The Isar plant in Bavaria, Germany, which was commissioned in 1979. Via Wikipedia
The world's nuclear reactors are getting old, which poses some big problems: How do we keep aging designs running safely while still relying on their power production? According to a new report from the UN's nuclear power watchdog, nuclear reactor safety improved worldwide last year, but the day in which we have to replace old reactors with new production capacity is approaching.
The International Atomic Energy Agency's Nuclear Safety Review 2013 report highlights strides made by nuclear power plants (NPPs) worldwide following 2011's Fukushima Daiichi disaster. According to the report, an "overwhelming majority" of countries that use nuclear power conducted stringent risk assessments and stress tests on their reactor networks in 2012, "with the aim of evaluating the design and safety aspects of plant robustness to protect against extreme events, including: defence in depth, safety margins, cliff edge effects, multiple failures, and the prolonged loss of support systems."
That focus on evaluation and preventative safety measures paid off. A key metric for safety the IAEA uses is total number of unplanned reactor shutdowns, known as scrams, per 7,000 operating hours. Whether automatic or manual, unplanned shutdowns of reactors are indicative that a reactor isn't operating properly, which is naturally a safety concern. According to the IAEA, shutdown rates have remained low in recent years, as shown by the graph at right, although the agency does say there is room for improvement.
Still, as the IAEA notes, "As of the end of 2012, safety performance indicator data on 437 NPPs and over 15,000 reactor-years of commercial operation showed that the operational safety level remained high." Overall, that's good news.
But of those 437 plants the IAEA received data on, 162 have been in operation for more than 30 years, and 22 for more than 40. While China and India have made big pushes for nuclear recently, much of the rest of the world remains reliant on reactors built during nuclear's golden age.
In the US, a cheap fracking boom has pushed expensive nuclear projects to the wayside. Meanwhile, American reactors get older. As the US Nuclear Regulatory Commission noted in a 2011 report, many US reactors are passing their expiration dates. The new IAEA report notes that the Fukushima disaster showed the importance of regularly updating reactors with new safety technology as it's developed, a lesson that it says nations have taken to heart.
Yet while reactors can be pushed beyond their designed lifespan, they won't run forever. Older reactors aren't as safe as newer ones, and eventually the cost of keeping them up to date is going to outweigh their utility. And thus we have the 800 pound gorilla: What do we do with decommissioned reactors and their radioactive material?
The IAEA studied the current state of transportation and disposal of nuclear material, and found that as the industry continues to grow, so have the number of potential problems in dealing with radioactive materials. Part of the issue is the increasing amount of radioactive material being moved around the world, either for reactor use or disposal, and the IAEA suggests a renewed focus on international regulations to try to bring everyone in line.
The larger problem, especially as reactors near decommission, is final disposal. From the report:
The current lack of available disposal facilities in countries for all types of radioactive waste. Although noticeable progress on the geological disposal of such waste has been made by some countries, the absence of such disposal facilities means that additional storage capacity is needed for radioactive waste and spent fuel.
That finding shouldn't come as too much of a surprise, as nuclear waste disposal remains a niche industry, and more capacity is only going to be developed as more fuel is disposed. But with an aging fleet, there's eventually going to be a relative surge in reactor decommissioning, which means a boost in demand for disposal capacity that's going to have to come from somewhere. And considering that we are talking about nuclear waste disposal, finding new space is a longer process than just chucking it all into a landfill.
So where does the IAEA report leave us? Where we've known to be for some time. The Fukushima disaster has obviously renewed focus on nuclear safety, which appears to have done the industry good. At the same time, the worldwide fleet continues to get older, and sometime soon we're going to start seeing a rise in plants being decommissioned. What we do with them, and how we replace them, remains a question that hasn't been fully answered.