Climate change

March 17, 2011

Think climate when judging nuclear power

Filed under: IFR (Integral Fast Reactor) Nuclear Power, Japan Earthquake — buildeco @ 7:50 am

by Barry Brook

Guest Post by Ben Heard. Ben is Director of Adelaide-based advisory firm ThinkClimate Consulting, a Masters graduate of Monash University in Corporate Environmental Sustainability, and a member of the TIA Environmental and Sustainability Action Committee. After several years with major consulting firms, Ben founded ThinkClimate and has since assisted a range of government, private and not-for profit organisations to measure, manage and reduce their greenhouse gas emissions and move towards more sustainable operations. Ben publishes regular articles aimed at challenging thinking and perceptions related to climate change at

(Editorial Note: [Barry Brook]: Ben is a relatively recent, but very welcome friend of mine, who is as passionate as I am about mitigating climate change. I really appreciate publishing his thoughts in this most difficult of times. Now, more than ever, we must stand up for what we believe is right]


On 8th March, I delivered a presentation to around 45 people, describing my journey from a position of nuclear power opponent to that of nuclear power proponent. The presentation was very well received and has generated much interest.

Just four days later, I saw those first appalling images of the tsunami hitting Japan, and realised that for the first time since 1986, a nuclear emergency situation was unfolding.

In all cases, I find it most distasteful when individuals or groups push agendas in the face of unfolding tragedy. Let me say at the outset that this is not my intention.

Sadly, many people and groups don’t share this sentiment, including a great many who have wasted no time in making grave and unfounded pronouncements regarding the safety of nuclear power, and how this event should impact Australia’s decision making in energy. This has been aided no end by a media bloc that has reflected the general state of ignorance that exists regarding nuclear power, as well as a preference for headlines ahead of sound information at this critical time. The whole situation has been all too predictable, but still most disappointing. It has reinforced one of the great truisms in understanding how we humans deal with risk: We are outraged and hyper-fearful of that which we do not understand, rather than that which is likely to do us harm. Rarely if ever are they the same thing.

Those who attended my presentation on the 8th March will have seen that I place a high value on two things in forming an opinion and making a decision: Facts and context. Facts without context can be dangerously misleading. In this newsletter therefore, I would like to present some of the basic facts and context of this event, as well as providing links to reliable and up-to-date sources of information to gain a more detailed understanding of the crisis. From there, I only ask that you maintain a critical frame of mind in considering the true implications of this event.

Firstly, the context. Japan is a densely populated chain of islands. It is the fourth largest economy in the world, and derives around 30% of its electricity from 55 nuclear reactors at 17 locations around the country. Japan has been using nuclear power for some time. As such some of the reactors are approaching 40 years of age, and are older designs by comparison with what would be built today.

On 11th March, Japan experienced an earthquake measuring 9.0 on the Richter Scale. The Richter Scale is logarithmic, meaning a 9 quake is ten times more powerful than an 8, 100 times more powerful than a 7 and so on. On this basis the quake was something like 100,000 times the force of that which struck Christchurch recently. It is only the 4th quake of greater than 9 magnitude in recorded history.

Just one hour later, a tsunami measuring up to 10 metres struck large parts of the Japanese coast. We have all seen the awesome and terrifying footage of this wave, which laid waste to nearly everything in its path.

So by way of context, what I would like you to do is take Japan’s population density, coastal geography and high penetration of nuclear energy. Then overlay a two-phase natural catastrophe, with only one hour between each phase. Each phase of the catastrophe is perhaps the most powerful of its kind that we will see in our lifetimes.

I am sure those of you who have ever conducted risk assessment exercises will agree that it would be difficult to construct, in our wildest imaginings, a scenario that would pose a more comprehensive and arduous test of the operational safety of nuclear power plants in the world today.

Lets now turn to the response of Japan’s nuclear power industry to this event, sticking at this stage to high level facts that are not in any way in dispute:

• When the earthquakes struck, Japan’s nuclear power stations did as they were designed to do and shut down with the insertion of control rods. This halted the nuclear chain reaction that generates the power. In response the plants rapidly dropped in power to around 5% of normal.

• Other (non-uranium) constituents of the fuel remained “hot” i.e. reacting, which is normal.

• Back up power systems (diesel generators) were applied to continue to provide cooling to the reactor core. This worked as expected.

• Approximately 1 hour later, two power plants housing seven nuclear reactors were struck by a 7 metre tsunami. These plants were Fukushima Daiichi and Fukushima Daini. This disabled the diesel generators that were in use, and all other back-up generators that were available. It is this second disaster that triggered the problems at these power plants, as the plants began to experience a loss of cooling on the fuel.

• Back-up cooling from batteries was applied, and provided cooling for approximately a further 8 hours

• Other measures have then needed to be implemented as this power source ran out. This has included pumping sea-water into the reactor core. This is not a preferred action as it causes some damage.

• Some portions of the fuel rods remained exposed from the coolant for long enough to heat up and melt. This is the meaning of “partial meltdown”

• Some build up of radioactivity has occurred within the reactor buildings. This has been periodically vented in a controlled way to maintain pressure within the reactor at a safe level. The radiation being vented is of a type that is short lived, decaying rapidly to harmless substances

• The venting gas has contained hydrogen. Unfortunately, perhaps due to not venting quickly enough, the hydrogen concentrations have become elevated and resulted in explosions occurring outside of the reactor building when the venting occurred

• Presently the reactor cores are being successfully cooled and progressively moved to a state of cold shutdown, meaning fully under control.

• Critically, throughout the disaster the integrity of the very strong Containment Structures, which separate the nuclear reactor from the outside world, has been maintained. The reactor building itself then contains the core of nuclear fuel, and these reactor buildings have also remained intact. This means there has never been a risk of a “Chernobyl-type” incident, with serious releases of radioactivity to the surrounding environment that would pose a threat to human health. The Chernobyl power stations had no such structure, which greatly increased the consequences of that accident.

• The incident has received a severity rating of INES 6. It is clearly very serious. The Three Mile Island Accident was a 5. Chernobyl, however, was a 7 (the highest), and is a very different league.

For more detailed and technical information regarding these events, please look through and follow the regular updates and review some of the other excellent, more technical postings

There seems to be some suggestion that “but for the efforts” of the engineers, this situation would be worse. Well, that’s true, but at the same time, misleading. Passive safety is a great thing, be it nuclear power plants or the cars we drive. But at the end of the day, a key control measure in catastrophic events will always be a skilled and well trained work force with the knowledge and ability to respond to a changing situation. That’s as true for the power plants as for the rest of the country, where the army, police and other emergency services will play a vital role in mitigating the damage.

The bottom line of the events at Fukushima and the nuclear power sector more broadly would appear to be as follows:

• Zero deaths from radiation

• Zero release of radiation levels of a danger to human health, except for brief periods for those working within the plant compound (not Public exposure). These workers would be well protected and monitored to avoid excessive accumulated doses

• Minimal injuries (about a dozen) as a result of the hydrogen explosions

• No significant or lasting environmental impact whatsoever

• A major evacuation, which has no doubt been distressing for all involved

• 8 — 10 of Japan’s 55 nuclear reactors known to have varying levels of damage that will impact their ability to provide electricity. The remainder will no doubt require inspection, but would appear to be relatively undamaged.

The main contribution of note from the nuclear power sector has been dangerously misleading headlines and media reports, and a distraction from the greater tragedy unfolding in Japan, which is likely to have caused fatalities in the 10,000s, and left great areas of the country in total wreck and ruin.

So, combining the extraordinary context with that high level summary of facts, what conclusion should be drawn about the current and future role of nuclear power, particularly with regard to operational safety?

That is up to each of you, and I don’t want to push an agenda. If you want my conclusion, read on.

If Japan’s nuclear power sector can withstand the worst natural calamity I hope to ever see in my life and contribute no deaths, minimal injuries and minimal environmental impact, then nuclear power must be just about the sturdiest, best designed, best managed and least dangerous infrastructure in the world. And in a world that is quickly cooking itself through climate change, nuclear power must not be allowed to suffer from the hype, headlines and hyperbole that have stemmed from this tragic event.

Fear or facts. I choose facts. I hope you do too.


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