The tragic natural disasters that unfolded in Japan in March, and in particular their impact on cooling systems at the Fukushima-Diiachi nuclear installation, have prompted considerable soul-searching by the world’s energy policy makers as they wrestle with the challenges of security of energy supply and climate change.
Certainly, the earthquake and tsunami resulted in nuclear facilities the world over being reassessed, with a view to appraising their robustness to natural — if exceptional — phenomena. In Germany, for example, many nuclear installations have been ordered closed temporarily to allow a thorough assessment, while China has suspended its new build program for nuclear power until the new assessments are completed.
What has been much less widely publicized is the potential impact of a major earthquake bringing about the failure of an embankment dam. Indeed, at least one Japanese dam reportedly did fail in the aftermath of the magnitude 9 earthquake on March 11.
When this dam collapsed on March 12, the resulting flood apparently washed away a number of houses and damaged others, leaving several people missing and others dead. Fujinuma Dam, on a tributary of the Abukuma River in Fukushima Prefecture, was reported to be 17.5 meters high and 133 meters long.
Relevant authorities subsequently inspected 252 dams in the region, of which seven were found to be damaged. Six earthen embankment dams were determined to have shallow cracks, and one concrete gravity dam suffered a small-scale earth slide in the reservoir area. However, given the scale of this earthquake and its after effects, these findings seem to affirm the high construction standards used during the development of these structures.
While it is clear that these worrying developments have not attracted the particular scrutiny of the world’s press, they are, nonetheless, hugely significant in light of the ongoing push to develop more hydroelectric capacity in response to the world’s energy security and climate challenges. Around the globe, new hydroelectric developments are under way, alongside repowering and refurbishment programs that are both expanding hydro capacity and extending project lifespans.
The very longevity of hydro projects, one of their key advantages, makes it even more likely that any particular installation will be exposed to such rare events over the course of its perhaps 100 year or more lifespan. And as such it is vital that these installations are able to withstand potentially rare, albeit significant events.
There is already some evidence of this cautious policy being put in place beyond the shores of Japan. In the Philippines, for example, National Irrigation Administration (NIA) chief Antonio Nangel is reportedly forming a technical working group to assess the structural soundness of Angat Dam, which sits on the Marikina geological fault line.
“We will study it. I will form the technical working group to look into its physical aspects,” Nangel reportedly said, adding: “At the time it was designed, Angat Dam was found to be stable. Even all the dams that we have in the Philippines are all safe and we see no problem,” he said.
And here is perhaps the nub of the issue: Angat, like the Fukushima nuclear facility and most likely Fujinuma Dam too, clearly met the design standards of the day, but do the standards of 40 years ago necessarily stand up to modern-day scrutiny? There is perhaps a more obvious similarity between the hydro and nuclear industries. Like the civil nuclear sector, the hydropower industry already goes to incredible lengths to ensure that failures never occur. It would perhaps be prudent for dam operators worldwide to mimic the nuclear industry in another way and ensure that all potentially vulnerable facilities are now assessed for robustness in the event of a major earthquake, even in areas that are generally considered to have a low occurrence of seismic events.
Some indication of the scale of such a task is provided by our feature on page 16, which delivers an outlook on the future of hydro development worldwide from the U.S. Energy Information Administration. Stepping away from conventional hydro altogether, on page 22 we take a look at developments in the new hydro sector of ocean/tidal/stream technology, where testing facilities are helping to accelerate commercialization.
Don’t forget, too, this is our annual directory edition. This issue includes our buyers’ guide to the hydro industry, a comprehensive listing of all those companies providing products and services to this sector. We hope this information proves to be useful in the year ahead.