March 13, 2011

more expert reaction to concerns about nuclear reactor following Japanese earthquake

Further comments on the Fukushima nuclear disaster.

Prof Richard Wakeford, Dalton Nuclear Institute, University of Manchester, said:

“The reactor cores were still hot when the reactor shut down (essentially when the chain reaction stops), as time goes on that radioactive decay heat will get less and the problem will get less. In this case, the diesel generators that ran the cooling systems were flooded by the tsunami, so sea water is now being used to cool the core. If the fuel is uncovered by cooling water it could become so hot it begins to melt – if all the fuel is uncovered you could get a large scale meltdown.  So Japanese authorities are doing all they can at the moment to keep the core cooled with seawater.

“This is a well known potential accident scenario, so the regulatory authorities ensure that there are appropriate plans in place to ensure that cooling water is kept pumping. Ultimately in this case there was be provision to put seawater through the core to ensure that the core is covered and cooled. 

“There will be intense monitoring around the site of the reactors for release of radiation. We will know immediately if there had been a major release – and this clearly hasn’t happened at the moment.

“The Japanese authorities are doing the right thing by evacuating people just in case the worst happens. If it did, there are measures that will be taken – for example, to counteract radioactive iodine people would be given stable iodine tablets that would block the uptake of radioactive iodine by the thyroid. They would also put out a food ban from the affected area.

“This approach is very different to Chernobyl where the authorities were in denial and did not act to protect the population (they did not issue iodine tablets or stop people eating local food)  – many of the thyroid cancers seen could have been prevented by taking action immediately.”

Prof Robin Grimes, Professor of Materials Physics, Imperial, said:

“One important thing to remember is that all nuclear fuel that has been in a reactor for some time will have generated some plutonium, but that this is significantly less radioactive than the fission products. Consequently this has much less radiological significance.”

Ian Hanson, Senior Lecturer in Forensic Archaeology, Bournemouth University, (currently on sabbatical at the International Commission on Missing Persons) said:

“Often with disaster situations numbers of people reported missing is very high initially – but this is often because multiple agencies are collecting information and individual missing people will be reported multiple times.

”We have seen this discrepancy before at 9/11- people were reported missing by multiple people to multiple agencies, and it is only once a united database of missing is collated that the true figure is known. 9/11 saw the number of missing drop rapidly from first days estimates of 20,000 to 10,000 then 5,000…then the true figure of just under 3,000 over time. We may see the same thing here as lists are amalgamated.”