On August 14th the largest electrical blackout in history caused sixteen nuclear plants to automatically shut down in the U.S. and Canada.
Nuclear power plants run on offsite power, not their own reactors.
If the electrical grid fails, reactors are designed to automatically close down. One or more diesel generators are supposed to start up, with capacity to power basic safety equipment, including the cooling system. If generators fail, the reactor cannot be restarted without offsite power.
David Lochbaum of the Union of Conerned Scientists compares this to a car without a battery, further explaining, "Nuclear reactors will automatically trip upon detection that the electrical grid is going down. Nuclear plants generate electricity by passing steam through a turbine. The electrical grid going down is to a nuclear reactor and its turbine/generator what stepping on the clutch is to a manual transmission car engine when traveling at 65 mph. To protect the turbine from spinning too fast with its ‘clutch depressed,’ valves that admit steam to the turbine close in seconds. Since the steam no longer has anyplace to go, there’s a pressure pulse racing back towards the reactor. To limit the size of this pressure pulse, the reactor automatically trips. With the reactor down, there’s less steam with no place to go. As long as it is available, offsite power is the preferred power source for the nuclear plant. However, once the electrical grid fails, the emergency diesel generator automatically starts and supplies power to safety equipment. The emergency diesel generators cannot provide enough power to operate the non-safety equipment at the plant."
Attacks, ice, or wind storms can also knock out transmission lines to nuclear plants for extended periods. Nuclear plants that lose all power can quickly be converted into giant "dirty bombs", wind-driven clouds of radioactive isotopes.
Something has to continually pump circulating cooling water to the reactor and to the giant, densely-packed waste fuel pools, or those fuel rods, active and spent, will catch fire and reproduce Chernobyl, or worse. Restoring off-site power to the 16 nuclear plants during the blackout – long before reactors powered back up – was a high priority in order to restore safety and security systems.
But back-up generators may have been strained and some may have failed. Reporting will not be available to the public for weeks, meaning there may have been close calls about which we know nothing at this point. Many are concerned about what happens if the diesel generators runout of gas. When asked about whether that presented a potential danger, Lochbaum said, "The long-term threat to the EDGs [emergency diesel generators] is not lack of fuel but lack of cool." Emergency diesel generators are tested for one hour per year. Every five years, testing is required for a full day, but not under conditions encountered if the generators must run for hours in hot weather. Most blackouts occur during hot weather when electricity demand is high. This is also when the air-cooling of diesel generators is least effective, and overheating is most likely.
LOOP, industry jargon for "loss of offsite power", is considered the leading contributor to reactor core risk due to the recognized unreliability of emergency diesel generators.
On April 26, 1986, a complex of four nuclear reactors in the Ukrainian town of Chernobyl ran a safety test. The Soviet nuclear power program wanted to find out if it could bypass the cost of a technologically complex system that would crank up emergency diesel generators within seconds in the event of a loss of external power – a loss like that which just shut down 16 nuclear reactors in the northeastern United States and parts of Canada.
Just as those nuclear plants automatically shut down during the blackout, Soviet nuclear plants were designed to automatically shut down, because nuclear plants can become very unstable if they slow down. At Chernobyl, they wanted to see if they could provide enough backup cooling to the reactor with their own remaining nuclear-generated power as the reactor wound down, at least for a few minutes, while they manually brought the diesel back-up generators on line.
That experiment failed spectacularly and created the biggest nuclear power disaster on record. The reactor quickly heated up and exploded, contaminating over 6,000 square kilometers with dangerous isotopes for centuries and triggering the forced resettlement of 415 towns. Again, the goal of this tragic experiment was to delay the use of emergency diesel generators in the event of a grid shutdown. Operators ran a test to see if they could wait a few minutes before starting emergency diesel generators – in case of loss of offsite power like that in the U.S. and Canada.
Many diesel generators have failed in the U.S., 138 between 1985 and 2000 by my reckoning.
In some cases, a reactor core might last up to eight hours without backup generators – although deteriorating conditions could damage safety systems and impair workers’ ability to protect the core.
At the Fermi plant near Detroit, all four backup generators were found inoperable on February 1, 2003. Had the regional blackout happened at that time, there could have been a full-scale evacuation called for the Detroit area, further complicated because sirens to alert citizens within ten miles would not have worked because the electricity was off. Reportedly, the sirens at all 16 nuclear plants affected by the blackout were rendered inoperable.
In June 1998 a tornado downed all external transmission lines at Ohio’s Davis-Besse plant. The diesel generators ran for twenty-six hours until they overheated and failed. The outside air was 93 degrees. One of the outside transmission lines had been restored one hour prior to the EDG failure.
According to Public Citizen, there have been 15 instances in the past 12 months in which emergency generators have either malfunctioned or failed to operate at all, in certain cases leading to plant shutdowns. On several occasions all backup generators failed at once.
The Brunswick I unit in Southport, NC lost off-site power for nine hours in March 2000, during which time both emergency generators failed simultaneously. One was restarted in 18 minutes, after water surrounding the core had risen several degrees.
Failures of emergency diesel generators (EDGs) occur frequently – 138 have been recorded since 1985, the majority discovered during tests when there was no emergency requiring their immediate use. Fifty-nine of these failures were failures to start, and 79 were failures to run. Causes of failure ranged from design error, to manufacturing error, construction/installation error, design modification error, accidental actions, incorrect procedure or failure to follow procedure, inadequate training, inadequate maintenance, fire/smoke, humidity, high/low temperature, electromagnetic disruption, radiation, bio-organisms, dirt, bad weather, and calibration failures. This wide spectrum of error-variables, for a system upon which the reactor core and spent fuel pools depend during a blackout, create an incalculable number of unforeseen consequences. This is comparable to having a vehicle, upon which your life may depend, sitting unused in a parking lot for a year at a time, then depending on it to take you out of harm’s way at 100 miles per hour.
The NRC regularly allows nuclear plant operators to violate safety regulations.
Since 2000, the NRC has issued 106 Notices of Enforcement Discretion (NOED), which allowed utilities to continue operations even while in violation of regulations that require it to shut down for safety purposes. This is like the police allowing drivers to skip vision tests or drive while under the influence. NOEDs have been issued to plants regarding their faulty diesel generators.
Due to industry and NRC secrecy, paradoxically invoking security as a justification for that secrecy, the public may never know the extent of problems experienced with diesel generators at the 16 plants affected by the recent blackout.
The Bush administration wants to license a hundred more of these things.
"The massive failure that knocked out power to the Northeast and Midwest U.S. and Canada looks like the disastrous blackouts of 1965 and 1977," said Lloyd Dumas, author of "Lethal Arrogance: Human Fallibility and Dangerous Technologies". "Once again we are reminded of our technological vulnerability and the impossibility of eliminating failure. Electric systems were connected together to make blackouts a thing of the past. In 1965, when part of the grid failed and the rest took over, the strain caused more to fail. The system designed to prevent blackouts triggered a progressive collapse that blacked out the entire Northeast United States."
"Technology," however, as Dr. Alf Hornborg, professor of Human Ecology at Lund University in Sweden says, "is a social phenomenon." There is no way to understand how technological successes and failures occur without looking at social relations, in particular public policy.
Besides the technological response to the blackouts of decades past, there was a policy response. Former US Secretary of Energy Bill Richardson has said that "in the search for the source of [the August 14] blackout, the underlying cause has been all but ignored: deregulation. In principle, deregulation of the power industry was supposed to use the discipline of free markets to generate just the right amount of electricity at the right price. But electric power, it turns out, is not like ordinary commodities. Electricity can’t be stored in large quantities, and the system needs a lot of spare generating and transmission capacity for periods of peak demand like hot days in August. The power system also requires a great deal of planning and coordination, and it needs incentives for somebody to maintain and upgrade transmission lines. Deregulation has failed on all these grounds. Yet it has few critics. Evidently, even calamities like the Enron scandal and now the most serious blackout in American history are not enough to shake faith in the theory."
Nor the attendant faith in lethal technologies, it would seem. Within the whole cascade of energy disorder that occurred on August 14th, how near the brink of a radiological accident did we come? "For our own good", we may never know.
STAN GOFF is the author of "Hideous Dream: A Soldier’s Memoir of the US Invasion of Haiti" (Soft Skull Press, 2000) and of the upcoming book "Full Spectrum Disorder" (Soft Skull Press, 2003). He is a member of the BRING THEM HOME NOW! coordinating committee, a retired Special Forces master sergeant, and the father of an active duty soldier. Email for BRING THEM HOME NOW! is firstname.lastname@example.org.
Goff can be reached at: email@example.com