A Sharper Safety Picture

Posted: July 22, 2013 - 3:19pm | Y-12 Report | Volume 10, Issue 1 | 2013

UPF will provide workers with a more controlled environment in which employees’ exposure levels can continue to decrease.

Imagine working with a radioactive material, like uranium, that’s the consistency of baby powder. How do you ensure the health and safety of employees and monitor their exposure? Now factor in working in facilities that were built as far back as 70 years ago. Y‑12’s Radiological Control, or RADCON, program sets out each day to safeguard site employees, the environment and the public. The Y‑12 program is a recognized leader in worker protection within the Nuclear Security Enterprise.

The Department of Energy sets the maximum annual radiation exposure to 5,000 millirems. Any dose below this limit is assumed to be in the “safe” zone. Just to be sure, Y‑12 sets its annual administrative control level at 1,000 millirems. During 2012, Y‑12 radiological workers received doses well below that level, with an average dose of 22 millirems for people who were monitored for both internal and external radiation exposure.

During Y‑12’s early years, standards for the control and movement of radioactive material within the site were not the same as they are today, which is why the site has uranium legacy issues decades later. Today, a radiological worker is defined as someone who in one year could potentially receive a radiation dose of 100 millirems, the equivalent of about 10 chest X-rays. These workers have many protection tools and analyses available: engineering controls (ventilation systems), radiological work permits (instructions specific to work in radiological areas), personal protective equipment (respirator, gloves), RADCON technicians and bioassay tests (urine and fecal samples), to cite a few.

To monitor for occupational radiation exposure, RADCON has four programs that are accredited by the DOE Laboratory Accreditation Program, or DOELAP: the Lung Counter Program, bioassay Program, Whole body Personnel Dosimetry Program and the Extremity Dosimetry Program. DOELAP implements performance standards for Department of Energy contractor external dosimetry and radiobioassay programs through periodic performance testing and on-site program assessments.

“The Whole body Personnel Dosimetry Program and the Extremity Dosimetry Program determine an individual’s dose due to radiation that is external to the body,” said Lisa Snapp, lead internal dosimetrist at Y‑12. “The Lung Counter and the bioassay programs determine the dose from radioactive material taken into the body through breathing, ingestion or absorption through the skin.”

Through the decades, Y‑12 employees gained knowledge of working with uranium, and process improvements followed. No longer were employees taking breaks in the same areas in which they worked. Requirements changed, monitoring data improved and more personnel were added to the job to monitor safe work practices.

“In the 1980s, we had seven RADCON techs covering the site,” RADCON supervisor Scott Ammons said. He’s one of about 110 technicians who monitor work areas for elevated radiation and contamination levels during hands-on work. “We have more eyes in the field. The equipment we use today alerts us sooner if there’s a discrepancy. With improved monitoring techniques, our exposure level is decreasing.”

Y‑12 has monitored employees with bioassay tests since 1950, and in the late 1990s fecal sampling was added when necessary. “The added sampling is similar to a black-and-white TV from the 1950s,” Snapp said. “You see the picture, but if you look at it on today’s LCD TV, you see a sharper definition of the picture.”

Technician supervisor Stanley “Buzz” Leffew said, “When you consider the improved work planning, engineering controls and the sharing of the knowledge we’ve gained from working with the material, we are providing better RADCON support.”

RADCON support will continue to improve once the Uranium Processing Facility is built. UPF will provide workers with a more controlled environment in which employees’ exposure levels can continue to decrease.