17 Jun 2010: Report

The Nuclear Power Resurgence:
How Safe Are the New Reactors?

As utilities seek to build new nuclear power plants in the U.S. and around the world, the latest generation of reactors feature improvements over older technologies. But even as attention focuses on nuclear as an alternative to fossil fuels, questions remain about whether the newer reactors are sufficiently foolproof to be adopted on a large scale.

by susan q. stranahan

In 2007, the first application to build a new reactor in the United States in more than three decades was filed with the Nuclear Regulatory Commission (NRC). By the end of that year, four more applications had landed at the agency. In 2008, 12 additional applications arrived, with one more filed in 2009. Nuclear backers proclaimed a “renaissance” underway.

The NRC, which over the years had lost personnel because of a shortage of work, geared up, hiring 1,000 new staffers to handle the licensing requests. Things got so crowded at the Office of New Reactors that in May the agency broke ground for a third office building in suburban Washington.

A new generation of nuclear power is indeed taking shape, driven, in large part, by a growing sense among environmentalists and policymakers that any strategy to wean the U.S. off planet-warming fossil fuels must include construction of more nuclear power plants. But how safe will this new generation of nuclear power plants be in comparison to the existing fleet of 104 plants that currently generate 20 percent of the nation’s electricity?

Perhaps the most critical difference is that the new designs are simpler and rely less on human or mechanical intervention in the case of accidents. Settling on a standard design was one recommendation made after the 1979 accident at Three Mile Island. Some designs, for example, use gravity to provide emergency cooling water rather than pumps, which can fail. Some reactors now have redundant safety features, like extra pumps. In addition, the NRC has increased regulatory scrutiny of the new designs, ordering, for example, additional safety features or engineering changes to improve delivery of emergency cooling water.

Russ Bell, director of new plant licensing at the industry’s Nuclear Energy Institute in Washington, maintains that the new plants will be extraordinarily safe. Government risk assessments for the new reactor designs say that an accident that could damage the reactors’ cores would likely occur once every 10 million years — an order or two of magnitude lower than the U.S’s existing nuclear power plants. And even were a core-damaging accident to occur, Bell says that does not mean radiation would escape, since the reactors have containment buildings and systems designed to prevent releases of radioactivity.

Since the terrorist attacks of Sept. 11, 2001, all containment structures on new nuclear plant designs in the U.S. have been re-engineered to withstand the direct impact of a jetliner. This does not mean, however, that new containment designs are foolproof. The containment structure on a popular Westinghouse design, which seven utilities are now considering building, has been upgraded, but the NRC determined it probably won’t withstand a severe earthquake.

Five New Reactor Designs
Under Review by the U.S.

Nuclear Plant
The growing attractiveness of nuclear power plants as an alternative to burning fossil fuels, coupled with generous federal tax credits and loan guarantees for new reactor construction, has led to a sharp increase in applications to build new nuclear plants in the United States. The Nuclear Regulatory Commission is now reviewing five new reactor designs.
It’s also worth noting that the NRC does not require the new plants to be any safer than existing ones. Rather, it only requires the plants to “provide the same degree of protection” as the current generation of reactors.

The new reactors remain a work in progress. Even without knowing exactly what the finished reactors will look like — or cost — some utilities have already made their choices, spurred on by promises of federal subsidies and political pressure to cut carbon emissions. In a speech to industry leaders in May, Nuclear Energy Institute CEO Marvin Fertel said that the construction of nuclear reactors to provide additional power and to replace older plants — U.S. reactors are limited to 60 years of operation — means that 187 new nuclear power plants must be built by 2050.

Many outside the industry believe that figure is unrealistically high.

Elsewhere around the globe, nuclear power expansion is underway. Today, 436 reactors are operating in 31 countries, generating about 15 percent of the world’s electricity. Fifty reactors are under construction, primarily in China, South Korea, and Russia, with the fastest growth in Asia. India, France, and Finland also are building new plants.

Although the new U.S. reactors will have some “design enhancements” — digital controls versus analog dials, for example — “at bottom they are based on familiar and proven technology,” says Bell. The two underlying
Most experts don’t expect a new reactor operating in the U.S. before late 2016 or early 2017.
technologies – pressurized water reactors and boiling water — have been around since the start of the nuclear power era. (In a pressurized water reactor, superheated water is pumped under high pressure to the reactor core; the heated water then transfers its thermal energy to a secondary steam system that turns a turbine to generate electricity. In a boiling water reactor, the water is injected directly into the core, creating a water-steam mixture that turns the turbine. Most reactors in the U.S. are pressurized water reactors.)

Those technical similarities are a good thing, according to nuclear safety watchdogs. “The further away you are from systems in common use and from actual construction experience, the bigger the uncertainties are going to be,” says Edwin Lyman, senior scientist with the Union of Concerned Scientists, which has been evaluating reactor safety for four decades.

Under ideal circumstances, there would be just one or two designs under consideration, not five. Settling on a “standardized” design was among the recommendations made by nuclear advocates and critics alike in the aftermath of 1979’s accident at Three Mile Island in Pennsylvania. Having just one or two “off-the-shelf” designs would simplify licensing, construction and operation, and hold down costs. This country’s existing reactors are custom-made; no two are alike, which means they are extremely complex to build, run, and regulate.

But companies hoping to dominate the U.S. market have filed applications to build a variety of designs, and the NRC has committed to reviewing the massive documentation for each.

For many at the NRC, this is new work: Half the agency’s workforce has been on the job for less than five years. And the information provided by the manufacturers is sometimes lacking. Last year, NRC chairman Gregory B. Jaczko complained that “we have incomplete designs and less than high-quality applications submitted for review.”

It will be at least 2012 before the first new design wins final approval from the NRC. The four other designs are lined up behind that on the NRC’s calendar, pushing licensing into the middle of the decade. Indeed, the approval process already is behind schedule because of safety issues with some reactor designs, such as the integrity of the containment dome around the AP 1000 design from Westinghouse.

Most experts don’t expect a new reactor to be operating in this country before late 2016 or early 2017.

The pace of design reviews and licensing contrasts sharply with the political push to build new nuclear plants, which are regarded by many on Capitol
One reason utilities are committing to new construction is to snag financial inducements from Washington.
Hill and in the White House as key to combating climate change. That has created the curious situation in which utilities have announced plans to build reactors from specific vendors before they know everything about what they’re buying. Part of the reason utilities are committing to new construction now is to snag attractive financial inducements from Washington that are being offered on a first-come, first-served basis.

In recent months, the Obama administration and nuclear backers in Congress have beefed up incentives first offered in the 2005 Energy Policy Act. In February, the White House announced $18.5 billion in tax credits, as well as loan guarantees for new reactors. The Kerry-Lieberman climate bill would raise the guarantees to $54 billion, and some in Congress favor no limits. (The loan guarantees are regarded as critical to help utilities cut their borrowing costs for the first new reactors, each of which is expected to cost $10 billion to $12 billion.)

What are the designs under review and what new features do they include?

One important distinction is whether the reactors rely on “active” emergency cooling systems (which depend on mechanical equipment and uninterrupted electrical power supplies) or “passive” systems (which rely on gravity or other natural features). Current reactors utilize active systems. Adoption of passive systems was ranked high on the list of recommended safety changes in the aftermath of Three Mile Island, although passive systems could pose risks, such as being unable to supply enough water where it’s needed, when it’s needed.

There is very little actual experience in either the construction or operation of the new reactor designs to guide utilities in making their choices. “There doesn’t seem to be much difference in the price ranges of the various designs,” says Lyman. “But a lot of the cost will have to do with the
When risks from external events are factored in, the new reactors are no safer than older ones.
learning curve of building new reactors again.” (There have been no new reactor construction starts since 1977.)

Will this new generation of reactors be safer than the current nuclear plants? Ask that of the industry’s Russ Bell and he chooses his words carefully, because to imply that the new reactors are “safer” than the old ones infers that the existing plants are less safe. “We think all our plants are safe,” he says.

The industry has performed complex mathematical analyses called probabilistic risk assessments to measure the likelihood of a serious accident, says Bell. “When you run the numbers on the newer designs, as you’d expect, the chance of a damaged core or release of radiation accident is much, much lower than the current fleet,” he says. “But the numbers are very low for all the plants.”

The analysis is limited, however. Computed risks for new reactors are lower than for current designs “when only internal events are considered,” according to a 2009 report that the Nuclear Energy Institute wrote for the NRC. (That includes fires or pipe breaks, for example.) But when risks of damage caused by external events — earthquakes, for example — are factored in, the new reactors are no safer than older reactors. In addition, because utilities have no operating experience with the new reactors, the probable risk assessments are purely theoretical and not as reliable as years of actual operating data from existing plants.

While the NRC continues its evaluation of the five reactors, Lyman argues that none is as safe as it could be. The new designs are engineered only to withstand a predictable sequence of events, something engineers theorize may happen. In nuclear parlance that is called a “design basis accident.” The new reactors, like their older counterparts, are not designed to survive an unexpected sequence of events. That is the critical flaw, says Lyman: “Three Mile Island was a beyond-design-basis accident.”

Editor’s note, June 17, 2010: An earlier version of this article incorrectly stated the basis of British and Finnish concerns about Areva’s Evolutionary Power Reactor. The British and Finns raised concerns about the reactor’s control and instrumentation systems, not about the reactor’s containment integrity.

POSTED ON 17 Jun 2010 IN Biodiversity Energy Oceans Policy & Politics Policy & Politics North America 


"each of which is expected to cost $10 billion to $12 billion"

My understanding is that the majority of applications are for twin reactors. I.E. One control house, two reactors.

Hence, we get press releases stating the new nuclear 'plant' is expected to cost $10-$12 billion.

Which is quite different from a 1,000 megawatt reactor is expected to cost between $10-$12 billion.

Posted by harrywr2 on 17 Jun 2010

Nuclear power is the safest kind, bar none, for everybody.

Deaths per terrawatt year [twy] for energy industries, including Chernobyl. terra=mega mega [There are zero sources of energy that cause zero deaths, but not having the electricity causes the far more deaths because not having electricity is a form of poverty.]

fuel......... ........fatalities... .....who......... .......deaths
per twy

coal......... .........6400...... ......workers...........

natural gas..... ..1200...... .....workers and public...

hydro........ .......4000..... .......public............

nuclear........ .........31...... ......workers............

Nuclear power is proven to be the safest. Source: "The Revenge of Gaia" by James Lovelock page 102. As you can see, psychological problems are preventing the wider use of nuclear power. Chernobyl is included.

There is a list of factory built [modular] nuclear power plants at

If you want a lower up-front cost and rapid installation, this list is for you.

Posted by Asteroid Miner on 17 Jun 2010

While this piece spreads a patina of neutrality regarding nuclear energy, it is nonetheless an unbalanced article. Simply quoting someone from each side of the debate does not create balance. Here’s one example: of the four pull-quotes chosen, each is negative.

In fact, the current generation of nuclear power plants are safe and reliable, the next generation will be even more safe and reliable.

The validity of several assumptions in this piece is unclear, but it is important to clarify the factually incorrect comment below.

“And the British and French have declared that one nuclear reactor being proposed in the U.S., and built by the French company, AREVA, doesn’t meet their minimum standards for containment integrity.”

This is simply not true. Regulators in Europe and the US carefully review and certify reactor designs, including the EPR reactor, and questions are part of this process. But the fundamental safety of the EPR has not been called into question.

In addition, the Union of Concerned Scientists (which employs the same Ed Lyman quoted extensively in this piece), has said this about AREVA’s EPR reactor, particularly regarding the safety of the containment structure:

“Of the new designs under consideration in the United States, only one—known as the European Power Reactor or EPR—appears to have the potential to be significantly safer and more secure against terrorist attack.”


Posted by Jarret Adams on 17 Jun 2010

Progress Energy, a utility in Florida pursuing two Westinghouse AP1000s, recently said that the cost of each unit was estimated to be around $11 billion.

The review schedule of the flawed AP1000 design has been on hold until Westinghouse provides new design documentation to the NRC. The design is not certified or licensed, yet President Obama has declared new reactors to be "safe and clean" when announcing a loan guarantee bailout to Southern Company (for two reactors at plant Vogtle in GA). Sounds like some troubling meddling in the regulatory process. Southern Company has until June 18 to accept the loan guarantee offer or not.

Posted by Tom in South Carolina on 17 Jun 2010

Beyond-design-basis accidents should have less consequences with well designed reactors, because any well designed reactor reduces even the effect of a core melting.

But reducing the probability of a core damage from once every million years to once every 10 million years may not worth the effort, since there are a lot of other possible casualities which are not directly related to the inner workings of a nuclear plant.

Posted by Martin Holzherr on 17 Jun 2010

"The review schedule of the flawed AP1000 design"

The standard changed, doesn't have anything to do with the design being 'flawed'.

"The AP1000 initial shield building consisted of a reinforced concrete design, which was certified in December 2005...In response to world events, the NRC challenged new plant design organizations to meet enhanced aircraft impact design standards."

Posted by harrywr2 on 17 Jun 2010

"...questions remain about whether the newer reactors are sufficiently foolproof to be adopted on a large scale."

Cannot imagine that this is an issue. As expensive as these are, there is little to fear from 'adoption on a large scale'. Were a dozen or two to be built in the next twenty years, they would not constitute a 'scale' that could or would be considered 'large'. Tech advances can and will keep up with these little steam plants, and -- if we're paying attention -- they will continue to do so. The longer we twiddle our thumbs, however, the slower the rate of tech advance will be, and the more likely we are to build something that will not reflect an advance in technology for another ten years. When it comes to technology, and knowledge, if you don't use it you lose it; and we've lost a lot already talking about what else is in Pandora's box. It's time to move.

Posted by Pascvaks on 19 Jun 2010

Is the oil spill in the gulf of Mexiko a beyond-design-basis accident?
Certainly, because in the oil industry there is nothing what could be called a design-basis accident

Posted by Martin Holzherr on 22 Jun 2010

No they're not safe. They all leak radiation. And where's a safe place to put radioactive waste that has a half life of 25,000 years? I don't know of any. And neither do the world's leading scientists.

Posted by John Simms on 25 Jun 2010

Some people in America believe in "free market enterprise." However, atomic fission can not exist in a free market since it would be subject to free market risk assessment, i.e. insurance. Atomic power has been indemnified from market insurance since 1957 (see your homeowners policy and the Price-Anderson Act). It is subject to other schemes as well (such as the fraud of "nuclear waste").

Besides not being attractive to Wall Street for decades, this means this uneconomical scheme does not even work under corrupted capitalism.

Are the proposed multibillion dollar taxpayer handouts about to make America even worse off by misallocating public funds and talent toward atomic (last US order 1977) instead of renewables and end-use upgrades?

I think we have too many types of "meltdowns" already to be tempting fate. Clean energy is more eco-nomical for future public support (including reducing the public cost subsidy for one thousand new NRC regulators) and has been widely supported by the public for decades.

Posted by James Newberry on 27 Jun 2010

There is no safe way of dealing with radioactive waste...hole in ground? dumping yard? how can they keep the growing population out of reach?

Posted by Smitha Kamath on 02 Jul 2010

Article too narrow in scope. Readers urged to read "Energy From Thorium" blogspot thoroughly. Costs are halved. Safety is inherent in that reactions are at atmospheric pressure and temp co-efficient of reactivity is negative. Waste half-life is 30 years and reactor can "eat" all current reactor "waste" as well as plutonium. Two proof-of-concept reactors were built and run at Oak Ridge in the 60's-70's. You & I paid for all this and now the French, Czechs, Japanese have downloaded the ORNL files and are hard at work furthering the designs. Should we stand aside for that?

Posted by Lloyd D Brace on 07 Jul 2010

Pebble Bed Reactors are by far the safest basic design for nuclear power. Unlike any other designs it is passively safe requiring no intervention to slow down reaction when core temperatures go outside of the designed operating range. Additional passive and active safety measures should still be included regardless. The vast majority of nuclear waste can still be used as fuel in several other designs such as breeder reactors.

Posted by PK on 23 Jul 2010

The hyper concern about nuclear safety and other nuclear issues such as the supposed waste problem pale into insignificance compared to the problems associated with the continuing use of the fossil fuels.

The wastes of fossil fuels are causing planetary scale changes such as ocean acidification and climate change that, some such as Jim Hansen say, could even set in motion a train of events resulting in Earth's oceans boiling away so that Earth would never have life again.

The wastes of the nuclear plants have all been contained since day one and are sitting in cooling ponds or in casks at the reactor sites, waiting for a political decision as to where they can be carted off to. They are having no effect on anything. The idea that there is no solution as to where they or what's left after reprocessing can be carted off to, is ridiculous.

Almost 1000 nuclear bombs were exploded near Yucca Mountain, which was why the site was chosen for a waste repository - who could have expected that the citizens would suddenly decide simply transporting dry casks to Yucca would be too dangerous for them to allow it?

Posted by David Lewis on 04 Aug 2010

How can you possibly not address the issue of nuclear waste and the absence of any solution to this problem?

Posted by Howard Brandstein on 11 Aug 2010

Why has no one mentioned the outrageous cost to fund nuclear power.....we can debate the safety, AND the health risks...but what about the lack of financial transparency on the entire fuel cycle; i.e. uranium exploration, mining and milling, conversion, enrichment, fabrication and decommissioning....including the Department of Energy's legacy managment costs to monitor the waste dumps forever! What does this cost taxpayers annually?

If anyone has a document that reports these costs in total I would greatly appreciate a copy. I've been told that much of the money for nuclear power is subsidized. I'm an accountant and can't get this info to compare with the alternatives...solar, wind etc.

Loans and free money from the government (subsidies, grants, etc.) should be comparable for all energy sources. What are my tax dollars paying to support nuclear power, solar, wind, etc...?

Posted by Joan Seeman on 14 Oct 2010

Accident/terrorism safety is only one of a host of very problematic issues with nuclear, and this report does not make me feel optimistic even about that aspect.

Factor in such issues as long-term waste storage of hundreds of thousands of years...extremely inadequate insurance...troubling health effects and radiation releases...the very poor safety record of the nuclear industry in general (thousands of minor incidents that could potentially have been much worse)...energy losses in mining, milling, processing, transmission, etc--and I don't think we should be going there. If this investment were diverted toward genuinely clean technologies including "negawatts" (deep reduction in energy need through conservation redesigns) as well as solar, wind, small-scale hydro, geothermal--we'd be much better off.

Posted by Shel Horowitz on 17 Oct 2010

Good Article. But you cannot ruleout completely nuclear power as there are several uses for nuclear power in agriculture,medicine etc.,

Dr.A.Jagadeesh Nellore(AP),India

Posted by Dr.A.Jagadeeesh on 21 Mar 2011

Comments have been closed on this feature.
susan q. stranahanABOUT THE AUTHOR
Susan Q. Stranahan is an award-winning journalist who has written about the environment and energy for more than three decades. She was a staff writer for the Philadelphia Inquirer from 1972 to 2000, is the author of Susquehanna, River of Dreams, and has written for numerous publications, including the Los Angeles Times, Washington Post, Fortune, Time, and Rolling Stone. She lives on Chebeague Island, Maine. In an earlier article for Yale Environment 360, she wrote about the threat of methane being released from the bottom of the fast-melting Arctic Ocean.



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