Back in early March, an offshore earthquake of magnitude 9.0 – that makes it very serious – generated a tsunami which struck the east coast of Japan with torrential force. Quite apart from the loss of life and destruction of property was the sudden disabling of coolant pumps at the Fukushima Dai-ichi nuclear power station, which prevented the three working reactors from being shut down normally.
The conjunction of “nuclear”, “reactor”, “overheating” and also “plutonium” set alarm bells ringing among those who scrabble around the dunghill that is Grubstreet. Headless chicken mode was duly engaged. All concerned immediately deployed the very scary word “Chernobyl” while neglecting the longer and less scary “Three Mile Island Reactor 2” (TMI2).
There were allusions to fiery piles of radioactive graphite, despite Fukushima Dai-ichi not using graphite as a moderator, unlike Chernobyl. No hack seemed able to see that the Japanese plant had containment vessels around its reactors, which the Russian RBMK reactors did not. Venting of hydrogen leading to hydrogen detonations spooked the press yet further.
Here on Zelo Street an attempt was made to put things in proportion: you can view the extent of the prescience HERE, HERE, HERE, HERE, HERE and HERE.
The story subsequently went quiet, as nobody died as a result of radioactive release or contamination, but has returned to the news arena in the last couple of days as Japanese Prime Minister Yoshihiko Noda has declared that Fukushima Dai-ichi is in “cold shutdown”. That means reactor core temperatures are well below 100 Celsius, although there is a long clean-up process to come.
All of which means that, as I said more than once back in March, this is primarily an economic, rather than an environmental, disaster. It was thus with TMI2, although in that case, keeping all radioactive material within the primary containment meant that there was no clean-up required anywhere outside it. It should also be borne in mind that any new nuclear power plants in the UK would be of a similar type.
That means Pressurised Water Reactor (PWR) technology, which was used in the last nuclear station to be completed in the UK at Sizewell B, and which has been used extensively in France. Unlike the Boiling Water Reactor (BWR) technology of Fukushima Dai-ichi, radioactive steam does not leave the reactor building, which should make use of PWR technology yet safer.
So my advice is once again that one should not panic: a worst case incident at a nuclear power station built half decently – even to 1970s standards – means the outcome is more likely to be TMI2, rather than Chernobyl.
The design GE used at Fukushima seems like it was specifically optimised to make natural disasters as bad as they could conceivably be. "Where shall we store spent fuel?" "I don't know, how about ON TOP OF THE REACTOR?"
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