Many analytical techniques in analysing the actinoids involve the use of gloveboxes. Gloveboxes represent the highest level of containment for hands-on access. They are totally enclosed apart from filtered air inlets and outlets thus providing a phsical barrier which allows handling of sample with higher levels of alpha activity than is permitted in fumehoods. Gloveboxes do not provide significant protection from beta gamma radiation although some boxes are equpped with local shielding in the form of lead sheet to reduce the radiation field.
Typically gloveboxes fall into two catergories i.e. wet and dry. "Wet" gloveboxes are used for handling acids and liquors (provoided that they are compatible wit thematerials used to construct gloveboxes) while "dry" boxes are used for handling mainly PuO2 and/or Pu/U oxide powders or pellets.
gloveboxes are used when the total exposed alpha activity would exceed the fumehood limit of 3.7E+06 Bq.
The radioactive material content of a glovebox must be kept to a practical minimum. The total inventory of fissile material allowed in each laboratory is determined with reference to criticality control and indicated on the doors of the labs and on boards inside the labs. Individual limits on gloveboxes are displayed on them.
The controlled area enviromental gamma radiation limit for unrestricted access is 100 µSv hr-1 with a building action limit of 25 µSv hr-1 at which shielding, barriers or, at least, signs are provided as appropriate. The action limit for contact dose is 500 µSv hr-1 beta gamma above which TLD's (thermoluminescent dosimeters), lead loaded gloves and remote handling (in a highly active cell) are progressively required
a) contact clothing (normally a lab coat with clipped or tapped cuffs, safety shoes and socks)
b) film badge
c) safety spectacles
d) rubber gloves ("surgeon's" gloves)
Its at this point where i would have liked to have gone into more detail about the various analytical procedures and methods invloved with analysing the actinoids. However, these methods are controlled by BNFL and therefore I cant publish them.
Author: James Lowrey (document modification date: 20th May 2003)