Recently, the MERCSF-N computer program was developed to calculate RR for fast neutrons transmitted through homogeneous mixtures and composites (El-Khayatt and El-Sayed Abdo, 2009).
El-Khayatt (2011) reported a new program, known as the NXcom program, to calculate both fast neutrons effective removal crosssections and c-rays (or X-ray) attenuation coefficients for any homogeneous mixture or composite.