Launch of online archive International Journal of Radioactive Materials Transport Packaging, Transport, Storage & Security of Radioactive Materials

The penetration of aerosols through fine capillaries J. P. Mitchell, R. T. Edwards and M. H. E. Ball A practical procedure has not been developed and accepted internationally to quantify the leakage of aerosols in tests of radioactivity transport flasks. Hence it is necessary to understand how aerosols penetrate model pathways that have leakage rates close to the limits set by standards of flask integrity. A novel procedure has been developed to study the penetration of particles ranging from 0.5 to 15 mm volume equivalent diameter through capillaries varying from 20 to 80 mm bore and from 10 to 50 mm in length. The penetration of these particles was smaller than expected from a comparison of particle diameter with capillary bore, and showed a linear correlation with flow Reynolds number when both variables were plotted on a logarithmic scale. The lack of particle size dependent penetration was explained in terms of the capillary operating as an aerosol sampler in calm conditions. Int. J. Radioactive Mater. Trans., 1990, 1, (2), 101–116 Proposed brittle fracture acceptance criteria under accident conditions K. E. Wieser, H. Frenz and I. Jeschenz Shipping containers for radioactive materials are required to retain integrity under accident conditions, which may be jeopardised by brittle fracture of the containment system. Internationally agreed criteria for the safe design of shipping containers with respect to brittle fracture are not yet part of the International Atomic Energy Agency’s Regulations for the Safe Transport of Radioactive Materials. By adaption of relevant portions of the ASME Code it is possible to propose criteria based upon classic fracture mechanics and using generally agreed standardised materials fracture toughness data, or, in the case of ‘new’ materials, lower bound or 3s-values. The need for safety demonstrations is discussed; in particular, drop testing of pre-cracked prototypes. It is shown that such investigations should not be part of licensing procedures.