Position evaluation of ex-core neutron flux measurement in new type graphite reactors

Several concepts of new reactors use graphite. Some them graphite as a moderator, some reflector. There are at least two these graphitetype under development in the Czech Republic. Both An in-core measurement might be impossible to because various reasons, for instance, high temperature or aggressive environment. Therefore, this article focuses on ex-core neutron flux system placed reflector and optimization detector position. A set experiments were performed LR-0 reactor. The is light water reactor with well-defined field, which can used different material insertion tests testing its influence criticality. modifications cores modelled Monte Carlo codes Serpent KENO. calculations verification criticality course core Further investigation was focused presence distribution core. also verify calculations. Based results article, optimal position detectors proposed.