MCNPX-CINDER90 Simulation of the APT Radionuclide Production by ghkgkyyt


									                       MCNPX-CINDER’90 Simulation of APT
                 Radionuclide Production and Decay Heat Experiments

           C.T. Kelsey, J.L. Ullmann, K.A. Woloshun, G. Muhrer and E.J. Pitcher
           Los Alamos Neutron Science Center, Los Alamos National Laboratory,
                       P.O. Box 1663, Los Alamos, NM 87545, USA

Radionuclide production and decay heat experiments were run in the mid 1990s as part of the
Accelerator Production of Tritium (APT) project for the purpose of validating transmutation
calculations performed using the LAHET, MCNP and CINDER’90 codes. Since the
experiment reports comparing code and measurement results were released LAHET and
MCNP have been combined to form MCNPX and development of MCNPX and CINDER’90
has continued. The results of radionuclide inventory calculations using MCNPX and
CINDER’90 are used for safety basis and design calculations and a large part of the
foundation for their validity remains the APT experiments. Software quality management
requires verification that modified code continues to perform as expected. Here the most
recent versions of MCNPX and CINDER’90 were used to simulate the experiments. Both
MCNPX’s default Bertini physics process and the recently added CEM03 process were
considered. Calculation and measurement results were compared. MCNPX-CINDER’90
agreement with measurement using either Bertini or CEM03 physics is comparable to that of
the original LAHET-MCNP-CINDER’90 simulations. In general individual radionuclide
activities appear to be predicted within a factor of two about half the time and decay heat to
within 10 percent.

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