Activity Determination

Determining the activity for Radioactive Waste:

• Count an aliquot of liquid waste from each container on a Liquid Scintillation Counter
• Convert CPM/aliquot to uCi/container
  
  CPM/ML / EFFICIENCY = DPM/ML;
  DPM/ML x number of ML's = DPM/container; then
  DPM/container / 2.22 x 10⁶ DPM/uCi = uCi/container
  

Liquid Scintillation Vials (LSV)

• Estimate activity from vial counts

Solid Waste (SW)

• (Total Activity Used - LW - LSV) = SW

Correcting For Decay

A_F = A_O e ^-kt

• A_F = final activity
• A_O = original activity
• k = 0.693/half life in days
• t = time elapsed in days

Simpler Method

A_F = A_O / 2^x

• A_F = Final activity
• A_O = Original acitivity
• x = Number of days elapsed / half life in days

Questions to Radiation Safety Office.