Japan’s Nuclear PP: What Went Wrong?


The Fukushima Daiichi nuclear plant has been rocked by explosions following Japan’s massive earthquake on 11 March. Follow this step-by-step guide to fint out what went wrong.

A massive earthquake hit northern Japan on 11 March and the nuclear reactors at Fushima Daiichi were shut down. COntrol rods were activated to stop nuclear reactions that generate power.

Power was affected by the quake and resulting tsunami, meaning reactor cooling systems, which stop fuel heating to unsafe leverls, failed. cooling is needed even if a reactor is shut down because the fuel sitll gives off heat.

The lack of power meant water stopped circulating and began to boil, creating steam. As the water boiled away, it is thought the fuel rods were exposed to air, causing them to heat furthere, partially melting their zirconium alloy castings.

The zirconium alloy reacted with the steam, creating highly-volatile hydrogen gas. Engineers vented the gas and steam from the reactor containment vessel, but it exploded, ripping off the roof of the outer building.

Officials have now taken the unusual step of swamping the reactors with sea water as an emergency coolant. They are also using boric acid, which hampers nuclear reactions.

CAUSE AND MAYHEM. The 8.9 magnitude earthquake combined with the tsunami had an adverse effect on Japanese Nuclear Power Plant. Thousands of people are believed to have died, and millions are spending a fourth night without water, food, electricity or gas. More than 500,000 people have been left homeless.

RADIATION LEAKS CONTINUE. Radiation levels continues to leak on the grounds of Fukushima-1 plant that worker pouring water into the cooling pool had to stop and all of the facility’s 800 workers have to evacuate the site.

THE AMOUNT OF RADIOACTIVE MATERIAL THAT HAS BEEN RELEASED. The World Health Organization’s representative in China says there is no evidence of any significant international spread of radiation.

HARM ON RADIOACTIVE MATERIALS. Radioactive iodine could be harmful to young people living near the plant. After the 1986 Chernobyl nuclear disaster there were some cases of thyroid cancer as a result. However, people who are promptly issued with iodine tablets ought to be safe. Radioactive caesium accumulates in soft tissue, while plutonium accumulates in the bone and liver. Radioactive nitrogen decays within seconds of its release, and argon poses no threat to health.

WHEN WILL IT LAST? Radioactive iodine decays quite quickly. Most will have disappeared within a month. Radioactive caesium does not last long in the body – most has gone within a year. However, it lingers in the environment and can continue to present a problem for many years.

PLANNED SHUTDOWN’S AFTERMATH. Japan relies on nuclear power for one-third of its electricity, with 54 power plants built since 1966. In total, about 11 of Japan’s nuclear power stations remain shut down following the earthquake and tsunami; industry sources say that in all cases—even at Fukushima Daiichi—the plants responded as they were designed to do, shutting down the fission reaction automatically.

 

 

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Posted on March 17, 2011, in Current News and tagged , , , , , , . Bookmark the permalink. Leave a comment.

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