RIBOT-5, 0-D Burnup for 5 Group BWR or PWR Lattice

1 - Nature of physical problem solved: Same as RIBOT - Calculation of burn-up dependent nuclear constants for pressurized or boiling water reactors in zero dimensional model. Four neutron groups are used. Microscopic constants are fitted from SOFOCATE and MUFT. Disadvantage factors are calculated with Amouyal-Benoist method. Cluster factors have been fitted by a series of PDQ. The constants have been carefully calibrated by comparison with experiments (enriched UO2, UO2-PUO2, UO2-THO2 lattices in H2O). An extra thermal group has been included (between.2 eV and.625 eV) - it is particularly suitable when Pu or burnable poisons are present. 2 - Method of solution: Same as RIBOT - Extensive use of the fitting method has been made in order to decrease the calculation time and the computer memory. The extensive comparison with experiments ensures a good precision of the results. Standard error of the eigenvalues (80 experiments) is.7 per cent delta - k. 3 - Restrictions on the complexity of the problem: Same as RIBOT - Use should be limited in the range of lattices where an effective comparison with experiments has been made - 1 < VM/VU < 4, 1 < Enrichment of U-235 in percent < 6, 0 < Enrichment of Pu in per cent < l, .4 cm < r-zero < .8 cm