Answer six questions

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The Obama Administration’s shutdown of the quarter-century-long, $15 billion effort to dispose of 65,000 tons of U.S. spent nuclear reactor fuel in Nevada’s Yucca Mountain could be the latest of many les- sons learned around the world. Unforeseen technical problems have abounded there and at proposed disposal sites around the world, but no certain deal breakers have turned up.

Yet, despite the absence of insurmount- able geologic or engineering obstacles, no permanent repository for spent reactor fuel has been built anywhere. Every coun- try looking for a place to dispose of its wastes has stumbled in its early tries to site repositories. Almost invariably, a govern- ment decides which site would be suitable, it announces its decision, an uproar ensues from the locals, the government defends its chosen site, but eventually it is forced to abandon its choice as untenable.

In the wake of the 2010 abandonment of

the Yucca Mountain program, the U.S. advi- sory Nuclear Waste Technical Review Board (NWTRB) puts the United States among those nations whose waste-disposal pro- grams “either have lost public trust and con- fi dence or seem never to have merited it at all,” as the board stated in an April report to Congress. (Yet, ironically, the United States is the only country in the world to open and operate a nuclear waste repository: a facility for storing waste from the nuclear weapons program that doesn’t include spent fuel.)

So as the Administration’s Blue Ribbon Commission on America’s Nuclear Future prepares to deliver its draft report (see p. 148), many authoritative groups have been driving home the lessons learned from Yucca Mountain and around the world. NWTRB put it most succinctly: “The interdependencies, both subtle and overt, between the technical, social, and political forces are inescapable.”

Uniformly dismal failure In the 1950s, when coun- tries f irst started ponder- ing how to dispose of spent nuclear fuel from power plants and radio- active waste from nuclear weapons production, the solution seemed straight- forward enough. Nuclear waste contains isotopes of elements that will remain radioactive for thousands t o m a ny h u n d r e d s o f thousands of years. Rock formations hundreds of meters beneath the sur- face have been there, lit- tle disturbed, for millions if not billions of years. So put the wastes in tun- nels in the rock, seal the tunnels, and the problem would be solved. Layers of

deeply buried salt were an early favorite; if there’s salt still there after millions of years, water—which can corrode stored waste and carry it back into the environment—won’t be a factor. But whatever medium was at hand—salt, granite, clay, or volcanic ash turned to stone called tuff—looked promis- ing to the government’s experts charged with fi nding a suitable site.

Despite the promising geology, the top- down approach just didn’t pan out. Whether it was salt in Germany or old bedrock in the United Kingdom, Canada, or Scandinavia, “almost all countries that have tried to site repositories have had one or more failures,” notes a June draft report, Spent Fuel From Nuclear Power Reactors, from the Inter- national Panel on Fissile Materials (IPFM), an independent group of nuclear experts.

In the United States, 4 decades of govern- ment efforts were marked “by heavy hand- edness on the part of the federal government and political uprisings in a succession of states where it proposed to site repositories,” notes the IPFM report. An early setback came near Lyons, Kansas, where in 1970 the Atomic Energy Commission (AEC)— the forerunner of today’s Department of Energy (DOE)—decided to entomb highly radioactive wastes from nuclear weapons production in an abandoned salt mine. In 1957, a U.S. National Academies report had

Light at the End of the Radwaste Disposal Tunnel Could Be Real A long run of failures could fi nally drive the United States to follow other countries’ lead and accept radioactive waste disposal as the sociotechnological problem that it is

R A D I O A C T I V E W A S T E D I S P O S A L

Yucca Mountain. The now- abandoned repository site’s rock is perhaps the planet’s most thoroughly studied.

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recommended layered salt formations for

such wastes because, over time, salt would

fl ow to seal in the wastes.

But the head of the Kansas Geological

Survey urged more study of the integrity of

the proposed Lyons repository. AEC agreed

but continued its preparatory work anyway.

Fearing a fait accompli, the IPFM report

says, Kansans and their politicians rose to

oppose the plan. Technical revelations then

lit the fuse on a by-now-politically-unstable

situation. It turned out that the site had long

ago been peppered with oil and gas wells

with no assurance they had all been securely

plugged. And several years earlier, a min-

ing company pumping water into the for-

mation nearby to dissolve and extract salt

had 640 cubic meters of water go missing,

suggesting that the salt geology was more

complex and less well understood than the

academies had assumed. AEC abandoned

the site in 1971.

Yucca Mountain’s cycle from decision

to abandonment was far more protracted.

Acting under the 1982 Nuclear Waste

Policy Act, DOE had selected three can-

didate sites: salt in Texas, basalt in Wash-

ington state, and volcanic tuff at Nevada’s

Yucca Mountain.

Technically, Yucca Mountain looked

promising. The spent fuel would be well

above the water table and therefore exposed

to the vanishingly small amount of water

seeping from the desert above. The decisive

factor, however, was political. At the time, the

Democratic Party controlled both houses of

the U.S. Congress, and the powerful speaker

of the House represented Texas while the

House majority leader represented Washing-

ton state. Nevada’s delegation, however, was

split between Democrats and Republicans

and was new to Congress. In 1987, Congress

struck the Texas and Washington sites from

the list, leaving Yucca Mountain the only

candidate in the running. Nevadans still call

the act the “screw Nevada bill.”

If Yucca Mountain had proved to be the

perfect repository site, it might not have

been abandoned, but investigations soon

started to tarnish its luster. That’s normal

for site evaluations; as geophysicist Wendell

Weart told Science in 1999, “You never feel

quite as comfortable about a site as the day

you start to study it.”

Yucca Mountain’s unwelcome surprises

included the possibility of earthquakes and

volcanic eruptions (Science, 8 November

1996, p. 913) and fears, later allayed, that the

repository itself might explode like

a nuclear bomb (Science, 30 June

1995, p. 1836). But the overarching

concern has been the discovery that

water seeps down through the moun-

tain many times faster than had been

thought. So, in the mountain’s oxygen-

rich interior, water laden with salt dis-

solved from the rock would drip onto

spent-fuel assemblies still hot from

their lingering radioactivity. That’s a

great recipe for corrosion. The seep-

ing brine would release radionuclides

from the spent fuel and carry them on

through the rock as far as the water

is going.

To make matters worse, the plan-

ning horizon for Yucca Mountain got

extended by a factor of 100. An acad-

emies study committee requested by

Congress concluded that the risk

of human exposure to radioactivity

should be estimated out to the time

of maximum exposure, when con-

tainment has failed and wastes have

spread. That upped the time scientists had to

predict the behavior of the repository and its

wastes from 10,000 years to 1 million years.

In response to such surprises, DOE hun-

kered down. “DOE lacked transparency in

developing its plans for the Yucca Mountain

repository,” an April report, Commercial

Nuclear Waste, from the U.S. Government

Accountability Off ice (GAO) concluded.

For example, instead of polling the broad

community for ideas, DOE designed tita-

nium drip shields on its own to protect the

waste. DOE did not “establish independent

scientifi c panels or any form of state over-

sight that might have given affected parties

more confi dence in the solutions,” the report

says; nor did it “promote state involvement

in key decisions and oversight.”

Could more transparency and coopera-

tion have saved the day? Mineralogist Rod-

ney Ewing of the University of Michigan,

Ann Arbor, a longtime critic of the Yucca

Mountain program, thinks so. “I really think

if there’s a strong scientifi c basis combined

with public empowerment, you can make

progress,” he says.

A more successful path As an example of how to do things right,

Ewing and other critics often cite another

The Swedish way. The KBS design: copper-clad wastes (yellow) encased in clay (pink) beneath 500 meters of granite.

Nuclear Waste Repositories —Past and Future?

WIPP Carlsbad, NM

Operating

Salt

Operating

Yucca Mountain, NV

Abandoned 2010

Mostly dry volcanic tuff, oxidizing

$15 billion spent; well studied

Hanford, WA

Dropped

Wet basalt reducing

TBD

Status:

Geologic medium:

Advantages:

Deaf Smith County, TX

Dropped

Salt

TBD

NUCLEAR WASTE NEWSFOCUS

Forsmark, Sweden

Selected

Wet basalt reducing

Local support engineered barriers

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DOE radwaste repository, the Waste Isola- tion Pilot Plant (WIPP) near Carlsbad, New Mexico (Science, 12 March 1999, p. 1626). “It wasn’t an easy sell,” Ewing says. “There were substantial objections to WIPP. But there was a process of public and scientifi c engagement, so at the end you could say, this makes sense. It worked, but it took time”— 30 years of time.

WIPP did start with several advantages over Yucca Mountain. First, the people of Carlsbad wanted it. When community lead- ers heard about the abandonment of the Lyons site, they offered their own layered

salt as a replacement. They had just lost a major employer, a potash mining company, and were looking for an economic boost. And they were already familiar with the risks of mining, not to mention those from nearby nuclear testing. Their interest would never waiver.

The state of New Mexico, having con- stituencies other than Carlsbad to consider and a long and sometimes strained history of state-federal relations, was not so receptive. Nongovernmental organizations (NGOs), including environmental groups, objected to the Carlsbad site as well. But unlike the way Yucca Mountain turned out, a fl urry of lawsuits brought by the state and NGOs led to concessions from DOE and constructive interventions by Congress. A quasi-inde- pendent Environmental Evaluation Group with both state and federal funding provided credible scientifi c information to the state

and the public when inevitable technical issues arose. And a signed agreement made the state “equal partners with DOE in the development of WIPP,” says Mark Gaffi gan, lead author of the GAO report.

Congressional legislation helped, too. It limited WIPP to defense-related waste such as rags, protective clothes, and tools contaminated with toxic, long-lived radio- nuclides including plutonium. The absence of high-level wastes such as thermally hot spent fuel eased relations between DOE and the state and simplifi ed the repository design. Legislation also gave oversight of

the repository to the U.S. Environmental Protection Agency, which was able to retain the 10,000-year standard for maintaining repository integrity without going to a mil- lion-year standard. And legislation provided New Mexico with $280 million in compen- sation over 14 years. WIPP received its fi rst wastes in 1999; today, 9000 shipments of wastes totaling 71,000 cubic meters have been stored there.

No one else has managed to open a repository for anything but low-level wastes, but two countries—Sweden and Finland— have gotten as far as selecting sites, although they have not yet given them fi nal approval. As laid out in an IPFM report chapter by physicist Johan Swahn of the NGO Offi ce for Nuclear Waste Review (MKG), Sweden started with some advantages. For one, Swe- den began its site search with a relatively robust repository design in hand. Unlike the

approach at Yucca Mountain, the Swedish KBS method developed by SKB, the nuclear waste company responsible for ultimate dis- posal, does not depend solely on geology for containment. Spent fuel would be encased in 5 centimeters of copper surrounded by extremely low-permeability clay.

Sweden was also able to make changes in midstream. After provoking public outcries with uninvited exploratory drilling for a site, SKB backtracked and asked communities to volunteer as repository sites with the right to back out at any point. As in the case of WIPP, volunteers were looking for economic ben- efi ts. And they also were familiar with things nuclear; each of the two f inalists already had a nuclear plant and one had a low-level waste site, the other a centralized facility for temporary spent-fuel storage. The Swedish government instituted a relatively open and consultative site-approval process, going so far as to fund NGOs such as MKG to moni- tor the process. And, in contrast to Yucca Mountain, that process sets a more practi- cal standard to shoot for. It does not depend solely on quantitative calculations of the risk of repository failure out to a million years. Beyond a few hundreds of thousands of years, more qualitative arguments for repos- itory safety can be made.

A U.S. way ahead?

After seeing these and other reports, hearing testimony, and making site visits, the Obama Administration’s Blue Ribbon Commission looks set to recommend later this month a consent-based, transparent, and flexible approach to nuclear waste disposal. How- ever, even strictly applying lessons learned from Sweden and WIPP won’t guarantee smooth sailing. For one thing, the technical challenges of storing nuclear waste safely for many millennia have not gone away. In Sweden, for example, after 30 years of development, the KBS disposal system has developed what could be a major problem. Laboratory studies have lately raised the possibility that the copper cladding meant to shield the waste from groundwater may be much more prone to corrosion than anyone had suspected. The site-approval process, now under way, will consider just how sig- nifi cant a problem that is.

On the social side, the United States is not Sweden, Swahn points out. “Your polit- ical system has more diff iculties than we have dealing with these sorts of issues,” he says. “Trust is important in this country, and people trust the system. That is very, very different.”

–RICHARD A. KERR

Awaiting disposal. These casks contain the spent fuel from the production of 110 billion kilowatt-hours

of electricity during 28 years by the Connecticut Yankee nuclear power plant.

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