Japan fires up nuclear power again, but can it ever be safe enough?

August 17, 2015 by Ben Heard And Barry W. Brook, The Conversation

After two years without any nuclear power in response to the 2011 Fukushima earthquake, tsunami and subsequent nuclear crisis, Japan has restarted its first reactor, Sendai 1.

Following the Fukushima event, Japan's generators were gradually shut down. Before the earthquake, nuclear power accounted for around 30% of Japan's electricity. After the shutdown, fossil fuels largely picked up the slack and have been doing the heavy lifting ever since, causing a sustained rise in greenhouse gas emissions.

The restart of Sendai 1 is good news for Japan's response to climate change, and comes with heightened safety regulations around nuclear energy. Based on our assessment of the evidence, this only makes a safe industry safer. But there are still large psychological barriers to overcome.

Visiting Fukushima

In May this year we returned to the megalapolis of Tokyo, following our visit to Fukushima prefecture and the site of the destroyed Daiichi reactors.

We carried dosimeters (a device that measures radiation) through the 20 km radius exclusion zone and wore them at the site. At the very foot of unit 1, the dose rate was serious (greater than 400 microsieverts per hour). Just a couple of hundred metres away at the undamaged reactor 6, the rate was normal background (less than 5 microsieverts per hour).

Our cumulative dose for the site visit during the course of that day was about one-seventh the dose we received on our flights to Tokyo.

The nuclear accident destroyed four of the six reactors at this site. The decommissioning will take a long time. But it did not irrecoverably poison a landscape. Formal expert studies have shown that the radiation has caused and will cause no discernible human harm.

The psychology of a nuclear disaster

The most serious outcomes have, again, been psychological hurt inflicted on those affected. As we heard first-hand from officials in Naraha town, "unfounded rumours" continue to be one of the biggest obstacles for the community to recover from this event.

The prolonged closure of the rest of the largely undamaged Japanese fleet of reactors also led to a steep increase in fossil fuel importation, hurting the Japanese economy and sending greenhouse emissions rising steeply. Japan's recent electricity supply has come to resemble Australia's dependence on fossil fuels. That's not a good thing, unless you sell fossil fuels.

Yet despite the economic hit and the massive setback to its previously announced climate change targets, Japan has been struggling to restart its reactors. When we visited the Japan Atomic Industrial Forum on this same visit, the mood was sober. Public opinion was holding hard against nuclear. The restart was far from certain despite exhaustive checks and approvals.

One in our number was prescient when he said that Prime Minister Shinzo Abe's government will simply need to spend political capital, restart reactors and manage the response. That appears to have been the case with the restart of 30-year-old, 890-megawatt Sendai 1 reactor this week.

Making a safe industry safer

No informed observer argues that the failings displayed at Fukushima, both technical and procedural, were not serious. So how can people, most of all the Japanese, feel confident in the restart of other reactors?

The Japanese regulator took strong action with major boosts in safety standards. Here are some of those new actions:

A nuclear plant must be designed to withstand a larger than any recorded event - which includes the 2011 events. As a result, major new seawall infrastructure has been installed to protect plants.

The major failure at Fukushima, the loss of power to the reactor, has been addressed. Off-site power supply must now be from two fully independent circuits. Previously, two emergency on-site generators were required. This has been boosted to a third permanent installed generator, plus two mobile units located in nearby elevated terrain, all with a seven-day fuel supply. These requirements apply to all plants.

Previously, internal flooding was not regarded as a plausible event. Now it is. No matter the hypothetical cause, all critical buildings must demonstrate protection from flooding, for example through the installation of new watertight doors.

At Fukushima Daiichi, the loss of cooling in the core during the first day of the accident led to the buildup of steam and hydrogen gas in the reactor pressure vessel. After delays due to power loss to the pressure pumps, these gases were eventually released from the containment vessel, but the power failure meant that venting from the reactor building itself to the outside failed. The highly volatile hydrogen gas accumulated and chemical explosions subsequently ensued.

There are new systems tied to the additional backup power supply to ensure prompter venting from the containment vessel. Permanently installed filtered venting systems are now in place to then vent any gases from the reactor building.

If containment does fail, large-scale water cannons will be deployed to douse the reactor building and prevent the dispersion of material away from site.

Reactors that have been operating for more than 30 years will require assessment of structure, systems and components at year 30 and every decade thereafter. Operational lives are limited to 40 years with one potential extension of not more than 20 years.

Such extraordinary measures, piled on top of a sector that has operated very safely bar one accident triggered by an extraordinary external catastrophe, will make the very safe even safer.

But do we feel safe?

Despite the increase in regulation, many people still feel unsafe around nuclear energy. This may in fact be because of the high levels of regulation – if something needs so much attention, it must be dangerous, right?

We can contrast this with the risks of fossil fuels. More than 7 million deaths are attributed to air pollution annually, with an important contributor to this figure. Burning coal for energy and heat contributes 20% of greenhouse gases that are warming the earth every year. That all happens when they are in perfect working order.

Will nuclear technology ever win hearts and minds to scale-up and replace coal?

The focus now is on "stupid-proofing" nuclear technology - making nuclear power immune to human error (also called "walk-away safe"). Reactor technology is heading increasingly in this direction.

Today's designs like the AP-1000 from Westinghouse go a long way towards "stupid" safety. It will likely be metal-fuelled, liquid-metal-cooled recycling reactors like the PRISM, or fluid-fuelled reactors like the IMSR from Terrestrial Energy (for whom Ben has consulted) or the ThorCon reactor that decisively change the game for nuclear technology.

All of these designs incorporate "inherent" safety systems. Rather than requiring an operator, they rely on physical principles to regulate the reactor (for instance, gravity-fed cooling systems or the expansion of the fuel with heat).

Can Japan and the world be confident their nuclear sector is safe? The only evidence-based conclusion we can reach is "yes". But it may take fundamental changes in the technology before most people will believe it.

Explore further: Japan's nuclear industry pledges to refire reactors

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40 comments

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gkam
1.2 / 5 (21) Aug 17, 2015
Not too smart. The reactor is not yet in full production, and they already have a volcano nearby threatening to erupt.

Not too smart.
WillieWard
3.7 / 5 (3) Aug 18, 2015
Not too smart.
it can wake up Godzilla!
gkam
1.2 / 5 (21) Aug 18, 2015
Has anybody told them of the cost of Vogtle?

How about Hinckley? No?

The troubles in Europe? No?

Do they plead ignorance?
gkam
1.2 / 5 (21) Aug 18, 2015
Once again, let's compare any wind farm and the Vogtle plants in Georgia. The nukes are not finished yet, but they already have such high costs, that the cost to PRODUCE power, not sell it, will be around THIRTEEN cents /kWh!

Compare that to the actual contract prices for wind, less than three cents, and PV, which is less than four cents. Then what do they do with the intensely-radioactive nuclear waste, since they cannot even store it safely?

Why would ANYBODY want nuke power?
WillieWard
5 / 5 (2) Aug 18, 2015
let's compare any wind farm..and PV
Almost out-of-phase with demand, need to be backed by fossil fuels as baseload; even for free, still ecologically expensive, millions birds and bats butchered, large wildlife's habitats taken, kill more than nuclear per gigawatt produced.
gkam
1.2 / 5 (21) Aug 18, 2015
Nope. When we put the wind turbines up at Altamont, they gave us the power EXACTLY when we needed it, with no fuel requirements, no toxic wastes, no huge need for cooling water, and it was exactly where we wanted to use it, so there were no transmission costs, like we would need for coal and nukes, which have to be sited according to propinquity of vast amounts of water.

We'll have to put up more PV and wind, since we will have to shut down Diablo Canyon.
gkam
1.2 / 5 (21) Aug 18, 2015
Willie is running out of excuses for nukes. The danger is well-known, but the ultimate costs of having to guard the immense stores of high-level radioactive waste for the required 240,000 years cannot be estimated, let alone guaranteed.

We have not even figured out a sure way to do it, even after 60 years of looking. Why do we continue to make more, in systems too costly to operate?

Tell us, Willie.
WillieWard
4 / 5 (3) Aug 18, 2015
The danger is well-known
Renewables cause more fatalities and environmental impact per terawatt-hour than nuclear. Wind and solar need to be backed by fossil fuels, aside heavy governmental subsidies, hence its real cost is not so affordable as it has been claimed, is its price just another green scam to lure taxpayers?

WillieWard
3.7 / 5 (3) Aug 18, 2015
radioactive waste
Manufacturing just five wind turbines produces 1 ton of radioactive residue and 75 tons of toxic, acidic water used to leach out the required neodymium.
gkam
1.2 / 5 (21) Aug 18, 2015
Operating one nuclear plant produces what? The cores are a hundred tons or so, for each fueling. They get so intensely radioactive and exothermic, they have to be kept covered with water or they will eventually melt down and turn to vapor.

How do you plan to guarantee all those old, exothermic, deadly wastes are kept covered and cooled for decades, if the companies go out of business and walk away?
WillieWard
3.7 / 5 (3) Aug 18, 2015
radioactive and exothermic
Earth's core is radioactive and exothermic given origin to geothermal energy sources.
http://www.world-...Uranium/
gkam
1.2 / 5 (21) Aug 18, 2015
"Earth's core is radioactive and exothermic "
--------------------------------------

Yeah, and anybody there is DEAD!
gkam
1.2 / 5 (21) Aug 19, 2015
The Japanese government pronounced that volcano safe just before it erupted!

Who will trust these corporate-owned goons?
TheGhostofOtto1923
4.6 / 5 (20) Aug 19, 2015
Not too smart. The reactor is not yet in full production, and they already have a volcano nearby threatening to erupt.

Not too smart.
This volcano is over 30mi away and poses no danger to the facility.

George is just having another spastic reaction to sensationalist news reports.
WillieWard
3.7 / 5 (3) Aug 19, 2015
volcano safe just before it erupted!
Nature is unsafe, go to a safer planet but be careful of black holes and supernovas.
gkam
1.2 / 5 (21) Aug 19, 2015
"This volcano is over 30mi away and poses no danger to the facility."
--------------------------------------

Stop the evacuations! Otto, the nuclear expert, who does not even know how they work, says it is safe! And anyone who can come onto a science forum and scream nasties in all caps must be really smart.

All he needs now is a public fixation to prove his psychopathy.
TheGhostofOtto1923
4.6 / 5 (20) Aug 19, 2015
"Stop the evacuations! Otto, the nuclear expert, who does not even know how they work, says it is safe!

All he needs now is a public fixation to prove his psychopathy.
-Says george the bullshit artiste who thinks that doing job shop validation ona single system, offsite, makes him an expert. Oh and actually standing in a control room.

What evacuations are you talking about? Those around the plant which is over 30mi away?
All he needs now is a public fixation to prove his psychopathy
"Psychopaths just have what it takes to defraud and bilk others: they can be fast talkers, they can be charming, they can be self-assured and at ease in social situations; they are cool under pressure, unfazed by the possibility of being found out, and totally ruthless. And even when they are exposed, they can carry on as if nothing has happened, often making their accusers the targets of accusations of being victimized by THEM."

-Just who do you think youre kidding?
gkam
1.2 / 5 (21) Aug 19, 2015
"they can be charming, they can be self-assured and at ease in social situations; they are cool under pressure, unfazed by the possibility of being found out,"
--------------------------------------

You are just saying that to exclude yourself from the category. It won't work.

You are the one with the fixation.
TheGhostofOtto1923
4.6 / 5 (20) Aug 20, 2015
You forgot the important part.

"... unfazed by the possibility of being found out, and totally ruthless. And even when they are exposed, they can carry on as if nothing has happened, often making their accusers the targets of accusations of being victimized by THEM."

-You're a psychopath and are being treated for it down at the VA, undoubtedly because it affected your relationships or legal status.

Of course this is speculation based on lots of evidence which you yourself have provided.

Your treatment is not working so well is it?

WHAT evacuations are you talking about??

Answer the question.
gkam
1.2 / 5 (21) Aug 20, 2015
Oh, . . have they found and "cleaned up" the seething, hot, radioactive masses which used to be Fukushima cores?

They cannot even view them because the intense radioactivity kills everything, including their robots!!

I suggest we send in Eikka, Willie, and otto, with denglish in front. They can show us they are really, really right, and nukes are safe.
WillieWard
3.7 / 5 (3) Aug 20, 2015
..radioactive masses which used to be Fukushima cores..
intense radioactivity kills everything, including their robots..
If radiation were so dangerous ..., but it is not, no one died from radiation in Daiichi.
but gskam claims that it kills even robots. Comic!
They cannot even view them because the intense radioactivity kills everything..
Only special people, like gskam, that can see "The Emperor's New Clothes", sees the robots being killed. gskam is very unique, honest with himself as in the tale.
gkam
1.2 / 5 (21) Aug 20, 2015
Here ya go, Willie.

http://www.cnn.co...dex.html

Got an apology?
WillieWard
3.7 / 5 (3) Aug 20, 2015
.. http://www.cnn.co...dex.html ..
The robot's internal components seem intentionally left exposed to be damaged by anything.
It seems there is no intention to solve the problem in short term, maybe influence/stratagem of green/anti-nuclear lobbyists to delay and make more expensive the task.
http://i2.cdn.tur...-169.jpg
gkam
1 / 5 (20) Aug 20, 2015
Yeah, some nuclear apologist ventures some guess about what killed it, when we KNOW it was the intense radioactivity. And the robot designers did NOT intentionally make it vulnerable. What psycho crap.
TheGhostofOtto1923
4.8 / 5 (19) Aug 22, 2015
What evacuations george?

There are no evacuations except for right near the volcano. Certainly not 30mi away at the nuke plant.

You're a lying, cheating fraud.
gkam
1.2 / 5 (21) Aug 22, 2015
They were warned,
http://www.foxnew...ruption/
and the evacuations have been planned. They are now awaiting to see what happens.

Meanwhile, the startup is having trouble:
http://www.japant...-problem
WillieWard
5 / 5 (3) Aug 22, 2015
They were warned,
Godzilla is waking up to kill all of us, no safe place on the earth.
gkam
1.2 / 5 (21) Aug 22, 2015
Yes, and Godzilla is the metaphor for nuclear technology.
WillieWard
3 / 5 (4) Aug 22, 2015
metaphor
A world powered 100% by wind and solar, but secretively compensated by fossil fuels, is a metaphor for unicorn fart energy.
wilhelm_schneider
5 / 5 (2) Aug 31, 2015
I read your comments from Germany. Stopping nuclear power and subsidizing wind and solar power is the most stupid decision our government ever made. we have the most expensive power system in Europe (29€cent per kw/h) and it goes worst every year. The subsidy is €28 billion/year. While our remaining NPP's are perfect running (capacity factor 91% - the same in your Country) wind and solar generation is complete instable (capacity factor 17% resp. 9.5%).
wind power destroyes the landscapes, kills birds, needs a full repowering after 15 years and it works intermittand all the time. Forget wind and sunpower and built new NPP the best energy source of all.
gkam
1 / 5 (18) Aug 31, 2015
wilhelm_schneider have you looked into the problems with the new nuclear plants? How about the costs? Are you willing to take the waste?
gkam
1 / 5 (17) Aug 31, 2015
It is happening as we speak: Coal and nuclear plants are closing. The costs of Vogtle and Hinckley C are now becoming obvious and terrify the nukers. The new models are not yet proven, and are already behind schedule and over cost, and out of competition with alternatives.
gkam
1 / 5 (18) Aug 31, 2015
The Sendai Reactor is already having trouble, and is not even up to full power yet. Also, there have been TWO volcano warnings about two different volcanoes nearby now becoming active, although the government said they would not.

We may soon see what the next Japanese nuclear disaster looks like.
WillieWard
3.7 / 5 (3) Aug 31, 2015
volcanoes
gskam is an untiring shameless/unethical "greenie lie machine"; scaremongers like him provoke irrational panic, abortions, heartattacks, and suicides, on misinformed populations, they kill more radiation.
wilhelm_schneider
5 / 5 (3) Aug 31, 2015
gkam (?) I know the problems of the cost overun wth the construction of new NPP in the US and France/Finland (EPR1600) Ask the NRC an DOE. We have in the USA and in Europe a caotic over-regulation after the the DAICHII disaster. I know also the Situation in China, India, Korea, Russia and UAE, a complete different situation with the same demand for safety regulations. It works much better, despite they face also rising costs. This is not alone a NPP problem, we have huge rising costs in every tech Project. And what waste?. Used fuel is no waste. It is simply a political Problem - in your Country and here in Germany. It is crazy to listen the hearings in our Administrations and in the Environment Departments. My opinion: These Groups don't want a solution because the anti nuke world needs this never ending issue. Finally. Sendai has 100% full power and don't care about the volcano, that is another issue. stay cool.
gkam
1 / 5 (18) Aug 31, 2015
"And what waste?. Used fuel is no waste. It is simply a political Problem "
------------------------------

Oh good! How soon can we send you ours?
wilhelm_schneider
5 / 5 (4) Aug 31, 2015
Nuclear power is cheaper than every alternativ sources. In 2012 we opened an offshore Windpark (BARD I). Until now it is not full running. 80 wind-units each 5 MW/h, 400 MW/h total capacity. Enough to generate 1.6 TW/h with 4000 full capasity hours/year. meanwhile the costs exceed € 3 Billion. Our 9 remaining NPP's generated in 2014 ca. 99 TW/h, an average of 11 TW/H. To replace one NPP with windpower you need 7 Windparks BARD I. Since you need net-stability you have to add 80% of the installed wind capacity for standby Gas-Utilities.
And you Need a grid for transport of electricity. Simply 600 miles to our Industrie-centers in the west and south. Still an unsolved future Project. This all is more than 5 fold more expensive as 1 NPP with full baseload and highest availability and reliability. A NPP runs for 60 years and needs no repowering after 15-20 years. And no helicpters are used for the extrem high maintenance costs for offshore Windparks. This is our reality.
gkam
1 / 5 (18) Aug 31, 2015
Why are you crying to me about the decisions made by your people? We have had wind, PV, geothermal, all kinds of gas, alternative sources of all kinds for over 40 years in California. But we were more careful and intelligent about their integration into our power systems.

We knew what we could expect, and the power was "sold" before the systems were built.
WillieWard
3.7 / 5 (3) Aug 31, 2015
we have had wind, PV..
Ecologically hypocritical means of energy generation that kill more than nuclear per gigawatt produced.
gkam
1 / 5 (18) Aug 31, 2015
Excelon and First Energy are having real problems trying to keep their money-losing nuke plants online. They want customer subsidies to keep those wheezing old-fashioned units online, being obsolete.

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