Is there any known cure for long term effects caused by the russian chernobyl accident?

Get the facts. There are militants who would like to make you think that if you were exposed, you should feel sick all the time. This is politics, it is not true, and it can actually cause symptoms. The scientific studies have demonstrated little disease apart form an increase in low-grade thyroid cancers even among those most heavily exposed. If you feel ill, look for a different cause with your doctor's help.
No. Cells remember genetic damage caused by ionizing radiation. Minimization of additional radiation exposure is reasonable. Mri imaging is preferred.