Good news: A meltdown would kill fewer than we thought

The evil that one man does

Of course.

Because the whole nuclear industry is a conspiracy of evil men intent on destroying the planet – nothing else! – all led by Lewis Page.

And surely we all know nuclear technology is inherently Evil(TM), therefore any and all reports purporting to demonstrate it's any less than a total, utter, irreparable disaster waiting to happen were no doubt forged by said conspirators.

Good thing we have the Eco-Fighters(C) to save us from the harms of nuclear energy, and lead us to our true, windmill-powered future!

Spent fuel pools - disaster waiting to happen

The biggest common problem by far of all current commercial nuclear plants is the treatment of their "spent" fuel pools.

0. It takes a long time for fuel to reach safe levels of radiation output. Until then, the fuel must be actively kept cool. Also, spent fuel pools are normally kept in secondary containment which can be of greatly varying quality, as Fukushima perfectly demonstrated.

1. In the meantime, accidents or disasters can cause fuel rod pools to drain, or fuel rods to fall on each other and initiate re-criticality.

2. In addition, often, particularly in older designs, spent fuel pools are used for scheduled maintenance to temporarily store active fuel unloaded from the live reactors. This means it becomes absolutely critical to keep the fuel cooled, covered (due to moderation) and contained.

3. The amount of fuel in spent fuel pools is ever increasing because it is highly expensive to re-process and even more expensive (or impossible these days) to just dump fuel under a mountain. In the US, for example, the largest nuclear fuel waste repository which is Yucca mountain has been closed to further waste storage from the commercial industry.

I can actually believe this NRC study in isolation in light of modern standards of primary vessel containment, cooling and even power loss. However, I do not believe ANY nuclear agency in the world has done a thorough analysis of the real risk of spent fuel pools.

In addition, I hold responsible the NRC and other nuclear agencies worldwide for their complete lack of encouraging technological innovation in both overall safety standards and new generator technologies. For the former issue, the agencies are too close to whom they regulate (a bit like the financial industry where its even worse) since the incumbent companies have financial incentives to change as slowly as possible. For the latter issue, they have been too slow to reduce the regulatory burden for *small* innovative reactor design construction, especially the new Gen IV designs.

Why not just build a better reactor?

Oh wait, they have.

How old was the Fukushima reactor? Its design is probably older than most if not all of the posters here. Since that time, reactor design has improved, reducing the risks of a meltdown.

Also note that Fukushima wasn't just the result of a poor design. TEPCO (I believe thats the company that built and ran the reactor, modified the landscape by taking down natural barriers to the sea so that the reactor would be built on hard ground. While at the time of construction, this was the practice, however to reduce costs they took out a natural barrier so that they could easily offload supplies from ships. (Per WSJ report.)

They also didn't plan for the size of the Tsunami and while its deficiencies were pointed out, they were not yet fixed.

Looking at the nuclear reactors of the same generation in the US, they would not face the same level of risk that the reactors in Japan faced. And note that in the US only a percentage of the reactors are of the same generation as the one in Japan.

The sad thing is that we need Nuclear power until we can actually get fusion reactors working.

Of course we could kill off a large percentage of the world's population to reduce our bio mass and food requirements so that we can use those crop lands for bio fuel....

Soylent Green is made from people!

Chemistry

If there is any water around, the Cesium will react to form CsOH plus hydrogen gas. Melt-downs from slow uncovering of the fuel (e.g. TMI and Fukushima) still leave copious amounts of water in the reactor vessel to react with the cesium. The earlier estimates for 60% did not take water into account.

The experience with TMI was that six orders of magnitude less radioactive iodine was released compared to what had been expected.

What caused them to change their tune?

I'm sure it's nothing to do with them being a vested interest in the nuclear power industry and there being a significant accident/string of accidents in Japan that have dented public confidence in the whole creating-radioactive-shit-for-future-generations-to-worry-about industry...

@ VeganVegan

I have been much involved in calculating and assessing nuclear accident scenarios. Also with railway safety, which uses similar methods.

The reason this sort of re-evaluation can arise is that when a plant is designed, and some design data is needed but cannot easily be obtained, particularly material behaviour in extreme conditions, a very pessimistic assumption is made. You might call it a "wild guess" but it is a a >pessimistic< one, for example for the purposes of deciding how much reserve fire-fighting water should be available on site.

But, in the nuclear industry at least, these calculations are often re-checked (re-visited we call it), typically on a 5 yearly basis, to see if any new data has become available that could change the conclusions. What can then happen is that someone has meanwhile done some tests (for example how much Cs would "plate out" on nearby surfaces rather than escape from the pipework and building) which give a much more realistic figure than the original very pessimistic estimate.

What we are really concerned about is to check that the design basis remains pessimistic. In the time I worked in the industry I have never known it otherwise. It is not the object to downgrade the plant by removing safety features. I notice that this particular thing came to light because outsiders asked about it, not because it was the intent of the plant management to take advantage of it.

Some of you guys seem to make the ridiculous assumtion that these nuclear plants are in the hands of cavaliers and clowns. I find that somewhat insulting. The guys I have worked with in the UK nuclear industry are about the most capable and conscientious engineers, scientists and mathemeticians I have ever met. I found the level and detail of thought and precautions that goes into the work astonishing when I first joined, even coming from the railway industry - which is itself an industry with an extremely high safety ethic.

Computer models depend on the model, and the information unputted

Most people here are sysadmins, or used to be before moving up in the world. (Though there is an increasing pollution of users on el reg)

That means that most people are well aware of the term GIGO, when it comes to data modelling. If the model and the information put into it is good then most people here would accept it. Conversely, if the information or the computer model is not good then most of the IT people won't consider it valid, unlike the users who tend to accept *anything* coming from a computer as gospel.

Re : Computer Modelling

: I though that wasn't "real science" according to most people here.

Well the real science would of course to unplug a few reactors (of different designs of course) and measure the resulting radiation output. Probably best try in different weather conditions too so every factor is considered.

You may find that some people (myself included) may object to the "real science" option so modelling is all we have. Yes there have been a comple of disasters but since the likes of 3 mile weren't under labarory conditions I don't think they count

<sarcasm off>

Not really

Imagine a reactor in a moderately built up area, with maybe 100,000 living within 10 miles of it.

1 in 4000 in this scenario equals 25 people.

Add an order of magnitude so that 1 million live in the zone, and its 250. this is a city size really, not sure how many reactors are next to cities? (seriously, I don't know. Sounds a bit irresponsible to me)

This would be tragic for those who got it, but it doesn't equal a shit load of people.

You think 1 in 4000 is bad?

On December 2nd 1984, the Union Carbide pesticide plant in Bhopal, India suffered a leak from a containment tank, and a large amount of methyl isocyanate was released into the atmosphere. This resulted in 2,259 immediate deaths, and a further 1,528 deaths shortly afterwards. 558,125 people were injured, 3,900 of whom suffered permanent disabling injuries.

The population of Bhopal is currently given as a little shy of 3 million people, in 1984 it would probably have been around half of this. Most of those people would not be living within ten miles, so I think it is fair to say that the risk of death to those living within ten miles would be far greater than 1 in 4000 (by at least two orders of magnitude). Note also that the background rate of death by isocyanate poisoning is zero, as oppsoed to the background rate of cancer, which is about 1 in 2 (death from cancer is approximately 1 in 4).

What this 1 in 4000 rate actually means then, is that a person's risk of developing cancer over their lifetime is increased by approximately 0.05% if a nuclear power plant within ten miles melts down and they aren't evacuated in time.

Now, it is important to note that the Bhopal plant was a chemical plant, not a nuclear one, but my point is to illustrate that the worst-case scenario for a nuclear plant is orders of magnitude less bad than the worst case scenario from a simple old chemical plant, albeit one handling large amounts of very poisonous reagents.

I'm not suggesting that a meltdown is not a bad thing, but at the same time, it's not a 'scorched earth' disaster either. If you read the Wikipedia article about the Bhopal tragedy, you'll see that this very much was.

Oh good-

That means we have nothing to hide. So stop watching us.

Also worth noting

That coal fired power stations release radioactive material into the atmosphere during normal use, and the ash produced is also mildly radioactive, whereas nuclear powered ones don't unless something has gone wrong. This is because coal contains trace amounts of uranium and thorium, which are concentrated by the combustion of the main constituents of coal (mostly carbon, hydrocarbons, and sulphur compounds), which produces gaseous oxides. The phosphorus and metal oxides left in the ash are solids.

Because people don't understand or care about real risk

Stop smoking, stop tanning, cut down on your barbequeues and friend food and processed meat. There; your lifetime chance of cancer has probably decreased by a measurable amount. Might do you good to move out of urban areas, too. Oh, and learn about restricted calorie diets and other hair-shirt means of longevity. But who is going to bother with all that, if they aren't already some sort of vegan?

Or alternatively, to increase your life expectancy, don't drive.

Anyway, you're missing the point. People get cancer; if you're not on course for a case of fatal heart disease this is what you get to look forward to. Nuclear power's health impact is pretty negligible at this point.

In the event of a massive Earthquake,

any sensible operator of a nuclear plant will immediately shut down the reactors to prevent damage and escape of radioactive material.

At this point, older designs of reactor, such as those at Fukushima, which require active cooling systems, need an alternative power source.

Normally, this is not a problem, as Fukushima was both conencted to the grid, and had backup diesel generators to keep the cooling running for as long as needed. Unfortunately, there was a pesky little 13 metre tsunami that came along and wiped these out.

Now, it could be argued that the plant was not sited in the most sensible place possible, being, as it was, facing one of the worlds largest and most active subduction faults, and that they should maybe have expected the odd tsunami. The one that happened, however, was a bit of a biggie.

Given the huge number of deaths, and the trillions of $currency worth of damage to the infrastructure of Japan directly caused by the tsunami, I think zero deaths from the radioactive leakage/fallout and a little extra evacuation around a damaged power station were actually a bloody good result.

I'm sorry...

did you miss the mass hysteria over Fukushima earlier this year?

Those who fail to learn from history

are probably doomed to go trolling internet forums like this one. Can you provide any references for these 'experts' saying a reactor explosion was 'impossible'?

I seem to recall that quite a few of the big and exciting nuclear incidents not the result of natural causes were down to reactor staff Doing Something Stupid. Chernobyl, Sellafield, SL-1, whatever.

There are so many differences between Chernobyl and even old school reactors like Fukushima, its hard to know where to start (you might consider learning about containment buildings). Problem is, we don't get nice new reactor designs thanks to a combination of renewable fanaticism and panicky nimbies who don't understand the issues crippling any research and any hope of building decent new nuke plants.

I hope you're all prepared to live in a future where electricity is a middle class luxury. I'm sure the proles will take that in their stride, right?

well

that would be why they do not build reactors like that any more (and only the russians where silly enought to build them in the first place)

and even so the casuilities where less than on some of there other propanger advantures

Getting your facts right might help

Well, except for the fact that chernobyl wasn't a watercooled reactor....

Pripyat

The town where the Chernobyl reactor was sited...

...is now a nature reserve and tourist destination.

The reason that people didn't move back there after they were evacuated is that they were re-housed, mostly in more modern and better housing.

Yes, Chernobyl was a bad nuclear accident. Anything involving a reactor exploding and catching fire and ending up with no containment has to be classed as such, but in reality, the vast majority of those killed or badly injured were those in the control room at the time, and the cleanup crews. Bearing in mind that the cleanup crews were dosed with several orders of magnitude over the lifetime safe dose of radiation, it is quite impressive to note that of those that suffered leukaemia, the 5-year survival was 43%.

The alternative is solar power

The world has plenty of barren desert. Covering a very small fraction of this with solar panels would generate all the electricity currently generated in nuclear plants. It's still a small fraction to replace all other electricity generation.

Yes, there are problems yet to solve. All that I've seen boil down to economics, not physics. Energy supply between sunset and sunrise is the hardest. Possible solutions include pumped gravity storage - best integrated with a tidal barrage; molten salt thermal storage, flow-battery storage (do we have enough Vanadium?), flywheel storage, electrolytic hydrogen storage, underground salt-cavern compressed-air storage.

If we can get 20% efficiency from a thin-film solar panel manufacturable by a continuous process, that doesn't require impossible amounts of rare elements, the economics will start to look attractive, even compared to burning coal. Another ten years and we may be there.

Depending on who does the calculating, solar economics may be ahead of nuclear already. (It certainly is for daylight hours, but an all-solar solution requires energy storage to be costed in. That's hard to do because the present electrical infrastructure does not include any massive energy-storage facilities. )