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CAMERON HURLEY 

Radioisotopes InSmoke Alarms andNuclear Waste

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 There are three main types of nuclear radiation, alpha, beta and gamma. Hthe properties of alpha, beta and gamma-

Tpes O! Radiation

AL"HA #ETA $AMMA

Nature Helium particle-2 neutrons & 2

protons

Fast movingelectron

Shortwavelength ofelectromagneti

c radiation

C%ar&e 2 elementarycharge

-! elementarycharge

"ncharged

Ionisin& Strong #ea$ %ery #ea$

"enetration Few cm in air Few meters inair

evercompletely

absorbed

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'adioisotopes are used in many areas of science and technology li$e med

nuclear power, nuclear weapon and archaeological dating. ( lot of peopleradiation can be harmful for your health, however a lot of people don*t reahave radioactive sources in their home li$e smo$e alarms.

+ost smo$e alarms contain an articially produced radioisotope of (m(mericium-2! is a radioactive substance, so why is it used in smo$e alarms

Smo$e alarms are important devices that help to save lives in an emergenc

occurs. There are two main types of smo$e alarms, rst one uses radioactive an ioni)ation chamber which causes a steady electric current to /ow. 0f smo$the chamber changes the electric current level which triggers an alarm. alarms contain americium-2! in them, and are more common because the1pensive.

Are Smoke Alarms 'an&erous(

 The other type doesn*t use radioactive materials, instead it usesa photoelectric sensor to detect the changes of light levels causedby smo$e.

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(mericium was discovered in !3 during the +anhattan 4ro5ect in the "Swhen plutonium was bombarded with neutrons in a nuclear reactor in the "nof 6hicago.

)acts o! Americium*+,-

Americium. "ro/le

• (mericium has a half life of 72.8 years

• (mericium-2! was the rst isotope of (mericium to be discovered.

• (mericium-2! decays into eptunium-278, though (lpha decay and 9decay

•   4lutonium-2! decays into (mericium-2!, through :eta decay

• ;ne gram of (mericium is enough for three million smo$e detectors

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Half life is the time it ta$es for aeach single atom to have a 3<=chance of decaying.

 The half life of (mericium 2! is72.8 years, so it ta$e 72.8 yearsbefore > (mericium 2! decays,than a further 72.8 years until >of that sample decays, which isthe same as saying it ta$es ?@3.years until A of the original(mericium 2! has decayed. (ndthis pattern continues untileventually all of the (mericiumhas decayed into eptunium 278.

W%at is a Hal!*Li!e(

 Bears

   H  a   l   f   C   i   f  e

72.8 ?@3.

(m 2

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Smo$e alarm are safe to have in your home, even though there is radiation in smo$e ais also everywhere else, the food we eat, the air we breathe, $nown as bac$ground ra The dose we receive from a smo$e alarm at a distance of one meter is one thousandtradiation we receive from the bac$ground radiation in (ustralia. So that*s <.<<2 millisiev

 The radioactive source is e1tremely insoluble so if swallowed would not be absorbedbody but instead pass straight through the digestive system. :ut still it would be wise nyour smo$e alarm.

Dven in a re the radiation from the smo$e alarm would not become an inhalation ha)arthe temperature is at or above !2<< degrees. The average re won*t get over abdegrees.

0f you want to dispose of a smo$e alarm it is safe to do so in the domestic rubbish bin bthe level of radiation being emitted isn*t dangerous. :ut if for some reason you want toof more than !< smo$e alarms at one time it must be treated as radioactive waste.

Can Smoke Alarm A0ect YourHealt%(

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0t all depends on how the dose you receive, dose ismeasured in Sieverts.

• <.<! Sieverts are absorbed the dosage is still prettysafe

• <.! Sieverts are absorbed no immediate health aEectsmay occur, however your chance of getting cancer maybe increased

• ! Sievert are absorbed it can cause some health eEectsoccur however you are most li$ely to recover fromthem, but once again your chances of getting cancer

• !< Sievert are absorbed is going to cause immediatehealth aEects and will lead to death

Ho1 Muc% Radiation Will 2ill You(

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uclear waste is material that nuclear fuel becomes after it is used in a reactor. #ha0t loo$s li$e the fuel that was loaded into the reactor. However even $now it loo$s simarent completely the same. :efore power was made the fuel consisted of mostly "rao1ygen and steel but afterwards the "ranium atoms spilt into various forms of Going this create nuclear waste, which is dangerous and radioactive and can remathousands of years. 0t so radioactive that if you stood within a few meters of unshielded you would receive a high and lethal amount of radioactive dose in a fewvery serious because it can lead to things li$e acute radiation sic$ness which will $illfew days

W%at is Nuclear Waste(

So $nowing how dangerous the waste is, it made sure to neverbe unshielded and is $ept underwater for a few years until theradiation decays to levels that are safe to be shielded byconcrete in large storage cas$s.

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uclear radiation can commonly be put into one of the following four groups

E3empt 1aste 4 5er lo1 le5el 1aste-this type contains radioactive materials wa level considered as not harmful to people of the environment around. 0t can be pfood processing companies, chemical companies and steel companies.

Lo1 le5el 1aste-contains a small amount of short-lived radioactive materials. 0t doshielding and is normally incinerated before being buried. +aterials can include soma hospitable li$e their tools or clothing.

Intermediate le5el 1aste-materials that contain higher amounts of radioactivityshielding. 0ncludes such things as chemical sludges, metal fuel of cladding6 #henitems from this level it can be done though by being solidied in concrete or bitume

Hi&% le5el 1aste-contains ssion products and transuranic elements generated frocore. 6an arise from situations li$e getting uranium fuel from a reactor. This leradioactive so shielding and cooling +"ST be used. High level waste come in two mthe fuel itself or 2J waste from reprocessing the used fuel.

'i0erent Tpes o! Nuclear Waste(

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6urrently most of the nuclear waste being created is being stored in underwateis because water is a great shield for nuclear waste. (nd it*s then planned thwaste will end up stored deep underground.

;ther methods include 'ecycling uclear #aste. :ecause nuclear waste is maof "ranium this "ranium from the waste can then be reused for more fuecontains that <= of "ranium. This can be done by chemically processiadvanced fast reactors. 6urrently France and Kapan some of the only count

their waste, however they only recycle once before disposing of the waste anyis that recycling this waste can sometimes lead to creating 4lutonium which isnuclear weapons.

(lternatively we could use Thorium as a fuel, this would mean sw"raniumL4lutonium based fuel to a ThoriumL"ranium based fuel. Going so wito occur without creating any 4lutonium.

W%at to do 1it% Nuclear Waste(

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Sievert-the measurement of dose eIuivalent of radiation

4hotoelectric sensor-a device that detects the presence of an ob5ect btransmitter

Half Cife-the time it ta$es for > of a sample of radioisotopes to decay

uclear #aste-is waste material that is radioactive

 Transuranic-an element with a higher atomic number then "ranium

Solidied-To ma$e something become hard or soild

$lossar

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"ICTURES

0 am (mericium-httpLLsciencepar$.etacude.comLl)oneLelementsLchemicalMsymbol.php

(mericium Gecay- uwlbrachyclass<?<.wi$ifoundry.com

(mericium 9raph- Gecay- www2.lbl.gov

(lpha, :eta, 9amma 4eneratraion- httpLLblogs.agu.orgLwildwildscienceL2<<L<L<!Lhow-much-radiation-

uclear 'eactor-%ttp*771116look!ordia&nosis6com7mes%8in!o6p%p(term9Nuclear:Reactors4lan&9-

Sievert 4ic-sok6riksarki5et6se7s;l7"resentation6asp3(id9<=>< 

WE#SITES

+ental Floss-httpLLmental/oss.comLarticleL72!2Lhow-do-smo$e-alarms-wor$

'adiation (nswers- httpLLwww.radiationanswers.orgLradiation-and-meLeEects-of-radiation.html  

#hy StuE #or$s- 1%stu01orks6com7%ome*impro5ement7%ouse%old*sa!et7/re7smoke6%tml

#orld uclear (ssociation- httpLLwww.world-nuclear.orgLinfoLnon-power-nuclear-applicationsLradioisotopesLsmo$e-detectors-and-am

(ustralian 'adiation 4rotection (nd uclear Saftey (gency- httpLLwww.arpansa.gov.auLradiationprotectionLfactsheetsLisMsmo$edet

:logosphere- does-it-ta$e-to-$ill-youL

#hat is uclear.com-httpLLwww.whatisnuclear.comLarticlesLwaste.html

#orld uclear (ssociation-%ttp.7711161orld*nuclear6or&7in!o7nuclear*!uel*ccle7nuclear*1astes7radioacti5e*1aste*ma

#i;lio&rap%