mr. kleiman, when we hear about risk and how the risk is manifested, do we know...this an immediate risk? are the people who are there nearby immediately see signs of radiation poisoning or exposure or this something that only surfaces eventually? >> those workers in the plant themselves, if they're exposed to significant levels of radiation, will experience what's called acute radiation syndrome. these are at much higher levels than what's been reported since so far, but symptoms such as nausea, gastrointestinal distress and a change in their bone marrow. these occur at doses of about 8.8 sieverts to one sievert. that's not been reported so far but we can presume that there are levels inside the plant, hopefully regions that the plant workers are not in right now, where those levels are present. for the general population, as distance increases, radiation exposure drops dramatically and based on the figures we've been given it's unlikely anyone would have any kind of symptoms from radiation exposure outside of the immediate vicinity of the plant. >> ifill: we are a