Traces of plutonium not considered a riskTraces of plutonium have been found in seawater around the Korean Peninsula though they are not higher than levels detected in the past, a state nuclear safety body said yesterday.
The Korea Institute of Nuclear Safety (KINS) said minuscule amounts of plutonium 239-240 have been detected in 12 of 23 sites checked from March 23 to April 6.
Concentration levels were roughly the same as readings collected from 2005 onward, the institute said, adding that the levels were too small to pose any serious health risks to humans.
Sites that reported plutonium isotopes are Jeju Island in the South Sea, Dokdo and Ulleung Island in the East Sea and several areas along the country’s eastern and southern coasts.
Plutonium, a very heavy radioactive isotope with a half-life of 24,000 years, is not found in nature and is a by-product of a nuclear fission reaction.
“The plutonium that is being picked up was probably released into the atmosphere by nuclear tests conducted in the 1950s and 1960s by such countries as the United States, the Soviet Union and China,” said Yun Ju-yong, a KINS radiation expert. Tests conducted by France in the South Pacific may have also contributed to the plutonium in the water.
He said, however, that judging by the amount detected, the plutonium probably did not come from Japan, although more tests need to be carried out.
KINS, meanwhile, said that with radionuclides being found in the water and air throughout the country, it will step up monitoring and make all findings public.
South Korea first reported radionuclides in the air on March 28, more than two weeks after the stricken Fukushima nuclear station in Japan started releasing radioactive particles into the environment.
한글 관련 기사 [연합]
"일부 바닷물서 플루토늄..평소 수준"
2005~2010년 조사 당시 농도와 비슷
우리나라 연근해 일부 지역 바닷물에서 방사성 물질인 플루토늄(PU-239, PU-240)이 검출됐으나, 이는 이번 일본 후쿠시마 원전 사고로 추가 유입된 것이 아니라는 분석 결과가 나왔다.
한국원자력안전기술원(KINS)은 지난달 26일부터 이달 6일까지 근해 및 원해 21곳의 표층 해수와 제주도 동·남쪽 원해 50m 깊이 해수를 모아 분석한 결과, 0.00280~0.00414mBq/㎏의 플루토늄이 확인됐다고 밝혔다.
최근 6년(2005~2010년)간 한반도 주변해역 21개 지점에서 표층 해수 검사 시 농도 범위인 0.00190~0.0180mBq/㎏와 비교해 큰 차이가 없다는 게 기술원 측의 설명이다.
그러나 기술원은 일본 원전 사고의 영향을 지속적으로 감시하기 위해 해마다 두 차례 진행하던 해양방사능 조사를 매월 하는 등 상시 감시 체계를 유지한다고 덧붙였다.