Live webchat with Professor Paddy Regan, nuclear physicist, tonight, 21 Mar, 8-9pm

[GeraldineMumsnet]

We're very pleased that Paddy Regan, professor of physics at the University of Surrey in Guildford, is our webchat guest this evening between 8pm and 9pm.

In the wake of the Fukushima crisis in Japan, you asked on this thread if we could get a nuclear physicist on. So thanks to Prof Regan for agreeing to come on to MN.

He's a Fellow of the Institute of Physics, and holds visiting researcher and teaching positions at Yale University and the University of Notre Dame.

He's interested in measurements of naturally occurring radioactive materials (NORM) in the environment using gamma-ray spectroscopic techniques.

In his 'spare' time, he says he plays a poor game of squash, even worse golf and tries to do the occasional sponsored run for the Mental Health Charity MIND. He is married to Susie, a nurse, and they have four children.

Well, his answer to me about going to Japan next month seemed to be that it should be about as risky as having a week in Cornwall, which was roughly what I had told my over-anxious parents anyway. I'm still planning to go.... can I bring over some Easter eggs to cheer you all up, Sakura?

thanks exexpat, you were really great on that other thread but this thread has not been reassuring. A holiday is one thing, but living here day in day out is another. He didn't answer any of my questions.

I've had enough of this idea that if a person criticizes the nuclear industry they're being "hysterical" It sounds like such a fob-off. And he even said that we "need" nuclear energy, but he didn't address the fact that human beings are clearly wasteful and in fact don't "need" all the energy they use. We don't "need" Disneyland and other such bullshit places. What we "need" is an environment were we are unlikely to get cancer.

Sorry, I really thought I'd wake up this morning and find some reassuring posts from the prof on this thread. Sadly that has not been the case.

One of the websites I've been keeping an eye on is this one - continuously updated geiger counter readings from a scientist in Hino city, Tokyo.

Apart from a couple of small spikes last week which seemed to coincide with the explosions at Fukushima, the trend seems to be ticking along at slightly higher than normal (but still safe) levels - a bit lower than average background for Cornwall, as far as I can work out.

I think if I were still living in Tokyo I would be staying put for the moment - but of course everything feels different when you are in the middle of it.

thanks

@sakura

I'm the only one here in Japan and he didn't answer any of my questions Especially, "would you stay in Japan if you were me"
The non-answers tell me all I need to know really

Sorry Sakura if I missed your questions last night...they were coming thick and fast and I couldn't type fast enough......
I have a number of friends on Tokyo who are academic nuclear physics researchers (at RIKEN) and they tell me that the main worry for them is the worry of more earthquakes. The radiation levels as measured from the releases at Fukushima so far certainly show up on their measuring equipment, but this really shows how sensitive this equipment is. The levels are not around 0.3 microsiverts per hour, which is higher than normal background, but still small. Also, the radionuclei in this are mostly radio-iodide which has a half-life of ~8 days and will therefore drop signficantly over the next two weeks. The overall levels of radiation are very small compared to the known health effects of radiation. This web site has a good chart which I hope puts the radiation health risks into perspective

xkcd.com/radiation/

regards Paddy Regan

@sakura

thanks

that should be 'now about 3....' not 'not abour 3...'...my typing needs more practice.

thank you for coming back on. Appreciate it.

"Also, the radionuclei in this are mostly radio-iodide which has a half-life of ~8 days and will therefore drop signficantly over the next two weeks."

This was actually quite reassuring to read. I'm fairly certain the radiation will reach where I live but if it has a rapid half-life of ~8 days then that is quite significant. I have been worried that once the radiation was with us, it would stay with us for a long long time.

I don't think the risk of earthquake cancels out the worry of the radiation though!

Oh My Good Lord, what an absolutely LOVELY guy.

I'm sorry I missed the chat but it's very interesting to read. I'm sure you must be a Mumsnetter's husband or something, you're just too too nice!

thankyou for coming and talking to us.

This was a really good webchat, very interesting - and what a nice man. - More charming academics please

"More charming academics please "
yep

"Also, the radionuclei in this are mostly radio-iodide which has a half-life of ~8 days and will therefore drop signficantly over the next two weeks."

It's the word 'mostly' in this sentence which I find worrying. What about the other types, what risk do they pose if any? I gather from the chat that Paddy thinks there isn't anything really to be concerned about (?)

The Japanese authorities ave announced today that Tokyo tap water is radioactive and may be dangerous to babies. That is likely to be due to radioactive iodine.

The plant is still intermittently on fire and at least one fo the reactors is now at over 500 degrees centigrade and getting hotter.

The reconnection of the electric supply is only to the control rooms and not the pumps. Reactor number 2 needs a new pump entirely.

thanks for the update BeenBeta. I shall be drinking and cooking with imported Evian!!

Sakura, a friend of mine in Tokyo sent me a link to this site which gives radiation readings for water in all the prefectures - I can't remember exactly where you are, but although Tokyo seems to be the highest, from a quick glance, it is still well under the national limits. (I think the link opens in the original Japanese, but if you can't read that there's a google translate option at top left).

sakura - I am trying not to be eternally depressIng on this issue and stick to facts but frankly it just is not getting better really at the plant.

The supposed reconnection of the electric supply to the pumps is not happening and I have seen thermal images of each reactor building and they are very very hot indeed and well above design temperatures.

The radiation level at reatcor 2 is at it highest level ever according to this mornings reports and worst still Kyodo news is reporting a neutron beam has been observed 13 times coming from the plant up to 1.5 km away.

"But the measured neutron beam may be evidence that uranium and plutonium leaked from the plant's nuclear reactors and spent nuclear fuels have discharged a small amount of neutron beams through nuclear fission."

I dont care what anyone says - that is not good news. In my view, the plant and the nuclear fuel in it is beginning to seriously degrade and in severe danger of emitting mass quantities of radiation to the environment.

What is a neutron beam, BB? Do you mind putting it in layman's terms for me/us?

The fuel rods in a reactor emit neutrons as a normal part of the nuclear fission process.

The fact that neutron emisisons are being detected in large quantities suggest that they are being emitted by fuel rods somewhere in the plant. Either because the reactor containment vessel has been ruptured and the core is exposed, or because the rods have melted and leaked out of the reactor or because rods are exposed to air in the spent rod pools and are getting hot and emitting a lot more radiation than would normally be allowed.

The beam is not dangerous in itself - just an indicator that there is further damage occuring to reactors and rods.

A week ago we were being reassured the plant was stable and electric was being reconnected and the pumps would be restarted. That is not the case.

thank you BeenBeta I search for information, but it is not always easy to find now - maybe I'm overly suspicious by nature, but I still feel the risks are played down and the information that is out there is overly technical so normal people don't have a clue what is going on...

I agree, Jenpet. BeenBeta, do you know of a website where this issue is being discussed more openly?

thankyou, that helps

Beenbeta, the media seems to be very quiet? From what you've said, the situation is now more potentially dangerous than it was a week ago? There is part of me that wonders whether this is because the 'powers that be' realise there is little more than can do and things will get worse before they get better?

We need Paddy back again perhaps? If only to reassure...That said from what Paddy implied the consequences of a worst case scenario would not be particularly dire, which should reassure Sakura and others in Japan. I am thinking of them and others I know there.

I keep a check on Kyodo News and NHK News.

The media outside Japan are quiet because other news stories have come along like Libya. There is nothing dramatically new happening so it has dropped out of sight. The cameras and reporters cannot go into the plant so they can only go to press conferences and that does not produce exciting pictures.

The most frightening thing I read was a first hand account of a Japanese fireman who had been called to the site for the first time. He said he and his colleagues were mentally prepared for the radiation threat but not the scenes of utter physical devastation at the plant.

Also Reuters which is reporting radiation at 500 milisieverts per hour at reactor 2 which is the danger zone.

I read that a dose of 10 sievert in one dose will usually kill through organ failure so standing next to the reactor for 20 hours will give a worker that big a dose.

Hence they have to keep withdrawing workers.

Thanks for the links.