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 www.thinkclimateconsulting.com.au.
(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]
Update: This is a revision of an earlier post from ThinkClimate, reflecting the useful contributions of BNC readers, the evolving situation in Japan, and focussing on the broader message regarding our future decision making in energy
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. This journey has taken me around three years. The goal of my presentation was to foster healthy discussion of the potential future role of nuclear power in Australia, a nation with among the highest per capita greenhouse gas emissions in the world. 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 article 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 implications of this event for national and global energy supply.
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 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. They are older designs (Generation 2) in comparison with what can be built today (Generation 3+ or Generation 3++).
On 11th March, Japan experienced an earthquake in near Sendai 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. Prior to this event the United States Geological Survey had only 6 recorded earthquakes of 9.0 or greater. While Richter Scale measures total energy of a quake, another other key measure of severity of an earthquake, often more relevant for human impacts, is peak ground acceleration (PGA). In this case it appears the Sendai quake was moderate, with PGA of around 0.5. This compares with the recent Christchurch quake, with a smaller Richter Scale value, but a much higher PGA of 2.2. Taken together, we can safely say that this quake was moderate to severe.
However, 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. This gives us a final and tragic element of context, being the greater tragedy unfolding in Japan. This catastrophe is likely to have caused fatalities in the 10,000s, and left great areas of the country in total wreck and ruin.
So by way of context, what I would like you to do is take an island nation with high population density and extensive coastal geography. Then overlay a high penetration of nuclear energy, with multiple reactors, in multiple locations, including some approaching end of life. Then overlay a two-phase natural catastrophe, with only one hour between each phase. The first phase is moderate to severe, and the second phase is catastrophic.
I am sure those of you who have ever conducted risk assessment exercises will agree that even if the job was to think worst case, it would be difficult to construct a scenario that would pose a more comprehensive and arduous test of the operational safety of nuclear power plants in the world today. That doesn’t mean this was completely unforeseeable, nor that better plans were not possible. But risk assessment means examining the interaction of multiple, relevant criteria. Altering some or all of the factors described above would change the baseline risk. For example, envisage a more severe quake, but in a more thinly populated nation. Depending on the extent to which you alter each factor, the overall risk of human harm could go up, or it could go down.
My assessment is that with all criteria taken together, the events unfolding in Japan represent quite an extraordinarily severe test of the operational safety of global nuclear power in 2011.
Let’s now turn to the response of Japan’s nuclear power plants to this event, sticking at this stage, as best I can, to high level facts that are not 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 introduced 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. The plants in question were Fukushima Daiichi and Fukushima Daini. These are Generation 2 Boiling Water Reactors (BWRs), each have been in operation for around 40 years.
- The tsunami 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.
There now appears to be a cascade of difficulties as a result of this loss of power. Controlled venting of radioactive gas has led to explosions as hydrogen levels have elevated. These explosions have caused injuries and resulted in further damage to some parts of the reactors, increasing the scale of this emergency. While most of the reactors have been brought to a safe condition, dangers remain. Some spent fuel, that has been used already, but needs to be cooled off for a few years before being moved to dry storage, appears to have becomes exposed. Again, the loss of power has created a concern here, and there are high levels of radioactivity near one of the pools. The impact is a local one; they are solid fuel rods, and the radioactivity is not easily dispersed as it is with a gas. But it is making the job of bringing things under control much harder. 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 go straight to www.bravenewclimate.com.au and follow the daily 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.
At present, the events at Fukushima have not resulted in any deaths attributable to nuclear power. The eventual impact of the releases of radiation to the environment cannot be known at this time, but most of the dispersed radiation, that has come as a gas, is likely to be very short lived . There has been a major evacuation, which has no doubt been highly distressing for all involved and entails risks of its own. But it was a wise procedure that stayed a step ahead of the difficulties at the power station. Injuries have been minimal in the context of this catastrophe (about a dozen related to the hydrogen explosions). The situation for the workers has certainly become riskier with elevated levels of radiation from the cooling pond and the larger releases of radioactive gas and this situation remains live. 8 — 10 of Japan’s 55 nuclear reactors are 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.
So, combining the extraordinary context with that high level summary of facts, what early conclusion might be drawn about the current and future role of nuclear power, particularly with regard to operational safety? Do we remain open to talking about nuclear power, or shut ourselves from that discussion? What do we do as a globe, riding a warming trajectory that ends in utter catastrophe, yet still hunting down and burning fossil fuels, liquidating lives as we go and polluting our air with soot, sulphur, and greenhouse gas? What do we do when nuclear power frightens us so much but, compared to other energy sources, harms us so little? What do we do in Australia, where we have never trod the nuclear path, remaining steadfastly at the teat of coal, with a clean state to transition to the very best nuclear technology? What about in rapidly developing nations, hungry for energy to bring their people out of poverty and under pressure to reign in greenhouse gas emissions? What about those developed nations with high levels of nuclear already, who could only return to fossil fuels to meet the demand?
It is up to each of you to answer those questions, and I don’t want to push an agenda. If you want my conclusion, read on.
We are witnessing the third severe incident in the 50 year history of the nuclear power industry, an industry which now has over 14,000 reactor years of experience. An extensive nuclear power sector, including some 40 year old reactors, in a densely populated nation has been tested by a catastrophic natural calamity. To date, two power stations of older design have experienced very serious emergencies, but contributed no deaths, minimal injuries in the context of the catastrophe, and environmental impacts that will likely be transitory and local. The nuclear power industry can, must, and will learn crucial lessons to further mitigate against such an emergency. But the history of the industry and the outcomes of this event so far suggest to me that, at their most basic, nuclear power stations must be among the sturdiest and least dangerous infrastructure in the world. And in a world that is quickly cooking itself through climate change, informed discussion on 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.