Submission Title
Presentation Type
Invited
Start Date
18-12-2018 11:00 AM
Abstract
Recently, a number of reactor-physics experiments were conducted at the University of Wisconsin Nuclear Reactor (UWNR) using a set of 7 micro-pocket fission detector (MPFD) probes and 3 resistance temperature detector (RTD) probes. The UWNR core is a TRIGA-fueled, MTR conversion using 2x2 fuel bundles separated by coolant channels. Each MPFD probe contained 4 detectors, and each RTD probe contained 6 detectors, all arranged uniformly along the active fuel height. These probes were placed in four different configurations to measure fluxes and temperatures in every accessible coolant channel for a variety of steady-state and transient operations. Relative fluxes can be inferred from multiple foil-activation measurements made in a reference location. Steady-state experiments were performed at multiple powers between 100 kW and 500 kW and with several control rod configurations. Transient experiments included ramps of different periods, square waves of different final powers, and pulses, which lead to powers close to 1 GW over short (~10 ms) durations. An initial assessment of the experiments indicated that approximately 17 of the 28 MPFDs functioned as expected, with some malfunctioning MPFDs in each probe. For all but the reactor-pulse experiments, two probes were operated in pulse mode, while the others were operated in current mode. All probes were operated in current mode for the reactor pulses. A formal evaluation of the measurements is underway and will form part of a planned, evaluated benchmark experiment for inclusion in the International Handbook of Evaluated Reactor Physics Benchmark Experiments.
Recommended Citation
Roberts, J. A.; Ochs, T. R.; Nichols, D. M.; Fu, W.; Cheng, Y.; Boyington, J. C.; McGregor, D. S.; Wilson, P. P.H.; Agasie, R. J.; Edwards, C. S.; and Park, Y-H. (2018). "Preliminary Assessment of Steady-state and Transient Reaction-Rate Measurements at the University of Wisconsin Nuclear Reactor," Symposium on Advanced Sensors and Modeling Techniques for Nuclear Reactor Safety. https://newprairiepress.org/asemot/2018/fullprogram/31
Preliminary Assessment of Steady-state and Transient Reaction-Rate Measurements at the University of Wisconsin Nuclear Reactor
Recently, a number of reactor-physics experiments were conducted at the University of Wisconsin Nuclear Reactor (UWNR) using a set of 7 micro-pocket fission detector (MPFD) probes and 3 resistance temperature detector (RTD) probes. The UWNR core is a TRIGA-fueled, MTR conversion using 2x2 fuel bundles separated by coolant channels. Each MPFD probe contained 4 detectors, and each RTD probe contained 6 detectors, all arranged uniformly along the active fuel height. These probes were placed in four different configurations to measure fluxes and temperatures in every accessible coolant channel for a variety of steady-state and transient operations. Relative fluxes can be inferred from multiple foil-activation measurements made in a reference location. Steady-state experiments were performed at multiple powers between 100 kW and 500 kW and with several control rod configurations. Transient experiments included ramps of different periods, square waves of different final powers, and pulses, which lead to powers close to 1 GW over short (~10 ms) durations. An initial assessment of the experiments indicated that approximately 17 of the 28 MPFDs functioned as expected, with some malfunctioning MPFDs in each probe. For all but the reactor-pulse experiments, two probes were operated in pulse mode, while the others were operated in current mode. All probes were operated in current mode for the reactor pulses. A formal evaluation of the measurements is underway and will form part of a planned, evaluated benchmark experiment for inclusion in the International Handbook of Evaluated Reactor Physics Benchmark Experiments.
