Measurement of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter

Measurement of neutron flux distribution of the Static Critical Experiment Facility (STACY) heterogeneous core in the Nuclear Fuel Cycle Safety Research Facility (NUCEF) in Japan Atomic Energy Research Institute (JAERI) by a position sensitive proportional counter (PSPC) was performed. As a result of measurement, the neutron flux distribution data with good statistical precision in critical and subcritical state of the STACY was obtained by the PSPC. The position precision of the PSPC is found to be less than ±1.3 cm from the results of position calibration measurement. And the neutron flux distribution at the location of PSPC was calculated by using the continuous energy Monte Carlo code MCNP. The difference between calculation result and measurement result was within 11% in the range from half height of critical solution level to height of critical solution level. The calculation result was in good agreement with the measurement result with respect to the shape of neutron flux distribution. (author)