Structure - STD-1128-98master0319

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

All valves that are not functionally required to be in contact with contaminated

liquids should be located in nonradiation areas (e.g., steam, air, water) in

accordance with IAEA Safety Series No. 30 (IAEA, 1981).

Process valves should not be located at low points in the piping except in cases

where it is necessary in order to properly drain the piping when needed.

Valve seals and gaskets should be resistant to radiation damage.

Straight-through valves generally should be used to simplify maintenance and

minimize particle traps.

Valves should be designed to operate in the stem-up orientation, which would limit

potential leakage when the pipe is unpressurized. Valves and flanges should be

located to minimize the consequences of contamination from leaks.

Generally, process solutions should have primary and secondary confinement.

However, in rare instances where process solutions are allowed to flow outside of

confinement, they should flow only by gravity and the pressure head should be

limited to an equivalent of about 10 feet of water.

The corrosion resistance of the primary block valve and/or check valve and all

associated piping in the in-cell and/or contaminated areas should be equivalent.

The use of pumps in contaminated piping systems should be avoided to reduce

potential contamination problems that result from pressurization and to reduce the

maintenance requirements associated with pumping. The use of gravity flow, jets,

vacuum, or airlifts is a suitable alternative. Vacuum transfers are preferred. If jets

or airlift transfers are used, an adequate waste-air cleanup system should be

provided.

C.4.3.2 Structure

Floors should be designed in accordance with code requirements considering the

maximum loads anticipated.

C.4.3.3 Storage

In-process storage should not be permitted; however, temporary storage of the

product in the process area until it can be taken to an appropriate storage area

should be permitted.

Storage facilities in the process areas should be designed to prevent the exposure of

operating personnel and to meet the requirements for security and safeguards.

C.4.3.4 Shielding

Provisions should be made to accommodate the shielding of all items in the process

area. All structures (e.g., floors, walls, and glove boxes) may require additional

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