Early Questions After Japan
Published: March 17, 2011
As Japan’s nuclear crisis unfolds, nations around the world are looking at the safety of their nuclear reactors — as they should. But most are also waiting until all the facts are in before deciding whether or how to change their nuclear plans. The Obama administration has vowed to learn from the Japanese experience and incorporate new safety approaches if needed.
That makes sense to us — so long as there is rigorous follow-through. The operator of the stricken plant, the Tokyo Electric Power Company, and the Japanese government have been disturbingly opaque about what is happening at the Fukushima Daiichi complex and about efforts to prevent a meltdown and the potential public threat.
That has deepened anxieties in Japan and around the world and led the United States government to take the extraordinary step of announcing that the damage to at least one of the crippled reactors may be far worse than Tokyo had admitted — and urging Americans there to
move further away from the official safety perimeter.
Still, enough is known to begin raising questions about our own nuclear operations. We hope regulators and industry leaders are equally forthcoming about this country’s vulnerabilities and challenges.
One of the first questions is whether current evacuation plans are robust enough. The Nuclear Regulatory Commission requires plant operators to alert the public within a 10-mile radius if a dangerous plume of radioactivity will be heading their way, and local officials decide whether to order an evacuation. The American Embassy in Japan, based on advice from Washington regulators, has told Americans there to evacuate to a radius of about 50 miles from the Fukushima plant.
Why wouldn’t a worst-case accident here merit the same caution? The difficulty, of course, is that some plants — including Indian Point north of New York City — are within 50 miles of
millions of people. Regulators will need to clarify this discrepancy or start coming up with more ambitious evacuation plans.
Regulators need to immediately review their safety analyses of two California plants, which, like the Fukushima plant, are located on the coast and near geological faults and might theoretically face the double calamity of an earthquake and tsunami.
The type of reactors used at the Fukushima plant — made by the General Electric Company,
they are known as Mark 1 boiling-water reactors — have long been known to have weak
containment systems. In Japan, they appear to have been ruptured by explosions of escaping hydrogen. American regulators will need to determine whether similar reactors in this country are vulnerable and whether modifications in newer versions have made them sufficiently safe.
The stricken Japanese complex housed six reactors in close proximity; explosions, fires and radiation spread damage among four of them and has made rescue efforts harder. Regulators will need to look at whether American nuclear plants with multiple reactors are vulnerable to the same cascading effects. In recent days, a new danger has emerged in the spent fuel pools adjacent to the reactors. At least one has apparently lost its cooling water and another is cracked and possibly losing water. If the fuel catches fire, it could spew radiation over a large area. Regulators here may need to expedite the removal of some spent fuel from pools to dry storage in casks.
So far, the all-important lesson would seem to be: have sufficient emergency power at hand to keep cooling water circulating in the reactors to prevent a meltdown.
The Japanese reactors seem to have survived one of the most powerful earthquakes ever recorded without major structural damage. The crisis developed because the plant lost electrical power from the grid and the tsunami knocked out its backup diesel generators. American regulators must ensure that all nuclear plants have enough mobile generators or other backup
power in place if their first two lines of defense are disabled.