Monday, February 27, 2012

Fukushima: 1 year later...

The first anniversary of the Fukushima disaster is coming up, and being an IB student, I have left this blog completely dusted during exams and work. Now that work load has eased a bit , I might as well write an update on what has happened when I "abandoned" this blog.

Fukushima Daiichi
The plant has been officially called "stabilized" or in cool shutdown for almost half an year now, meaning that the water inside the core is less than 100 Degrees Celsius. All reactors has been confirmed to be taken offline contrary to earlier believe that only 1-4 will be taken offline. Reactor 1,2,3 has officially been confirmed that meltdown did occur in those reactors. An intern investigation from the Japanese authorities has been published, the report from Japanese authorities blamed multiple small factors that lead to one large disaster. A full report will be released during summer of 2012.

Other nuclear power plants in Japan
This is probably the most striking. Since the Fukushima Daiichi shutdown, lots of other reactors that were not harmed by the earthquake were shut down for "stress tests". They were not allowed to return into operation. There are currently only 2 (of the 54) nuclear reactors still in operation. With ~25% of electricity generated by nuclear power plants, it is quite obvious that there may not be enough electricity generated (though no blackouts at the moment). This situation may become worse during summer when more and more energy is required to cool down cities (via Air-conditioning, law of thermodynamics)

The cleanup from the disaster will take decades, as there is still decontamination to complete as well as solving the current energy crisis faced by Japan.

Monday, March 14, 2011

New Update- Fukushima Dai-Ichi and others

At the time of writing, another accident has occured or unfolding.

Fukushima Dai-ichi Reactor 2 (1973, General Electric, 784 MW), exploded on 6.10 JST, 15th March. Radiation level has risen to ~2000 mSv. The reason for this explosion is caused by whatever happened to other reactors after the disaster (read my other blog posts). However, the cast is not breached

Reactor 4 (1978, 784MW, Hitach) in Fukushima Dai-ichi is also reported on fire right now.

Other Power Plants in Japan

Tokai nuclear power plant (東海発電所), First nuclear power plant in Japan, located in Tokai, Naka District, Ibaraki Prefecture, operated by Japan Atomic Power Company, with an output of ~1000MW. Reactor 1 was based off the British Magnox reactor, opened in 1966, closed in 1998. Reactor 2 is a BWR, started working on the 1978. It has suffered cooling failure but no explosions were reported.

Onagawa Nuclear power plant (女川原子力発電所), managed by Tohoku Electric power company, this is the fastest built nuclear power plant in the world, it began building on 1980, and was completed on 1984. This is  Reactor Number 3 (825MW, 2002, Toshiba). A fire broke out in reactor 3's turbine assembly and it was shut down.

What we know so far

Hi all, welcome to my blog, where I have to write down as much things about the Fukushima (福島) Nuclear power plant. So I would like to start this with an Intro.

Bit of Background
In every blog I write, I would usually give a bit of context. So Japan is a MEDC country, with around 38% of electricity generated from Nuclear sources and 53 nuclear reactors.

Fukushima I Nuclear Power plant (Known in Japan as Fukushima Dai-ichi) is a Nuclear power plant located in Okuma, Futaba District, Fukushima prefecture. There is 6 Boiling Water Reactors (BWR) in that power station designed by General Electric, with a total output of ~4.7 GW. Constriction of the plant began on 1966 and it was first commissioned in March 26, 1971. This nuclear power station is run by Tokyo Electric Power Company (TEPC) and also the first nuclear power station in Japan to be constructed and ran fully by TEPC.

11.5 Km to the south of Fukushima Dai-ichi, we have Fukushima II Nuclear Power plant (Fukushima Dai-Ni). This time located in the town of Naraha and Tomioka. There is a total of 4 BWR in this plant. Commissioned in 1982. Each generator has an output of 1.1GW.

So what do we know as of this blog post?
What happened recently was the Sendai Earthquake which registers as 9.0 by the USGS, where the coolant system failed, and causing a near thermal meltdown. The Japanese government has declared an Atomic power emergency.

In Fukushima Dai-ichi, reactor 1 (built by GE and commissioned on Jan. 1970), has suffered an partial meltdown of the core, due to the failure of the coolant pumping system. The failure is first reported on 16.36 11/3/2011, when the coolant level is below normal. The failure of the coolant pump is caused by the Tsunami that hit that city. On 3.36 PM JST of 12/3/2011, there was an explosion that happened in the building of reactor 1. The external concrete structure was blown but the metal container for the reactor seems intact. It was later determined that the buildup of hydrogen in the building caused this explosion.

At the same power plant, reactor 3 (1976 by Toshiba) also has problems. It was reported on 13/3/2011 that the emergency cooling system has failed, and using any means necessary to pump water into the reactor to keep the reactor cool. The workers pumped water with Boric acid and later sea water into the reactor to keep it cool. On 12.33 PM JST, a government official hinted that a partial meltdown may be on the war. On 14/3/2011 11.55 JST, there was an explosion of the Nuclear reactor building. TEPC reports 1 worker is injured and 7 missing. However, there isn't a breach of the reactor container. Causes unknown but highly likely be hydrogen buildup.