However, nuclear reactors generate 100 grams of the substance worldwide each year.
然而，每年全球各地的核反应堆都会产生100克左右这样的物质。
2
Cesium-137, with a half-life of 30 years, is another dangerous substance emitted in a full-scale nuclear meltdown.
核反应堆完全熔解后，会释放出另一种危险物质铯- 137。铯- 137的半衰期为30年。
3
Who is issuing this advisory following reports of people in Japan and elsewhere who are using the substance in response to radiation leaks from nuclear plants in northeastern Japan.