22,000 becquerels measured in worker’s lungs
Sources at Japan’s science ministry have told NHK that up to 22,000 becquerels of radioactivity have been detected in the lungs of a worker accidentally exposed to radioactive materials at a nuclear research facility.
The worker is one of 5 who were exposed to the contaminants on Tuesday at the Japan Atomic Energy Agency’s Oarai Research and Development Center in Ibaraki Prefecture, northeast of Tokyo.
The workers were inspecting fuel storage containers when a bag containing a powdered radioactive substance tore open, spilling its contents and contaminating the men’s gloves and protective clothing.
The Agency had said at the time that up to 24 becquerels had been detected in the nasal passages of 3 of the workers.
The science ministry said the maximum level of 22,000 becquerels was logged when the workers were rechecked by a different machine.
The country’s Nuclear Regulation Authority secretariat says the nuclear material detected was plutonium 239.
All 5 men have been taken to the National Institute of Radiological Sciences in Chiba City, near Tokyo, for more detailed examinations.
The Executive Officer of the National Institutes for Quantum and Radiological Science and Technology, Makoto Akashi, says he has never heard of 22,000 becquerels being detected in a human body in Japan.
Akashi says the figure, if accurate, is quite high.
He says the impact on the worker’s health will vary depending on the type of nuclide that entered his body.
Expert points at possible complications
A medical expert says he thinks that the worker will survive the exposure but that he may have future health problems.
Keiichi Nakagawa, Associate Professor of the University of Tokyo, said that this is the first case in Japan where 22,000 becquerels of radioactivity has been measured in a human body.
Nakagawa said he assumes that the agency’s officials based their calculation on the worst case scenario of the worker continuing to be affected by radiation over the next 50 years without receiving any treatment.
He said 12 sieverts of radiation would be fatal as a single external exposure. But he said that the health impacts of an internal exposure would emerge over 50 years.
Nakagawa noted that in some cases, leukemia patients are exposed to a total of 12 sieverts of radiation during therapy.
He said that he expected that the worker will recover with treatment to expel the contaminants.
But the expert said if radioactive materials stay in the worker’s body for a long time, there is a possibility that he may develop pneumonitis that causes breathing difficulties or other conditions.
Workers exposed to radiation at facility
An accident at a nuclear research facility near Tokyo has led to 5 workers being exposed to radioactive substances. One was found to have 22,000 becquerels of radioactive contaminants in his lungs.
The 5 workers were inspecting fuel storage containers on Tuesday at the Atomic Energy Agency’s Oarai Research and Development Center in Ibaraki Prefecture.
A bag inside a container ripped open, spilling its contents of powdered plutonium, uranium and other material. The substances contaminated the men’s protective clothing and gloves.
On Wednesday, the agency checked the workers with a device that measures radiation emitted from the body.
The highest reading they detected was 22,000 becquerels of plutonium-239 in the lungs of one worker.
The exact level of his exposure remains unknown.
An agency official explained that this figure amounts to 12 sieverts of internal exposure over 50 years. The official did not rule out future health problems for the man in his 50s, who was reportedly closest to the bag when it ripped.
The agency gave the workers medical treatment to expel the contaminants, and then transferred them to the National Institute of Radiological Sciences in Chiba city for further checks.
The agency says the spill did not affect the environment outside the research facility.
The exact level of the 4 other workers’ exposure remains unknown.
The Nuclear Regulation Authority will examine the agency’s safety measures after it provides a report on the accident’s cause.