hankyoreh

The Korea Atomic Energy Research Institute’s website

A leak of radioactive material discovered in stream soil within the Korea Atomic Energy Research Institute (KAERI) in Daejeon early last month has been attributed to a combination of mismanagement -- including lax operation of facilities -- and design issues with the facilities involved in the leak. With design issues only now discovered well over 30 years after the natural evaporation facilities in question were built in 1982, the institute appears likely to face criticism for mismanagement.

At its 114th meeting on Jan. 31, the Nuclear Safety and Security Commission (NSSC) received a report from the secretariat on findings from an interim investigation launched on Jan. 21 into the leakage of radioactive materials at KAERI. On Jan. 22, the NSSC announced that an incident had taken place in which artificial radioactive radionuclide materials leaked from natural evaporation facilities at KAERI, including cesium-137, cesium-134, and cobalt-60. The natural evaporation facilities are used to evaporate extremely low-level radioactive liquid waste (185 becquerels per liter and under) from the institute to filter the sludge.

The Nuclear Safety and Security Commission (NSSC) blamed the facility operator’s inexperience for a leak of contaminated water that was supposed to evaporate inside the facility. When a faulty filter prevented the water from flowing properly, the operator set the valve on max to increase the water volume instead of immediately replacing the filter. The valve was left at that setting even after the filter was replaced, causing the water to overflow and leak into the machine room.

The operator then poured that water down the drain in the service room, sending it flowing into the storm drain outside the facility. The operator had mistakenly believed that the service room drain was connected to the contaminated water storage tank in the basement. This operator has reportedly been working at the facility since last year. Another factor in the incident were design flaws that allowed water from the collection channel to spill into the machine room and that connected the building’s pipes directly to the storm drain outside.

Investigators also learned that around 50 liters of contaminated water has leaked every time the institute replaces the filter on its natural evaporation facility. Assuming that the filter has been changed 13 times altogether, at an interval of two or so years for the past 30 years, a total of 650 liters of contaminated water has leaked.

After receiving the final report in March, the NSSC plans to hold another discussion about what administrative measures or other disciplinary action should be taken against the responsible parties and what should be done to prevent a recurrence.

By Kim Eun-hyoung, staff reporter

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