How to Clean Up Nuclear Waste

8/6/2019 How to Clean Up Nuclear Waste

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Table of Contents:

Part 1: What is nuclear waste?

Part 2: how to deal with nuclearwaste

Page 3: Storage

Page 5: RecyclingPage 7: Other ways

Part 3: what have you learned?


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What is nuclear waste?

So you dont know what nuclear waste is. Well before youlearn that, you need to know how to pronounce is. So heregoes. Try saying it aloud a few times. Nuclear waste (New-

clear Way-sta) Great job! Continue reading to find out moreabout this unknown topic!

Nuclear waste is the radioactive waste left over from nuclear reactors,nuclear research projects, and nuclear bomb production. Nuclearwaste is divided into low, medium, and high-level waste by the

amount of radioactivity the waste produces. Although nuclear wastecan be very dangerous, and should not be handled by anyone withoutprofessional training, it is not necessarily more dangerous than

chemical poisons such as ricin and botulin.

The largest source of nuclear waste is naturally occurring radioactivematerial (NORM). Nuclear waste from NORM is not usually highly


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radioactive, and might be safe to hold, although it may producedangerous levels of radioactive radon gas.

The waste, sometimes called spent fuel, is dangerously radioactive,and remains so for thousands of years. When it first comes out of thereactor, it is so toxic that if you stood within a few meters of it while itwas unshielded, you would receive a lethal radioactive dose within a

few seconds and would die of acuteradiationsickness within a fewdays. Hence, all the worry about it.

The spent fuel is never unshielded. It is kept underwater for a fewyears until the radiation decays to levels that can be shielded by

concrete in large storage casks. The final disposal of this spent fuel isa hot topic, and is often an argument against the use of nuclear

reactors. Options include deep geologic storage and recycling. Thesun would consume it nicely if we could get into space, but since

rockets are so unreliable, we cant afford to risk atmospheric dispersalon lift-off.

Okay, so lets review!

-Nuclear waste (New-Clear Way-Sta) is radioactive waste left over froma bunch of nuclear things.

-NORM is the largest source of nuclear waste!

-There are high, medium, and low levels of nuclear waste.

-The waste is dangerously radioactive. DONT TOUCH IT.

Got it? GOOD! Lets move on!


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Storage:

There are two types of storage for waste: temporary andpermanent. We touched a little on this topic on the previous

page, but to reiterate our point, temporary is storage for ashort time until people find something else to do with it.

Permanent storage is the topic that is currently beingdebated, ideas include recycling, shoving it into large

concrete containers, and you know, shooting it into spaceand stuff.

Temporary Storage:

The spent fuel rods from a nuclear reactor are the most radioactive ofall nuclear wastes. There is no permanent storage site of spent fuel

rods. Temporary storage is being used while a permanent site issearched for and prepared.

When the spent fuel rods are removed from the reactor core, they areextremely hot and have to be cooled down. Most nuclear power plants

have a temporary storage pool next to the reactor and the spent rodsare placed in the pool, so that they can cool down. The pool is not

filled with ordinary water but with boric acid. It helps to absorb someof the radiation given off by the radioactive nuclei inside the spentrods. The spent fuel rods are supposed to stay in the pool for onlyabout 6 months, but because there isnt a permanent storage site,

they can stay there for many years.


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Permanent Storage:

The most hopeful option to permanently remove waste is burying thewaste in the ground. This is called "deep geological disposal". If a

spent fuel rod is not contained, it could come in contact with humansand wildlife, which would be dangerous. Also, if the waste is beingstored underground, it should be stored in an area where there is

little groundwater flowing through. If groundwater flows through awaste storage site, it could erode the containment canisters and carry

waste away into the environment.

When choosing a disposal site, it must have little geological activity.We wouldnt want to put a waste disposal site on top of a fault line, incase an earthquake will occur, which will release the buried waste into

the environment. The waste will probably be stored in large casksdesigned to withstand corrosion, impacts, radiation, and temperature

extremes.


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Recycling:

Reprocessing is a series of chemical operations that separatesplutonium and uranium from other nuclear waste contained in the

used (spent) fuel from nuclear power reactors. The separatedplutonium can be used to fuel reactors, but also to make nuclear

weapons.

There are only two commercial reprocessing plants in the world -Sellafield in the UK and Cogema in France. But Japan is developing

its own plant at Rokkashomura.


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This produces three things - uranium (96%) andplutonium (1%) and highly radioactive waste (3%.

The reusable uranium is turned into a powderedform, processed into fuel pellets and sent back for

use in nuclear reactors.

Plutonium can be combined with uranium andturned into a mixed oxide fuel called Mox.

The leftover waste is turned into a powder and

mixed with glass to produce a pellet and goes intostorage for eventual return to the customer.

Despite the benefits from nuclear reprocessing, reprocessing has beencontroversial because of the potential to contribute to nuclear

proliferation (the spread of nuclear weapons), the potentialvulnerability to nuclear terrorism (threat of using nuclear weapons),and because of its high cost compared to the once-through fuel cycle.


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Other ways:

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Sulfide sponge:

Finding Sr2+ ions is like searching for a needle in a haystack: non-radioactive ions of sodium (Na+) and calcium (Ca2+) are a million

times more numerous, and positively charged and around the same

size. Current nuclear waste treatments are not effective atdistinguishing between these different metals, which can frustrate

cleaning efforts. It works well in both very basic and very acidicconditions found in different nuclear waste. It is also easy to makefrom inexpensive materials. The theory hasnt been proven yet, but

scientists from Northwestern are looking to spread the idea.


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Algae

U.S. researchers say common freshwater algae can take outradioactive strontium from water and could be used to clean up

nuclear waste.

Scientists at Northwestern University and Argonne National

Laboratory say Strontium 90 is one of the more dangerousradioactive fission materials created within a nuclear reactor and ispresent in the 80 million gallons of radioactive waste sludge stored in

the United States.

The researchers say Closterium moniliferum, one of the bright greenalgae often seen in ponds, can recycle strontium in the form of

barium-strontium-sulfate crystals.

"Nuclear waste cleanup is a problem we have to solve," senior

researcher Derk Joester, who experienced Chernobyl's radioactivefallout when he was a teenager living in southern Germany, said.Even if all the nuclear reactors were to shut down tomorrow, the

existing volume of waste is great, and it is costly to store.We need toisolate highly radioactive 'high-level' waste from 'low-level' waste," he

said. "The algae offer a mechanism for doing this, which we wouldlike to understand and optimize."


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Well, what have you learned?

Through lots of evidence that weve given you, you should know

pretty much everything about nuclear waste. We made sure tomention the opinion of smart scientist guys too.

Nuclear waste is a highly debated topic that has influenced society ona large scale. It is debated not only for its use of power, but also for its

disposal.

From when nuclear waste was first disposed, the scientific world hascome a long way in devising multiple ways to dispose of it, as well as

get the process approved by the society.

The researchers that formulated theories on nuclear waste have madea large contribution not only to society, but to the scientific world.

This topic will likely be explored further in the future.


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How to Clean Up Nuclear Waste

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