Study: Fukushima Radiation Not a Health Threat in U.S.
For all you folks that rushed to the drug store to stock up on iodine following the Fukushima nuclear reactor meltdown in March, rest easy. Researchers from the University of California San Diego (UCSD) have released the first quantitative study of radiation leaked from the meltdown, and the result is that although radiation levels across California spiked because of the meltdown, it was not enough to warrant any hazard to human health in the U.S.
Atmospheric chemists from UCSD were led by Mark Thiemens, Dean of the Division of Physical Sciences at UCSD, in an effort to measure radioactive sulfur levels in the air following the meltdown. When nuclear fuel rods melt, neutrons are released, and collide with chloride ions in the seawater used to cool the reactors. This results in the loss of a proton from the nucleus of the chloride atom, turning it into a radioactive form of sulfur. To avoid hydrogen (another product of the cooling process) from exploding, the vapors from the seawater are released into the atmosphere. When introduced to the air, the radioactive sulfur reacts with oxygen to make sulfur dioxide gas and sulfate particles.
These particles were carried via winds from Japan to North America, sparking alarm that the U.S. and Canada would experience the same kind of radioactive fallout seen in neighboring countries to the Chernobyl disaster of 1986. But fears of mutated babies, high cancer rates and radioactive crops may be put to rest with the UCSD study’s findings.
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Thiemens and his team noticed an unprecedented spike in radioactive sulfur in the air following news of the meltdown, and using a model based on the National Oceanic and Atmospheric Administration’s observations of atmospheric conditions were able to pinpoint that the radiation was indeed coming from Fukushima. The team then calculated how much radiation was actually leaked, concluding that 400 billion neutrons were released per square meter surface of the reactor’s cooling ponds.
"You know how much seawater they used, how far neutrons will penetrate into the seawater and the size of the chloride ion," says team member Antra Priyadarshi. "From that, you can calculate how many neutrons must have reacted with chlorine to make radioactive sulfur."
The team believes that for the levels of radiation observed in California, the concentrations a kilometer above the ocean around Fukushima must have been 365 times higher than normal levels. In California, the team measured 1501 atoms of radioactive sulfur in sulfate particles per every cubic meter of air. Yet, despite the higher than normal levels observed in California within the team’s four-day testing period, the team concludes that the levels are not dangerous to human health.
"Although the spike that we measured was very high compared to background levels of radioactive sulfur, the absolute amount of radiation that reached California was small," said Thiemens. "The levels we recorded aren't a concern for human health. In fact, it took sensitive instruments, measuring radioactive decay for hours after lengthy collection of the particles, to precisely measure the amount of radiation."
Major move forward for UK’s nascent marine energy sector
Although the industry is small and the technologies are limited, marine-based energy systems look to be taking off as “the world’s most powerful tidal turbine” begins grid-connected power generation at the European Marine Energy Centre.
At around 74 metres long, the turbine single-handedly holds the potential to supply the annual electricity demand to approximately 2,000 homes within the UK and offset 2,200 tonnes of CO2 per year.
Orbital Marine Power, a privately held Scottish-based company, announced the turbine is set to operate for around 15 years in the waters surrounding Orkney, Scotland, where the 2-megawatt O2 turbine weighing around 680 metric tons will be linked to a local on-land electricity network via a subsea cable.
How optimistic is the outlook for the UK’s turbine bid?
Described as a “major milestone for O2” by CEO of Orbital Marine Power Andrew Scott, the turbine will also supply additional power to generate ‘green hydrogen’ through the use of a land-based electrolyser in the hopes it will demonstrate the “decarbonisation of wider energy requirements.”
“Our vision is that this project is the trigger to the harnessing of tidal stream resources around the world to play a role in tackling climate change whilst creating a new, low-carbon industrial sector,” says Scott in a statement.
The Scottish Government has awarded £3.4 million through the Saltire Tidal Energy Challenge Fund to support the project’s construction, while public lenders also contributed to the financial requirements of the tidal turbine through the ethical investment platform Abundance Investment.
“The deployment of Orbital Marine Power’s O2, the world’s most powerful tidal turbine, is a proud moment for Scotland and a significant milestone in our journey to net zero,” says Michael Matheson, the Cabinet Secretary for Net-Zero, Energy and Transport for the Scottish Government.
“With our abundant natural resources, expertise and ambition, Scotland is ideally placed to harness the enormous global market for marine energy whilst helping deliver a net-zero economy.
“That’s why the Scottish Government has consistently supported the marine energy sector for over 10 years.”
However, Orbital Marine CEO Scott believes there’s potential to commercialise the technology being used in the project with the prospect of working towards more efficient and advanced marine energy projects in the future.
“We believe pioneering our vision in the UK can deliver on a broad spectrum of political initiatives across net-zero, levelling up and building back better at the same time as demonstrating global leadership in the area of low carbon innovation that is essential to creating a more sustainable future for the generations to come.”
The UK’s growing marine energy endeavours
This latest tidal turbine project isn’t a first for marine energy in the UK. The Port of London Authority permitted the River Thames to become a temporary home for trials into tidal energy technology and, more recently, a research project spanning the course of a year is set to focus on the potential tidal, wave, and floating wind technology holds for the future efficiency of renewable energy. The research is due to take place off of the Southwest coast of England on the Isles of Scilly