Benchmark of heat deposition measurement techniques in the SAFARI-1 reactor using MCNP5

In-core calorimetry is a valuable experimental technique for measurement of total nuclear heating rates. This technique is adopted in an experiment performed in the South African First Atomic Reactor Installation (SAFARI-1 reactor). The objective of the experiment is to provide experimental data of nuclear heating for materials: molybdenum and stainless steel (SS 304). The experiment was conducted in core channel B6 at low reactor power, 5 MW. This paper presents results of a Monte Carlo simulation of this experiment by comparison of the calculated (C) to experimental (E) nuclear heating values. Calculations were performed using a Monte Carlo N-Particle (MCNP5) code version 1.4. The amount of heat deposited in core channel B6 using the track length estimate of energy deposition in a cell (F6) in a neutron-photon coupled mode (mode n p) and as well using the pulsed height tally (*F8) which gives the energy distribution of pulses created in a detector. Below the core centreline, relative errors in nuclear heating values for stainless steel range from 11% to 16% compared to a range of 1% to 6% in molybdenum. Above the core centreline, stainless steel exhibits relative errors, from 1% to 19% whereas the relative errors in molybdenum range from 5% to 34%. (author)