Skip to main content

No Seismic Risk List at the NRC

Earlier today, an article appeared on that raised a few eyebrows:

The reactor with the highest risk rating is 24 miles north of New York City, in the village of Buchanan, N.Y., at the Indian Point Energy Center. There, on the east bank of the Hudson, Indian Point nuclear reactor No. 3 has the highest risk of earthquake damage in the country, according to new NRC risk estimates provided to

A ranking of the 104 nuclear reactors is shown at the bottom of this article, listing the NRC estimate of risk of catastrophic failure caused by earthquake.

This is what reporters should do – try to ferret out information- and what reporters should not do – incorrectly present the information.

The problem here is that NRC has no such ranking and no such list. Instead, the “list” is something much more tentative in nature:

The objective of the GI-199 Safety/Risk Assessment was to perform a conservative, screening-level assessment to evaluate if further investigations of seismic safety for operating reactors in the central and eastern U.S. (CEUS) are warranted consistent with NRC directives. The results of the GI-199 SRA should not be interpreted as definitive estimates of plant-specific seismic risk. The nature of the information used (both seismic hazard data and plant-level fragility information) make these estimates useful only as a screening tool. The NRC does not rank plants by seismic risk.

If I read this correctly, the NRC was loosely compiling some information to use as guidance for taking further steps. The information was not intended to be considered definitive. Here’s what the NRC considers definitive.

During the mid-to late-1990s, the NRC staff reassessed the margin beyond the design basis as part of the Individual Plant Examination of External Events (IPEEE) program. The results of the GI-199 assessment demonstrate that the probability of exceeding the design basis ground motion may have increased at some sites, but only by a relatively small amount. In addition, the Safety/Risk Assessment stage results indicate that the probabilities of seismic core damage are lower than the guidelines for taking immediate action.

That’s more like it. Ground motion (or ground acceleration) is different than a Richter scale measurement, but both concern earthquakes.

Operating nuclear plants in the United States remain safe, with no need for immediate action. This determination is based on NRC staff reviews of updated seismic hazard information and the conclusions of the Generic Issue 199 Screening Panel. Existing plants were designed with considerable margin to be able to withstand the ground motions from the “deterministic” or “scenario earthquake” that accounted for the largest earthquake expected in the area around the plant.

I’m not enough of a seismologist to know how the Japan earthquake fits into this equation.

In any event, we need to wait until Japanese authorities have determined the relative damage done to the Fukushima Daiichi plant by the earthquake and by the tsunami.

MSNBC might do better to tone down sensationalism and recognize the complexity of the issues involved in an “earthquake list.”


Atomikrabbit said…
MSNBC viewers don't want science, nuance, or complexity - they want their raw meat antinuclear talking points.

Popular posts from this blog

A Billion Miles Under Nuclear Energy (Updated)

And the winner is…Cassini-Huygens, in triple overtime.

The spaceship conceived in 1982 and launched fifteen years later, will crash into Saturn on September 15, after a mission of 19 years and 355 days, powered by the audacity and technical prowess of scientists and engineers from 17 different countries, and 72 pounds of plutonium.

The mission was so successful that it was extended three times; it was intended to last only until 2008.

Since April, the ship has been continuing to orbit Saturn, swinging through the 1,500-mile gap between the planet and its rings, an area not previously explored. This is a good maneuver for a spaceship nearing the end of its mission, since colliding with a rock could end things early.

Cassini will dive a little deeper and plunge toward Saturn’s surface, where it will transmit data until it burns up in the planet’s atmosphere. The radio signal will arrive here early Friday morning, Eastern time. A NASA video explains.

In the years since Cassini has launc…

Sneak Peek

There's an invisible force powering and propelling our way of life.
It's all around us. You can't feel it. Smell it. Or taste it.
But it's there all the same. And if you look close enough, you can see all the amazing and wondrous things it does.
It not only powers our cities and towns.
And all the high-tech things we love.
It gives us the power to invent.
To explore.
To discover.
To create advanced technologies.
This invisible force creates jobs out of thin air.
It adds billions to our economy.
It's on even when we're not.
And stays on no matter what Mother Nature throws at it.
This invisible force takes us to the outer reaches of outer space.
And to the very depths of our oceans.
It brings us together. And it makes us better.
And most importantly, it has the power to do all this in our lifetime while barely leaving a trace.
Some people might say it's kind of unbelievable.
They wonder, what is this new power that does all these extraordinary things?

Missing the Point about Pennsylvania’s Nuclear Plants

A group that includes oil and gas companies in Pennsylvania released a study on Monday that argues that twenty years ago, planners underestimated the value of nuclear plants in the electricity market. According to the group, that means the state should now let the plants close.


The question confronting the state now isn’t what the companies that owned the reactors at the time of de-regulation got or didn’t get. It’s not a question of whether they were profitable in the '80s, '90s and '00s. It’s about now. Business works by looking at the present and making projections about the future.

Is losing the nuclear plants what’s best for the state going forward?

Pennsylvania needs clean air. It needs jobs. And it needs protection against over-reliance on a single fuel source.

What the reactors need is recognition of all the value they provide. The electricity market is depressed, and if electricity is treated as a simple commodity, with no regard for its benefit to clean air o…