Year
1989
Abstract
To enlarge the storage capacity of the spent fuel pools in nuclear power plants compact storage racks were developed. Common to all different designs is the fact that neutron-absorbing material is used to ensure subcriticality. Numerous neutron-absorbing materials were examined with regard to their application in nuclear power plants or independent storage facilities. One of these materials is borated stainless steel. The corrosion resistance of borated stainless steel was investigated under spent fuel storage pool conditions and found to be the same as the resistance of the respective stainless steel without boron. Radiation tests with a neutron flux higher than would be expected during 40 years of operation in spent fuel pools showed no material deterioration. The boron is homogenously incorporated in the austenitic matrix of the stainless steel, so subcriticality is ensured for lifetime and no in-service inspections are necessary; thus, additional radiation exposure to the operating personnel is avoided. The mechanical properties of borated stainless steel vary with the boron content; a design must be chosen in which the mechanical properties and the manufacturability of the stainless steel are not changed significantly, yet the neutron- absorbing effectiveness is ensured.