Physics investigations of a compact simulation of a large fast breeder reactor

SNEAK-10 was the first SNEAK assembly devoted to the investigation of certain neutronic properties of breeder reactors with a nominal power approximately 1200 MWel. The investigations were concentrated on flux tilts and related mutual control rod interactions, occuring upon changes of control insertion dephts. As the physical size and fuel inventory of such reactors significantly exceed the capacity of SNEAK the investigated cores had to be compacted by a factor of approximately 2, without affecting the phenomena of interest. This was achieved by the use of densified compositions without sodium and adequate reduction of the physical dimensions. Lacking sufficient amounts of plutonium, uranium fuel was used in all investigated configurations. The measured and calculated results indicate to what extent various claculational methods are able to predict criticality, control rod worths and flux distributions in large fast reactors. In particular they show where the use of a synthesis method or a direct three-dimensional calculation is advantageous. The KFKINR cross section set was used as a data base. (orig.) 891 RW