후쿠시마 원전 사고: 처리수의 삼중수소 수준이 일본의 운영 한계보다 낮습니다

International Atomic Energy Agency (IAEA) has confirmed that the tritium level in the fourth batch of diluted treated 물, which Tokyo Electric Power Company (TEPCO) started discharging on 28 February 2024, is far below the Japan’s operational limit.

Experts stationed at the site of the Fukushima 핵무기 힘 station (FDNPS) took samples after the treated 물 was diluted with 바닷물 in the discharge facilities on 28 February. The analysis confirmed that the tritium concentration is far below the operational limit of 1,500 becquerels per litre.

Japan is discharging the treated 물 from the FDNPS in batches. The previous three batches – a total of 23,400 cubic metres of 물 – were also confirmed by the IAEA to have contained tritium concentrations far below operational limits.

Since the accident in 2011, 물 is needed to continually cool the melted fuel and fuel debris at the Fukushima Daiichi NPS. In addition to the 물 pumped in for this purpose, groundwater also seeps into the site from the surrounding environment, and rainwater falls into the damaged reactor and turbine buildings. When 물 comes in contact with melted fuel, fuel debris and other radioactive substances, it becomes contaminated.

The contaminated 물 is 처리 된 through a filtration process known as Advanced Liquid Processing System (ALPS) which uses a series of chemical reactions to remove 62 radionuclides from contaminated water before being stored. However, tritium cannot be from the contaminated water through ALPS. Tritium can be recovered when it is highly concentrated in small amounts of water, for example at 핵무기 fusion facilities. However, the stored water at the Fukushima Daiichi NPS has a low concentration of tritium in a large volume of water and so the existing technologies are not applicable.

Tritium is a naturally occurring radioactive form of hydrogen (half-life 12.32 years) that is produced in the atmosphere when cosmic rays collide with air molecules and has the lowest radiological impact of all naturally occurring radionuclides in seawater. Tritium is also a by-product of operating 핵무기 power plants to produce electricity. It emits weak beta-particles, i.e., electrons, with an average energy of 5.7 keV (kiloelectron-volts), which can penetrate about 6.0 mm of air but cannot penetrate the body through human skin. It may present a radiation hazard if inhaled or ingested but is only harmful to humans in very large doses.

Currently, contaminated water produced at the Fukushima Daiichi NPS is treated and stored on site in specially prepared tanks. TEPCO, the plant operator, has installed roughly 1000 of these tanks at the Fukushima Daiichi NPS site to hold around 1.3 million cubic meters of the treated water (as of 2 June 2022). Since 2011, the volume of water in storage has increased steadily, and the current tank 공간 available to store this water is nearing full capacity.

오염된 물이 생성되는 속도를 크게 줄이기 위한 개선이 이루어졌지만 TEPCO는 해당 부지의 지속적인 해체를 보장하기 위해 장기적인 처리 솔루션이 필요하다고 결정했습니다. 2021년 2월, 일본 정부는 국내 규제 승인에 따라 약 XNUMX년 내에 시작될 통제된 방류를 통해 ALPS 처리된 물을 바다로 처리하는 방향을 설명하는 기본 정책을 발표했습니다.

On 11 March 2011, Japan was shaken by the Great East Japan (Tohoku) 지진. It was followed by a tsunami which resulted in waves reaching heights of more than 10 meters. The 지진 and tsunami led to a major accident at the Fukushima Daiichi 핵무기 Power Station, which was ultimately categorized as a Level 7 on the International 핵무기 and Radiological Event Scale, the same level as the 1986 Chernobyl 사고 그러나 후쿠시마의 공중 보건 결과는 훨씬 덜 심각합니다.

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