Decontamination facilities

At a hazardous waste site, remediation and decontamination facilities should be located in the CRZ, that is, the area between the exclusion zone (the contaminated area) and the support zone (the clean area). The level and types of remediation and decontamination procedures required depend on several site-specific factors ... 

Stations should be separated physically to prevent cross-contamination and should be arranged in order of decreasing contamination, preferably in a straight line. Separate flow patterns and stations should be provided to isolate workers from different contamination zones containing incompatible wastes. Entry and exit points should be conspicuously marked, and the entry to the CRZ from the exclusion zone should be separate from the entry to the exclusion zone from the CRZ. Dressing stations for entry to the CRZ should be separate from redressing areas for exit from the CRZ. Personnel who wish to enter clean areas of the decontamination facility, such as locker rooms, should be completely decontaminated. 

The service and support area, centrally located in the main building, provides for operational control and support functions such as surveillance, decontamination facilities, utility and environmental systems and chemical laboratories. 

The dryer room, incinerator and decontamination facilities provide the capability for detoxification and disposal of spent decon. 

Many patients should be able to remove their own clothing, place it in the appropriate plastic bag, and do their own soap and water decontamination. If the decontamination facility is outdoors, partial tents or curtains can ensure patient privacy (9). 

In an attempt to think outside the box, the U.S. Army Soldier and Biological Chemical Command (SBCCOM) attempted to discover possible alternative ambulatory decontamination facilities, which would be able to supplement standard shower decontamination in the event of a large scale mass casualty event. One such alternative would be to use an Olympic-sized, heated swimming pool. The SBCCOM calculated that such a swimming pool as a communal bath with soap (and the water already present) could decontaminate large numbers (well in excess of 100,000 people) of ambulatory casualties exposed to nonconvulsive doses of the nerve agent sarin (SBCCOM, January 2002). The dilution factor of the large quantity of water would keep it nontoxic for many tens, if not hundreds of thousands, of people. 

Figure 5. Reception and decontamination facilities at a Paris Plan Biotox reference hospital the emergency physicians are wearing level-C protection, stored at the hospital, with filtration respirators. Figure supplied by David Baker...

A filtered air supply should maintain a positive pressure relative to surrounding areas under all operational conditions and flush the area effectively. Moreover, particular attention should be paid to the protection of the zone of greatest risk, that is, the immediate environment to which the product and the cleaned components in contact with it are exposed. The various recommendations regarding air supplies and pressure differentials may need to be modified if it becomes necessary to contain materials such as pathogenic, highly toxic, radioactive, or five viral or bacterial materials. Decontamination facilities and the treatment of air leaving a dean area may be necessary for some operations. 

The removal of solid or liquid chemical agent from exposed individuals is the first step in preventing severe injury or death. Civilian Hazmat teams generally have basic decontamination plans in place, though proficiency may vary widely. Very few teams are staffed, equipped, or trained for mass decontamination. Hospitals need to be prepared to decontaminate patients, despite plans that call for field decontamination of all patients before transport to hospitals. However, few hospitals have formal decontamination facilities even fewer have dedicated outdoor facilities or an easy way of expanding their decontamination operations in an event involving mass casualties. 

Although the CRZ is less hazardous than the exclusion zone, just like in the exclusion zone, people in the CRZ should be in line of sight and must maintain constant communication. The decontamination facility should be so situated as to minimize the spread of contaminants. The facilities should be designed for quick response to decon requirements. The decon facility design should take the following into consideration ... 

Various components and mechanisms which are working in active sodium of the primary circuit need to be decontaminated before they are inspected, sent for maintenance or dismantled for repair without the risk of sodium fire and radio activity. The decontamination facility consists of three pits. Pit No.l 2 are used for large components viz., IHX, pump, etc. Pit No.3 is used for small components like guide tube, CRDM, level probes and core co-ordination measuring device (CCMD). 

Comparison of the extreme conditions at Chernobyl with a simulation of a reactor incident exercise in the UK suggests that the changing and decontamination facilities and the monitoring associated with these at UK stations require reassessment to ensure that they are adequate for real situations. 

Changing rooms and decontamination facilities should be provided that can accommodate the maximum use made during periods of intensive maintenance work. 

In some cases, it may be desirable to undertake some local decontamination of individual components before removing them and bringing them to the decontamination facility. Suitable equipment should be provided together with instructions for its use, which should be validated in order to prevent damage to equipment, undue exposure of personnel or spreading of contamination. 

Suitable provisions shall be made in the design and layout of the plant to minimise exposure and contamination from all sources of radioactivity. Such provisions shall include adequate design of systems and components with respect to low radiation exposure during maintenance and inspection, shielding from direct radiation, reduction of corrosion-product activation by specification of appropriate materials, means of monitoring, control of access to the plant, minimisation of the time to be spent in contaminated areas, and suitable decontamination facilities. 

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