Method of determining the amount of an isotopic mixture of noble gases present as a tag in a nuclear reactor fuel element

摘要

A predetermined small amount of krypton-85 is added to an isotopic mixture employed as a tag to identify a failed fuel element before this mixture is inserted into the void volume of the fuel element. The exterior of the plenum is gamma scanned and the reading obtained compared with the reading obtained by gamma scanning an element of the same configuration known by destructive examination to have contained an effective amount of isotopic mixture.