Moderation Factor Of Some Fuel Plate Type Models

Fuel plate type is one of the fuel types which is used in the research reactors and also in the isotop production reactors. The claddings area of this fuel plate type is bigger than another fuel type, so using of this fuel plate type is more interesting because the heat, which is produced by the fission process and also g heating, will be better transferred into the coolant. It means it is possible to get an high order of neutron flux. Based an this reason some factors, i.e. the enrichment Of 235U, Uranium density, mixing material in the meat region and also in the cladding, moderation ratio, must be calculated. The moderation factor has important meanings, i.e. the prismatic block fuel method would be lthe optimal using of the fuel element. The negative reactivity coefficient is required to fulfill the safety aspect. The moderation factor depends on the water volume between the fuel plates. In this paper will be discussed the moderation factor/ratio of the fuel plate type which has 15, 17, 19, 21, 23, 25, 27, 29, and 31 fuel plates with the some dimension except the cooling gap. The MIMS-D4 code was used for the calculation. The calculation showed that the fuel plate types, which is build until 23 fuel plates, area still over moderated condition. The reactivity cefatin of the above plate type is still negative