Friday's Magnitude 9 earthquake and resulting tsunami that laid waste to Japan's North Eastern coastline claiming at least 10,000 lives, has been overshadowed by Fukushima Dai-ichi, one of the worlds 15 largest nuclear power plants. A consensus of experts on Wednesday put the nuclear incident at number 6 - Serious Accident, one behind Chernobyl at number 7 - Major Accident. The Ukraine believes the "accidents" are comparable.
With the threat from Fukushima 1, many countries have now requested that their citizens return home. On Wednesday, surging radiation levels at the nuclear power plant forced emergency workers to withdraw; the operator has since ordered 50 technicians back to the site. However with the control rooms flooded and much of the site decimated from the huge tsunami that breached the plants inadequate defenses, the immense task must be difficult to say the least.
A developing low-pressure system has resulted in sometimes below zero degree temperatures with an advisory of gales and snow over the next few days, making any work to cool the reactors even more difficult. Fukushima’s wind direction has changed a number of times bringing some of the resulting radiation onshore but mainly remains North Westerly and offshore. The predominant wind direction into the North Pacific is North North Easterly, taking the radiation to Canada and the United States West coast. Reports of elevated radiation levels on the US coast have already been made on the 16th March.
An explosion of Unit 1 occurred on Saturday with an estimated 70 percent of the nuclear fuel rods damaged, however Tepco reported that the primary containment vessel appeared intact. The pumping of seawater to cool the reactor is apparently proceeding smoothly. Apart from steam releases, it is not known where the remainder of this irradiated water is going.
After exploding on Monday, Reactor 3 with the highest radiation levels was Tepco’s top priority. Attempts to drop water from helicopters have failed presumably because radiation levels are too high. US Army representatives have stated that their helicopters in the area were only for training purposes. On Tuesday the International Atomic Energy Agency (IAEA) has said that the containment vessel appears intact. However, Chief Cabinet Minister Yukio Edano said on Wednesday there is a "possibility" the vessel had been damaged.
After exploding on Monday, Reactor 3 with the highest radiation levels was Tepco’s top priority. Attempts to drop water from helicopters have failed presumably because radiation levels are too high. US Army representatives have stated that their helicopters in the area were only for training purposes. On Tuesday the International Atomic Energy Agency (IAEA) has said that the containment vessel appears intact. However, Chief Cabinet Minister Yukio Edano said on Wednesday there is a "possibility" the vessel had been damaged.
An explosion of Unit 2 on Tuesday damaged the suppression pool where pressure from the reactor is released. The blast may have also affected the integrity of the primary containment vessel. The fuel rods have become fully exposed with an estimated 33% damaged. There is clear evidence of partial nuclear meltdowns in reactors 1, 2 and 3.
On Tuesday a pool that housed spent fuel caught fire in Unit 4. The spent fuel pool is not inside a containment facility and posses a greater threat now that the outer wall is damaged. Tepco plans to build a road to Unit 4 when radiation levels fall so that water pumping to cool the reactor can commence. It has also been reported that fires broke out due to a fuel leak near a water pump at reactor 4.
The temperature of Reactors 5 and 6 have risen slightly with cooling proceedings continuing. This will render all six reactors inoperable in the future. Reactors 4, 5 and 6 had been shut down prior to the earthquake for planned maintenance. There has been confirmation that Reactor 3 uses MOX fuel which is far more dangerous if released into the atmosphere.
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| Sunday, March 13, 2011, the damaged Unit 1 |
Other than this information, officials have given only sparse information about the malfunctioning reactors, probably due to the recent imposition of Article 15 by the Japanese government (unconfirmed). Tepco has disabled public access to a live web cam and a certain amount of disinformation has been presented from pro nuclear representatives, the Japanese Government and Tepco.
Because of the crises, many countries have put on hold plans to build more nuclear reactors, some countries have also shut down their older power plants that use boiling water reactors BWR.
Because of the crises, many countries have put on hold plans to build more nuclear reactors, some countries have also shut down their older power plants that use boiling water reactors BWR.
