Wolseong Nuclear Power Plant, Unusual Detection of Nearby 'Cobalt-60 and Iodine-131'... Source Uncertain

Iodine-131 Detected at Nuclear Power Plant Discharge Outlet for the First Time in 4 Years in Last Year's Environmental Radiation Survey
Cobalt-60 Levels Five Times Higher Than Usual in First Half of Year... "Continued Attention Needed"

▲ Wolsong Nuclear Power Plant Panorama

[Asia Economy Yeongnam Reporting Headquarters, Reporter Park Dong-wook] In last year's environmental radioactivity survey around Wolseong Nuclear Power Plant, although the detected amounts of 'artificial radioactive nuclides' were extremely minimal, unlike previous years, Cobalt (Co)-60 and Iodine (I)-131 were detected at the plant facility's drainage outlet with significant differences depending on the inspection time, raising calls for continued attention.

According to the Wolseong Nuclear Power Headquarters on the 31st, the Radiation Science Research Institute of Kyungpook National University conducted an environmental radioactivity survey last year by collecting 832 samples from 76 points across 24 monitoring targets.

In this survey, radioactive Strontium (Sr-90), Tritium (H3), and Cesium (Cs-137) were detected at extremely minimal levels in biological and water samples from nearby points such as 'Nasan' and 'Naa', consistent with previous years. However, these levels were evaluated as routine and could also be measured in areas outside the nuclear power plant.

However, a notable point in last year's survey was that during the first half-year survey (April 23) at the drainage outlet of Wolseong Nuclear Power Plant Unit 1, Cobalt (Co)-60 was detected at 5.01 becquerels, about five times the average value (1.02 Bq/kg) measured by Kyungpook National University over the past five years, causing concern among investigators.

In the same area, the second half-year survey (October 17) showed a drop to 0.251 becquerels, an extremely minimal level. Cobalt-60 is an artificial radioactive isotope of cobalt, known to be used industrially as a substitute for X-rays and medically for cancer research and treatment.

Additionally, Iodine-131 was detected at 0.102 to 0.127 becquerels during the second half-year survey (December 4 and October 29) at the intake and drainage outlets of Wolseong Nuclear Power Plant. Although these levels are within the average range of the past five years (0.0793 to 0.128 Bq/kg), the fact that it had not been detected in the past three years has drawn attention. Wolseong Nuclear Power Plant reportedly reported this to the Nuclear Safety and Security Commission according to its internal regulations at the time.

A representative from the Radiation Science Research Institute at Kyungpook National University explained regarding the re-detection of Iodine-131, "It is presumed that some of the Iodine-131 administered to patients for thyroid cancer diagnosis or treatment has entered the environment, as seen in surface water samples from Ulsan, a comparison site."

They added, "Cesium (Cs)-137 and Strontium (Sr)-90 are nuclides widely present in the environment due to past atmospheric nuclear tests and the Chernobyl nuclear accident, and are detected regardless of nuclear power plant operation," emphasizing, "Due to the characteristics of the heavy water reactor type Wolseong Nuclear Power Plant, the tritium detected nearby is also at extremely minimal levels and is completely unrelated to human health effects."

Meanwhile, the Wolseong Nuclear Power Headquarters located in Naa-ri, Yangnam-myeon, Gyeongju City, operates five reactors in total: Units 2 to 4 and New Units 1 to 2. Wolseong Unit 1, the second nuclear power plant in Korea following Kori Unit 1, began operation in November 1982, was suspended in May 2017, and was permanently shut down on December 24, 2019.

This content was produced with the assistance of AI translation services.