http://www.bbc.co.uk/news/world-asia-18468685 With the proposed new build in the UK should we take this as a sign that nuclear is essential as part of the energy mix.

Here we go again bashing nuclear safety and the pereived risks from ionising radiation. There can be few areas of science and technology subject to such intense study and risk assessment as nuclear power generation. Sure radiation is very hazardous in the right circumstances. In reality the risks are of a very low risk order. If you want to keep watching Coronation St, please tell me what other power generation source is going to give the energy density to light up our houses. Wind power and solar and tidal have their place in the energy mix, but are simply never going to reliably produce the required energy when it is needed.

Ah, the old chestnut of a low probability/high consequence events once again raises fears of the destruction of the world due to capitalist incompetence and greed. We all know the immense difficulties associated with such assessments especially when associated with significant risks to society. I forget which psychologist it was who said “All else being equal, not many people would prefer to destroy the world. Even faceless corporations, meddling governments, reckless scientists, and other agents of doom, require a world in which to achieve their goals of profit, order, tenure, or other villainies. Therefore I suggest that if the Earth is destroyed, it will probably be by mistake.” That does illustrate, I think, that it is rather simplistic to dismiss such events with a criticism of total failure. If there can be any criticism of the Japanese authorities it is that they failed to update their impact assessments with regard to the protective measures required for tsunamis. All the information I have read is clear that all the countermeasures taken when Fukushima Daiichi was designed and sited in the 1960s were considered acceptable in relation to the scientific knowledge then available with regard to tsunami wave height for that particular coastline. Some changes to the plant had been made based on an increased wave height predictions around 2001 but these were relatively minor and did not protect against the tsunami generated by the rare and complex double quake that caused it. All the reactors at four nuclear power plants in the region that were operating at the time shut down automatically when the quake hit and were cold within a few days. Subsequent inspection showed no significant damage to any from the earthquake. As to a failure to "think the unthinkable", the Japanese Earthquake Committee had completed a report that was due for publication in April 2011. The report did indeed consider the unthinkable by looking at the worst case scenario citing an event from over 1000 years ago and amongst other matters it concluded that the region should be alerted of the risk of a similar disaster striking again. So, with the benefit of hindsight we might observe that there was possibly a tardy response to changing evidence about tsunami generation and wave heights but little else I think. As to the restarting of the reactors at this time. Yes, there are very pressing societal reasons to restart them; not desperation but a pragmatic response to the situation developing. Remember we are not talking about restarting those damaged by the tsunami. Why should they not be restarted unless they have been assessed as being unprotected against the latest tsunami data for wave heights etc. Remember many were not damaged and failed to safety as designed. They were shut down as a precaution and to allow a review. No doubt any relevant changes to procedure would have been part of the decision to restart. P48

Not in any meaningful sense, however, since without exposure to radiation we'd all be dead - it would just be a barren rock hurtling through space. You can't meaningfully say "radiation is harmful in any circumstance" when your life depends on it. Even if you mean to caveat it as 'ionising radiation', if it were meaningfully dangerous we'd never go upstairs (3m increase in elevation increases your radiation dose detectably), and we'd evacuate Cornwall, Wales, chunks of the Pennines, and anywhere else with significant Radon exposure - which swamps the radiation exposure from nuclear power sources.

At the end of the day, and at the end of their lives, the reactor core and much of the surrounding structure will still be lethally radioactive for many times the length of time our civilisation has existed. Nuclear fusion as a source of heat for power is several decades away, if not longer.  Whether radiation is tolerable in low doses is not the issue, nor is whether radiation led to ....... us. What happens at the end of the reactors life to the lethally radioactive materials is.  No answer to that yet, unless you consider that burying it is an answer rather than a stopgap. As was noticed in Japan, a reactor vessel constructed to withstand a 747 flying into it (!) was rendered ineffective by a simple lack of electricity. At this time the IAEA seems to have stopped updating the state of the Fukushima reactors most affected, and the fuel rod storage "pools" which at the time presented more risk than the reators. So you'll forgive me if I am sceptical about things nuclear. Maybe things will change when the UK finally figures out what to do with the three million cubic metres of high-level waste it has stored  ? Without making more.

I suppose like everything else it’s down to risk assessment!

How about the statement: “You are more likely to be killed/injured working on a building site than due to nuclear accident”? Discuss

Slightly off topic but: Car Sagan once said or wrote about civilizations (anywhere in the Universe) in respect of power and enegy that until humanity on planet earth (currently classed as a "0" Civilization) can harness the sun they would be backward : A "0" civilization is one using fossil fuels and some nuclear energy. A "1" civilization is one utilising the energy from their sun. A "2" civilization is one utilising the energy from their solar system. and so on. A start has been made to utilise the sun's energy in the form of photovoltaire cells etc, but humanity has a long way to go (tongue in cheek -hundreds or thousands of years) to be classed as a "1" civilization where nuclear energy would be consigned to the dustbin. Rich

What about the radio avtive component in your domestic smoke detector? Unless we get the finger out i suspect the 3 day week of the 70s will be back. Tony

David: You assert that "wind and wave power is expensive, unreliable and insignificant in the demands in the future."... You omit solar, and you omit tidal, you lightly dismiss wave, and you ignore the massive investment in wind currently under way across the UK.... Are you really dismissing all renewables generation without further explanation? Personally, I believe there is a need for nuclear in the short to medium terms.... But I also believe that 'renewables' tidal, wind, wave and solar will play an increasing role over the medium - long term. Imagine a solar array across the sahara supplying energy to power Europe (Photovoltaic or solar steam generation).... Or tidal barrages across the Severn, Clyde, Thames and Tay estuaries - that could equally power Europe for the foreseeable future.... We might not want to contemplate these projects just now... They may seem environmenetally gruesome. But if the alternative is lights out, then surely we need to keep an open mind. Gas coal and wood will not keep us going much longer. Steve

So you have never made a mistake or error - for whatever reason, lack of knowledge, making false assumptions, not knowing what you don't know, lapse of judgement. As regards assumptions - these are made through out design engineering. For this particular case, at the time of design, assuming a 9m tsunami may well have been a reasonable assumption based on past history/geological evidence/scientific knowledge at the time of earthquakes and tsunamis in this region of the world - probably the early/mid-1970's. This is not to say, that the plant/tsunami protection shouldn't have been improved over the years, if geological knowledge/research etc had shown the risk was different / greater than the original design criteria. In the UK safety cases are reviewed about every 5years. I wouldn't be so bold to suggest, that it wouldn't happen in the UK. But I would be pretty sure that if geological experts came to the conclusion that the risk of tsunami to UK power stations had changed sufficiently to warrant further action - then this would be flagged up in a safety case review. I have read the geological review, written about 8years ago, re-assessing the risks of tsunami events to the UK. I no longer have access, to the report. But the conclusion was, that there is no credible scenario for the UK. The caveat is of course 'in the state of current geological knowledge and understanding' So, yes, the sea bed under the North Sea could suddenly rise up and flood out one of the east coast N-stations - but is it likely? I very, very much doubt it. As for flawed design - maybe/maybe not at the time of design. With the light of current knowledge, better designs are now available e.g. natural cooling - not requiring back up cooling systems, reactors that inherently 'shut down' as opposed to requiring positive action to shut them down. So what risks are you prepared to take - both as an individual and as a society to ensure adequate power supplies for the country?

John, Nobody will ever convince you it's completely safe. The sad thing is you have dismissed every person within the nuclear industry as being liars or incompetent.

Try reading this document, discussing tsunami risks to the UK http://archive.defra.gov...ments/risk/tsunami05.pdf Of course if you are of the mindset that the risks ere too great, you won't believe it. Government and big business conspiracy theories are true

Sigh! Ultimately all accidents are caused by human error. As uranium originates from rocks underground, returning it to underground storage seems the most prudent long term storage option. Basic radiation safety - distance/shielding/time. Can't decide if you are taking a troll position or because of your stated 'prove it is completely safe' outlook - but you haven't indicated what level of risk you and society should accept for the benefits of nuclear power. Nuclear power is not 100% safe, that could never be claimed for any human activity - but it can be made something approaching that figure - is the country prepared to accept the residual risk? Lower consumption would be good, as it would reduce the amount of power generating capacity the country needs. The argument is, what is the makeup of the various electrical generating options. During my time in safety (16yrs +) taking a balanced view of the risks and possible mitigation measures has been driven home - but all obviously dependent upon credible hazards and risks being identified. Applying the current state of knowledge of both safety management and risk assessment techniques, with the application of engineering and scientifice practices. Closed and infexlible minds leads to lower safety standards over time. I find it most odd on this forum that there are often numerous replies about RIDDOR questionss, PAT etc - but come to a big topic that affects the safety of large parts of the population and there are relatively few replies, by safety professionals. I guess nuclear safety is in the 'too hard' box.

No scientist will ever say that something is 100% This is taken by those with an axe to grind (whatever the subject) as proof that something shouldn't be done. The Japanese have reduced their energy reduction strategy by 5%, following the start of the oi reactor, in the kansai region and it's not even summer. Other prefectures are sure to follow suit. As for fuel disposal you can either dispose of it in repositorys or burn it up in mod fuel. There is also a lot of work going on to artificially age the waste at the moment. This could significantly reduce the activity prior to disposal.

As pseudonym suggests at #32, I guess that most forum users like myself have insufficient knowledge of radioactivity and nuclear power generation to be willing to engage in this thread. However, I’ll have a go with the help of information I found during some internet delving about health risks to uranium miners. (This delving began after I saw a response by Merv to another thread in which he mentioned having worked in a uranium mine.) Among my findings was a presentation at http://www.ratical.org/r...aring/GordonEdwards.html entitled “Uranium: Known Facts and Hidden Dangers” by Gordon Edwards, a Canadian, at a conference in Salzburg in 1992. It improved my knowledge of radioactivity, not least because I hadn’t previously been aware that radioactive elements comprise a sequence of decay products starting from uranium and ending with the element lead which is highly toxic but not radioactive. Also the decay products (including radium which decays to form radon gas, which in turn forms ‘radon daughters’ such as polonium) are much more radioactive than uranium. Edwards mentions that Canada was the first major commercial producer of uranium - originally supplied to the USA and UK for use in atomic bombs, and thereafter additionally for nuclear power stations. This industry has left what could be described as a massive dirty legacy in the form of some 200 million tons of tailings, i.e. deposits of finely crushed rock left after mined/quarried uranium ore has been processed to extract the uranium. The tailings continuously emit radon gas which is readily spread by wind including light breezes and leads to radon daughters entering the environment, including water and food chains, over enormous distances. These aspects and how radioactivity can cause harm are covered in more detail in a paper “Human Health Implications of Uranium Mining and Nuclear Power Generation” by Canadian doctors Cathy Vakil and Linda Harvey (2009) and available at http://www.safewater.org...ationsUraniumNuclear.pdf As to whether the UK should continue with or expand its complement of nuclear power stations, I don’t know the answer. In principle, nuclear energy is like other energies such as fire and electricity and has to be kept under firm control in order to be useful without being harmful. However, unlike fire and electricity, it seems that nuclear energy generation requires considerable control (in terms of technical complexity, need for reliability and financial cost) to match its high potential for harm. Also, though the UK doesn’t have to contend with uranium tailings, it does have to deal with the safe disposal of radioactive waste from its nuclear power stations, including ones which are no longer producing electricity. Though there seems to be fairly common agreement that burying radioactive waste deep underground is the best option, there is disagreement about the most appropriate geological formations in which to bury it. While some experts argue that hard stable rock formations are best, others have suggested that ‘soft’ formations such as London Clay might be better. However, as such formations in the UK tend to exist under South East England with its densely populated areas, it’s inevitable that any proposal to use them would be vociferously resisted by most people, including politicians!

To balance out the Nuclear Free Canada view from 20 years ago http://www.nei.org/resou...sures-in-uranium-mining/

Well, I suppose it could be stored underground. It's a timescale thing. How long. I suppose the best that could be expected is that the radioactivity could have decayed by the time geological activity moves things closer together. Future generations will know eventually.