Regulations on radioactive material production may need to be amended to better address public safety, the Atomic Energy Council (AEC) said yesterday after it admitted that radiation levels had increased slightly at National Tsing-hua University (NTHU).
The university-operated radioactive medicine plant changed an ingredient in its production process, causing radiation levels nearby to increase.
“In the most recent routine radiation test, the AEC found that in nearby plants, dust and floating particles near NTHU’s iodine-131 production plant, the content of radioactive iodine had increased,” AEC Department of Radiation Protection deputy director Liu Wen-si (劉文熙) said.
In previous routine checks, iodine-131 would sometimes be found in one of the three samples — plants, dust or air particles — but the last test revealed that all three samples contained iodine, Liu said.
“The council was unaware at first that the production process had been changed … but NTHU later informed us that in an effort to increase production, the school had changed one of the ingredients,” Liu said.
The change in ingredients did not need to be approved by the council as the law does not regulate the ingredients that plants can use in their production, Liu said.
When asked why the change of an ingredient would cause such an incident, Liu said that the school told the AEC that the change induced a pH shift in the process, but he did not know the exact reaction involved because it concerned medical chemistry.
The potential danger did not evolve into a full-fledged hazard as the increase was slight and within the regulated amount. As such, the AEC has asked the school to formulate a plan to improve upon the situation within 14 days, Liu said.
Asked whether NTHU had violated radiation management regulations by implementing such a change, Liu said: “At the moment, we are not ruling that the school violated the regulations.”
“While the procedure of such a production process is regulated by the council, the laws don’t regulate the types of ingredients used … it would be too harsh to say that NTHU had violated regulations,” Liu said.
Iodine-131 is mainly used to treat thyroid cancer, Liu said.
“Because iodine naturally accumulates in the thyroid when absorbed, the radiation in the iodine can kill cancerous cells,” he said.
However, if excessive amounts of the material is released and absorbed by humans, the iodine will similarly accumulate and damage thyroid cells in healthy people, he said.
NTHU dean of research and development Lin Youn-long (林永隆) yesterday told the Taipei Times that it was “incorrect” to describe the incident as a “leak.”
Iodine is produced in a laboratory chamber and during the process, some gaseous iodine would be released into the air after being filtered through carbon, Lin said.
Scientists need to test the nearby environment to make sure the level of iodine does not exceed the council’s maximum safety standard, Lin said.
Lin said the level of iodine at the school would “fluctuate,” but it never exceeded the council’s standards. He also said that the council had warned the school of a “rising tendency” lately.
When asked if the tendency was a result of changes in the production process, Lin said he could not detail the process, but that “it was necessary for the production process to change and improve over time.”