EPJ Web Conf.
Volume 247, 2021PHYSOR2020 – International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future
|Number of page(s)||8|
|Section||Research Reactors and Facilities|
|Published online||22 February 2021|
REACTOR NOISE EXPERIMENTS CONSIDERING HIGH FREQUENCIES IN THE IPEN/MB-01 REACTOR
Instituto de Pesquisas Energéticas e Nucleares Av. Prof. Lineu Prestes, 2242 CEP 05508000 São Paulo, SP, Brasil
Published online: 22 February 2021
Reactor noise experiments at high frequencies (up to 100 kHz) in subcritical configurations have been performed at the IPEN/MB-01 research reactor facility. The core configuration considered a short version of the IPEN/MB-01 core in a 24 × 26 rectangular array of fuel rods. The subcritical configurations considered the control banks totally withdrawn and the moderator poisoned with H3BO3. The boron concentrations were: 286.8 ± 10 and 578.6 ± 10 ppm. The pulses of two 3He detectors in the reflector region were summed and inserted into the IPEN/MB-01 Correlator and the APSD (Auto Power Spectral Density) was inferred through a mathematical model. The analysis reveals that the APSD in this frequency range is best described by a four-mode decay model. According to the two-region two-group (thermal and fast) kinetic model developed in this work, the first two decay modes describe the thermal group and the other two describe the fast group. After a tedious and severe analyses of the least-square fit of the experimental data, it was concluded that the kinetic behavior of the thermal and fast neutrons can be considered uncoupled. The analysis of the experimental data is still in progress and only the thermal group of the case of 286.8 ppm of boron was analyzed and some parameters could be inferred. The most important one so far is the prompt neutron generation time in the core region that could be inferred with a good level of accuracy.
Key words: Reactor Noise / APSD Measurements / Reflected Core Model / Neutron Generation Time / Two-Group kinetic Model
© The Authors, published by EDP Sciences, 2021
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.