Hot Laboratory

a room for working with high-activity radioactive compounds (to hundreds of thousands of curies).

A hot laboratory is used for studying the chemical and physicomechanical properties of irradiated nuclear fuel and working out its process flow diagrams, for investigating various properties of transuranium elements (neptunium, plutonium, americium, curium) and the methods of isolating them, and for preparing powerful sources of α, β, and γ-radiation. A hot laboratory is divided into separate sections and consists of working compartments (“hot cells,” with rooms for operators; laboratories with protective bays; and a storehouse for radioactive wastes) and ancillary compartments (sanitary cubicles with showers, places for workers to change into special protective clothing, and so on).

Work with high-activity preparations demands that complex biological measures be taken to protect the staff and surrounding population against ionizing radiation and contamination by radioactive substances. A hot laboratory is equipped with powerful suction-and-exhaust ventilation that provides for an exchange of air from ten to 30 times per hour, dust removal and air conditioning in the forced-ventilation system, and effective multistage filtration of the air removed that completely excludes the possibility of the discharge into the air of radioactive contamination in vapor or aerosol form. A hot laboratory has an autonomous internal drainage system with receiving containers for the collection of liquid radioactive wastes and the subsequent removal to a place of burial. The interior surfaces of a hot laboratory have coatings that are easily decontaminated (stainless steel, oil-base paint, plastic compounds).

In a hot laboratory all work with radioactive substances is carried out only from a distance; the laboratory is equipped for this through a process chain of hot chambers and cells. interconnected by a system for transporting preparations and samples both between the various compartments and with the storage area for the radioactive materials. Hot cells are hermetic chambers with strong biological shielding. They are made of high-density materials: barytoconcrete, cast iron, or lead. For better decontamination, the interior surfaces of the hot cells are lined with stainless steel coated by oil paints, polyethylene film, or other replaceable films. In hot chambers and cells the control of all processes is carried out from so-called operators’ compartments with various kinds of manipulators that have mechanical, electric, or hydraulic drives or with special mechanisms designed to carry out one or more of the simpler operations.

Ordinarily the hot laboratory is part of a radiochemical laboratory complex, planned in zones on the principle of diminishing activity. The zones are separated from one another by steel or concrete biological shield walls and are equipped with automatic-block sanitary cubicles that are linked to a radiation monitoring system. The protective system and the systems of strict radiation monitoring, signaling, and automatic blocking ensure the complete biological safety of the staff and the surrounding area, both from radioactive radiation and from contamination by radioactive materials.