The Nuclear Power Thread

[anorlunda]

Why are we discussing terrorist tactics to blow up a nuclear power plant? That would not be tolerated in any other PF thread.

By PF rules, I should delete the posts discussing those tactics and replies to the deleted posts. But I'll not do it this time because I can't be sure which post originated it.

If you want this thread to continue, keep it adult.

 

[mheslep]

@anorlunda, the US Nuclear Regulatory Commission now has post 911 requirements in place like 50.150 Aircraft impact assessment for new reactors, a major regulatory change applied after the start of construction of new reactors in the southeast US, and which significantly impacted the cost of those projects. It would be difficult to discuss the cost of nuclear power without understanding the boundaries of worst case accident.

I imagine some guidelines should apply to the discussion. I suppose any details about the mechanism of how to destroy a reactor are irrelevant.

 

[jim hardy]

By PF rules, I should delete the posts discussing those tactics and replies to the deleted posts. But I'll not do it this time because I can't be sure which post originated it.

I suppose any details about the mechanism of how to destroy a reactor are irrelevant.

well, loose lips sink ships. I'll edit my previous post now. old jim

 

[ISamson]

I have noticed that even Isaac Asimov in the Foundation Trilogy talks that nuclear power is the future, regarding science and electricity.
What do you think?

 

[jim hardy]

What do you think?

Decisions and golf swings have one thing in common - their rightness or wrongness is determined by the follow through..
If you stick by a decision and do your honest best it'll almost always come out just fine.
Nuclear power requires more rigorous follow through than most other societal decisions because the consequences .of failure are so spectacular. And a longer one because the waste has to be managed.

We're more than capable of handling the science and engineering required for a successful nuclear power program.
I do question whether as a society we've got the maturity for the century long follow through it's going to take to run a plant for fifty or sixty years then get its spent fuel ready for re-use.

Fukushima showed the folly of pride and refusal to face facts like those ancient warning stones on the hill above the plant marked "Don't build below here you'll get washed away" . Mythology addresses it too but hardly anybody studies that anymore.

I see news articles about shutting down Diablo Canyon over fish eggs. Makes me shake my head and think "Let them eat caviar" .

To answer your question,
i think we will come back to Nuclear Power sometime in the future - after the computer influence on human thought patterns makes society more logical.

my two cents , and overpriced at that.

old jim

 

[etudiant]

Jim Hardy said:
I think we will come back to Nuclear Power sometime in the future - after the computer influence on human thought patterns makes society more logical. --

In a world that is increasingly irrational, because computers have taught our children to just 'look up the answer' rather than to think for themselves, that seems very unlikely to me. The degree to which absurdities such as catastrophic AGW have become articles of faith, based on shoddy computer modeling, simply underscores the trend. We are losing the ability to maintain what we have, much less innovate for a nuclear future.

 

[bhobba]

I have noticed that even Isaac Asimov in the Foundation Trilogy talks that nuclear power is the future, regarding science and electricity. What do you think?

My view? Its an important part of our future energy supply mix - provided people are rational - which they are not. Out here is Australia it's pretty much forbidden to even discuss it - you are called a loon yada yada yada. I tell people about this forum where they can get the facts - not a single one has decided to do that.

What is the consequence? In one year the price of electricity in one of our state's (Victoria) nearly doubled - many say its because that state has a 50% renewable policy. Anti renewable types will say that, but not tell you the full truth, just as the pro renewable types will not tell you things either - they both sit in their entrenched positions and ignore facts. The fact is only 16% of that rise was from the switch to renewable's. Mostly it was from what's called gold plating of our network so the energy suppliers can justify charging higher prices to the government agency that keeps a watch on these things. It's the good old profit motive plus a dab of government interference - they don't really mix that well - but that is another story not part of the scope of this forum.

An ex prime-minister of ours Bob Hawke likes to attend a certain 'Hippy' festival every year - mostly his views are greeted with cheers of endorsement - but one, very true thing IMHO, he believes in is greeted with boo after boo. You see Australia has vast amounts of arid desert. A perfect dumping ground for nuclear waste. He thinks we should profit from it - by allowing countries to dump - for a fee of course - their waste here. After doing that we can build a few of those newfangled Nuclear power pants that burn waste as fuel. Sounds rational to me - but the audience doesn't think so - ah well we are all different. Good on Bob for not backing down though.

Like the debate about nuclear, truth is often stranger than the fiction spun by those that want to put their spin on it.

I personally sit here hoping we get fusion power - fast - to stop the idiocy - but that dream still seems a long way off. And having spoken to rabid anti nuclear types - they are against even that - they have zero understanding of the difference between fusion power and fission power - its nuclear - it must be bad. Sad really - but the reality.

Thanks
Bill

 

[bhobba]

In a world that is increasingly irrational, because computers have taught our children to just 'look up the answer' rather than to think for themselves, that seems very unlikely to me. The degree to which absurdities such as catastrophic AGW have become articles of faith, based on shoddy computer modeling, simply underscores the trend.

Shoddy modelling - its just that modelling complex things is hard and some people don't realize it so put too much faith in it.

Why are we becoming increasingly irrational - that's a hard one - but I think people, at least here in Aus, not taking the hard stem subjects where the following video should be watched by all students once a day is partly to blame:


Once you understand that, and I mean really understand it until its fixed into your very being - much of these issues will disappear.

Just my view of course - and subject to exactly the same standard of Brian Cox and Feynman.

That's why this forum is so important IMHO - people learn that here by practical application eg the demand for reputable sources when you sprout something - and even then they can be wrong. They understand our best guess at 'truth' is provisional - we update it as more information comes in. Contrast that to the attitude of some political leaders - 2+2 = 5 - and make no mistake about it - anyone that disagrees is a communist, member of the loony left or rabid right - take your pick - there are tons about - rather than - well our best guess is 2+2 = 4, we have logic that shows its true with very good certainty - but we can still be wrong. The latter is a much better philosophy IMHO. As far as reputable sources go - many thanks to good old Professor Asimov - I basically stole it from him. Yes Professor Asimov - he was actually a Professor of Biochemistry before moving over to science fiction writing while moonlighting as a Shakespeare critic. He poked fun at humanities, of course they didn't like it - but he had the last laugh when it was revealed he also was a well respected Shakespeare scholar. He even has a book on it:
https://www.amazon.com/dp/0517268256/?tag=pfamazon01-20

Thanks
Bill

 

[mheslep]

Out here is Australia it's pretty much forbidden to even discuss it - you are called a loon yada yada yada

What's loony?

 

[bhobba]

What's loony?

Good one.

And that's why - if you even bring it up - watch out - as constantly happens to our former prime minister who to his credit refuses to back down.

Democracy in Australia. Yes its enshrined in our constitution - but we do have our own - what to call it -flavor - some good - some - well not so good. But this forum is not the place to discuss it.

Thanks
Bill

 

[minerva]

"i think we will come back to Nuclear Power sometime in the future"

Will it be - as Bernard Cohen titled his book - before it's too late?

 

[minerva]

"I would open the containment (say, by blowing up a hole in its wall)"

It's a massive structure of reinforced solid concrete. Stick a brick of C4 on it if you like - it will hardly do much.

Cutting open the reactor building, for refurbishments and the like, is a massive engineering undertaking.

"haul a few tons of C4 under the reactor"

Under what, the reactor pressure vessel?
How are you going to get in there?

In the control rod drive area in a BWR, the explosion would certainly knock out the control rod drives, but the system would already be tripped. But the reactor pressure vessel is a massive steel object anchored to a massive concrete foundation.

Remember, a 3GWt reactor produces 1 TNT-tonne of thermal energy every 1.4 seconds. A tonne of TNT-equivalent is not that much energy.

"Major release of fission products and actinides"

How? You haven't shown that, and I call BS, given the real-world nature of a nuclear power reactor.

"The purpose of explosives would be merely to crack RPV open and sever it from all piping. Then decay heating will do the rest."

So you're now admitting that your supposed catastrophic scenario is just a LOCA - just like Three Mile Island and doesn't hurt anyone. A large-break LOCA is within design basis.

 

[Astronuc]

First AP1000 reactor enters commercial operation
21 September 2018
http://www.world-nuclear-news.org/Articles/First-AP1000-reactor-enters-commercial-operation

In September 2007, Westinghouse and its partner the Shaw Group received authorisation to construct four AP1000 units in China: two at Sanmen in Zhejiang province and two more at Haiyang in Shandong province. Construction of Sanmen 1 began in April 2009, while first concrete for Sanmen 2 was poured in December 2009. Construction of Haiyang 1 and 2 began in September 2009 and June 2010, respectively.

Unit 1 of the Haiyang plant attained first criticality on 8 August and was grid connected on 17 August. Haiyang 2 is expected to start up in 2019.

With Sanmen 1 now in commercial operation, CNNC has a total of 19 power reactors in operation with an installed capacity of 16,716 MWe.

Vogtle 3 and 4 are the only new nuclear units currently under construction in the USA. Construction of Vogtle unit 3 began in March 2013 and unit 4 in November the same year. Construction of two AP1000s at VC Summer in South Carolina was abandoned in August 2017.
http://www.world-nuclear-news.org/Articles/Oglethorpe-to-vote-on-Vogtle-future

 

[Astronuc]

Nuclear startup will fold after failing to deliver reactors that run on spent fuel

Transatomic Power, an MIT spinout that drew wide attention and millions in funding, is shutting down almost two years after the firm backtracked on bold claims for its design of a molten-salt reactor.

https://www.technologyreview.com/th...ng-to-deliver-reactor-that-ran-on-spent-fuel/

 

[etudiant]

Hitachi is throwing in the towel on its UK nuclear plans, apparently because the prices offered for the power were inadequate.
https://www.bloomberg.com/news/arti...ns-ditched-as-hitachi-sees-2-8-billion-charge

It seems that no one in the West is able to build nuclear plants on a stable cost and schedule basis any more. That does not bode well for the industry, as it suggests that absent new approaches, there won't be any more business.
Does anyone have some suggestions or ideas that could revitalize this sector?

 

[HowlerMonkey]

This seems to be a problem with any large scale project.

The grabbing hands are simply draining funds before they can be put to proper use.

 

[etudiant]

This seems to be a problem with any large scale project.

The grabbing hands are simply draining funds before they can be put to proper use.

Seems to be a very widespread phenomenon.
The Sinop nuclear project in Turkey was similarly abandoned because of cost growth.
There must be some cultural or structural issue, as it is just implausible that everyone is incompetent.

 

[jim hardy]

There must be some cultural or structural issue,

British writer C Northcote Parkinson expressed it beautifully in his books The Law of Delay. and Parkinson's Law.
Paraphrasing, "Bureaucracy grows to occupy the available money" ..

Parkinson's Law was translated into many languages. It was highly popular in the Soviet Union and the Communist bloc.[3] In 1986, Alessandro Natta complained about the swelling bureaucracy in Italy. Mikhail Gorbachev responded that "Parkinson's law works everywhere."[4]

 

[etudiant]

British writer C Northcote Parkinson expressed it beautifully in his books The Law of Delay. and Parkinson's Law.
Paraphrasing, "Bureaucracy grows to occupy the available money" ..

Unquestionably true, but the Sinop project was Mitsubishi and the Turkish government, somewhat removed from the domestic bureaucracies.
So there must be something more happening than just normal Parkinson's law effects.
What concerns me is that right now, China and perhaps Russia seem to be the only countries where big civil and power engineering projects are still getting executed. If we've lost that skill. it will be very expensive to rebuild.

 

[artis]

From one of those links that Astronuc posted about the failure of Transatomic it is said that they plan to release all their research in order for others to be able to use it and build on it, does anyone know has that already happened and if that was meant as a serious intention for the greater good?

 

[jim hardy]

So there must be something more happening than just normal Parkinson's law effects.
What concerns me is that right now, China and perhaps Russia seem to be the only countries where big civil and power engineering projects are still getting executed. If we've lost that skill. it will be very expensive to rebuild.

I've wracked my brain for decades about that subject.
"Law of diminishing returns" is in play. As design approaches perfection the cost of incremental improvements grows.
You know, every tenfold improvement costs the same be it from 9% to 90% or from 90% tp 99% or 99% to 99.9% .
And we demand perfection.
Maybe that's why the old-timers wrote the "Tower of Babel" myth . We can't get there.
In any big project the Accountants speak in "Business Case", Engineers speak in "Punch List", Schedulers speak in "Gantt Chart", and Project Management speaks in "Milestones" .
Our tongues are confused.

What I decided is that in the late 20th century, management science fell behind physical science.
As you suggest that's a cultural problem not a technical one

Maybe your generation can fix it. My generation's Parkinson and Pirsig i think were looking in the right direction.

old jim

 

[Rive]

Does anyone have some suggestions or ideas that could revitalize this sector?

A shift in the leading economical paradigm would help a lot.

It's a very interesting idea to except return within two decades at most. Sometimes I wonder if anybody ever tried to apply those expectations for ourselves? 'Growing up' from diapers to possibly self-reliant adult usually takes 20+ years (and still many years till 'return'). Along the actual business directives the most effective would be to die out.

 

[etudiant]

A shift in the leading economical paradigm would help a lot.

It's a very interesting idea to except return within two decades at most. Sometimes I wonder if anybody ever tried to apply those expectations for ourselves? 'Growing up' from diapers to possibly self-reliant adult usually takes 20+ years (and still many years till 'return'). Along the actual business directives the most effective would be to die out.

Judging by the European birth rates, that last opinion seems to be widely held...

More to the immediate point however, interest rates and hence discount rates used to compare investment returns are currently at all time lows. Nuclear has long lead times, so it should benefit from these low discount rates. When the cycle turns and rates rise again, nuclear economics will be hurt more than shorter term investments. That darkens the outlook even further.

 

[Astronuc]

Finally! Flamanville EPR hot tests to start next month
22 January 2019

Hot functional testing of the Flamanville EPR in France, which had been scheduled to start before the end of 2018, will now begin in February, EDF said yesterday. The loading of fuel into the 1650 MWe pressurised water reactor (PWR) is still expected by the end of this year.

In December, unit 1 of the Taishan plant in China's Guangdong province became the first EPR to enter commercial operation. Taishan 2 is scheduled to begin commercial operation this year. Olkiluoto 3 in Finland, the first-of-a-kind EPR, has completed hot functional tests and is preparing to load fuel.

 EPR Unit      Start of Construction
Olkiluoto-3      August 12, 2005
Flamanville 3    December 4, 1007
Taishan 1        November 18, 2009
Taishan 2        April 15, 2010

https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant
https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=860

https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plant
https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=873

https://en.wikipedia.org/wiki/Taishan_Nuclear_Power_Plant
https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=918
https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=919

 

[FLRW]

Jim Hardy said:
I think we will come back to Nuclear Power sometime in the future - after the computer influence on human thought patterns makes society more logical. --

In a world that is increasingly irrational, because computers have taught our children to just 'look up the answer' rather than to think for themselves, that seems very unlikely to me. The degree to which absurdities such as catastrophic AGW have become articles of faith, based on shoddy computer modeling, simply underscores the trend. We are losing the ability to maintain what we have, much less innovate for a nuclear future.

As a retired nuclear engineer that is new to this forum, I think fusion reactors are the future of nuclear power.
Chinese state researchers and the Lockheed Martin corporation are both aiming to be first to develop practical fusion power sometime in the 2020s.

 

[essenmein]

New to the thread and basically feel our energy production should be 100% nuclear, fission for now, fusion in the future if we get it going.

Re spent fuel and waste (apologies if this has been discussed), I thought part of the problem is that the nuclear industry started largely to produce weapons grade materials, which is why IFR reactors heavily regulated (non prolif etc), however IFR can burn in principle all the fuel, this would allow us to consume our current wast stock and produce nearly zero waste. Sure there will be small amounts of bad stuff that will need to be stored, or potentially neutralized in newer reactors. Thorium would get around that proliferation issue, but thorium fuel reactors not well developed because no possibility of nuclear weapon grade materials, thorium fueled IFR molten salt would be great.

Another interesting idea never properly followed because pure fusion is more of a priority is the fission/fusion hybrid. Basically non net energy producing fusion reactor as a fast neutron source that triggers fission in other wise nonfissile fuels, eg spent fuel or thorium. Inherently safe because there is no need for critical mass. Molten salt loop with neutron source cavity, extract heat as it exits the neutron chamber and then goes back around.

The costs would be much more manageable if building more smaller reactors vs single large highly specialized buildings.

I'm a huge fan of SMR.

 

[Astronuc]

. . . the nuclear industry started largely to produce weapons grade materials

No, the nuclear industry, i.e., commercial nuclear power industry, was never intended to produce weapons grade material. There were special production reactors, outside of the commercial power generating plants, that were used for that purpose. Fast reactor technology, including IFR, was restricted and some information remains restricted.

 

[artis]

Well maybe not in the US, but as far as I know in the USSR they did plan to use commercial reactors (some of them at least) for plutonium production one of the reasons why the RBMK was chosen as it had the option to refuel while being online, I think I've read that other countries had similar ideas,I'm sure others will be able to explain this better.

 

[essenmein]

Both in the US and then USSR the civilian programs sprang up from military development, so while they may not be intended to produce weapons grade materials, they can, which is the issue. I would say this is largely because they inherited the basic technology developed early on that was intended to make weapons grade stuff, EBR-1 was the first reactor to make electricity and it was a research breeder.

There doesn't seem to be much motivation to build thorium reactors and there is clear evidence historically that this is mainly due to the lack of weapons applications.

Eg from wiki:
"Weinberg realized that you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. . . . his team built a working reactor . . . . and he spent the rest of his 18-year tenure trying to make thorium the heart of the nation’s atomic power effort. He failed. Uranium reactors had already been established, and Hyman Rickover, de facto head of the US nuclear program, wanted the plutonium from uranium-powered nuclear plants to make bombs. Increasingly shunted aside, Weinberg was finally forced out in 1973.[10] "

 

[Rive]

while they may not be intended to produce weapons grade materials, they can, which is the issue. I would say this is largely because they inherited the basic technology developed early on...

Well, that statement would require some work to back it up, especially if you stick with that present time. As far as I know many of the Gen. I. reactors indeed had dual purpose: some of the Gen.II. were still able to produce Pu on acceptable scale (but I don't know about actual example when it happened): but further on Pu more and more became hindrance instead. Gen.III. already cannot be used to produce Pu - unless you totally ruin the economy of the operation.

One has to admit that Gen.I. reactors were kept operational for surprisinly long time, but right now the only example still running should be somewhere in North Korea (I mean, commercial reactor. At least, in name.)
Some RBMKs are still running from Gen. II.. That's indeed an issue but not really because of any possibility of Pu production.

 

[essenmein]

Well, that statement would require some work to back it up, especially if you stick with that present time. As far as I know many of the Gen. I. reactors indeed had dual purpose: some of the Gen.II. were still able to produce Pu on acceptable scale (but I don't know about actual example when it happened): but further on Pu more and more became hindrance instead. Gen.III. already cannot be used to produce Pu - unless you totally ruin the economy of the operation.

One has to admit that Gen.I. reactors were kept operational for surprisinly long time, but right now the only example still running should be somewhere in North Korea (I mean, commercial reactor. At least, in name.)
Some RBMKs are still running from Gen. II.. That's indeed an issue but not really because of any possibility of Pu production.

Keep in mind was generalizing a little to avoid writing a novel as well as talking historically, ie there is no denying the nuclear industry sprang from the military programs in the early 50's, that doesn't mean today all plants exist to make bomb materials. Then a nuclear program includes all the things needed for such a program, eg fuel processing, enrichment, reactors etc. So if you can enrich uranium, its not a large leap to enrich that uranium further to make weapons, both U235 and Pu239 are suitable for the big booms.

 

[Astronuc]

Both in the US and then USSR the civilian programs sprang up from military development, so while they may not be intended to produce weapons grade materials, they can, which is the issue. I would say this is largely because they inherited the basic technology developed early on that was intended to make weapons grade stuff, EBR-1 was the first reactor to make electricity and it was a research breeder.

While there is a loose connection between civilian nuclear power programs and those developed for the military, commercial nuclear plants were never designed to produce weapons material, certainly not LWRs. The US had 9 production reactors at the Hanford site - starting with B-reactor (1943-1968) and ending with N-reactor (1963-1987). N-reactor was the only plant built for dual-purpose, including electrical generation.
https://www.hanford.gov/page.cfm/BReactorhttps://www.hanford.gov/page.cfm/NReactor
LWRs more or less grew out of the Naval propulsion program, and there was no plan to make weapons material. The four major manufacturers were Westinghouse, General Electric, Combustion Engineering and Babcock and Wilcox, and there were minor players like Allis-Chalmers (which had purchased ACF Industries Nuclear Energy Products Division).

The USSR also has dedicated production reactors, not including the RBMK type, which were not civilian.
http://scienceandglobalsecurity.org/archive/sgs19diakov.pdf
On the other hand, British Magnox reactors were designed with the dual purpose of producing electrical power and plutonium-239 for the nascent nuclear weapons program in Britain.

There doesn't seem to be much motivation to build thorium reactors and there is clear evidence historically that this is mainly due to the lack of weapons applications.

Not so.

"Weinberg realized that you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. . . . his team built a working reactor . . . . and he spent the rest of his 18-year tenure trying to make thorium the heart of the nation’s atomic power effort. He failed. Uranium reactors had already been established, and Hyman Rickover, de facto head of the US nuclear program, wanted the plutonium from uranium-powered nuclear plants to make bombs. Increasingly shunted aside, Weinberg was finally forced out in 1973.[10] "

The statement is from an article by journalist Richard Martin in Wired magazine and reflects his opinion, not the reality at the time. AEC wanted to pursue liquid metal fast reactor technology, while discontinuing the molten salt program, which was originally tied to Aircraft Nuclear Propulsion. There were still numerous technical challenges in MSR technology at the time. The whole Wikipedia article is problematic.

Rickover was head of the Naval Nuclear Propulsion program, not "the defacto head of US nuclear program."

A light water breeder reactor concept (using thorium) was tested at Shippingport, August 1977 - September 1982 for about 29,000 effective full power hours.
Argonne National Laboratory, ANL-87-2, FINAL REPORT FOR THE LIGHT WATER BREEDER REACTOR
PROOF-OF-BREEDING ANALYTICAL SUPPORT PROJECT, May 1987
https://inis.iaea.org/collection/NCLCollectionStore/_Public/19/005/19005808.pdf
WAPD-1600, Water Coold Breeder Program Summary Report, October 1987
https://www.osti.gov/servlets/purl/6957197
Another program was conducted at Indian Point 1. The fuel was processed at West Valley Nuclear Fuel Services (Nov 1968 - Jan 1969) and shipped to ORNL as U-nitrate solution. ORNL converted the nitrate to oxide form. (ORNL/TM-13600)

People are taking a look at Molten Salt Concepts again, including both chloride and fluoride based systems.

 

[HowlerMonkey]

Maybe the fact that rbmk reactors only require 2% refined uranium and could possibly manufacture plutonium on the cheap?
A guess ...but super unlikely since there are much more efficient ways to manufacture weapons grade fuel.
Being able to run a reactor on 2% enriched fuel is probably cheaper.

 

[Astronuc]

Unfortunately, Pilgrim Nuclear Power Station Shut Down Permanently, as of May 31, 2019
https://www.entergynewsroom.com/news/pilgrim-nuclear-power-station-shut-down-permanently/

PLYMOUTH, Mass. – Control room operators at Entergy’s Pilgrim Nuclear Power Station, located in Plymouth, Massachusetts, shut down its reactor for the final time on Friday, May 31, at 5:28 p.m. The decision to shut down Pilgrim was the result of a number of financial factors, including low wholesale energy prices.

Entergy’s remaining operating nuclear power plants in merchant power markets - Indian Point Unit 2 and Unit 3, in New York, and Palisades Power Plant, in Michigan, are scheduled to be shut down in 2020, 2021, and 2022, respectively. These closures, along with the sale of these plants to decommissioning specialty companies, mark the end of Entergy’s participation in merchant power markets and its return to a pure-play utility.

https://boston.cbslocal.com/2019/05/31/pilgrim-nuclear-power-plant-plymouth-massachusetts/
https://www.boston.com/news/local-news/2019/05/31/pilgrim-nuclear-power-plant-shutdown
https://www.wpri.com/news/top-video/pilgrim-s-shutdown-ends-nuclear-power-era-in-massachusetts_20190531224753/2043258034

 

[Astronuc]

The problem with non-scientific media reporting on science, engineering or technology in which the author is not an expert:

To control the rate of fission in a nuclear power plant, reactors use control rods. Constructed from elements such as silver and iridium, the control rods absorb neutrons released during fission and slow down the rate of fission.

from
https://www.vice.com/en_us/article/597k9x/why-the-chernobyl-nuclear-reactor-exploded
Many western PWRs use silver-indium-cadmium (Ag-In-Cd, or AIC for short). The above quote mentions silver and iridium. We do not use iridium, but indium. Be careful in reading non-scientific literature/media articles.