Post-accident survey of the unit 4 reactor of the Chernobyl nuclear power plant

On the Possible Magnetic Mechanism of Shortening the Runaway of RBMK-1000 Reactor at Chernobyl Nuclear Power Plant

“…First, note that the bursting depressurization of reactor and flying reactor's away apart indicated, most probably, on rather homogeneous increase of neutron density. 11 Moreover, already in the pioneering papers by Fermi, 12 the allowance for spatial inhomogeneity under condition of a small positive excess reactivity was shown to suppress high spatial harmonics. For a high enough reactivity, the high spatial harmonics grow up, at least, slower that the fundamental one.…”

The key role of sample analysis in Fukushima Dai-Ichi decommissioning, debris management, and accident progression investigation

“…The first analysis of highly radioactive samples collected in premises below the burned-through reactor's base plate showed that fuel fragments and molten corium reacted with concrete and serpentinite and formed a highly radioactive silicate melt (called silicate-rich corium or "Chernobyl lava"). Three main sources of "lava" were observed during visual inspections of the destroyed reactor and related dose rate measurements (Borovoi et al, 1990;Kiselev et al, 1992;Pazukhin, 1994). EPMA, XRD, Raman spectroscopy, and FIBassisted TEM of inclusions extracted from silicate matrices of Chernobyl "lava" and "pumice" showed the presence of U-Zr-O solid solutions of various crystalline structures, UOx (relicts of a fuel pellet), metallic inclusions, and uranium-rich artificial zircon (Zr 1x U x )SiO 4 (Anderson et al, 1993;Trotabas et al, 1993;Burakov, 2020).…”

U.S.-Russian experts NATO collaborative research grant exchange visit meeting on excess Pu ceramics formulations and characterizations

“…The "lava" spilled and hardened under the reactor~,15-17'j.A black and brown "lava" may be distinguished, as well as "porous ceramics" a product of brown "lava" coming into contact with water. The volume of visually studied "lava" exceed 190 m3, the quantity of fhel bound with them , in the dissolving form and solid inclusions, accounted, presumably, from 11 to 33°/0of the whole fuel volume of 4th Unit [17].…”