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Article on Yucca Mountain on Technology Review



Dear RADSAFE Members,



Perhaps someone else has posted this before, and if

so, I apologize. I found the article on Yucca Mountain

by Prof. Richard A. Muller of UC Berkeley interesting.

If you like the article, I would like to recommend

that you read the original article at the web site

below because the original has good links.



Tosh Ushino

Global Dosimetry Solutions, Inc.

---------------



http://www.technologyreview.com/articles/wo_muller031204.asp?trk=nl



The Witch of Yucca Mountain 

More research on nuclear waste storage won.t reassure

the public



By Richard A. Muller

Technology for Presidents

March 12, 2004



There is an almost primal fear of radioactivity. It

may be a new manifestation of an old Jungian

archetype: the fear of unseen danger, perhaps

originally a predator or enemy lurking in ambush.

Other incarnations include the fear of witches, germs,

communists, and monsters under our beds. But

radioactivity is worse. Not only is the threat hidden,

but so is the attack. Your genes are invisibly

mutated, showing no sign of the assault until a decade

or two later when the damage manifests itself in a

growing cancer. 



I put radioactivity on this witch list in an effort to

make sense of the furor over nuclear waste storage at

the Yucca Mountain facility in Nevada. When I work out

the numbers, I find the dangers of storing our waste

there to be small compared to the dangers of not doing

so, and significantly smaller than many other dangers

we ignore. And yet a contentious debate continues.

More research is demanded, and yet every bit of

additional research seems to raise new questions that

exacerbate the public.s fear and distrust. 



I.ve discussed Yucca Mountain with scientists,

politicians, and many concerned citizens. The

politicians believe it to be a scientific issue, and

the scientists think it is a political one. Both are

in favor of more research.scientists because that is

what they do, and politicians because they think the

research will answer the key questions. But I don.t

think it will. 



Let me review some pertinent facts. The underground

tunnels at Yucca Mountain are designed to hold 77,000

tons of high-level nuclear waste. The most dangerous

part of this consists of .fission fragments. such as

strontium-90 and iodine-131, the unstable nuclei

created when the uranium nucleus splits. Because these

isotopes have a shorter half-life than uranium, the

waste is about a thousand times more radioactive than

the original ore. It takes 10,000 years for the waste

(not including plutonium, which is also produced in

the reactor, and which I.ll discuss later) to decay

back to the radioactive level of the mined uranium.

Based largely on this number, people have searched for

a site that will remain secure for 10,000 years. After

that, we are better off than if we left the uranium in

the ground, so 10,000 years of safety is clearly good

enough. 



How can we plan to keep Yucca Mountain secure for this

long? What will the world be like 10,000 years from

now? Think backwards in order to appreciate the time

involved: ten thousand years ago humans had just

discovered agriculture, and writing wouldn.t be

invented for another 5,000 years. Can we possibly see

10,000 years into the future? No. It is ridiculous to

think we could. So nuclear waste storage is obviously

unacceptable. Right?



Of course, calling storage unacceptable is itself an

unacceptable answer. We have the waste and we have to

do something with it. But the problem isn.t really as

hard as I just portrayed it. We don.t need absolute

security for 10,000 years. A more reasonable goal is

to reduce the risk of leakage to 0.1 percent, i.e. to

one chance in a thousand. Since the radioactivity is

only 1,000 times worse than that of the uranium we

removed from the ground, that means that the net risk

(probability times danger) is 1,000 x 0.001 = 1.that

is, basically the same as the risk if we hadn.t mined

the uranium in the first place. (I am assuming the

unproven .linear hypothesis. that total cancer risk is

independent of individual doses or dose ratebut my

argument won.t depend strongly on its validity.)



Moreover, we don.t need this 0.1 percent level of

security for the full 10,000 years. After 300 years,

the fission fragment radioactivity will have decreased

by a factor of 10; it will only be 100 times as great

as the mined uranium. So by then, we should rationally

require only a 1 percent risk that all of the waste

leaks out. That.s a lot easier than guaranteeing

absolute containment for 10,000 years. Moreover, this

calculation assumes 100 percent of the waste escapes.

For leakage of 1 percent of the waste, we can accept a

100 percent probability. The storage problem is

beginning to seem tractable. 



But the unobtainable.and unnecessary.criterion of

absolute security dominates the public discussion. The

Department of Energy continues to search Yucca

Mountain for unknown earthquake faults, and many

people assume that the acceptability of the facility

depends on the absence of any such faults. Find a new

fault.rule Yucca Mountain out. But the issue should

not be whether there will be an earthquake in the next

10,000 years, but whether there will be a sufficiently

large earthquake in the next 300 years to cause 10

percent of the waste to escape its glass capsules and

reach ground water with greater than 1 percent

probability. Absolute security is too extreme a goal,

since even the original uranium in the ground didn.t

provide it. 



But why compare the danger of waste storage only to

the danger of the uranium originally mined? Why not

compare it to the larger danger of the uranium left in

the ground? Colorado, where much of the uranium is

obtained, is a geologically active region, full of

faults and fissures and mountains rising out of the

prairie, and there are about a billion tons of uranium

in its surface rock. (This number is based on the fact

that granite typically contains 4 parts per million of

uranium. I take the area of the Colorado Rockies to be

about 300 by 400 kilometers, and consider only rock

from the surface to 1,000 meters depth.) The

radioactivity in this uranium is 20 times greater than

the legal limit for Yucca Mountain, and will take more

than 13 billion years.not just a few hundred.for the

radioactivity to drop by a factor of ten. Yet water

that runs through, around, and over this radioactive

rock is the source of the Colorado River, and is used

for drinking water in much of the west, including Los

Angeles and San Diego. And unlike the glass pellets

that store the waste in Yucca Mountain, most of the

uranium in the Colorado ground is water-soluble. Here

is the absurd-sounding conclusion: if the Yucca

Mountain facility was at full capacity and all the

waste leaked out of its glass containment immediately

and managed to reach ground water, the danger would

still be 20 times less than that currently posed by

natural uranium leaching into the Colorado River. 



I don.t mean to imply waste from Yucca Mountain is not

dangerous. The Colorado River example only illustrates

that when we worry about mysterious and unfamiliar

dangers, we sometimes lose perspective. Every way I do

the calculation, I reach the same conclusion: waste

leakage from Yucca Mountain is not a great danger. Put

the waste in glass pellets in a reasonably stable

geologic formation, and start worrying about real

threats.such as the dangers of continued burning of

fossil fuels. 



A related issue is the risk of mishaps and attacks

while transporting nuclear waste to the Yucca Mountain

site. The present plans call for the waste to be

carried in thick reinforced concrete cylinders that

can survive high-speed crashes without leaking. In

fact, it would be very hard for a terrorist to open

the containers, or use the waste in radiological

weapons. The smart terrorist is more likely to hijack

a tanker truck full of gasoline, chlorine, or some

other common toxic material and then blow it up in a

city. 



So why are we worrying about transporting nuclear

waste? The answer is ironic: we have gone to such

lengths to assure the safety of the transport that the

public thinks the danger is even greater. Images on

evening newscasts of concrete containers being dropped

from five-story buildings, smashing into the ground

and bouncing undamaged, do not reassure the public.

This is a consequence of the .where there.s smoke

there.s fire paradox. of public safety. Raise the

standards, increase the safety, do more research,

study the problem in greater depth, and in the process

you will improve safety and frighten the public. After

all, would scientists work so hard if the threat

weren.t real?



Well-meaning scientists sometimes try to quench the

furor by proposing advanced technological alternatives

to Yucca Mountain storage, such as rocketing the waste

into the sun, or burying it in a tectonic subducting

zone at sea, where a continental plate will slowly

carry it into the deep Earth. Such exotic solutions

strongly suggest that the problem is truly

intractable, and they only further exacerbate the

public fear. 



Let me return now to the danger of the plutonium in

the waste. Plutonium is not a fission fragment; it is

produced in the reactor when uranium absorbs neutrons.

But unlike the fission fragments, plutonium doesn.t go

away by a factor of 10 in 300 years; its half-life is

24,000 years. Not only that, but many people think

plutonium is the most dangerous material known to man.



Plutonium is certainly dangerous if you make nuclear

weapons out of it. If turned into an aerosol and

inhaled, it is more toxic than anthrax.and that.s very

toxic. But when ingested (e.g. from ground water) it

isn.t. According to the linear hypothesis, when

consumed by a group of people, we expect about one

extra cancer for each half-gram of plutonium

swallowed. That is bad, but not a record-setter.

Botulism toxin (found in poorly prepared mayonnaise)

is a thousand times worse. The horrendous danger of

ingested plutonium is an urban legend.believed to be

true by many people, yet false. Moreover, I think it a

mistake to bury the plutonium with the waste. It is a

good fuel for reactors, as valuable as uranium. I

sense that original reason for burying it (rather than

extracting and using it) was to keep the public from

worrying about it, but that approach has backfired. 



By any reasonable measure I can find, the Yucca

Mountain facility is plenty safe enough. It is far

safer to put the waste there than to leave it on site

at the nuclear plants where it was made and is

currently stored. We should start moving it to Yucca

Mountain as soon as possible. Research should

continue, because more knowledge is good, but the hope

that it will reassure the public is forlorn. Further

studies are no more likely to reduce public concern

now than scientific research would have calmed the

fears of the people of Salem in 1692. 



Richard A. Muller, a 1982 MacArthur Fellow, is a

physics professor at the University of California,

Berkeley, where he teaches a course called .Physics

for Future Presidents.. Since 1972, he has been a

Jason consultant on U.S. national security.



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