The mission was planned to past two yrs, but as of May 2018 the probes were still running at in excess of double the envisioned mission lifetime. Having said that, gas reserves are running low and also the probes will very likely retire in another couple of years. The Chernobyl https://radiationzonebetweenearth82087.signalwiki.com/1432136/radiation_zones_on_earth_an_overview