New measurement technique improves nuclear data critical for reactor fuel
Scientists have developed a more precise way to measure a key nuclear reaction in plutonium-239, addressing a decade-long priority gap in reactor safety data. The advance matters for nuclear utilities and policymakers because accurate cross-section measurements are essential for safe operation of fast reactors and mixed-oxide fuel systems worldwide.
Originaltitel: Multi-section fission ionization chamber for measurement of <sup>239</sup><em>Pu</em>(<em>n</em>, γ) reaction in fission tagging method
<p>The Pu-239(n, gamma) reaction cross section is very important for operation of both thermal and fast reactors, when loaded with MOX fuels. According to the NEA/OECD High Priority Request List the precision of cross section data for this reaction should be improved. The cross section of (n, f) reaction is much higher compared to (n, gamma) for this isotope. In such conditions the fission tagging technique could be applied to identify the fission background. In the past, this technique was successfully used for capture measurements at the n_TOF facility at CERN. The multi-section fission ionization chamber was constructed and used in the combination with Total Absorption Calorimeter (TAC) for detecting gamma rays for the precise measurement of Pu-239(n, gamma) reaction cross section at the n_TOF facility.</p>