The source is fake-newish by the new Twitter standards, but who else would talk about this (even for Halloween)?

Get Ready for a New Chernobyl in Ukraine -- Oriental Review

According to analysts from Energy Research & Social Science [actuallya journal title], there is an 80% probability of a "serious accident" at one of Ukraine's nuclear power plants before the year 2020. This is due both to the increased burden on the nuclear plants caused by the widespread shutdowns of Ukraine's thermal power plants (the raw material they consumed - coal from the Donbass - is in critically short supply) and also because of the severe physical deterioration of their Soviet-era nuclear equipment and the catastrophic underfunding of this industry.

Plus, the Ukrainians are determined to replace Russian fuel assemblies by Westinghouse's product, even if experimental and practical experience has been dire.

the accident rate at Ukraine's nuclear plants has increased 400% since 2010 [...]

In addition to the use of knockoff fuel, the biggest reason for the increased number of incidents at Ukraine's nuclear plants has been the chronic underfunding of the industry. In the 25 years since the collapse of the USSR, literally not a cent has been invested in that sector. But in the meantime, the reactors that have outlived their 30-year lifespan either need to be closed (which would cost money that Energoatom does not have) or have their service life extended [...]

[...] Kiev arbitrarily decided to extend the operation of the reactors back in 2015, but it was not until 2017 - after the fact - that it sent that (pre-approved) program to update the nuclear plants to its neighboring countries and international environmental organizations for study.

This was a simultaneous breach of two UN Conventions that require signatories to obtain public and intergovernmental approval prior to (not after) commencing work at a nuclear power plant [...]

Serious concerns are being raised about the fact that the Ukrainian state agencies responsible for nuclear energy have not yet devised ways to dispose of the spent nuclear fuel and other radioactive waste, now that the service life of the reactors has been extended and given the fact that Ukraine is refusing to use Russian storage facilities.

So the play with nuclear stuff is as incompetent and irresponsible as you could imagine? Trump and Brexiters may envy.