Older Linear Accelerators with Depleted Uranium Counterweights

Varian low/single photon energy linear accelerator machines manufactured in the 1970’s through the early 1990’s often contain depleted uranium shielding (also referred to as counterweights), a radioactive material that must be handled appropriately during the removal and disposal of this equipment.

NRC regulations require such material to be disposed of properly.

Below is a list of machines that require special handling for removal and disposal.

• Varian Clinac 4 linear accelerators (manufactured from 1972 to 1990)
• Varian Clinac 4/80 linear accelerators
• Varian Clinac 4/100 linear accelerators
• Varian Clinac 6X linear accelerators (manufactured from 1975 to 1978)
• Varian Clinac 6/100 linear accelerators (manufactured from 1979 to 1989)
• Varian 600C’s up to serial number 172 (manufactured from 1989 to 1993)

While the amount of depleted uranium counterweights can vary per machine, here is a typical amount found in Varian Clinac 6/100’s.

The amount in these  DU counterweights is as follows:

• Primary collimator – 96 lbs.
• Secondary collimator – 300 lbs.
• Faceplate shield:- 17 lbs.
• Gun shield disks (3) – 40 lbs. x 3

Total is 533 lbs.

Disposal of this material by low waste radioactive material disposal companies can range in price, and is often quoted on a per pound basis.  When the material is picked up, the facility will receive a certificate of disposal.
Transportation of such hazardous material also requires a special license.

Depleted uranium counterweights are one among many factors that make removing older linear accelerator systems so complex. When faced with this situation, it’s important to work with a reputable linac specialist. For over 18 years, ROS has been safely and professionally removing and disposing linear accelerators and other heavy, hard-to-remove medical equipment.  If you are in need of radiation therapy equipment disposal services, or any other radiation oncology equipment removal services, please reach out to one of our qualified team members to see how ROS can help you today.

About Radiology Oncology Systems

Radiology Oncology Systems, headquartered in San Diego, California, provides medical equipment solutions to customers worldwide, including hospitals, clinics, veterinary practices, OEMs, and other equipment and service providers. ROS specializes in CT, MRI, nuclear medicine, linear accelerator, and oncology equipment, and also sells related upgrades, products, and accessories. Radiology Oncology Systems is a US distributor of CYRPA patient positioning lasers and the SafeCT dose-reduction software system. For more information, please visit www.OncologySystems.com.