The recent images from Japan – swaying skyscrapers, the tsunami’s shocking devastation and the Fukushima Daiichi nuclear power plant crisis – are harrowing. Our hearts go out to all of those affected by this unprecedented earthquake.
As we watch the events unfold at the Fukushima nuclear power plant we are struck by how yet again the interdependencies of water and energy are on full display. The central problem at the plant is the failure of the plant’s reactor cooling system. (Not to be confused with the steam condenser cooling system that cools steam after it turns a power plant’s turbines.) After the tsunami, backup generators that power the motors, valves and instruments that provide cooling water for the plant’s reactors failed. Cooling water could no longer be circulated into the core, allowing the fuel rods to generate so much heat that the water began to evaporate, exposing the fuel rods to the air. Once exposed, the fuel rods overheat and, in the worst case scenario, melt, releasing radioactive steam.
Not to be ignored are the spent fuel rods which in Japan, as in America, are largely kept in storage pools at the power plants. The storage pools are designed to keep the spent fuel rods from overheating, but as in the reactor cores, the lack of power is allowing the rods to evaporate the remaining cooling water, posing yet another – and perhaps more serious – radiation danger.
To avoid the nightmare full-meltdown scenario, seawater is being injected into the reactors and spent fuel pools to cool the fuel rods, a last-ditch attempt that ensures they will never operate again. As of now a skeleton crew of brave technicians is struggling to keep dumping water onto the fuel rods, and the situation remains critical.
While emergency cooling water availability is not a problem for the Fukushima plant because it sits next to the ocean, limited access to electricity is making it difficult to pump that abundant water into the reactors and spent fuel pools. And here lies the water dilemma for any outdated power plant, fossil-fuel or nuclear: proximity to the ocean brings a ready supply of cooling water, but also exposure to sea level rise and once-in-a-lifetime dangers like tsunamis. Plants located inland which rely on freshwater from lakes or rivers for cooling water might be safe from oceanic threats, but are subject to droughts, floods and water temperature swings.
Many of the United States' power plants are archaic, with fossil fuel plants that date back to the 1940s and nuclear plants built in the early 1970s. In fact there are 23 nuclear power plants in the country that are of the same outdated model as the Fukushima plant. Since 2002, new United States power plants are required to use closed-cycle cooling, a far less water-dependent form of steam condenser cooling than outmoded once-through cooling. (Again, this is not the same kind of cooling system used to keep nuclear plant reactor cores operating safely.) Yet there are over 500 aging power plants in the United States that still rely on once-through cooling. The EPA is now poised to release a rule that ideally will encourage many older power plants to upgrade their antiquated cooling system technology. These aging plants continue to operate because they are profitable, but as we've seen in Japan, power plants that rely on obsolete technology pose unexpected dangers and have hidden costs.
For now the focus must remain on the safety of the people of Japan. But we also need to rethink how the United States generates power and ramp up renewable energy and energy efficiency. We have to face the reality that our own country’s rapidly-aging power plants – both nuclear and fossil fueled – must be replaced by new, efficient technology. We can have a safer and cleaner energy future, but we must first overcome our nation’s short-sighted resistance to change.