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AUSTRALIA’S REACTOR

Our exclusive tour of Lucas Heights!

BABIES FROM SKIN CELLS The future of human cloning?

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1600KM/H STORMS:

The Solar System’s Extreme Weather!

Have we already found

ANOTHER EARTH? • THE EARTH-LIKE EXOPLANETS WE COULD CALL HOME • THE NEW TELESCOPES THAT WILL FIND THEM • THE REAL SCIENCE OF EXTRATERRESTRIAL LIFE

INDONESIAN EARTHQUAKES

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Could they threaten Australia?

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WILL FLOATING CITIES SAVE THE ENVIRONMENT?

ISSUE #23

3OCEAN HOMES

COMING UP...

High-tech sea station for oceanographers A 58-metre-tall vessel resembling a spaceship from a sci-fi film will allow scientists to live, work and study the ocean from within its very depths.

ARCHITECT KOEN OLTHUIS/WATERSTUDIO.NL/DUTCH DOCKLANDS

An island made of homes Real estate developer Dutch Docklands is redefining waterfront property with The Ocean Flower, an artificial atoll in the Maldives boasting 185 floating luxury homes. The buildings will sit on floating concrete foam blocks (typically used for Dutch houseboats) that rise and fall to adapt to the water level. Their heavy foundations

should keep the structures relatively stable, and they will be attached to the seafloor by cables like those used for drilling rigs. The villas are now on sale and start at 710,000 Euros for 163 square metres.

T

The Ocean Flower Where: Maldives When: Within five years

Apartments on (top of) the water made of a patented type of foam concrete, with a modular design to allow for expansion.

The Citadel Where: Westland, the Netherlands When: December 2014

Dubbing itself the Googleplex of the sea, Blueseed is envisioned as an “incubator” for IT start-ups from across the globe — a complex combining working and living space that is anchored 22 kilometres off Silicon Valley in international waters so that its

inhabitants can avoid the cumbersome US immigration process. Monthly rents are expected to be comparable to (or even less than) those on land, and so far the project has attracted interest from more than 300 start-ups — more than a quarter of which are from the US Blueseed Where: San Francisco Bay, US When: Mid-2014

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SeaOrbiter Where: Monaco and France When: 2014

The SeaOrbiter will provide a permanent presence with a window to what is under the surface of the sea.

— Jacques Rougerie, architect

Jacques Rougerie has always been fascinated by the sea, drawing his inspiration for the SeaOrbiter from decades of innovative projects that have sought to shed light on the planet’s final frontier — including a number that he designed himself.

SEAORBITER/JACQUES ROUGERIE

BLUESEED

Entrepreneurs at sea

SEAORBITER/JACQUES ROUGERIE

More than 50 per cent of the Netherlands lies less than a metre above sea level, and flooding is common. Consequently, architect Koen Olthuis has designed a floating complex of 60 apartments, complete with trees and greenhouses, now under construction in a canal near the city of Naaldwijk. The complex will be set atop a floating foundation

he brainchild of French architect Jacques Rougerie, the SeaOrbiter is a marine laboratory like no other. Not only will it host scientists conducting research on the ocean, it will do so from a unique vantage point — in the sea itself. The futuristic craft is intended to sail the world’s waters while teams of researchers carry out experiments and collect data on the marine world.

Following tests of a three-metre-tall scale model in Norway, the floating lab is currently under construction and is expected to sail from Monaco in early 2014. The first expedition will be in the Mediterranean Sea; the following year, the SeaOrbiter will begin a two-year mission in the Gulf Stream.

Almost 50 per cent of the vessel is situated below the water, part of a special design that guarantees its stability and will enable scientists to work even in rough seas. A wind turbine at the top of the vessel will supply part of the energy needed, with more coming from an entire deck lined with solar cells, and although it is designed mainly to drift, propellers are available when manoeuvring is necessary, such as for docking. The project has garnered support throughout the marine science community, as well as from the European Space Agency and NASA, which plan to use the SeaOrbiter to train astronauts.

27.0 m: Radio and satellite antennas allow scientists to send daily web and TV updates to the outside world.

Wind turbine

18.5 m: The lookout deck affords a 360-degree panorama of the surrounding ocean.

Deck with 350 square metres of solar cells Outside deck with two handling cranes 11.5 m: Boat storage

9.4 m: Upper deck and engine room; control room for missions above the sea Platform lift for divers

Retractable rear access ladder

6.8 m: Diving room and scientific wet lab 4.2 m: Command bridge with navigation equipment 1.6 m: Labs, medical zone, and fitness area for the crew – 1.0 m: Bunks area and captain’s cabin

Underwater training platform for divers

– 3.6 m: Bunks area and VIP cabin

Stern thruster – 6.2 m: Communication zone and sanitary area

– 8.8 m: Living quarters (in atmospheric pressure) – 11.6 m: Living quarters in pressurised mode with access to dive pit and submarines (located another 2 metres below the surface) Winch and abyssal platform Dive pit for divers and miniature submarines

– 31 m: This is as far as the retractable keel can reach; its 180-tonne weight stabilises the orbiter.

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The Indian Ocean is a geological hot spot

The Indo-Australian Plate 7.9 magnitude 7.9 magnitude

The Indo-Australian tectonic plate is sliding under the Sunda plate — and is simultaneously being twisted apart as its southern end moves faster than its northern one.

N W

4

8.3 magnitude

E

2

1 8.6 magnitude

3

Four fractures in three minutes 1. On Apr. 11, 2012, a 150-kilometre crack

S INDIA

appeared in the seafloor, causing an earthquake that measured 8.6 on the Richter scale.

Eurasian Plate

2. About 40 seconds later, a new 200-kilometre rupture appeared at a right angle to the first one, accompanied by a 7.9-magnitude tremor.

37.6 mm/year

Sunda Plate 40.6 mm/year

Philippine Plate

Somalia Plate

8.6-magnitude quake

SUMATRA

DEFORMATION ZONE

49.1 mm/year

48.2 mm/year

50.1 mm/year

Indo-Australian Plate

breathed a sigh of relief, scientists were scratching their heads. At the time, most seismologists thought that an earthquake with a magnitude above 8 could only be caused by the type of temblor that would also trigger a tsunami if it were to strike the ocean floor.

Geologists know that earthquakes originate along deep cracks in the Earth’s crust, known as faults. Most earthquakes occur along the borders of the tectonic plates that make up the planet’s crust. There are seven major tectonic plates, and many smaller ones, which move about each other, powered by their own weight and forces in the Earth’s interior.

Major earthquakes occur when these plates collide, and that movement occurs in two different planes. In normal and reverse 56

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49.1 mm/year

(or thrust) earthquakes, one plate slides vertically under the other in what scientists call a subduction zone. For example, on the western side of South America, the Nazca Plate slides under the South American Plate, pushing up vast stretches of rock, which is the process that formed the Andes Mountains. Off Sumatra, the Indo-Australian Plate slides under the Sunda Plate and the resulting vertical motion can generate a huge ripple across the ocean, which is what happened on Dec. 26, 2004.

In strike-slip earthquakes, the plates slide horizontally past each other. These are the types of tremors that occur along the San Andreas Fault near San Francisco, which happen as the immense stress between the plates is released. Such quakes don’t displace water to nearly the extent as

AUSTRALIA

vertical quakes, and thus don’t cause tsunamis when they strike the ocean floor.

Their magnitude is usually below 8.

Armed with seismographic data from sensors all over the globe, scientists have begun to study the April quake in detail. And as they have pored over each of its mysteries, it has become clear that something big is under way. After examining its epicentre deep under the Indian Ocean, scientists have stumbled onto a geological sensation: One of the world’s largest tectonic plates is being twisted apart.

MYSTERY #1:

The quake’s epicentre was unexpected.

Unlike the 2004 earthquake, the temblor that struck last April did not occur along the border between two plates. Scientists

Sunda Plate

The underground stretches — and cracks The April 2012 earthquake was a strike-slip quake; these types of temblors occur when the plates move in opposite directions along a rupture line, or fault.

9.1 magnitude quake of 2004

A

SUMATRA

Bedrock at rest

Fault

For 45 million years, the area in which the April quake struck has been relatively quiet. The dotted line marks a fault in the deformation zone where two pieces of bedrock border each other.

No stress

TRENCH

Bedrock under stress

B

Stress occurs in the Indo-Australian Plate, and the bedrock on each side of the fault is slowly pulled in opposite directions. Small amounts of stress can be absorbed by the rock, which is slightly flexible.

3. After another 30 seconds, the bedrock moved around a third fault running parallel to the first one, registering 8.3 on the Richter scale.

4. Some 75 seconds later, a final, 7.9-magnitude earthquake lasting 15 seconds occurred at a fourth fault some 200 kilometres away.

Increased stress

Bedrock settles

C

Finally, the bedrock is overstretched and there is abrupt movement along the fault: an earthquake. In last April’s quake, the bedrock shifted by as much as 40 metres before coming back to rest.

Release

DEFORMATION ZONE: The region where stress across the plate triggers dislocation.

Tsunami

Plate: The Earth’s crust consists of an estimated 13 stiff

plates floating on a softer, warmer layer of rock.

Richter: A logarithmic scale indicating the magnitude

Vertical fault

of earthquakes; the most violent one so far measured 9.5.

Epicentre: The point on the surface located vertically above the point where the earthquake begins.

Why was there no tsunami?

In order for a tsunami to occur, the earth must move vertically, displacing enough water to create a tall wave, as was the case when the Indo-Australian Plate slid into the Sunda Trench in December 2004. In strikeslip quakes, the motion is horizontal.

= Plate motion

pinpointed its origin at the centre of the IndoAustralian Plate, 200 kilometres west of the earlier quake’s epicentre and a considerable distance from where the Indo-Australian plate slides under Sumatra’s Sunda Plate, creating a giant deep-sea trench. This location meant that the quake didn’t have a vertical component, as the 2004 quake did, but was horizontal, like those along the San Andreas Fault. This explained why it failed to generate a massive tsunami, but also contributed to another mystery.

MYSTERY #2:

The quake was unusually violent.

Initially, the quake’s magnitude was pegged at 8.9, which would have made it the sixth most violent earthquake ever recorded.

Eventually its magnitude was downgraded to

8.6, putting it at 15th on the list of the most violent quakes. However, it was the strongest that seismologists have ever observed at the centre of a plate, and the most violent one involving horizontal motion, releasing as much seismic energy at the centre of the Indo-Australian Plate in one event as would normally be released in 1,000 years. These types of earthquakes are rarely measured at a magnitude above 7, which is why seismologists did not recognise the April quake as a strike-slip immediately, and why they expected a tsunami to ensue.

MYSTERY #3:

The crust cracked in all directions.

Deep below the seafloor, the quake cracked the Earth’s crust in the most complex patterns that seismologists have ever seen.

Normally, earthquakes take place along a single fault, but last April, no fewer than four faults were involved — three of which were perpendicular to the fourth. The ruptures spread from fault to fault along an unexpected, tortuous path and with a force exceeding any quakes recorded at similar strike-slip faults, including the San Andreas, New Zealand’s Alpine Fault, or the Anatolian Fault in Turkey.

By comparison, the Great 1906 San Francisco Earthquake involved motion on only a single fault. If it had been similar to Sumatra’s April quake, the consequences would have been inconceivable.

MYSTERY #4:

The quake stretched across the world A few hours after the quake, the first major scienceillustrated.com.au

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FEATURE | nuclear phsyics

HEART OF

GOLD SPENDING TIME WITH THE OPEN POOL AUSTRALIAN LIGHTWATER REACTOR

AUSTRALIA’S ONLY NUCLEAR REACTOR PROVIDES VITAL SERVICES FOR MEDICINE, AND IS A TRIUMPH OF HUMAN INGENUITY AND HIGH-TECH DESIGN. SO WHY DO SO MANY PEOPLE OPPOSE IT?

D

riving along the Heathcote Road in southeastern Sydney, I could be anywhere. The two-lane bitchumen is flanked by dense scrub. Heading sound, early morning traffic is light. Fifteen minutes later I take a lefthand turn and head toward Menai. The road is just the same. A few minutes on, I’m vaguely aware of a high chainlink fence flanking the right-hand tabledrain, but I don’t pay it much attention. The sign to ANSTO - the Australian Nuclear Science and Technology Organisation - looms suddenly, and only as I pull into the right hand turn lane do I realise I’ve driven past Australia’s only nuclear reactor... without even seeing it.

In fact there are two reactors at Lucas Heights. One, called HIFAR, the High Flux Australian Reactor, was switched on by Prime Minister Robert Menzies in 1958. It did research work until 2007 and is now well into the process of being decommissioned. It should be completely cool by 2018.

The second, much newer reactor is OPAL. The Open Pool Australian Lightwater reactor began working in April 2007, and is of a much more sophisticated design than HIFAR. The key feature is that it uses very low enriched Uranium (see boxout, next page) - and that means it doesn’t make weapons-grade byproducts.

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Story by: Anthony Fordham Today, I’m here to visit OPAL, and see some of the processes ANSTO uses to irradiate materials and then prepare them for industrial use. Much of OPAL’s work goes into making medical-grade isotopes, radioactive materials that are used mainly to either image a patient’s internal organs, or to treat cancer via radiotherapy. But OPAL also makes very high grade silicon for use in IT, and it provides neutron flux beams that are shot out into a connected building where scientists can book time on various instruments for their own experiments.

What OPAL isn’t is a nuclear power reactor. Its thermal output is only 20 megawatts. (By comparison, Victoria’s Hazelwood Power Station, a coal-fired generator, has a net output of 1470 megawatts, and the Kashiwazaki-Kariwa nuclear plant in Japan - the world’s biggest - produces 8,212 mW). OPAL is instead a research reactor, designed explicitly to enable scientists to conduct nuclear experiments safely, and produce a minimum amount of radioactive waste.

SAFETY AND SECURITY When I arrive, I’m quickly outnumbered by ANSTO staff.

There’s a representative from the organisation’s media team of course, and a nuclear scientist who often takes groups on educational tours of the ANSTO campus.

They’re excited today because permission has been

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FEATURE | nuclear physics

GENTECH GENERATORS As well as a research reactor, ANSTO has a production line factory which builds, well, Molybdenum-99MoTechnetium-99mTc-Sterile Generators. What the heck are they?

On the outside, a plastic bucket. On the inside, a lead-lined chamber with a small ampoule of Molybdenum-99. This decays into Technetium-99, an isotope that’s extremely useful for imaging the brain and thyroid. A doctor injects the Technetium-99 into the patient, the body metabolises the isotope, and a scanner is used to image, say, tumours or other problems. It’s a world-leading nuclear medicine technology, and in extreme demand.

A steel basket protects the reactor from aeroplanes (top) while a worker moves an ingot of silicon toward the round pool that holds the core (middle).

Samples (below) await radiation or removal from the access pool.

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given for us to actually go in on the reactor floor and look into the reactor core. The scientist herself has never actually been inside the reactor - this will be her first time. Unlike large power station reactors which have their coolant under very high pressure, OPAL is an open pool reactor where the core is cooled by water at normal pressure. Water is actually an excellent radiation shield, and the advantage of an open pool is that the reactor core can be accessed easily.

Naturally, access to the reactor is heavily controlled, because after all, there’s several kilograms of uranium sitting at the bottom of the tank, and technicians are moving materials in and out of the pool all the time. The fewer people who can walk around in the area, the safer the reactor.

But today we’ll all be going in. I’m also encouraged to take photographs with my own camera ANSTO is very keen to make it known

that, even though they maintain suitably strict security around the reactor, they don’t have anything to hide. OPAL’s design is commercially proprietary, yes, but it’s not sinisterly “top secret” or militant in any way.

However, this is the first tour I’ve ever been on where I’ve been flanked by a member of a security team run by the Australian Federal Police. She’ll be double-checking all my photos, just to make sure they don’t show entryways or exits, or security systems.

We drive from the visitor’s area up through a series of security checkpoints. Then, as we crest the hill on which OPAL sits, the first thing I can’t help but notice is what appears to be a gigantic deep fryer basket sitting over the top of the reactor building.

Nuclear reactors are designed with “containment” in mind. The interior is kept at a lower air pressure, so in the unlikely event of an explosion, air will rush IN, rather than materials blowing OUT. The “basket” on top of the whole building is designed for a single purpose: to shred aeroplanes.

When OPAL was built, it looked like Sydney was sure to get a second airport nearby. After running various probabilities, it was decided it was worth building a cage specially strengthened to shred a plane’s fuselage while bouncing the fuelfilled wings and explosive jet engines into a nearby paddock. Since then, that airport has gone on hold, and it looks like the cage has become a case of security overkill. It’s interesting that ANSTO primarily views the risk of plane impact as one of an accidental crash, rather than a terrorist attack.

YES, IT REALLY GLOWS Inside the building, through more security checks, we reach a foyer full of models of the reactor. We can see the pool goes down 10 metres, where the core sits surrounded by complex pipes, machines, slots, turntables and more. In a case nearby is a long piece of dull metal,

And at the bottom, there it is.

The ultimate nuclear cliche.

The water at the base of the pool, most intense around the square core, glows blue. square in cross-section, modelled after one of the uranium fuel rods. It’s surprisingly small, but I’m told that uranium is actually 70% denser than lead (later, back at the education centre, I’m able to test the difference in weight between an ingot of lead and an ingot of depleted uranium, and it’s startling). Sixteen of these rods make up the core.

The OPAL reactor core is 30,000 times smaller than the reactor core at Chernobyl that’s right, 30,000 - and isn’t much larger than the average wheelie bin. Yet it’s still big enough that, once the fission reactions inside go critical and fission becomes self-sustaining, it can be used to produce enough radioisotopes to supply a significant portion of the world’s nuclear medicine needs.

After the foyer, we go through more security checks, get different passes, go through some airlocks, and are met by another ANSTO representative in charge of safety. She has us suit up - not in full-on sealed radiation suits with those dustbin helmets, but still yellow overcoats, blue gloves, and blue slip-on covers for our shoes. Then, we go through the containment airlock and into the reactor itself.

My first impression? It’s much like a cheese factory. Lots of stainless steel, big “vats”, pipes and taps and lots of stuff scrawled on whiteboards. But stepping forward to the edge of the pool (there’s a chest-high “lip” around the edge, though I do wear a sort of bungie thing to stop my glasses falling in) I look down and instead of churning milk, there’s a 10m deep pool filled with more pipes and flanges and unaccountable bits of grating than I’ve ever seen, even in a sci-fi videogame.

And at the bottom, there it is. The ultimate nuclear cliche. The water at the base of the pool, most intense around the square core but still visible toward the edge, glows blue. Not the sickly, poisonous green that Hollywood likes to use to scare people, but a vibrant, high-tech and obviously high-energy blue. It’s called Cherenkov Radiation, caused by the core emitting particles travelling faster than the speed of light in water, which slam into water molecules and cause them to release a blue photon. Which I see, 10 metres above, as light.

It’s the main thing that tells me this isn’t just

OPAL is an open-pool reactor, where the primary shield is water. This gives easy access to the relatively tiny core.

A QUESTION OF ENRICHMENT Uranium is the only material that occurs in nature that can be used to start a nuclear fission reaction. Specifically, an isotope of uranium called uranium-235 is unstable enough to be used in reactors and bombs alike. Most uranium - 99% of it in fact - comes in the form of uranium-238 which can’t sustain a fission reaction by itself. It’s still radioactive, releasing an alpha particle, but it has a very long half-life of 4.47 billion years.

Uranium-235 is more unstable, though its half-life is still an epic 704 million years.

Uranium-238 can be “transmuted” into uranium-235 through a process called enrichment.

The more highly enriched a chunk of uranium, the more fissile it is, and the more useful for high energy reactions and, sadly, making weapons. A reactor with less uranium-235 is considered to be low-enriched, and its inherently safer - at least from a weapons security perspective.

OPAL has been deliberately designed to operate with very low enriched uranium, which limits the amount of plutonium and other materials it produces as a byproduct of fission. scienceillustrated.com.au

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FEATURE | NUCLEAR PHYSICS

LIQUID NITROGEN ON TAP One of the coolest things about the ANSTO campus is the taps. Yes, the taps. In the sections of the facility where medical products are assembled, there are taps for hot water, cold water, and liquid nitrogen. Out the back, there’s a big tank full of liquid nitrogen. It comes in on a truck. Why are we mentioning this? We just think it’s cool. Geddit?

another industrial chemical plant. That glow, to the unknowing eye, has no source. Most of the lights we see day to day have a point-source (or at least a strip, in the case of a fluoro tube). This glow just comes from, well, the water itself. It’s fascinating.

MAKING MEDICINE (AND OTHER THINGS) After a while, ANSTO technicians arrive to insert some silicon ingots into the reactor. The ingots are placed near the core, and the radiation sleeting out of the uranium hits the silicon, cracking some of its atoms into phosphorus - it’s called neutron transmutation doping. This makes the silicon conductive (pure crystalline silicon does not conduct electricity) and useful to the high end of the IT industry.

Elsewhere in the core, other materials are being irradiated to produce such isotopes as Technetium-99, and Samarium-153. In fact, OPAL makes enough medical-grade material to fully fund 30% of its operating costs. The rest is borne by the Commonwealth.

After watching the technicians at work, it becomes clear to me that what they’re doing, in essence, is baking.

They have a fire (the radioactive core), and they put things around the fire, at precise distances, for a precise amount of time. Some of the things (such as the silicon), they rotate so they “bake” evenly.

Of course, where things get technical is the neutron beam. This is, at its simplest, a hole in the wall of the reactor which bounces neutrons into the attached Bragg Institute building. Here, the neutrons are reflected into various scientific instruments, nicknamed after various Aussie animals like ECHIDNA (it looks spiky), WOMBAT (it’s a bruteforce device), KOALA (it does one unique thing like a Koala only eats gum leaves), and others. Universities and other institutes compete for time on the instruments, and the research ranges from hard core theoretical physics to testing the effectiveness of laminates, glue and other materials. And of course much more.

What’s impressive about the whole setup is that OPAL is a working reactor, it’s the heart of an industrial facility that actually makes things. Useful things, things that even save lives or ease the suffering of people with terminal diseases.

After we leave the reactor room, we discard our protective clothing and pass back through a series of scanners that compare our outgoing radioactivity with how 64

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An ANSTO worker manipulates a radioactive sample inside a hot box - a lead-lined chamber With years of practice, operators can lift and stack cylinders like these as if they were using their bare hands

FEATURE | NUCLEAR PHYSICS

LIQUID NITROGEN ON TAP One of the coolest things about the ANSTO campus is the taps. Yes, the taps. In the sections of the facility where medical products are assembled, there are taps for hot water, cold water, and liquid nitrogen. Out the back, there’s a big tank full of liquid nitrogen. It comes in on a truck. Why are we mentioning this? We just think it’s cool. Geddit?

another industrial chemical plant. That glow, to the unknowing eye, has no source. Most of the lights we see day to day have a point-source (or at least a strip, in the case of a fluoro tube). This glow just comes from, well, the water itself. It’s fascinating.

MAKING MEDICINE (AND OTHER THINGS) After a while, ANSTO technicians arrive to insert some silicon ingots into the reactor. The ingots are placed near the core, and the radiation sleeting out of the uranium hits the silicon, cracking some of its atoms into phosphorus - it’s called neutron transmutation doping. This makes the silicon conductive (pure crystalline silicon does not conduct electricity) and useful to the high end of the IT industry.

Elsewhere in the core, other materials are being irradiated to produce such isotopes as Technetium-99, and Samarium-153. In fact, OPAL makes enough medical-grade material to fully fund 30% of its operating costs. The rest is borne by the Commonwealth.

After watching the technicians at work, it becomes clear to me that what they’re doing, in essence, is baking.

They have a fire (the radioactive core), and they put things around the fire, at precise distances, for a precise amount of time. Some of the things (such as the silicon), they rotate so they “bake” evenly.

Of course, where things get technical is the neutron beam. This is, at its simplest, a hole in the wall of the reactor which bounces neutrons into the attached Bragg Institute building. Here, the neutrons are reflected into various scientific instruments, nicknamed after various Aussie animals like ECHIDNA (it looks spiky), WOMBAT (it’s a bruteforce device), KOALA (it does one unique thing like a Koala only eats gum leaves), and others. Universities and other institutes compete for time on the instruments, and the research ranges from hard core theoretical physics to testing the effectiveness of laminates, glue and other materials. And of course much more.

What’s impressive about the whole setup is that OPAL is a working reactor, it’s the heart of an industrial facility that actually makes things. Useful things, things that even save lives or ease the suffering of people with terminal diseases.

After we leave the reactor room, we discard our protective clothing and pass back through a series of scanners that compare our outgoing radioactivity with how 64

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An ANSTO worker manipulates a radioactive sample inside a hot box - a lead-lined chamber With years of practice, operators can life and stack cylinders like these as if they were using their bare hands

The OPAL reactor produces radioisotopes that are used in medical imaging (to detect cancers and other illnesses) and radiotherapy.

radioactive we were on the way in. Despite standing on a service bridge looking directly into the active core of a nuclear reactor, with nothing between me and several kilograms of uranium except 10 metres of very clean but otherwise ordinary water, my reading is still zero.

WHY THE FEAR? Unlike, say a coal-fired power station with its massive turbines, or the floor of a factory stamping car parts out of sheets of steel, inside OPAL there are no huge things spinning around at fantastic speed. There’s no molten metal, or poisonous gas at insane pressures or temperatures. Yes, there’s danger there. But there’s danger keeping two tonnes of rolling metal with a tank full of explosive hydrocarbons outside your living room window. But unless you’re very stupid, your car probably won’t explode.

Yet, despite this, many Australians are opposed to the idea of nuclear power in this country, and specifically opposed to OPAL even though it’s not a power station (in fact the reactor consumes a massive amount of electricity). Yes, if a reactor goes bad - a big reactor, anyway - the results are wide-reaching and last for a long time. But the same is true of any industrial chemical plant, or asbestos mine, or any of a hundred other industries that produce toxic materials that hang around in the ecosystem for hundreds or even thousands of years.

We can trot out all the statistics we like about how particulates from coal stations have killed more people than all the nuclear accidents (and the two nuclear bombs in Japan) combined. We can point to America’s “superfund” sites, places rendered so toxic by standard chemicals that children are born deformed

just like around Chernobyl. We can point to lead in petrol, which has affected the brains of probably millions of people.

But somehow, that spectre of a radioactive cloud, of words like “cesium” and “strontium” and concepts like “half-life” and the trifoil radioactivity symbol terrify us more than all these other things.

It’s probably the weapons that do it. The knowledge that the science behind such useful tools as the OPAL reactor has been used to create bombs so powerful they rival earthquakes and volcanoes in terms of energy released. That splitting an atom can destroy a city, while fusing two atoms can destroy an entire country.

ANSTO, out there at Lucas Heights, is probably one of the most tightly run industrial chemical facilities in the country. It has permanent AFP officers on site, 24 hours a day. It’s subject to incredible scrutiny, and more than all of this, ANSTO staff themselves want to prove that their technology is safe. It’s not just some commercial concern looking to save a few bucks by cutting half the security team and only running emergency drills every other month.

The campus at Lucas Heights isn’t some slap-in-the-face to the still overwhelming desire among Australians to not use nuclear power in this country. It doesn’t produce the kind of waste that can be stolen to make nuclear weapons (dirty bombs though, maybe). It makes bone cancer medicine for children, and OPAL is one of the world’s hardest working, most reliable, and best medical reactors.

Blanket acceptance of nuclear technology would be a mistake, yes.

Accidents, when they happen, are beyond terrible. But at the same time, blanket refusal to take advantage of what this technology can give us is a mistake too.

When OPAL isn’t running at full output, such as in 2008 when it was shut down to repair a water leak, people in hospitals die.

I left ANSTO in a thoughtful mood. I spent the day looking at an incredible world-class facility, built by engineers and scientists who are leaders in their field. A place that, far from poisoning the world, makes materials that cure disease. To dismiss it as a relic of the Cold War is just wrong.

WHAT IS A HALF-LIFE? Radioactive isotopes like uranium-235 or plutonium-239 emit particles from within their atoms - this is what they “radiate”. Every time a particle - such as an alpha particle, which two protons and two neutrons - is radiated, the mix of atoms in the piece of radioactive material changes. The more particles are emitted, the fewer atoms of the isotope remain. Eventually, half of the isotope will have decayed into a different material (or more accurately, a mix of different materials). This span is called the half-life.

Many people are concerned that isotopes with very long half-lives (like uranium-238’s 4.47 billion years!) are extremely dangerous because they stay radioactive effectively forever. But in fact, an isotope with a long half-life emits much less radiation (in a set period of time) than one with a short half-life, and so there’s less chance of a particle hitting your body and, perhaps, causing cancer. Radioactivity from uranium-235 is still dangerous if you handle a large sample, but an isotope like radium-226 with a half-life of 1601 years is so active it actually glows. It’s roughly three million times more radioactive than uranium... but on the plus side, it doesn’t occur in its pure form in nature. scienceillustrated.com.au

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