[ransomnote]

More at link. THere aren't any rules for how often stored radioactive materials are inspected. This container had not been opened in 26 years and radioactive decay probably resulted in helium, pressurizing the container. Reading the whole thing, it's just sad that the public is at the mercy of the nuclear industry. Protection offered by government to rebut regulation and oversight by the public has produced an industry lacking professional standards and knowledge and it shows. The recent Hanford (WA) "accident" reflects similar backward thinking and management.

[ransomnote]

A few months ago, a 400 foot hole opened up in a tunnel containing rail cars filled with radioactive waste (Hanford, WA). But it’s not the only problem there and just glancing around I found this from 2 years ago:
“On Dec. 10, radioactive contamination was found on the elbow of a worker after the suit had been removed. It was one of several incidents at the Plutonium Finishing Plant during the past six months, including incidents of skin contamination.”
http://www.tri-cityherald.com/news/local/hanford/article50600355.html

[Carl Vehse]

"The powdery substances had been encased in a double-wrapped plastic bag placed inside the container, whose lid was fastened with six bolts. When one of the workers opened the lid, the black powder sprayed out under pressure, exposing the men to radiation."

Sounds like there may have been some residual moisture and/or nitric acid left in the powder, and radiolysis of the moisture by the plutonium's alpha radiation resulted in the production of hydrogen or nitrogen oxide gas. The gas pressure in the sealed container caused some of the radioactive powder to blow out when the lid of the container was unbolted. The main danger is worker inhalation of the plutonium dust as blew out of the container. External radiation is minor for that amount of plutonium or uranium.