A claim: radioactivity can be reduced by bacteria. See this link:

http://pages.csam.montclair.edu/~kowalski/...2vysotskii.html

Radioactive Cs-137 is mostly responsible for meltdowns of spent reactor fuel.

Ludwik Kowalski (see Wikipedia)
.

The claimed observation has been published in a peer-reviewed article where?
The claimed observation has been replicated where?

Depending on biochemical activity and assay technique, it is entirely possible that the cesium is being preferentially accumulated in a part of the container not being fairly surveyed by the ongoing experiment. Therefore details of the experimental setup are crucial even if the authors of the claims are wholly fraudulent. The observation protocol has been described in detail where?

Extraordinary claims require extraordinary support.

Edit.