MCNPTM Monte Carlo: a precis of MCNPKenneth J. AdamsTransport Methods Group, XTM MS B226Los Alamos National Laboratory, Los Alamos, NM, 87545ABSTRACTMCNPTM* is a general purpose tiiree-dimensional time-dependent neutron, photon, and electron transport code. It ishighly portable and user-oriented, and backed by stringent software quality assurance practices and extensive experi-mental benchmarks. The cross section database is based upon the best evaluations available. MCNP incorporatesstate-of-the-art analog and adaptive Monte Carlo techniques. The code is documented in a 600 page manual1 which isaugmented by numerous Los Alamos technical reports which detail various aspects of the code. MCNP representsover a megahour of development and refinement over the past 50