By Robert Alvarez, an Institute for Policy Studies senior scholar who served as a senior policy adviser to the Energy Department’s secretary and deputy assistant secretary from 1993 to 1999 (LOS ANGELES TIMES, 23/03/11):
The nuclear crisis at the Daiichi complex in Fukushima, Japan, has turned a spotlight on the severe dangers involved in storing spent nuclear fuel in pools. But the danger is not new.
In 2003, I cowrote a report with a group of academics, nuclear industry executives, former government officials and other researchers warning that spent fuel pools at U.S. nuclear power plants were vulnerable. The drainage of a pool might cause a catastrophic radiation fire, we reported, which could render an area uninhabitable greater than that created by the Chernobyl accident (roughly half the size of New Jersey).
The Nuclear Regulatory Commission hotly disputed our paper, which prompted Congress to ask the National Academy of Sciences to sort out the controversy. In 2004, the academy reported that U.S. pools were vulnerable to terrorist attacks and catastrophic fires.
According to the academy: “It is not prudent to dismiss nuclear plants, including spent fuel storage facilities, as undesirable targets for terrorists…. Under some conditions, a terrorist attack that partially or completely drained a spent fuel pool could lead to a propagating zirconium cladding fire and release large quantities of radioactive materials to the environment.” The NRC responded with a failed attempt to block the academy’s report.
As we’re seeing in Japan, it isn’t only terrorist attacks that can pose serious threats to spent fuel pools. These ponds were designed to be temporary, and to store only a small fraction of what they currently hold in the United States. But in the absence of a permanent storage site, nuclear plants here have to store increasing amounts of highly radioactive spent fuel at their facilities.
For nearly 30 years, the NRC has made clear that the United States urgently needs to develop a permanent waste repository. But that has taken much longer than anyone envisioned, and it has meant that the nation’s 104 nuclear power plants are legally storing spent fuel in onsite cooling ponds much longer, and at higher densities (on average four times higher), than was originally intended. And now that the Obama administration has called off proposed plans to store nuclear waste at the Yucca Mountain site in Nevada, fuel is likely to remain at the plants where it was used for decades to come.
This presents a serious threat. Our report found that, as in Japan, U.S. nuclear safety authorities don’t require reactor operators to have backup power supplies to circulate water in the pools and keep them cool if there is a loss of offsite power. Some reactor control rooms in the U.S. lack instrumentation to keep track of the water levels in pools. At one reactor several years ago, water levels dropped after operators failed to look into the pool area. Some reactors may not have necessary water restoration capabilities for pools.
A variety of events could conceivably cause a loss of pool water, including leakage, evaporation, siphoning, pumping, aircraft impact, an earthquake, the accidental or deliberate drop of a fuel transport cask, reactor failure or an explosion inside or outside the pool building. Industry officials maintain that personnel would have sufficient time to provide an alternative cooling system before the spent fuel caught fire. But if the water level dropped to even a few feet above the spent fuel, the radiation doses in the pool building could be lethal.
A 1997 report that Brookhaven National Laboratory did for the NRC found that a severe pool fire could render about 188 square miles uninhabitable, cause as many as 28,000 cancer fatalities and cost $59 billion in damage.
In the wake of the unfolding nuclear crisis in Japan, we clearly need a new policy that takes into account the likelihood that spent fuel will remain in onsite storage for some time to come. In our 2003 study, we recommended that all U.S. spent fuel older than five years should be placed in dry, hardened storage containers, which would greatly reduce the fire risk if water were drained from reactor cooling ponds. Casks should be placed in either thick-walled structures or in earthen berms capable of withstanding plane and missile impacts. We estimated this could be accomplished with existing cask technology in 10 years at a cost of $3 billion to $7 billion.
Moreover, future reactors should be designed so that temporary cooling ponds are encased in heavy concrete. Germany took such steps 25 years ago in response to the threats posed by accidental fighter jet crashes and terrorist attacks.
Safely securing spent fuel should be a public safety priority of the highest degree in the United States. The cost of fixing America’s nuclear vulnerabilities may be high, but the price of doing too little is incalculable.
Fuente: Bitácora Almendrón. Tribuna Libre © Miguel Moliné Escalona