Possible future prospects for channel reactors

The safety of channel reactors can be improved further by removing graphite from the RBMK core and replacing it with gas and using steel instead of zirconium for the fuel-element cladding and channel tubes. Switching in one channel from 18 to a larger number of fuel elements with a smaller diameter will permit extensive testing of fuel elements for fast reactors in a variant with in-cassette heterogeneity. The removal of graphite from the core increases neutron leakage but does not change the effective multiplication coefficient, since neutron capture in graphite vanishes. The replacement of zirconium with steel decreases the leakage, since neutron balance is preserved in a working reactor because of the lower neutron leakage with higher neutron absorption in the fuel elements and tube channels.