Development of all metal filters for use in the nuclear industry

This paper summarizes the experiments performed by Pall Corporation Laboratories in Germany for qualification of a filtration system for venting of P.W.R. The basis for the parameters examined were different model calculations for a possible venting in P.W.R. The calculations gave process specifications for a filter venting system. Aside from principal demands on mechanical and thermal strength of the system, efficiency examinations under differing process conditions were necessary. Here the simulation of these possible process conditions by the test parameters used were essential. From the model calculations for examination of filter performance the following fluid conditions were chosen - dry to wet gas at temperatures up to 160 degree C and absolute pressures of 5.5 bar. Aerosols that are not affected in size, shape or other physical properties by those fluid parameters had to be used and under these conditions aerosol generation and measuring systems had to be evaluated. The important size range for this was below 1 micrometer, since these have been shown to be the hardest to remove