The Nuclear Power Thread

[eXorikos]

Is there a technical reason why in the UK it was chosen to build new nuclear powerplants rather than go for a lifetime extension? I am not very familiar with AGR design. I know Magnox fuel is no longer produced.

 

[rootone]

I think it was just a case of newer designs being more effective in various ways, just like you don't forever upgrade the same computer.

 

[eXorikos]

I think it was just a case of newer designs being more effective in various ways, just like you don't forever upgrade the same computer.

Of course, I was just asking what the technical reasons are. In many other countries using PWRs they did a lifetime extension, e.g. Netherlands and Belgium. So it appears to be cost-effective for a PWR, but apparently not so for AGR.

 

[Astronuc]

Some good summaries of LWR technology.

http://ocw.mit.edu/courses/nuclear-engineering/22-06-engineering-of-nuclear-systems-fall-2010/lectures-and-readings/MIT22_06F10_lec06a.pdf
http://ocw.mit.edu/courses/nuclear-engineering/22-06-engineering-of-nuclear-systems-fall-2010/lectures-and-readings/MIT22_06F10_lec06b.pdf

I did note some misinformation that will have to be corrected. The error relates to the description of PWR control rods, specifically the Ag-In-Cd control rods which are effectively black, not grey. Grey rods use Inconel or Ni-based metals, although Westinghouse is introducing a newer concept for grey rods in the AP-1000. Black control rods are used for shutdown, while grey rods may be used for power shaping and relatively small changes in reactivity, for example during load-following. Some EdF plants use grey rods for power maneuvering. B&W plants were designed with axial power shaping rods (APSRs), but otherwise most PWRs have not used grey rods.

http://ocw.mit.edu/courses/nuclear-...lear-systems-fall-2010/lectures-and-readings/

 

[TJM-Ex-Op]

What two or three things would you tell non-technical college age voters about nuclear power?

Dear Physics Forum nation,
I'm a long time nuclear professional, former Senior Reactor Operator in commercial nuclear power. I made a career change to consulting/contracting a short time ago. I recently helped some professors at the local junior college who were teaching a class called "Physics in Society" to non-science majors. I presented some info on nuclear power. I thought I did a good job of presenting a balanced objective case. It was well received so I was invited to return and integrate this more directly into the course. Meaning the material presented would be testable. Pretty awesome no? The course material presented by the professors covers reactor types, fuel cycle, stream cycle etc. I tried to emphasize how people are trained, the oversight, and the traits of a healthy nuclear safety culture. The professors challenged me asking, "What one or two things would you want young potential voters to know about nuclear power?"
So I thought I'd reach out to Physics Forum nation for help.
Some of my thoughts,

• Plants cannot blow up like a nuclear bomb
• The industry is highly regulated
• Personnel go through extensive initial and continual training
• Carbon emission goals proposed cannot be met without current nuclear plants
• Plants are built for the long term, decommissioning cost are factored into the cost to run. Plants are not discarded like an old steel mill.
• Plants are a vital part of the economic engine of the local community

I'm trying to develop one or two major takeaways. What do all think?
I welcome suggestions.
tjm

 

[jim hardy]

he professors challenged me asking, "What one or two things would you want young potential voters to know about nuclear power?"
So I thought I'd reach out to Physics Forum nation for help.
Some of my thoughts,

At the plant where i worked, two of the mechanical foremen took photographs of a refueling outage at the plant. They wanted a show&tell for their kids' elementary school.

They produced a great series of 35mm slides covering a refueling - from lifting the concrete covers off reactor cavity , removing head cables and insulation, detorque unbolt and lift reactor head , floodup , lift internals, swap fuel , put it all back together again.
That's everyday stuff and midnight oil to plant guys like you and me
but to somebody who's never seen a steam turbine or inside of a containment , that huge machinery is right out of sci-fi.
Our two foremen became local celebrities, every school within forty miles asked them to present their show..
Local media got wind and we hosted an enterrage of TV reporters. The pretty evening news anchor lady posed on our spent fuel crane, in yellows.

So

"What one or two things would you want young potential voters to know about nuclear power?"

I'd want them to know
their friends and neighbors work here
it's honest hard work
it's not spooky or scary science
the nuclear reactor itself works great for it was thought up by geniuses
99.9% of the work in a plant is on the mechanical systems surrounding the reactor.

This line changed my anti-nuke Mother in Law's thinking:
"The power reactor grew out of the Manhattan project.
That's unfortunate because the power reactor inherited the stigma of 'The Bomb' .
Had events unfolded in the reverse order, public opinion would be instead :
"What?
Somebody actually blew up perfectly good uranium? Profligate Wastrels ! Don't the fools know you can make electricity with that stuff? "

I use this analogy for non-science majors:
"You understand chemical reactions.
A reactor is to a bomb as firewood is to dynamite . "

So my advice is - bring your considerable experience into your presentation. Get real photos . My Walmart scanned my 35mm slides on to a cd-disc for a presentation 2013, hopefully they still have that ability for yours.

 

[Astronuc]

• Plants cannot blow up like a nuclear bomb

• The industry is highly regulated

• Personnel go through extensive initial and continual training

• Carbon emission goals proposed cannot be met without current nuclear plants

• Plants are built for the long term, decommissioning cost are factored into the cost to run. Plants are not discarded like an old steel mill.

• Plants are a vital part of the economic engine of the local community

It looks like 6 great take-aways. As for decommissioning, look at cases like Big Rock Point, and other examples.

I know a lot of folks in the nuclear industry and many are very involved in the outdoors and conservation. There are a lot of folks who enjoy outdoor sports, including camping, fishing and hunting with their friends and family, so they have a vested interest in maintaining the safety of nuclear plants.

 

[mheslep]

• Plants cannot blow up like a nuclear bomb

• The industry is highly regulated

• Personnel go through extensive initial and continual training

• Carbon emission goals proposed cannot be met without current nuclear plants

• Plants are built for the long term, decommissioning cost are factored into the cost to run. Plants are not discarded like an old steel mill.

• Plants are a vital part of the economic engine of the local community

US nuclear power has for decades been the bedrock of the clean US energy supply and with an excellent safety record. Today, new problems and new innovations have come to the fore that suggest a new approach to the discussion.

With regards to possible public fears about nuclear power, Fukushima is in the public's recent memory. So it is radiation leakage (not nuclear explosions) the prompts fears, fears encouraged by an active and irrational anti-nuclear community with connections to the fossil fuel industry. Notably, despite the great loss of life from the quake and tsunami at Fukushima, nobody died from radiation nor, per the World Health Organization, are any deaths from radiation causes likely to ever be detectable.

Your points 2,3,4, and 6 are all related to a real issue with nuclear power: the cost of new nuclear. As you are likely aware, the first nuclear plants in the US, before the creation of the NRC, were built relatively quickly in the hundreds of million dollar range (today's dollars). Now, Vogtle 3 and 4 will cost $15-16 billion with a ~ten year build time. It is this large cost that make the destruction of the Fukushima reactors a very large negative for a utility. By contrast, a new gas plant of similar size might cost a fifth the cost, can be built in 18 months, and does not require a large staff with "continual training", a security force, and permanent onsite regulators. So yes the industry is highly regulated, but is the particular US regulation appropriate? Does the current regulatory regime drive up costs unnecessarily and stifle innovation. Many new nuclear designs have been proposed, but recently DoE/NRC officials essentially testified that any non-light water reactor designs need not apply, though some of them could make a Fukushima type plant explosion not unlikely but impossible.

The point of nuclear power is to enable economic engines by means of clean and affordable energy; it should not be a jobs program.

 

[nikkkom]

By contrast, a new gas plant of similar size might cost a fifth the cost, can be built in 18 months, and does not require a large staff with "continual training", a security force, and permanent onsite regulators. So yes the industry is highly regulated, but is the particular US regulation appropriate? Does the current regulatory regime drive up costs unnecessarily and stifle innovation.

Even with all this heavy regulation, nuclear industry failed to create the feeling that reactors are safe and won't ever spew lots of radioactive materials to the environment. The facts are, reactors did do that, multiple times, and there were multiple close calls as well.

Why are you surprised general public is not eager to see "innovation" from this industry?

 

[mheslep]

As you know, harm from radiation is not defined by "lots of radioactive materials" in the environment as the environment already has lots of radioactive materials, but by a level of radio-toxicity that causes measurable short or long term fatalities or disease. While possible, that's never occurred from commercial reactors in the US nor from the Fukushima accident in Japan. Meanwhile, the emissions from coal plants continue to cause a very predictable and measurable harm via lung disease and the like every year.

 

[nikkkom]

As you know, harm from radiation is not defined by "lots of radioactive materials" in the environment as the environment already has lots of radioactive materials, but by a level of radio-toxicity that causes measurable short or long term fatalities or disease. While possible, that's never occurred from commercial reactors in the US nor from the Fukushima accident in Japan.

It did occur elsewhere.

Also, US and Japanese accidents were "close calls", they demonstrate that nuclear industry is incapable of delivering on its promise that nuclear power is safe.

I don't need to wait to actually see fuel pool fire and 10% of Japan rendered uninhabitable as a result, to conclude that nuclear power (as it is managed today) is not safe. It was enough for me to see that for 10 days in 2011, it was unknown what's going on in fuel pools at Fukushima, and there were no means to refill them.

Meanwhile, the emissions from coal plants continue to cause a very predictable and measurable harm via lung disease and the like every year.

Straw man argument which assumes that I'm a proponent of using coal as our main source of energy.

 

[mheslep]

It did occur elsewhere.

Yes, from a seriously flawed reactor design radically different from those in the West, a design soon to be discontinued if not already, and the operation of which was notoriously badly managed. Still, the number of fatalities from acute radiation sickness or fire (30) at Chernobyl was far lower than, say, the 1040 killed in Chinese coal mines in one recent year (2013).

...that nuclear power is safe... conclude that nuclear power (as it is managed today) is not safe.
...Straw man argument which assumes that I'm a proponent of using coal as our main source of energy.

Context is not a strawman, and "safety" in particular is a concept rendered meaningless without context, especially in on a topic where many would inject fear into the discussion when allowed to avoid evidence. Coal is particularly relevant to the safety discussion since China is i) by far the world's largest consumer or coal and ii) also has by far the world's largest collection of new reactors currently under construction (24). That is, in China, nuclear and coal are the two primary non-hydro alternatives for base load power.

One does not have to favor coal power, sitting in the dark without power, or even living close to the sea on Japan's Pacific coast without seawalls to assess the downside of those scenarios.

 

[nikkkom]

Yes, from a seriously flawed reactor design radically different from those in the West, a design soon to be discontinued if not already, and the operation of which was notoriously badly managed. Still, the number of fatalities from acute radiation sickness or fire (30) at Chernobyl was far lower than, say, the 1040 killed in Chinese coal mines in one recent year (2013).

I'm Ukrainian. So please, don't b.s. me about "low casualties of Chernobyl".

True, only a few people died from *acute* radiation sickness. No one knows how many people died from non-acute effects of radiation, but they are certainly in the thousands. Children in evacuated families of Pripyat quite often have a "bouquet" of ailments, they are statistically less healthy than other people.

None of these people took the risk of nuclear power *willingly*, unlike miners or say, policemen, who chose their profession knowing the danger.

Ukraine and Belarus will have hundreds of square kilometers of land unfit for permanent habitation for a century to come.

Japan has such land now, too. And it's pure strike of luck (wind direction at the time of accident) that its uninhabitable "nuclear" land is smaller than Ukraine's.

As it is currently managed, nuclear industry almost certainly will have another major incident in not too distant future. "We need no stinking filters on emergency vents" attitude.

 

[mheslep]

I'm Ukrainian. So please, don't b.s. me about "low casualties of Chernobyl".

True, only a few people died from *acute* radiation sickness. No one knows how many people died from non-acute effects of radiation, but they are certainly in the thousands. Children in evacuated families of Pripyat quite often have a "bouquet" of ailments, they are statistically less healthy than other people.

None of these people took the risk of nuclear power *willingly*, unlike miners or say, policemen, who chose their profession knowing the danger.

Ukraine and Belarus will have hundreds of square kilometers of land unfit for permanent habitation for a century to come.

Japan has such land now, too. And it's pure strike of luck (wind direction at the time of accident) that its uninhabitable "nuclear" land is smaller than Ukraine's.

As it is currently managed, nuclear industry almost certainly will have another major incident in not too distant future. "We need no stinking filters on emergency vents" attitude.

That's a narrative designed to end discussion. Here are some evidenced based claims with references to encourage discussion.

In the US where all the coal plants have scrubbers, as of http://www.catf.us/fossil/problems/power_plants/ emissions from plants, not from mining. The non-lethal impact rates from asthma, heart attack, and lost work days are far higher. These rates have since fallen in the US with the reduction in coal use. The mortality rate from plant emissions globally is likely far higher. Those inhaling PM for years were also not willing participates. As for the miners, clearly, absent nuclear power, a large body of workers must mine or drill to provide non-hydro dispatch-able electricity. Offering that miners know the risks of a task without any viable alternative is a thin argument.

Globally, the prevented deaths from nuclear power displacement of fossil fuel combustion has reached http://www.giss.nasa.gov/research/briefs/kharecha_02/

The Chernobyl accident occurred in a http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Power-Reactors/Appendices/RBMK-Reactors/, with a "positive void coefficient", and without containment as it is understood in the west. There are 11 remaining RBMK's in the world, all of them in Russia. They all received major modifications years ago to address PVC and other problems, and will close without replacement (by other RBMK).

With respect to Chernobyl's so called exclusion zone, the plant had three other reactors that were in part operated and manned daily for 23 years after the '86 accident in Unit 4 (i.e. until 2009). A labor force of thousands works in the area performing decommissioning.

Per WHO/UNSCEAR, the Chernobyl accident outcomes:

A total of up to 4000 people could eventually die of radiation exposure from the Chernobyl nuclear power plant (NPP) accident nearly 20 years ago,...
As of mid-2005, however, fewer than 50 deaths had been directly attributed to radiation from the disaster, almost all being highly exposed rescue workers, many who died within months of the accident but others who died as late as 2004.

and

Conclusions
The accident at the Chernobyl nuclear power plant in 1986 was a tragic event for its victims, and those most affected suffered major hardship. Some of the people who dealt with the emergency lost their lives. Although those exposed as children and the emergency and recovery workers are at increased risk of radiation-induced effects, the vast majority of the population need not live in fear of serious health consequences due to the radiation from the Chernobyl accident. For the most part, they were exposed to radiation levels comparable to or a few times higher than annual levels of natural background,...

A similar outcome might be obtained from a grossly negligent run and poorly designed industrial chemical plant. Common sense in the face of such an accident demands recognition of the need for well run and designed industrial chemical operations, not facile calls for an end to chemical plants as if they served no purpose.

 

[jim hardy]

As it is currently managed, nuclear industry almost certainly will have another major incident in not too distant future. "We need no stinking filters on emergency vents" attitude.

When Jimmy Carter stopped our breeder program about 1981, much to the consternation of us young nuke workers , i thought to myself:

Actually in one regard he's got the wisdom of Solomon. He sees the need to give civilian Management Science time to catch up with civilian Nuclear Science."

Not surprising, given his Navy background.

I'd love to ask him whether he thinks we've made it.

Anyhow the problems are societal not scientific.

old jim

 

[mheslep]

Assigning wisdom to the fast spectrum breeder cancellation for safety reasons requires the assumption that breeders are somehow more dangerous than light water thermal reactors with no spent fuel solution. Do you believe that's the case?

 

[jim hardy]

Assigning wisdom to the fast spectrum breeder cancellation for safety reasons requires the assumption that breeders are somehow more dangerous than light water thermal reactors

I don't see that connection at all. Wisdom is more realizing one's shortcomings , intelligence is doing something about dangers be they of internal or external origin.

And i don't believe it's true that breeders are more dangerous, indeed liquid sodium needn't even be pressurized..

Remember Three Mile Island was a fresh memory then.

I took Carter's action as recognition that the industry suffered from too rapid growth and too much zeal , resulting in a culture of cavalier overconfidence and haste . Hazards of youth .

The Kemeny report spoke to that

http://www.threemileisland.org/downloads/188.pdf

I took Carter's action as in the spirit
"Let's learn how to properly run these seventy-two reactors we've got right now before rushing headlong into a new generation of perhaps a thousand of them."

In 1986 the Russians punctuated that sentiment with exclamation marks and ! bold ! italic! underline ! at Chernobyl.

It's been thirty six years now since TMI .
Has the industry matured ? Is corporate America ready ?

I can only say we're a lot closer than we were in 1979.
I remain proud of where i worked for we improved greatly.old jim

 

[mheslep]

I agree with much of that and the cautions of Kemeny. What does any of that have to do with killing breeders? Like the Russians now, one can build two or three, no need for thousands.

 

[jim hardy]

What does any of that have to do with killing breeders? Like the Russians now, one can build two or three, no need for thousands.

? That depends on how far ahead one is looking to power civilization. I thought we were looking at a few decades of LWR's , then to breeders for ~500 years.

Hmmmm... it looks like a lot has happened since i got out of school in 1969...

India is focusing and prioritizing the construction and commissioning of its fleet of 500 MWe sodium-cooled fast reactors in which it will breed the required plutonium which is the key to unlocking the energy potential of thorium in its advanced heavy water reactors. This will take another 15-20 years, and so it will still be some time before India is using thorium energy to any extent. The 500 MWe prototype FBR under construction in Kalpakkam is expected to start up in 2014.

In 2009, despite the relaxation of trade restrictions on uranium, India reaffirmed its intention to proceed with developing the thorium cycle.

http://www.world-nuclear.org/info/Current-and-Future-Generation/Thorium/

 

[jim hardy]

Rambling but interesting article here. It looks at energy with a view to mankind's long term needs. http://bravenewclimate.com/2014/12/...d-depleted-uranium-and-the-centuries-to-come/

...one can calculate that in 2011, the average continuous power output of all the world’s energy generation systems of all types was 8.1 trillion watts, or, in more familiar power units, 8.1 million megawatts. The per capita average continuous power demand overall for all people on the planet was 2500 watts, roughly the power output of a small American suburban lawn mower; in 1973 that figure was roughly 2000 watts. Billions of people of course, had much less than a lawn mower’s worth of power on average in 2011 (and for that matter in 1973), whereas other people got to use several orders of magnitude more power than a “lawn mower’s worth” of power, driving, for instance, in swell Tesla electric cars by which they express, in unconscious drollery, their “concern” for the environment......

.........

Nuclear energy, and only nuclear energy, has the energy to mass density to be sustainable indefinitely at levels of energy production that involve a balance of human decency coupled to environmental justice.

Fermi – who despite his vast intellect is said to have been no elitist – understood, way back in the 1940’s, that we would require depleted uranium to be made into energy, and well more than half a century later, as we are in crisis whether we see it or not, it is very clear that he was, in recognizing this, handing us a key by which we might save what can still be yet saved at this point.

 

[mheslep]

I think that article summary is a bit off target about nuclear. Intermittent renewables plus storage can work technically, but as Bill Gates said recently, the cost would be "astronomical", leaving nuclear as the only affordable energy path.

 

[nikkkom]

That's a narrative designed to end discussion.

Indeed you are right. No amount of talk will persuade me. What could have persuaded me is if US plants had been proactive in heeding all the Fukushima warnings/lessons. Such as filtering on vent lines, additional power generators, battery-powered lights, additional water and pumps added on site. I did not see that. I see a willing disregard to act.

In the US where all the coal plants have scrubbers, as of http://www.catf.us/fossil/problems/power_plants/ emissions from plants, not from mining. The non-lethal impact rates from asthma, heart attack, and lost work days are far higher.

Heart attack because of the coal power plant is a LOL of the day for me, but more importantly, *why do you think I am a proponent of coal power plants?* I'm not!

With respect to Chernobyl's so called exclusion zone, the plant had three other reactors that were in part operated and manned daily for 23 years after the '86 accident in Unit 4 (i.e. until 2009). A labor force of thousands works in the area performing decommissioning.

How is all this helping us Ukrainians reclaim the lost economic value of these hundreds of square kilometers? Indeed, thousands still has to work on the plant, and be paid, even though it generated exactly $0 worth of electricity for the last 20 years.

 

[jim hardy]

Such as filtering on vent lines, additional power generators, battery-powered lights, additional water and pumps added on site. I did not see that.

I asked my not-yet retired friends about that, actually as a result of this thread.
I don't know if my old plant is typical
but they did all the above, and built a new building to house the stuff, and built a new hill for the building several feet higher than the rest of the site.

I don't know if that's widespread practice. There may be reasons not to advertise such preparations.

We're not heartless profiteers. We live downwind too.

old jim

 

[mheslep]

Indeed you are right. No amount of talk will persuade me.

That is to be in the grip of self righteous dogma, immune to contrary evidence. That's all fine, the world has room for such via guys standing on the corner holding a sign and chanting. Not very useful in this space.

but more importantly, *why do you think I am a proponent of coal power plants?* I'm not!

Enough with the strawmen, I said no such thing. I responded to what you did say, which was that coal victims signed up for the danger. Nonsense.

How is all this helping us Ukrainians...

Like the Indians in Bhopal, they insure that nobody is allowed to build a ready-to-blow-up industrial operation ever again.

though it generated exactly $0 worth of electricity for the last 20 years.

Nonsense. The *other* units continued operating for decades, saving the cost of millions of tons of coal or tcf of gas from Putin, all shouldered by a poor economy.

 

[Astronuc]

Assigning wisdom to the fast spectrum breeder cancellation for safety reasons requires the assumption that breeders are somehow more dangerous than light water thermal reactors with no spent fuel solution. Do you believe that's the case?

At the time, a commercial fast breeder reactor may have been problematic for the reasons cited by the Kemeny report. One potential problem would be failure of a steam generator and potential for a sodium-water reaction leading to ignition of hydrogen, whether a deflagration or explosion. Even at that point in the commercial industry, we hadn't yet experience the widespread degradation of steam generators that lead to their replacement - at significant cost to the utilities.

http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/steam-gen.html

TMI-2 was only about 62 effective full power days (efpd) into is first cycle when it the accident happened. The unit had achieved initial criticality in March 1978, and was placed in commercial operation during December 1978. The accident could have been a lot worse with respect to radiological consequences had it been in its third or fourth cycle with higher burnup fuel. As it was, TMI-2 was the initial core at the time when plants typically did annual cycles and fuel was discharged after it's third cycle. During the 1980s, plants began to transition to 18-month cycles, and then to 24-month cycles during the 1990s.

There were a lot of things that went wrong, including the lack of training on the part of the plant personnel.
http://www.washingtonpost.com/wp-srv/national/longterm/tmi/stories/chrono032889.htm

Anyway, the US did continue operation of EBR-II (1964-1994), which generated electricity, and FFTF (1980-1992), which generated a lot of heat that was dissipated into the air. Some folks wanted to produce electricity, but that was apparently at odds with various agencies.

http://www.ne.anl.gov/About/reactors/frt.shtml
http://www.ne.anl.gov/About/reactors/EBR2-NN-2004-2-2.pdf

http://www.hanford.gov/page.cfm/400areafftf

Quite a few of my friends, associates and colleagues worked at FFTF, and some at EBR-II.

 

[nikkkom]

Nonsense. The *other* units continued operating for decades

Wrong. By 1996, all units except Unit 3 were shut down. Unit 3 was shut down in 2000.

saving the cost of millions of tons of coal or tcf of gas from Putin, all shouldered by a poor economy.

It is estimated that the cost of Chernobyl cleanup is *larger* than the profit from all nuclear power generation in the USSR over its entire history. Thanks, we really appreciated "cheap" and "safe" electricity. My grandchildren will still need to pay for it, when I'm long dead.

 

[nikkkom]

That is to be in the grip of self righteous dogma, immune to contrary evidence.

I waited for the contrary evidence since 2011. Words are not evidence. Deeds are.

 

[mheslep]

One potential problem would be failure of a steam generator and potential for a sodium-water reaction leading to ignition of hydrogen, whether a deflagration or explosion.

Assuming you are referring to sodium cooled fast spectrum design something like this, how does any kind of failure of the remote steam generator off the secondary loop lead to a sodium - water reaction? I would think the hydrogen formation problem is many times more likely in the existing water cooled BWR/PWR designs with water and zirc rods under pressure in the pressure in the primary.

 

[mheslep]

Wrong. By 1996, all units except Unit 3 were shut down. Unit 3 was shut down in 2000...

Unit 1 ran 11 years after the accident closing at the end of '97, Unit 2 ran 5 years after the accident closing in '91, Unit 3 ran 14 years closing in late 2000.

 

[russ_watters]

Wrong. By 1996, all units except Unit 3 were shut down. Unit 3 was shut down in 2000.

Dial it back, nikkom: you carefully selected a 20 year time frame for your claim rather than the ~30 years since the meltdown in order to avoid acknowledging the power production that happened in the other ten years. That is not an open-minded, dispassionate analysis, it is twisting and misleading about facts to support a pre-selected conclusion. That sort of intellectual chicanery is not acceptable here. Perhaps more to the point, since you did that on purpose, it means you know that your position/analysis is flawed.

The date of when the plant was shut down isn't even the relevant issue: the issue is why. The plant was not, contrary to your implications, shut down because the area was uninhabitable, it was shut down because it was a flawed plant design and the international community pressured them to shut it down.

An even finer point on the issue: since Chernobyl was a known flawed plant design even before it melted down, it is not very relevant to the overall safety analysis and prospects moving forward.

 

[mheslep]

It is estimated that the cost of Chernobyl cleanup is *larger* than the profit from all nuclear power generation in the USSR over its entire history. Thanks, we really appreciated "cheap" and "safe" electricity. My grandchildren will still need to pay for it, when I'm long dead...

The NYT estimated the cost of the four jumbo aircraft deliberately crashed on 9/11/2001 cost $55 B in direct physical damage, $123 B in economic impacts, another $100 B in lost time at airports and so on. If the case was made that jumbo aircraft could never be made modestly safe, that these kinds of city-wrecking, catastrophic accidents are bound to happen every couple years, then perhaps some drastic reduction in aviation transport would be required. There is no such case. So too for nuclear power.

 

[Astronuc]

Assuming you are referring to sodium cooled fast spectrum design something like this, how does any kind of failure of the remote steam generator off the secondary loop lead to a sodium - water reaction? I would think the hydrogen formation problem is many times more likely in the existing water cooled BWR/PWR designs with water and zirc rods under pressure in the pressure in the primary.

I was referring to the Clinch River Breeder Reactor as it was designed in the 1970s, which did have two sodium loops and a pressurized-water loop (Rankine cycle).

Under normal conditions, the Zr-water reaction takes place slowly over the life of the fuel, which was 3 years, but now more like 4 to 6 years, or up to 8 in some cases. The corrosion produces a relatively small amount of hydrogen. The concern over aggressive hydrogen production applies under accident conditions where the fuel is overheated. I should also add that in PWRs, hydrogen is added to the water (~30-35 cc/kg) to suppress radiolysis of the coolant (water) in the core, and it is also added to BWRs under so-called hydrogen water chemistry, but that has been modified with the use of noble metals with so-called noble metal chemical addition.

In the case of Na-water, that could happen under normal operating conditions. See the link to the NRC backgrounder on steam generator replacement. During the 1970s, it was discovered that Inconel-600 tubes were eroding/corroding faster than anticipated, and occasional tube failure was a part of normal operation at a number of plants. Rather than serving 40 years as designed, many steam generators had to be replaced.

Another article on steam generators - http://www.power-eng.com/articles/print/volume-100/issue-1/features/steam-generator-replacement-overview.html

In the case of the Na-water heat exchanger, the water is necessarily under pressure. It was likely that a tube would fail on the waterside, and if water infiltrated the secondary Na loop, the concern was the vigorous hydrogen production. Now there was a concept that had a double tube (tube-in-tube) design. Nevertheless, the CRBR was cancelled.

I'm not sure about the EBR-II system, so I'll have to look into it.

When I entered graduate school in the early 1980s, I was enthusiastic about fast reactors and fusion. Then we had a visit from a manager of a fast reactor program who informed us that he was letting 300 people go and cancelling a fast reactor project. And fusion was always 10 or so years away. Nevertheless, some my research was on small compact fast reactors for space power applications.

 

[jim hardy]

Chernobyl was a known flawed plant design

i'd say more 'obsolete' than 'flawed'.

As i understand it's a scaled up version of our original Manhattan Project plutonium makers.

With their huge moderator void coefficient ($+4) there's some things you should never do like allow a mismatch between heat production and heat removal. Yet in the wee hours, somebody with incomplete understanding of that principle let it happen during an experiment and the reactor of course took off .
That's not the fault of the reactor. It's dilettantes tinkering with something they don't understand, which is a people failure.

That officialdom tried for days to cover it up speaks to the health of the organizations responsible ; same shortcomings as Kemeny described over here.

 

[mheslep]

That's not the fault of the reactor.

I disagree. Designs meant for regular, everyday operation and which inevitably result in catastrophic outcomes from the slightest deviation from textbook operation are flawed, and I submit this was the case with the early Soviet RBMKs. The positive void coefficient magnifies the slightest mistake rather than the other way around. The same concept applies in many other fields, aviation comes to mind via building aircraft that enter unstable control profiles with the slightest perturbation, and then blaming accidents on pilot error.

 

[jim hardy]

Designs meant for regular, everyday operation and which inevitably result in catastrophic outcomes from anything less than textbook operation are flawed,

That depends on who's going to operate them.
Are you also opposed to high performance aircraft ?

"Stay away from that wheelbarrow - you don't know nothin' about machinery" doesn't apply to properly trained folks.

 

[jim hardy]

I'm not sure about the EBR-II system, so I'll have to look into it.

more than anybody could want here...
http://www.redinc.com/examples/Docs-Images/EBR-II.pdf

 

[nikkkom]

Unit 1 ran 11 years after the accident closing at the end of '97, Unit 2 ran 5 years after the accident closing in '91, Unit 3 ran 14 years closing in late 2000.

Correction.
Unit 1 was stopped on November 30, 1996. Not 1997.

 

[nikkkom]

The date of when the plant was shut down isn't even the relevant issue: the issue is why. The plant was not, contrary to your implications, shut down because the area was uninhabitable

I did not say, and never meant, that plant was shut down because the area was uninhabitable. I talked about shutdown since after shutdown, the plant become purely a money sink pit, with not a dollar of revenue produced.

I am talking about this area because it has *other* economic value beside having nuclear plant standing on it. It's hundreds of square kilometers, the plant was just a tiny portion of it. The rest were towns, villages, farmland, forests.

Or rather, it HAD economic value. Most of that value is gone now. Now it needs to be guarded, which costs $$$ (and even with guards, people enter, steal and sell radioactive wood and scrap metal).

 

[mheslep]

I talked about shutdown since after shutdown, the plant become purely a money sink pit, with not a dollar of revenue produced.

As per above, only the Unit 4 accident-reactor was destroyed, not the entire plant as the balance went on to produce more electricity.

 

[mheslep]

That depends on who's going to operate them.
Are you also opposed to high performance aircraft ?

"Stay away from that wheelbarrow - you don't know nothin' about machinery" doesn't apply to properly trained folks.

If the goal is mass production of aircraft or nuclear reactors so that they can serve more than the niche needs of test pilots then the design requires some amount of resilience. The more walk-away safe that's built in the greater the benefit. Also, even with the best trained people running against a design as flawed as Chernobyl (no sec containment, positive void, graphite) sooner or later there will a human caused accident with enormous consequences. See the Challenger and Columbia accidents.

 

[QuantumPion]

I disagree. Designs meant for regular, everyday operation and which inevitably result in catastrophic outcomes from the slightest deviation from textbook operation are flawed, and I submit this was the case with the early Soviet RBMKs. The positive void coefficient magnifies the slightest mistake rather than the other way around. The same concept applies in many other fields, aviation comes to mind via building aircraft that enter unstable control profiles with the slightest perturbation, and then blaming accidents on pilot error.

If you operate any machinery contrary to how it was designed, against all operator instructions, bypassing all safety equipment and procedures, you can't very well blame the equipment when bad things happen. Chernobyl was the result of human error, not design flaw. If you run your car engine in the garage you will die of CO poisoning. That does not mean internal combustion engines are recklessly dangerous or inherently flawed.

 

[mheslep]

If machinery is incorrectly operated as you suggest, and entire range of outcomes is possible. A good design should i) make operation as intuitive and simple as possible, and ii) attempt to minimize the bad outcomes. Yes running the car in the garage is a bad move, but that does not make it ok to mount the gas tank on the front bumper with electrical wiring running through it, so that a would be fender-bender turns into death by fire.

 

[nikkkom]

It's hundreds of square kilometers, the plant was just a tiny portion of it. The rest were towns, villages, farmland, forests. Or rather, it HAD economic value. Most of that value is gone now.

Correction: not "hundreds of sq.km.", thousands.

The Exclusion Zone, where evacuation is mandatory to this day, is 2600 km^2

 

[Zackary Miller]

i'd say more 'obsolete' than 'flawed'.

As i understand it's a scaled up version of our original Manhattan Project plutonium makers.

With their huge moderator void coefficient ($+4) there's some things you should never do like allow a mismatch between heat production and heat removal. Yet in the wee hours, somebody with incomplete understanding of that principle let it happen during an experiment and the reactor of course took off .
That's not the fault of the reactor. It's dilettantes tinkering with something they don't understand, which is a people failure.

That officialdom tried for days to cover it up speaks to the health of the organizations responsible ; same shortcomings as Kemeny described over here.

Let's see, when you are designing something, whatever it might be, you generally make certain that idiots will not damage it. Yes, nothing can be completely fool proof, but you can make something fool resistant, as in making it so that if someone shuts down all safeties, brings it to a low power level so that the negative reactivity added by the water filling the pressure tubes has to be compensated with through control rod removal, that it does not cause widespread contamination.

Now, you may wonder, how was the RBMK stupidly designed? Well you do not have to look any farther than the lack of containment, positive void coefficient at low power levels, control rods that were graphite tipped as to cause minor voiding on reactor startup, and the fact that anything regarding the nuclear industry was automatically a state secret. It was an accident waiting to happen.

You do not simply design a airplane for example and make it so that moving it even slightly away from normal conditions will cause disaster, and with a nuclear reactor you do not design it so that a group of bumbling incompetents will not leave a large amount of land evacuated.

It is also interesting to note that the Hanford B reactor did not boil water or generate any electricity, rather the RBMK is a scaled up version of the Obninsk APS-1 reactor. Now, mind, there are definitely similarities between all of them, just the RBMK, from my limited understanding, appears to succeed in being even less safe than the Hanford reactors.

 

[QuantumPion]

Let's see, when you are designing something, whatever it might be, you generally make certain that idiots will not damage it. Yes, nothing can be completely fool proof, but you can make something fool resistant, as in making it so that if someone shuts down all safeties, brings it to a low power level so that the negative reactivity added by the water filling the pressure tubes has to be compensated with through control rod removal, that it does not cause widespread contamination.

That's not how things works in the real world. Things designed for the general public should be pretty idiotproof. But things designed to be operated by trained professionals are different. You could not design an airplane to be crashproof under all possible circumstances. That's why pilots require lots of training, practice, and certifications. The same goes for nuclear reactors. If an airline has a pilot shortage and tells someone untrained in how to fly a jumbo jet to make the next flight, and that flight ends up crashing due to his error, the fault is primarily with the airline. That does not mean airplanes are inherently too dangerous to fly.

 

[Astronuc]

Now, you may wonder, how was the RBMK stupidly designed? Well you do not have to look any farther than the lack of containment, positive void coefficient at low power levels, control rods that were graphite tipped as to cause minor voiding on reactor startup, and the fact that anything regarding the nuclear industry was automatically a state secret. It was an accident waiting to happen.

You do not simply design a airplane for example and make it so that moving it even slightly away from normal conditions will cause disaster, and with a nuclear reactor you do not design it so that a group of bumbling incompetents will not leave a large amount of land evacuated.

It is also interesting to note that the Hanford B reactor did not boil water or generate any electricity, rather the RBMK is a scaled up version of the Obninsk APS-1 reactor. Now, mind, there are definitely similarities between all of them, just the RBMK, from my limited understanding, appears to succeed in being even less safe than the Hanford reactors.

The RBMK was designed to produce Pu and electricity.
http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Power-Reactors/Appendices/RBMK-Reactors/

It is a pressurized water reactor, not designed to boil water in the core. I can be operated safely, but it was taken outside of it's design/performance envelope prior to the experiment that precipitated the accident. The experiment should never have been performed as conducted. Safety features should not have been deactivated. Such conduct is illegal, at least in the west and probably elsewhere as well.

The Hanford reactors were quite different from the RBMK design. Incidentally, "the last of Hanford’s nine plutonium production reactors to be built was the N Reactor. This reactor was called a dual purpose reactor in that it not only produced plutonium for America’s defense program, but it also generated electricity. It was the only reactor of its kind in the country."
http://www.hanford.gov/page.cfm/NReactor

 

[jim hardy]

Also, even with the best trained people running against a design as flawed as Chernobyl (no sec containment, positive void, graphite) sooner or later there will a human caused accident with enormous consequences. See the Challenger and Columbia accidents.

Doesn't change the fact that Chernobyl reactor was mis-operated.

Not that i like the RMBK design, and I'm on record saying it's bad enough to build such a contraption let alone turn it over to civilians.

Bad design played into Three Mile Island too, where somebody programmed the plant computer to print out question marks instead of the readings whenever the reactor's internal thermocouples measured higher than the program expected, something like 650 degF.. So operators were deprived of the reactor's temperature measurements exactly where and when they were needed most.
But the real culprit there was misdirection provided to operators; somebody went Obsessive-Compulsive about "Pressurized Thermal Shock" and directed plant operators to never let their pressurizer fill up. So they didn't. And that's mis-operation, and it was by procedure.

Ever seen a 707 do a Barrel Roll ?
www.youtube.com/watch?feature=player_embedded&v=Ra_khhzuFlE

 

[jim hardy]

just the RBMK, from my limited understanding, appears to succeed in being even less safe than the Hanford reactors.

They heated river water in a once-through cycle (Except N as noted by Astro).
Doubtless the marine life liked it in winter.

and with a nuclear reactor you do not design it so that a group of bumbling incompetents will not leave a large amount of land evacuated.

Double negative aside,
Anyone who turns such a machine over to such a group is too irresponsibile to own it..

 

[Astronuc]

Something to consider when developing an exotic nuclear fuel system.
https://www-nds.iaea.org/sgnucdat/a6.htm

 

[Astronuc]

Useful, and dated (1981) report, but some relevant background experience.

Control Rod Materials and Burnable Poisons
http://www.epri.com/abstracts/Pages/ProductAbstract.aspx?ProductId=NP-1974

I worked with both authors and one of the contributors.