DOSIMETRY DEMONSTRATION
Debbie Butler demonstrates how the radiation levels recorded by a optically stimulated luminescence dosimeter are recorded with a portable dosimeter reader.

REDSTONE ARSENAL, Ala. -- A bit of Redstone Arsenal technology is now on the ground in Japan, helping to ensure the safety of Soldiers and other U.S. government personnel entering radiation contaminated areas of the country - known as the Warm Zone and the Hot Zone -- to conduct search and rescue, and health and safety missions.

The Army Dosimetry Center, part of the Aviation and Missile Command's Test Measurement and Diagnostic Equipment Activity, is providing radiation detection support to the Pacific Command in Japan as part of Operation Tomodachi. USATA support began March 18, after it was determined that the March 11 earthquake and consequent tsunami had caused damage to Japanese nuclear power plants, resulting in the leakage of radiation. Since then, radiation levels in Japan have continued to rise.

The Army Dosimetry Center sent 2,000 Optically Stimulated Luminescence dosimeters and a portable dosimeter reader to Army Public Health Command personnel on the ground at Camp Zama, Japan, in support of PACOM.

"These dosimeters measure external radiation exposure," Bill Harris, chief of the Army Dosimetry Center, said. "They read beta, gamma, X-ray and neutron radiation.

"These particular dosimeters and dosimeter readers are actually new technology. Our current technology is a thermoluminescence dosimeter that has to be returned to our lab at Redstone so that we can read the radiation level. With the new technology, the dosimeters can be read in the field with a portable reader. The new technology can be monitored in theater and read on a daily basis."

The Army Dosimetry Center's support for the new OSL technology was accredited in 2008. When worn, it records the amount of individual radiation exposure. The dosimeter can be read in the field at any time with a portable dosimeter reader located at an Army medical clinic. If the radiation reading is above the minimal established dosage level, the dosimeter is returned to the Army Dosimetry Center at Redstone for an official "dose of record" reading. The exposed person is not allowed back into the suspected radiation area. If the radiation reading is at a safe level, the dosimeter can continue to be used.

The OSL dosimeters, known as whole-body dosimeters, are 2 1/2 by 1 1/4 inches in size and are worn on a person's body between the neck and the waist. They are commercial, off-the-shelf technology and are used in hospitals, nuclear plants and other places where radiation levels must be monitored. The dosimeters can be used for up to three months in the field before they are returned to Redstone for a dose of record reading.

The Army Dosimetry Center maintains inventory records and supplies dosimetry equipment throughout the Army as requested. In addition to providing dosimetry support, the Army Dosimetry Center also maintains all dosimetry related records.

"We have a database that dates back to 1954 and includes more than 12 million records," Harris said.

The center, which has been accredited by the National Voluntary Laboratory Accreditation Program since 1986, has 600 customers worldwide. The center's annual workload is in excess of 200,000 dosimeters. Soldiers, Army civilians and contractors in every state as well as in Germany, Korea, Iraq, Kuwait and Afghanistan have access to dosimeters if they work in an area where radiation levels could rise higher than normal standards.

Other customers include the Secret Service, NASA, Defense Logistics Agency and National Security Agency.

"Army hospitals are our biggest customers," Harris said. "Dosimeters are worn by physicians and any hospital personnel who work with diagnostic machines or radioactive material. They are also worn by Soldiers in Iraq and Afghanistan who work with mobile vehicle cargo inspection systems used at checkpoints. These systems use radiation such as X-rays to get images of what's inside trucks."

In regard to support in Japan, the Army Safety Office requested the Army Dosimetry Center's involvement as soon as it was discovered that radiation was leaking from the Fukushima Daiichi reactors. The Army Dosimetry Center's Andrew Brady, Gabriel Lockwood, Debbie Butler and Janie Bryant, and about 10 other employees took the lead in making sure the dosimeters and the dosimetry reader were shipped quickly.

"We got the call right in the middle of changing our technology," Harris said. "At the end of fiscal year 2010, we received funding to purchase new technology for overseas contingency operations. But instead of sending it to Afghanistan, Iraq or Kuwait, we made the first shipments to Japan."

The Army Dosimetry Center was in the process of establishing two satellite dosimetry laboratories in Germany and Korea when the Japanese earthquake struck. Original plans were to put a 200-capacity dosimeter reader in Germany and Korea and to use 10 single capacity readers at forward operating bases in Iraq, Afghanistan, Kuwait or other locations as required. When the Japan incident occurred, a single capacity reader was sent in an emergency shipment to Japan along with the 2,000 dosimeters.

"The equipment was here and available and U.S. operations in Japan needed it," Harris said. "We had an enormous team effort among our employees and other employees in our organization that helped make the shipment to Japan happen."
Before the shipment was sent, each dosimeter had to be tagged, inventoried and tested.

"We had to ship the first 1,000 dosimeters to the U.S. Army Public Health Command in Maryland because FedEx into Japan was shut down," Brady said. "A team from the Public Health Command got those to the Camp Zama medical clinic operating within PACOM. Then, a couple days later, we were able to send the second shipment of 1,000 dosimeters by FedEx into Japan."

All Department of Defense personnel entering the warm zone (within 125 miles of the nuclear power plants in Sindea) or hot zone (within 50 miles of the plants) must process through the Army's medical clinic at Camp Zama, where they are equipped with a dosimeter.

Other monitoring is also ongoing at the Camp Zama base to ensure air quality levels remain safe. As the nuclear situation evolves, the Army Dosimetry Center is participating in regular teleconferences to discuss radiation health issues in Japan.

"The situation is constantly evolving," Harris said. "The Army is being very conservative in the amount of radiation dose the individuals are allowed to take in. That level is 300 millirem. It is not harmful, and statistics show that 40 years from now the individual will not have any health-related issues associated with an exposure at that level."

Page last updated Fri September 30th, 2011 at 11:10