Sa. Bogatov et al., Plutonium isotopes in lava-like fuel-containing masses of the destroyed fourth block of the Chernobyl NPP, RADIOCHEMIS, 41(4), 1999, pp. 402-408
Weight fractions of plutonium isotopes in samples of lava-like fuel-contain
ing masses (LLFCMs) are determined, The experimental values exceed the calc
ulated data in statistically significant measure. The abnormal content of p
lutonium isotopes in LLFCMs is explained by formation of uranium-zirconium-
oxygen phases by the reaction between the plutonium-enriched periphery of t
he fuel pellets with the interior of the zirconium cladding of the fuel rod
in an inert or reducing medium.