevent further downward travel.