Shadowing Practice: The Magic of Thorium Nuclear Reactors - Learn English Speaking with Video

Les maken...
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Thorium is a kind of miraculous element.
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Thorium found in nature isn't fissile – the atom's nucleus won't split when it absorbs a neutron.
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And yet, if you put a chunk of this same thorium in a special nuclear reactor,
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after a while most of the thorium will be gone,
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a whole bunch of energy will have been generated,
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and you'll be left with typical byproducts of fission.
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It's as if thorium is fissile, even though it's not.
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This is the genius of thorium breeder reactors.
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Oh, and I should disclose here that this video is sponsored by Copenhagen Atomics,
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who are working to make thorium power a reality,
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but they didn't get any say in the video and didn't get to review it before posting.
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The standard oversimplified picture of a fission reactor is,
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a uranium nucleus splits apart,
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or fissions, releasing heat energy and two or three neutrons,
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and those neutrons go on to be captured by more uranium nuclei and cause them to fission,
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releasing more heat energy and more neutrons, and so on.
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The heat is used to generate electricity,
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the neutrons to maintain the fission chain reaction.
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However, the actual story is more complicated.
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When a nucleus splits, there are actually four things that can happen to the neutrons it emits.
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One, like we've already mentioned,
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they can be captured by a fissile atom like uranium-235,
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causing it to fission and release more neutrons,
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and this part has to happen on average at least once per fission to sustain the chain reaction.
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Two, neutrons can be captured by the nuclei of other atoms in the reactor,
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without causing fission, like maybe the metal case,
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or the moderator, or the control rods, or whatever.
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3 Neutrons can escape and leave the reactor entirely.
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Or 4 A neutron can be captured by an atom that's not fissile,
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and transmute it into an atom that is fissile.
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Because remember, these are atomic nuclei we're dealing with.
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Absorption of a neutron will turn uranium-238 into uranium-239,
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the number is just the total number of protons and neutrons.
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And uranium-239 can then radioactively decay into neptunium-239,
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which can then decay into plutonium-239, which is fissile.
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If the capture of a neutron transforms a non-fissile element into a fissile one,
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it's called a fertile capture.
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And fertile capture is what makes thorium useful.
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In fact, even in a normal uranium reactor,
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fertile capture accounts for over a third of the energy generated by the reactor.
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A normal nuclear reactor uses uranium-235,
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which is fissile, but naturally occurring uranium ore contains only 0.7% uranium-235.
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Almost all the rest is uranium-238,
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which is essentially non-fissile, but it is fertile.
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Even when using fuels with enriched levels of uranium-235 undergoing fission,
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there's so much non-fissile U-238 around that some of the chain reaction neutrons instead transform U-238 into plutonium-239,
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which can then fission.
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But U-235 doesn't make enough neutrons,
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and U-238 doesn't turn into plutonium easily enough
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that you can both sustain a fission chain reaction and continue to transform new fissile fuel.
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So at the end you're left with a big chunk of unfissioned but still full of radioactive waste, uranium-238.
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There's a different kind of reactor,
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called a fast breeder reactor,
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that uses plutonium as the primary fissile fuel,
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and uranium-238 as a fertile secondary source.
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This combination can both sustain the fission chain reaction and transform new fuel in a self-sustaining way.
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But fast breeder reactors are less researched,
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more expensive, and harder to run effectively.
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For now.
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This is where thorium comes in.
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The same route used in the transformation of uranium-238 to plutonium-239 can be replicated down here,
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starting instead with thorium-232.
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By adding a neutron, we get thorium-233,
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which decays to protactinium-233, which decays to uranium-233,
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which is fissile and can be used to generate energy.
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So if you load your reactor with thorium-232,
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which, remember, is not fissile,
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and you throw in some starter fissile fuel,
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then for each fission reaction,
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the number of new fissile atoms created is more than one on average,
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and the number of new atoms split is more than one on average,
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and remember those atoms give you more neutrons.
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So the transformation of thorium,
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and the fission of uranium,
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can keep going and going and going,
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until in principle, all of the thorium is gone.
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And crucially, thorium transformation can happen in a reactor that doesn't have the same challenges as a fast breeder reactor,
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and it gets rid of most of the long-lived radioactive waste.
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And thorium is more abundant than uranium,
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and doesn't need the expensive refining process to concentrate the fissile uranium-235,
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and so you can see why people get excited about thorium.
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There are, of course, challenges and downsides to making thorium reactors,
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which is why we don't have and so far have never had commercial energy generation from thorium.
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But that's fertile material for another time.
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Getting commercial power from thorium may soon be possible thanks to the work of organizations such as this video's sponsor, Copenhagen Atomics.
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Copenhagen Atomics is building compact,
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modular thorium reactors to produce cheap energy.
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Unlike traditional nuclear power stations,
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which are giant infrastructure projects,
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Copenhagen Atomics are designing a self-contained reactor unit that can fit inside a shipping container.
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The reactors are based on a design pioneered over 50 years ago that uses molten salt to carry the fuel,
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resulting in fewer lost neutrons and more complete combustion,
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so you get more energy for less waste.
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These reactors can also use plutonium waste from classic nuclear reactors as fuel,
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extracting ten times more energy out of spent nuclear fuel than the initial reactor did in the first place,
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and in doing so converting long-lived radioactive waste into short-lived radioactive waste.
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In theory, these reactors could run anything from grids to ships to moon bases.
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Check out Copenhagen Atomics website to learn more about their work.

Woordenschat en spreektips bij deze les

Deze spreekles op niveau C2 is gebaseerd op de video “The Magic of Thorium Nuclear Reactors”. Deze woorden komen het vaakst terug: reactor, thorium, uranium, fissile, neutron. Deze video bevat 98 zinnen en 988 woorden om na te spreken. Het gesproken deel duurt 4:44. De spreker praat snel, ongeveer 208 woorden per minuut, dus reken op verbonden en ingeslikte klanken. Slechts 71% van de woorden hoort bij de 3.000 meest gebruikte Engelse woorden, dus de woordenschat is pittig.

Belangrijke woorden in deze video

De 15 moeilijkste woorden uit de video, met uitspraak en betekenis:

WoordUitspraakBetekenis
reactor zelfstandig naamwoord/ɹiˈæktɚ/reactor
thorium zelfstandig naamwoord/ˈθɔːɹiəm/thorium
uranium zelfstandig naamwoord/ˌjuː.ˈɹeɪ.ni.əm/uranium, uraan
fissile bijvoeglijk naamwoord/ˈfɪsˌaɪ.əl/splijtbaar
neutron zelfstandig naamwoord/ˈnu.tɹɑn/neutron
fission zelfstandig naamwoord/ˈfɪʃən/splitsing
atom zelfstandig naamwoord/ˈætəm/atoom
plutonium zelfstandig naamwoord/pluːˈtoʊniəm/plutonium
nucleus zelfstandig naamwoord/ˈnuː.kli.əs/kern
fertile bijvoeglijk naamwoord/ˈfɝːtəl/vruchtbaar
radioactive bijvoeglijk naamwoord/ˌɹeɪdioʊˈæktɪv/radioactief
decay zelfstandig naamwoord/diˈkeɪ/verval
sustain werkwoord/səˈsteɪn/in stand houden
chunk zelfstandig naamwoord/t͡ʃʌŋk/stuk, brok
sponsor zelfstandig naamwoord/ˈspɒn.səː/sponsor

Phrasal verbs die je zult horen

WoordBetekenis
check out werkwoordonderzoeken

Grammatica in deze video

De structuren die de spreker het meest gebruikt, met de exacte woorden uit de video:

StructuurIn de video
Lijdende vorm be + voltooid deelwoord — het gaat om wat er gebeurt, niet om wie het doethave been generated · be left · is sponsored
Present perfect have/has + voltooid deelwoord — iets uit het verleden dat nu nog telthave been generated · we've already mentioned

Uitspraak om op te letten

De spreker gebruikt 13 samentrekkingen en verkorte vormen, zoals doesn't, didn't, don't. Spreek ze kort uit, zoals je ze hoort.

  • De klanken “sh” en “zh”: fission /ˈfɪʃən/, crucially /ˈkɹuːʃəli/, absorption /æbˈsɔɹp.ʃn̩/
  • Lange woorden — let op de klemtoon: uranium /ˌjuː.ˈɹeɪ.ni.əm/, radioactive /ˌɹeɪdioʊˈæktɪv/, miraculous /mɪˈɹæk.jʊ.ləs/, moderator /ˈmɒdəˌɹeɪtə(ɹ)/, protactinium /ˌpɹoʊ.tækˈtɪn.i.əm/

Klanken die Nederlandstaligen lastig vinden:

  • Stemhebbende eindmedeklinker — /b/, /d/, /g/, /z/, /v/ niet verscherpen: radioactive /ˌɹeɪdioʊˈæktɪv/, downside /ˈdaʊnˌsaɪd/, absorb /æbˈsɔɹb/, disclose /dɪsˈkləʊz/
  • /æ/ — opener dan de Nederlandse “e”: reactor /ɹiˈæktɚ/, atom /ˈætəm/, radioactive /ˌɹeɪdioʊˈæktɪv/, transform /tɹænsˈfɔɹm/, miraculous /mɪˈɹæk.jʊ.ləs/

Zo oefen je met deze video

  1. Luister de hele video één keer zonder te spreken en noteer de woorden die je niet kent.
  2. Begin op 0,75× snelheid, spreek zin voor zin na en ga terug naar normale snelheid zodra het makkelijk gaat.
  3. Neem jezelf op en vergelijk met het origineel; let daarbij op woorden als reactor, thorium, uranium.

Wat is de Shadowing-techniek?

Shadowing is een wetenschappelijk onderbouwde taalleermethode die oorspronkelijk is ontwikkeld voor professionele tolkentraining en gepopulariseerd door polyglot Dr. Alexander Arguelles. De methode is eenvoudig maar krachtig: je luistert naar native Engelse audio en herhaalt het onmiddellijk hardop — als een schaduw die de spreker volgt met slechts 1–2 seconden vertraging. In tegenstelling tot passief luisteren of grammaticadrills, dwingt shadowing je hersenen en mondspieren om echte spraakpatronen tegelijkertijd te verwerken en te reproduceren. Onderzoek toont aan dat het de uitspraaknauwkeurigheid, intonatie, ritme, verbonden spraak, luisterbegrip en spreekvaardigheid aanzienlijk verbetert — waardoor het een van de meest effectieve methoden is voor IELTS Speaking-voorbereiding en echte Engelse communicatie.

Shadowing-techniek: lees de volledige stap-voor-stap-gids →