Aerosol Generation during Plutonium Ingot Puncture by a Cumulative Jet

摘要

Computation methods were used to estimate the amount of aerosols generated when a cumulative jet from ahand-mortar punctures a plutonium ingot transported in a protective container. The procedure included two-,and three-dimensional calculations for the mechanical puncture of an ingot, calculations for the statisticalspectrum of particles coming from the destroyed plutonium, calculations for critical diameters of particles selfignitiondepending on their initial temperature and velocity, as well as calculations for the mass of plutoniumcombusting and converting into aerosols. For each stage, calculations were calibrated by available experimentaldata. The cumulative jet was demonstrated to puncture a hole with the diameter of about 15-18 mm in the ingot.In this case, the dispersed plutonium is ejected from the puncture zone in the form of small particles with thedimensions ranging from 0.1μm to 2· mm. A minor part of these particles is in the liquid phase, I.e. about 7% ofthe total mass of the dispersed plutonium. Liquid particles and some solid particles self-ignite immediately aftertheir occurrence and calculations show about 16% of plutonium mass ejected by the cumulative jet to convertinto aerosols. Estimates show only 36 % combusting mass to convert into respirable aerosols, I.e. only 0.2 %mass of transported plutonium.