Crud

[Rennhack]

A colloquial term for corrosion and wear products (rust particles, etc.) that become radioactive (i.e., activated) when exposed to radiation. Because the activated deposits were first discovered at Chalk River, a Canadian nuclear plant, "crud" has been used as shorthand for Chalk River Unidentified Deposits.

[Rennhack]

Crud
A colloquial term for corrosion and wear products (rust particles, etc.) that become radioactive (i.e., activated) when exposed to radiation. Because the activated deposits were first discovered at Chalk River, a Canadian nuclear plant, "crud" has been used as shorthand for Chalk River Unidentified Deposits.

http://www.nrc.gov/reading-rm/basic-ref/glossary/crud.html



CRUD: "...an acronym for 'Chalk River Unidentified Deposits.' ...black, highly radioactive substances found on the inside of piping and components at the Chalk River nuclear reactor ... CRUD has now become a standard industry term referring to minute, solid, corrosion products that travel into the reactor core, become highly radioactive, and then flow out of the reactor into other systems in the plant. ... CRUD can settle out in crevices or plate-out on the inside of piping in considerable quantities ... The major components of CRUD are iron, cobalt, chrome, and manganese ... CRUD is a concentrated source of radiation and represents a significant radiological risk because of its insolubility."

(United States Federal Energy Regulatory Commission, Testimony of James K. Joosten, September 15, 1997, pg. 13-14).