Radiological hazards from fission products

I. Possibility of Radiological Hazards from an Escape of Fission Products Historical Introduction. 

POSSIBILITY OF RADIOLOGICAL HAZARDS FROM AN ESCAPE OF FISSION PRODUCTS HISTORICAL INTRODUCTION... 

G. W. Marley and T, M, Fry, Radiological hazards from an escape of fission products and the implications in power reactor location. Pap. A/CONF. 8, p. 394 (1956). Proc. Int. Conf. Peaceful Uses Ai. Energy, Geneva 1955. 

The release of radiological materials in any specific accident scenario is usually less than the total inventory present, depending on the postulated confinement barrier failure in the DBA and the limitations to release Inherent In the physical form of the hazardous material. The source term released by initial confinement barrier failure may be reduced even further by mitigative effects which occur during transport or leakage from the facility to the environment. For example, filtration in the ventilation system will normally trap a large fraction of the fission products but would still allow the volatile noble gas fission products to be released from the HCF stack. 

Section 3.3.2.3.5, Accident Selection, identified one beyond DBA as, Multiple simultaneous errors or events that affect multiple SCBs, resulting in release of the contents of multiple targets. Release of the fission products from multiple targets (six) in a single SCB has already been analyzed in two DBAs Spill of Process Materials in an SCB and Fire in a Process SCB. The source term and consequences of the Multiple simultaneous errors or events... beyond DBA are discussed in Section 3.4.3.1 and S.4.3.2 below. Two additional hazards are discussed in Sections 3.4.3.3 and 3.4.3.4 as beyond DBAs to provide a perspective of the residual risk associated with the operation of the facility. These beyond DBAs are 1) seismic events resulting in a release of radiological material and 2) dispersal of radiological material by an explosion in the HCF. 

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