https://www.iaea.org/newscenter/focus/chernobyl/faqs
10. Is it safe to visit the area now?
One may certainly visit the Chernobyl area, including even the exclusion zone, which is a 30 kilometre radius surrounding the plant, all of whose reactors are now closed. Although some of the radioactive isotopes released into the atmosphere still linger (such as Strontium-90 and Caesium-137), they are at tolerable exposure levels for limited periods of time. Some residents of the exclusion zone have returned to their homes at their own free will, and they live in areas with higher than normal environmental radiation levels. However, these levels are not fatal. Exposure to low but unusual levels of radiation over a period of time is less dangerous than exposure to a huge amount at once, and studies have been unable to link any direct increase in cancer risks to chronic low-level exposure.