U in EM stain

[farmerr@ccmail.orst.edu]

    Alright all you NORM experts, I need your advice.  We are issuing an
    authorization for use of uranyl compounds for electron microscope (EM)
    staining.  Our state NORM regulations do not cite an exempt quantity
    for U, only an exempt concentration (0.05 wt %).  Standard protocol for
    the EM facility, which provides services to a variety of on and
    off-campus clients, is to return stained tissues (embedded in lucite)
    and the mounted sections used in the EM analysis to the client.

    I need to verify that the U concentration in the returned materials
    is below the 0.05 % limit.  Assaying for the amount of U in the
    materials is problematic, since the stained tissues are imbedded in the
    plastic.

    Any suggestions or novel approaches to this problem will be
    appreciated.

    Rainier Farmer
    Radiation Safety Officer
    Oregon State University
    (503) 737-2227