The risk from the recalled shrimp is "quite low," said Donald Schaffner, a food safety expert at Rutgers University. Cesium-137 is a byproduct of nuclear reactions.

A radioactive isotope known as Cesium-137, or Cs-137, has been detected in some packages of shrimp sold under Walmart's Great Value brand.

The U.S. Food and Drug Administration issued a public warning to not eat certain Great Value shrimp sold at Walmart because of it being possibly linked to contamination with the…