Leaching of actinides and other radionuclides from matrices of Chernobyl “lava” as analogues of vitrified HLW

Highlight
- New data on leaching and chemical alteration of Chernobyl “lava”.
- Unique highly radioactive glass-like material.
- Chernobyl “lava” can be considered as analogues of vitrified HLW.

The paper commemorates the 30th anniversary of the severe nuclear accident at the Fourth Unit of the Chernobyl Nuclear Power Plant. Results of the investigation of radioactive glassy lava-like materials formed as a result of the accident are presented. Leaching of Pu, Am and Cs in distilled water and sodium carbonate solution at 25 °C from matrices of black and brown Chernobyl “lava” is comparable, however, leaching of Cs from black “lava” in seawater at 25 and 90 °C is almost 2 times higher than that for brown “lava”. Chemical alteration of black and brown “lava” in seawater is much more intensive that in distilled water and sodium carbonate solution. Comparison of leaching behavior of Chernobyl “lava” and aged samples of nuclear glass is not clear so far because of the lack of data. Further study of Chernobyl “lava” as analogues of vitrified high level waste (HLW) and possibly, Fukushima's corium is needed.