Radioactive Waste
Radioactive Waste Quick Links
Radioactive Waste Removal Request
Radioactive Waste Removal Requests will now only be accepted through the Safety Management System. Please log in to the SMS, and from the Radioactive Waste tab in the Lab you are registered with, you will find the "Request Waste Pickup" button. Paper tickets will no longer be accepted.
Waste Labels and Containers
There are four categories of waste:
1. Liquid scintillation vials
- Safer type of cocktail (low flammability)
- Other types (high flammability, i.e. toluene, xylene)
2. Bulk liquid (one isotope/liquid jug)
- Aqueous liquid
- Non-Aqueous liquid
3. Dry solid
4. Biowaste (animal carcasses)
- Less than or equal to 111,000 DPM/gram.
- Greater than 111,000 DPM/gram.
To order more waste labels, please email dcon@vt.edu.
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.
AF = AO e -kt
- AF = final activity
- AO = original activity
- k = 0.693/half life in days
- t = time elapsed in days
Simpler method:
AF = AO / 2x
- AF = Final activity
- AO = Original acitivity
- x = Number of days elapsed / half life in days
Radioactive Material Safety Program
This document details the requirements for and expectations of all university use of radioisotopes, source materials and associated equipment. This program provides the information needed to work safely with all radioactive materials and ensures their security and control for use on campus and off-site locations.