Pressurized water test loop at the FR2 research reactor

A pressurized water test loop was built at the FR2 research reactor of the Nuclear Research Centre at Karlsruhe. The loop is for the forced convection cooling of irradiation specimens with high heat flux densities, especially for fuel specimens. The loop was built originally for the irradiation of MTR-type fuel plates, but it can also be used for irradiating specimens of other types provided they meet certain geometric and thermodynamic limiting conditions. The basic conception and the design of the loop, the design of the rigs used for the irradiation of fuel plates, some safety aspects and, finally, the experience accumulated during the test phase and during 2.5 years of in-pile operation are discussed. (GE)