Context:
The operator of the wrecked Fukushima nuclear power plant said that there are plans to build an undersea tunnel so that massive amounts of treated but still radioactive water can be released into the ocean about 1 km away from the plant to avoid interference with local fishing.
Relevance:
GS-III: Science and Technology, GS-III: Environment and Ecology (Waste Management)
Dimensions of the Article:
- Types of Nuclear Waste
- About Nuclear Waste Disposal
- About the Fukushima Incident
- Treatment of Fukushima water
Types of nuclear waste
- Low-level waste is made up of lightly-contaminated items like tools and work clothing from power plant operation and makes up the bulk of radioactive wastes. It represent 90% of the total volume of radioactive wastes, but contain only 1% of the radioactivity.
- Intermediate-level wastes might include used filters, steel components from within the reactor and some effluents from reprocessing.
- High-level wastes from nuclear generation, but they contain 95% of the radioactivity arising from nuclear power.
About Nuclear Waste Disposal
- Intermediate- and low-level wastes are disposed of closer to the surface, in many established repositories. Low-level waste disposal sites are purpose built, but are not much different from normal municipal waste sites.
- Low-level and intermediate wastes are buried close to the surface.
- High-level wastes require shielding and cooling, low-level wastes can be handled easily without shielding. High-level wastes can remain highly radioactive for thousands of years. They need to be disposed of deep underground in engineered facilities built in stable geological formations.
- The regular monitoring is done as per the requirements which are in line with the guidelines of International Atomic Energy Agency (IAEA).
- The monitoring of various environmental matrices such as air, water, soil etc., in and around the waste disposal facilities is carried out by independent Environmental Survey Laboratories (ESL) of Bhabha Atomic Research Centre (BARC) which are stationed at all the nuclear sites.
About the Fukushima Nuclear Disaster
- A nuclear disaster happened at Fukushima Daiichi Nuclear Power Plant on Japan’s coast in March 2011. An earthquake of magnitude 9.0 Ritcher scale caused a tsunami that flooded the critical control equipment of the nuclear power station and caused a meltdown.
- The Tokyo Electric Power Company or TEPCO is now dealing with a new issue of radioactive water piling up at the site. Japan is planning to release the water into the sea . Tokyo Electric Power Company Holdings Inc would begin the process of pumping out the water in about 2 years after the treatment process is completed. The process is expected to take decades to complete.
About the treatment of Fukushima Water
- The water needs to be filtered again to remove harmful isotopes and will be diluted to meet international standards before any release.
- The water will be filtered again to remove the isotopes leaving behind only tritium, which is a radioactive isotope of hydrogen hard to separate from water.
- Tepco would dilute the water until tritium level falls below the regulatory limits. It would be then pumped directly into the ocean.
- Tritium is considered to be less harmful to humans than other radioactive materials. Once released, the process would take 10 years to complete.
-Source: The Hindu
