Abstract: A method is invented of sealing through penetrations in fire rated barriers (walls or floors/ceilings), caused by metallic pipes, metallic conduits, metallic cable trays with cable inside, cables, metallic ducts and electric busways, by placing an external firestop seal comprising of cemetitious liquid material, which upon curing becomes rigid and heat absorbing. In order to obtain the same fire rating with the same rigid, cementitious fire stop material for an external seal as compared with an internal seal, the total depth of the external seal, on both sides of the fire barrier, was determined to be at most the same as the depth of the internal seal.

Abstract: A method for decreasing the amount of hazardous radioactive reactor waste materials by separation from the waste of materials having long-term risk potential and exposing these materials to a thermal neutron flux. The utilization of thermal neutrons enhances the natural decay rates of the hazardous materials while the separation for recycling of the hazardous materials prevents further transmutation of stable and short-lived nuclides.