Recently, while out shopping, a
Courier Mail* headline shouted out at me the words
:
NUCLEAR BOMBSHELL
Australia's first radioactive waste dump proposed just two hours from Brisbane!
[*= I don't read this paper, which is sensationalistic and puerile even in comparison to other Murdoch papers, but sometimes its headlines intrude themselves into my vision, and, as with a car crash, it can be difficult to look away.]
This was puzzling to me because there are already a number of radioactive waste dumps in Australia, and moreover, one of them is only about one hour's drive from Brisbane. It's known as the
Esk Storage Facility and it's located in a pine plantation about 10 km to the west of the town of Esk.
Here's a photo of it:
 |
The Esk Storage Facility
Hey Guys, there's already a nuclear waste dump on Brisbane's doorstep! |
And a picture of it from Google Earth:
 |
| The Esk Storage Facility from above |
This is a state government facility built in 1994 and it mainly holds old medical radioactive sources.
This place is located in the catchment area of the Wivenhoe Dam (the largest of the dams which provide Brisbane with its water). According to our elected representatives, this is not a problem:
... We have heard such outlandish cries in the past few months that the district has now been branded because of a problem that is merely a figment of the imagination.
And it would appear that these unsubstantiated emotional outcries have only just begun.
We had Esk Shire Chairman, Cr Jean Bray—in an effort to draw more attention—claiming that Brisbane's water supply was at risk. It shows how little she knows about the matter that is to be stored there.
The matter doesn't dissolve in water and is not affected by it in any way. The storage site in Brisbane went under in the 1974 floods.
There was also the claim that an accident while waste material was being transported across the dam wall could cause havoc. Why? It would merely sit on the bottom until it was located by monitoring equipment.
[Hansard - QLD Legislative Assembly 10
th Oct 1991]
Unfortunately, this statement is untrue [as a general rule, you can assume that when a politician launches into a withering attack like this, they are not telling the truth]. By far the greatest proportion of the radioactive waste (approx 87% as per a
report by the ARPANSA [Australian Radiation Protection and Nuclear Safety Agency]) held at this site is caesium-137. Caesium-137 is normally present in the form of caesium chloride; which is
highly water soluble. It is true such sources are hermetically sealed, however an accident that allowed such a source to get free could quite easily rupture the relatively thin encapsulation.
Fortunately this fact was realised because (according to the 1996 federal senate enquiry "
No Time To Waste" ) radioactive waste delivered to the Esk facility now takes a longer route around the dam to avoid passing over the dam wall.
I suppose it should go without saying, but radioactive waste is very nasty stuff.
Consider caesium-137; the stuff mentioned above. It's produced in large quantities in nuclear reactors. It's a major component of the fallout from Chernobyl and Fukushima. It's also used in medicine where its intense radiation is used to destroy cancer cells.
In 1987, there was an accident involving a medical Caesium-137 source. This was known as the "Goiânia incident", and it's documented in quite a bit of technical detail in a
report put out by the IAEA [International Atomic Energy Agency].
[Incidentally, there are a number of
incident reports of this type put out by the IAEA and they make fascinating reading, although be warned that in places there are photos of horrible radiation injuries that will turn your stomach.]
The story goes as follows:
In 1987 a radiotherapy source containing approximately 31 cc (that is to say,
slightly less than a shot-glass full) of caesium-137 chloride, was disassembled by a scrap metal merchant in the Brazilian city of Goiânia.
Unfortunately, in the words of the report, the following happened:
That night D.F. [a guy who had purchased the remains of the source from the scrap metal merchant] then went into the garage where the pieces had been placed and noticed a blue glow emanating from the source capsule. He thought it looked pretty and that the powder might be valuable (like a gemstone) or even supernatural, and took the capsule into the house. Over the next three days various neighbours, relatives and acquaintances were invited to see the capsule as a curiosity.
...
Subsequently there were several instances of people daubing the radioactive powder on their skin, as with the glitter used at carnival time.
As a result of this, the caesium chloride ended up more widely dispersed than would otherwise have happened. Eventually, after a number of people became seriously ill (and subsequently died), the true nature of the situation was recognised.
There was a prolonged and laborious cleanup, during which approximately 3500 m
3 of radioactive waste was removed from the area. This didn't even clean up all of the contamination (approx 14% was not accounted for), but merely brought radiation levels down to levels where people could safely move back into the area.If my calculations are right, this is
over 100 million times the volume of the radioactive material that caused the incident.
This gives some perspective on just how potent the stuff is, and just how difficult cleaning up after an accident can be.
It is not at all "radiophobic" to be scared of this shit.
This all said, I'm not lying awake at night worrying about the Esk facility. You have to stick this waste somewhere and a purpose-built facility like this is probably your best option.
Interestingly, there's actually not so much waste in the place. According to the ARPANSA report I quoted earlier, there's only a total of 5.3 TBq of total radioactivity stored there, which is a bit over 1/10th of the amount that was in the Goiânia source. [Why so little? I'm assuming it's because the really big radiotherapy sources are all still in use; caesium-137 has a half-life of a fraction over 30 years, so they're good for a long time and they're not something you'd throw away lightly.]
More interestingly, there is another place close to Brisbane that contain
much more radioactive material. This is the Narangba Food Irradiation Plant, which is located 30 km North of Brisbane.
 |
| The Narangba Food Irradiation Plant - looks like just another industrial building ... |
According to a
conference paper by the Australian Nuclear Association this facility was designed to accommodate up to 185 PBq of cobalt-60, although it was initially only loaded with 11 PBq. I haven't been able to determine whether the facility has subsequently been loaded up closer to its full capacity, but even 11 PBq is a
lot; it's a bit over
2000 times as much activity as is in the entire Esk facility. At full capacity, that would increase to nearly 35,000 times.
 |
... but contains over 2000 times as much radioactive material as the Esk nuclear waste dump.
[This photo is from the web site associated with this plant. I am not sure whether this shows the actual source array in use at Narangba, but it would probably look very similar to this.] |
Cobalt-60 has a half-life of a bit over 5 years, so the source elements have to be replenished regularly. I'm assuming they get their cobalt-60 from the Lucas Heights reactor, which means the replacement source elements have to be trucked right up the coast, through both Sydney and Brisbane. [I'm not sure what becomes of the depleted sources, they can't be going to the Esk facility because this only holds a total of 470 MBq of cobalt-60, which is far less than even a single source element. Presumably they currently keep them on site, although eventually they'll need to be disposed of.]
I'm not sure how worried we need to be about this, though. The source elements consist of pellets of metallic cobalt (which is chemically a fairly inert material), doubly encapsulated in stainless steel, so there's much less chance of widespread contamination occurring in the event of an accident than with some other isotopes.
I'm sure that there are extensive safety precautions taken during both the transport of the source elements and the operation of the plant itself...
Then again there's a saying that goes "you can't make anything truly foolproof, because fools are so ingenious". And this is amply borne out by a
fatal accident that occurred in the Nesvizh Irradiation Facility in Belarus in 1991 [which at that point was the fifth fatal accident to happen in an irradiation facility].
These places have some pretty fierce levels of radiation going on. A person would be subject to a lethal dose of radiation in approximately 30 seconds inside the irradiation chamber of such a facility. Consequently, there are some pretty elaborate safety precautions taken. Although there's a tendency (fostered by decades of cold war propaganda) to assume that in the old Soviet Union safety standards were lax and workers were incompetent, neither were the case here.
The operator who died was considered to be the most experienced operator at the plant. He had an engineering degree and had worked at the plant since its construction. He had had to pass a yearly examination on plant safety in order to retain his license to operate. This is a much higher level of both qualifications and experience than you'd find in the average Australian operator.
The entrance to the irradiation chamber consisted of a corridor with three separate right-angle bends in it (this was referred to as a "maze"). This was to ensure that there was no possibility of the radiation inside (which travels in straight lines from the source) getting out. At the entrance to this maze was one of the most unusual safety features that I've heard of; a
pit trap in the floor(!). There was a cover over the pit which was extended or retracted by an electric motor, and this this was interlocked, via a key mechanism, with the source in the chamber; basically you couldn't extend the cover over the pit unless the source was lowered into a safe position.
 |
| An unusual safety measure |
Beyond the pit was a pressure plate on the floor, which would automatically drop the source to a safe position should someone walk over it. There were also gamma ray monitoring probes at various points and several emergency stop buttons. The mechanism for raising and lowering the source was of course fail-safe, with the force of gravity returning the source to its safe position.
As to what went wrong, the report states diplomatically:
As in many accident investigations, ambiguities exist in the description of exactly what took place during the accident. The operator stated that his own recollection of events was somewhat hazy as he was feeling sleepy at the time. However, both the authorities and those who treated the operator reported that he also appeared reluctant to give any precise details.
It seems that the operator was alerted to a product jam and needed to enter the the irradiation chamber to clear it. He should have pressed the "source down" button on the control panel, removed the interlock key from this panel, used the interlock key to close the cover over the pit, and then checked for radiation before entering the chamber.
It's not clear whether he actually pressed the "source down" button (possibly he meant to but forgot), however he left the interlock key in the panel. This meant the pit was still open, but rather than return to retrieve the key, he used the electric motor that activated the cover as a stepping stone to get over the pit.
Investigators were unable to determine how he managed to get past the pressure plate without activating it (apparently, even taking a flying leap over it would have been very difficult), or if he did activate it, how the source subsequently managed to raise to the active position (and if so, how he failed to hear this happening).
He then failed to look at the portable radiation monitor he carried with him before entering the chamber. You'd almost want to conclude that he was committing suicide, however after about a minute in the chamber he noticed the source was up and ran out calling for help.
It's not a laughing matter, but I have a picture of the guy, fighting his way, Indiana Jones style, past safety feature after safety feature to get into the chamber.
But that's what human beings are like, and why you should never trust anyone who says that some inherently dangerous technology can be rendered 100% safe.
But I'm not lying awake at night worrying about the Narangba Food Irradiation Plant either. It's unlikely that any accident would result in widespread contamination. If someone does something excessively foolish working in the plant, they'll probably die an unpleasant death, but in the overall scheme of things, that's no worse than falling into vat of paint stripper, or any of the thousand other horrible ways people can die in industry.
[As to whether we
need to be irradiating food, that's a different story.]
One thing that
would make me lay awake at night - at least if I thought he could get away with it - is Malcolm Turnbull's apparent desire to create a dump in Australia to receive the world's nuclear waste. We are talking about high-level nuclear waste here, which is fiendishly difficult to deal with. So much so that
no country in the world has yet created a permanent high-level nuclear waste dump.
Turnbull appears to be strongly pro-nuclear, more so than he publicly admits. I'm not basing this on his public statements because I don't trust anything he says - but more that he has appointed strong (and in my opinion one-eyed) advocates of nuclear power - Ziggy Switkowski and Dr Alan Finkel - to important positions.
Why he would talk about a National Nuclear Waste Dump is a puzzle. It goes against the statement I made in my last post - which was that he was purely a political creature and stood for nothing. No purely political creature would dream of mentioning a National Nuclear Waste Dump; this idea has been under consideration on and off since at least as long ago as 1978, been subjected to committee after committee and report after report; and has ended up in the too-hard basket each time. [To make it clear; only the idea a national dump for waste existing within Australia was being considered. Until now no one had suggested taking waste from other countries.] Politically speaking, it's something to run a mile from. There are no winners - people are hardly going to thank you for
not putting a nuclear waste dump in their back yard - and you're guaranteed to make some pretty strong enemies of those who draw the short straw.
Is he so full of himself that he thinks he can get away with it? If so, isn't that a terrible indictment of the man that the one issue he feels strongly enough about to spend his political capital on is the construction of a
nuclear waste dump?
Or is it that he hadn't really meant to make a big issue of it, and it was blown out of proportion by Murdoch's gnomes in order to undermine him? This would also explain why the Mal Brough scandal
just happens to be coming to light now, years after the actual event, and why the media are only now starting to question Mal's handling on the NBN. It does seem that certain elements of the media [and not just the cartoonists] are heartbroken at Abbott's departure and want him back.
But let's not get side-tracked...
A few days ago (5
th Dec 2015) there was a shipment of nuclear waste into Australia. The story was that used nuclear fuel from from Lucas Heights had been shipped to France to be reprocessed and we're now getting it back. Basically, the French extract the plutonium and uranium (or as much of it as they can get) out the for their own purposes, and send us back the rest. [Actually, it's not quite as simple as this; they don't actually segregate the waste country-by-country, but simply send us back an equivalent quantity of waste from their stockpile.]
ANTSO [the Australian Nuclear Science and Technology Organisation] has put out a press release about this. It was full of pap to placate the proles. One thing that particularly caught my eye was this section in their
FAQ. Let's play "Spot the Falsehood":
Q. Is the waste returning to Australia dangerous?
No. Intermediate-level waste is only harmful if not managed properly. It does not generate significant heat and is shielded during handling, processing and storage as a precautionary measure.
As a comparison, the Zwilag facility in Switzerland holds over 20 similar containers to the one returning to Australia, including containers with much more radioactive material. Since it is so heavily shielded and well controlled, the employees of Zwilag can walk around next to those containers without special protective equipment.
The first sentence "
No.", reminds me of a quote from
The Hitchhiker's Guide to the Galaxy:
"this is obviously some strange use of the word safe that I wasn't previously aware of."
Look below at what's in this stuff; if you're not going to call it dangerous, then what in the name of Cthulhu
would you call dangerous?
The second sentence starts with "
Intermediate-level waste..", which we will see later is an incorrect categorisation.
The second sentence ends with "
.. Only harmful if not managed properly.", which is classic weasel-wording. Think about it: this statement is always true by definition. If something causes harm then you're not managing it properly. Even something that's extravagantly dangerous is "only harmful if not managed properly". That it might be incredibly difficult to manage properly, and have terrible consequences if you don't, is a different issue.
The third sentence starts "
It does not generate significant heat ...". As we'll see later this is not true. It puts out nearly 1 kW of heat; enough to cook your dinner on (although I wouldn't recommend doing this).
The third sentence ends by giving the false impression that the stuff is only shielded "
as a precautionary measure", implying that it barely needs to be shielded at all. [Edit - In fact, even the
massive amount of shielding present - each
container weights 112 tonnes and incorporates 200 mm thickness of steel, 67 mm of lead, plus a special neutron-absorbing resin - still results in an uncomfortably high level of radiation in the vicinity of the containers.]
As for being able to "
.. walk around next to those containers without special protective equipment", that's technically true but... The
radiation protection plan says that a person would be subjected to 5.0 μSv/hr working in the vicinity of these (heavily shielded) containers. That's around 30 times the background radiation level in Australia. If you were to work in this area 40 hrs/week 48 weeks/year, you'd be subjected to an annual dose of about 10 mSv. This is half of the maximum allowed annual dose for "occupationally exposed personnel" (but 10 times the maximum allowed for members of the public). Since in reality a person isn't going to need to be in this area for more than a few hours at a time, a couple of times a year, this is not at all a dangerous situation (at least assuming everything goes as expected). Nevertheless, it's somewhat disingenuous to imply that you can stroll around these containers with complete impunity.
[Edit: Oh yes, and the "
without special protective equipment" is also a deceptive statement. Protective clothing protects you from
contamination (which would not be an issue here unless the containers are leaking), but it does not protect you from
radiation. Why? because the thickness of lead required to give a useful amount shielding from gamma rays is far too great to incorporate into protective gear. According to a
document from Oak Ridge National Laboratory, even
one inch thickness of lead would be barely enough to reduce the radiation levels above to background levels. Consequently, it is wrong to assume that there is no danger just because protective clothing isn't needed.]
It took a lot of digging to find out what's in this waste, but
the truth is out there; in the form of a
supporting document to the
license application for building a store for this stuff.
Here's what we got for Christmas:
| Caesium-137 | 1.275 PBq |
| Strontium-90 | 8.559 PBq |
| Americium-241 | 340.6 g |
| Uranium | 18.36 kg |
| Plutonium | 391.8 g |
| Neodymium | 11.07 kg |
[They also state what was in the spent fuel we sent out, but I've omitted this for clarity.]
Our old friend caesium-137 is there:
25 times as much as the Goiânia source, and the French even did us a favour; we only got back a quarter of the caesium-137 we sent out. On the other hand, they gifted us 14 times the americium-241 we sent them (which is enough to make
over a billion smoke detectors), so swings and roundabouts.
There's an absolute
shed load of the equally dangerous strontium-90, and we've got back over a third of the plutonium we sent them.
The contents of the Esk repository are a rounding error compared to this (literally; they would at most affect only the last decimal place of all of these figures).
One thing that's interesting, is that they quote the heat output of this waste. This is actually an important factor because it's what separates High Level from Intermediate Level Waste, and it's one thing that makes High Level Waste difficult to deal with: you need to cocoon it in shielding to keep the radiation at bay, but this traps in the heat, and if you don't get rid of the heat, the temperature starts to rise and then bad things happen.
The stuff we sent out was putting out 2101 W of heat. The stuff we got back was putting out 950 W. The difference was almost entirely due to the lesser amount of caesium-137 we got back. Since spent nuclear fuel has all of the characteristics of High Level Nuclear Waste (but it isn't referred to as such, simply because it's not defined as "waste"), and what we got back puts out nearly half as much heat as the spent fuel (and would put out virtually the same if the French had given us back all our caesium-137 as they were entitled to do), how come this waste isn't classified as High Level?
I suppose it's just a matter of terminology, but it seems that people are going to great lengths to avoid calling a spade a spade.
Finally, I'll leave you with this comforting thought:
This waste is only a drop in the bucket compared to what we'd be seeing if Turnbull's dream came true. This was just the waste from a single 10 MW research reactor. The average power generation reactor is about 100 times the size of this and there are over 400 nuclear power plants in the world. They have many decades worth of waste stored away, waiting for someone to take it.
