Japanese Prime Minister Naoto Kan has warned of danger, following four explosions at the plant since Friday's earthquake and tsunami.
The authorities say radiation levels are now high enough to affect human health and people within 30km of the facility have been urged to remain indoors.
Stephanie Cooke, who is also the editor of the publication Nuclear Intelligence Weekly, says that is probably not wide enough.
She told Checkpoint she is also concerned about reports that workers who have been taking care of the cooling operation are evacuating the site.
