Double Chooz measures antineutrino afterglow from shut-down reactors

Researchers using the Double Chooz experiment in France have made the first quantitative measurement of residual antineutrinos emitted after nuclear reactors shut down, SciTechDaily reported, citing a Physical Review Letters study led by Anthony Onillon and Thierry Lasserre of the Max Planck Institute for Nuclear Physics in Heidelberg. When fission stops, long-lived fragments in partially used core fuel and nearby spent-fuel pools keep decaying and release a faint antineutrino flux that can last months or years. Double Chooz, installed underground about 400 meters from the Chooz plant's two cores, holds more than 30 cubic meters of liquid scintillator that records characteristic double-light signals from antineutrino interactions. Because antineutrinos pass through walls and shielding, the team says residual flux could help inspectors verify reactor status and spent-fuel inventories even when a plant is offline. DOI: 10.1103/dr26-j19g.