March 12, 2011 | 19
The extent of the damage at Japan’s Fukushima nuclear facility is still unknown, but comparisons to Chernobyl were inevitable as soon as fuel rods became exposed and an explosion rocked the site. But is the analogy accurate?
Chernobyl, the worst nuclear disaster thus far in the history of the industry, was the result of a drill that went catastrophically wrong on April 26, 1986. The drill, ironically, was intended to test a known time gap between a potential power failure and the performance of backup generator pumps. Workers had been made aware that the experiment would be taking place, but it still ended catastrophically.
Accidents–even unthinkably irrevocable accidents–do happen. The nuclear industry has measures in place, from protective containment barriers to backup generators, in case of an accident. A magnitude 9.0 earthquake, however, isn’t just an accident. It’s an encompassing situation that impacts every aspect of possible recovery in an ongoing, dynamic environment.
Another key difference is that the Chernobyl reactor used carbon to slow down neutrons, a key part of the fission reaction, while Fukushima’s reactor cores are cooled by light-water, which greatly reduces the amount of radioactive soot in the wind.
Nevertheless, the power grid at the Fukushima site, 150 miles from Tokyo, has been knocked out. Backup generators have been rendered useless by tsunami floods. The containment dome may have been damaged in the earthquake and batteries with an eight-hour life span are being flown in to augment those on site. Multiple reactor cores have been affected.
The explosion and plume of white that rose last night may have been the result of hydrogen deflagration and detonation. At least one study found that it’s possible for hydrogen buildup in a reactor core to form flammable and detonable mixtures, jeopardizing the containment integrity.
What is a Nuclear Meltdown?
A nuclear reactor core meltdown occurs when the fuel rod in the reactor core is unable to remain cool. Fuel rods in nuclear reactor cores are filled with uranium oxide ceramic pellets in zirconium cladding. When the "spent" rods are removed from the reactor core they are stored in pools with racks of rods at the bottom or dry casks, usually on site. Periodically the fuel rods are removed from reactor cores and refreshed.
While such rods are spent in terms of their usefulness in the reactor core, they still contain deadly radioisotopes that remain hazardous. Like the fuel rods in the reactor core, spent fuel rods must be kept cool or the release of cesium-137 and strontium-90, among other deadly radioisotopes, could result. Like nuclear power, which has "peaceful" and "wartime" uses, radioisotopes can be deadly when released unexpectedly into the environment in large doses but can also be used for medicinal purposes.
There’s less heat in the spent fuel rods than in the reactor core’s fuel rods, so the danger posed is less intense, but in an encompassing crisis such as a magnitude 9.0 earthquake affecting multiple sites at once, the ability to cool storage pools can be greatly impaired. While it takes longer for the spent fuel rods to become as hazardous as a reactor core meltdown, the ongoing nature of Japan’s crisis presents a unique hazard. The Fukushima facility is old, by the standards of modern technology, with construction having begun in the 1960’s and ending in 1971.
Toxic Waste and Fault Lines
Getting rid of nuclear waste is an issue that continues to plague the industry. In the United States, the Yucca Mountain waste repository project in Nevada, (with an estimated budget of $96 billion, of which over $13.5 billion was spent) was finally canceled by the Obama Administration amid concerns that the expense far exceeded the benefit of transporting spent fuel and storing it at the site. Nevada is one of the most seismically active states and it was discovered that the Yucca Mountain project was placed on a fault line.
In the United States, spent nuclear fuel is not reprocessed as it is in Japan. Various processes, such as deconversion of depleted uranium, are conducted, however. Depleted uranium is left over after uranium has been enriched for use in nuclear reactors or weapons, blurring the line between peaceful and wartime uses of nuclear power.
Many issues related to the process of creating and shipping depleted uranium have been identified. The United States uses depleted uranium to create weapons such as shells and projectiles, to enhance armor-piercing capability. When a weapon containing depleted uranium strikes a solid object a spray of radioactive dust results.
Depleted uranium is stored in 14 ton cylinders at the site of enrichment plants. According to the Nuclear Regulatory Commission, a chemical hazard exists from environmental exposure. The same is true for spent nuclear fuel stored on the site of nuclear plants.
A map of the Fukushima site, where a state of emergency has been declared for five nuclear reactors at two sites shows both a spent fuel rod pool and a dry storage facility. It’s unclear how much spent fuel is on the site and how much has been moved to the processing plant or interim facility. Spent fuel is generally cooled in pools for at least five years prior to being moved to dry casks or for reprocessing.
Hundreds of tons of Japan’s spent nuclear fuel have been moved for reprocessing at the Rokkasho facility. Rokkasho and other facilities are also in danger as aftershocks, blackouts and tsunami warnings remain in effect, impacting the ongoing ability to cool multiple endangered reactors and the spent fuel that once generated power from their cores. Der Speigel reported that Rokkasho is also running on emergency power.
The Improbable Can Occur
The complexity of the situation in Japan is significant and ongoing, and it’s likely that all of the reactor cores at Fukushima will remain offline for the foreseeable future. Despite the necessity to prepare for the worst to whatever degree it is possible, business models are not built around contingencies that seem so statistically improbable as to nearly be rendered unthinkable, and yet such events do occur. In the wake of Fukushima, 60,000 Germans are currently protesting the use of nuclear power by forming a human chain. Meanwhile the International Atomic Energy Agency is reporting that over 140,000 people have been evacuated from the regions around Japan’s nuclear power plants.
In the aftermath of Hurricane Katrina, the Waterford nuclear plant outside New Orleans was plunged into a blackout, reliant on backup generators to keep the reactor core and spent fuel on site cool. The issue didn’t make the news because it was a near miss, just as Three Mile Island notoriously missed being far more devastating by a few ticks.
Opinions around nuclear energy tend to be binary, with industry proponents acting as if nothing could possibly go wrong while critics, terrified of nuclear apocalypse, remain convinced that old nuclear plants are time bombs. A distinction is often made between peaceful and wartime uses of nuclear technology, but this is rendered irrelevant by the development of depleted uranium and by the earthquake in Japan, which shows that "peaceful" uses of nuclear power can have extremely damaging extrinsic consequences in the aftermath of a meta-emergency.
We have long been warned of what seems to be another improbable yet very real danger: 30,000 nuclear missiles stud the earth. The United States and Russia own 96 percent of these missiles. Russia keeps their Cold War Era missiles focused on the US and Canada, while the US targets Russian command centers.
On a regular day, running errands and living life, it’s hard to imagine how one of these thermonuclear weapons, many of which are connected to a hair-trigger response system, might not comply with the safety and security systems that have been created to keep them from dislodging. But as the mysterious white plume rose over Fukushima, the distant possibility of old systems and natural disasters pairing up to show us again how short-sighted we are came into sharp focus.
About the Author: Rita J. King is the Founder and Creative Director of Dancing Ink Productions, a company that works with global clients focused on the emergence of a new global culture and economy in the Imagination Age. For several years she worked as a journalist covering the nuclear industry, including a specific focus on Indian Point nuclear power plant on the Hudson River in Buchanan, New York.
King is Innovator-in-Residence at IBM’s Analytics Virtual Center, a former Senior Fellow at The Carnegie Council for Ethics in International Affairs in New York City and a current Senior Fellow at the Center for the Study of the Presidency & Congress in Washington DC. Her essays, various writings and works of art have been commissioned, published and exhibited globally.
Rita is a frequent international speaker on the subject of productive creative collaboration and the cultural and economic implications of the Imagination Age. Her work has been featured in or on The New York Times, the Village Voice, Press TV, TIME, CNN, NPR, The Guardian, BBC, Boing Boing, Wired, "MSNBC’s The News with Brian Williams," VentureBeat and strategy+business, among others.
Follow Rita on Twitter: @RitaJKing
The views expressed are those of the author and are not necessarily those of Scientific American.