Reactive materials, storage facilities

Dump Systems For an inhibitor injection or quench system, the inhibitor or quenching medium is transferred from an external supply to the reactive material in a dump system, the reactive material is transferred from the storage/handling facility to a safer location that is the same size or, more commonly, larger than the normal capacity of the facility. This allows depressurizing and deinventory of the reacting mass from the facility in an out-of-control situation, such as an incipient runaway reaction. 

Initiation of uncontrolled self-reactions at a given facility can occur in storage or during handling, mixing, physical processing or chemical reactions. A few of the many possible causes of uncontrolled reactions associated with self-reactive materials include the following ... 

Many inherently reactive materials are stored at chemical manufacturing facilities. Most commonly these are monomers for the production of plastics, fibre or elastomers. Under certain conditions, some normally stable materials may become reactive in the presence of a contaminant. To prevent spontaneous reaction in storage the materials are stored under conditions that eliminate, or almost eliminate, any reaction. 

Shipping casks, storage facilities, and process vessels involved in handling fissile materials contain neutronabsorbing materials—either for their neutron-absorbing properties or for structural reasons. These types of systems can be fiilly utilized, safely, only if the neutron absorbers are pnmcrly accounted for in the criticality analyses. The results from measurements on two such materials, copper and cqpper containing 1 wt% cadmium, were. .reported on previously. Since that time, the reactivity worths of several other materials, commonly considered for use as fixed neutron poisons, have been... 

Excess reactivity in the FUJI MSR is always kept very low, so that any unauthorized extraction of the fuel salt even in small amounts could be easily detected. By virtue of a high conversion ratio, the necessity of addition of fissile material remains small so the plant has no actual fresh or spent fuel storage facilities, which could otherwise be the possible target of diversion or theft ... 

The information in this publication is applicable to many industrial facilities not covered by process safety regulations such as the OSHA PSM Standard and the Seveso II Directive. Many reactive chemicals are not listed as regulated materials, and chemical reactivity hazards include uncontrolled chemical reactions between materials not considered as highly hazardous, or under conditions not typically encountered in storage and shipping. 

A method for determining the reactivity of highly sub-critical systems of fissile material, u ng neutron-noise power spectral densities in conjunction with a %f source, had previously been tested in two fast reactor critical assemblies (a mockup of the Fast Flux Test Facility reactor and unreflected enriched uranium metal assemblies ) and one thermal reactor (a light water moderated and reflected lattice of Oak Ridge Research Reactor ftiel elements. The last-mentkmed test demonstrated the effectiveness of the method in watermoderated systems and thereby prompted the prexnt study, of its application to facilities for fuel preparation, reprocessing, and storage. 

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