Development and application of critical calculation code KENO

KENO is a large code of Monte Carlo critical calculation, compiled by Oak Ridge National laboratory of U.S.A. and widely used in the world. It is improved all the time from the first appearing at 1969. Now it is up to KENO IV, KENO Va. They have great capacity of geometry, can be used in any problems of complex 3-dimension geometric figure, meanwhile, they can use cross section library of Hansen Roach 16 groups or AMPX type with their better ability of cross section. In addition, KENO Va has the characteristic in deal with large groups, which can save computer RAM. The program gives Keff as the main calculation. The paper introduces the major features of KENO program, its improvement, development, micro-computerization and popularized application