I’ve been involved in nuclear energy since 1947. In that year, I started working on nuclear energy at Argonne National Laboratories on safe and effective handling of spent nuclear fuel. In 2018 I retired from government work at the age of 92 but I continue to be involved in learning and educating about safe nuclear power.

After my time at Argonne, I obtained a doctorate in Chemical Engineering from MIT and was an assistant professor there for 4 years, worked at Oak Ridge National Laboratory for 18 years where I served as the Deputy Director of Chemical Technology Division, then for the Atomic Energy Commission starting in 1972, where I served as the Director of General Energy Development. In 1984 I was working for the Office of Civilian Radioactive Waste Management, trying to develop a long-term program for nuclear waste repositories, which was going well but was ultimately canceled due to political opposition.

Since that time I’ve been working primarily in the US Department of Energy on nuclear waste management broadly — recovery of unused energy, safe disposal, and trying as much as possible to be in touch with similar programs in other parts of the world (Russia, Canada, Japan, France, Finland, etc.) I try to visit and talk with people involved with those programs to learn and help steer the US’s efforts in the right direction.

My daughter and son-in-law will be helping me manage this AMA, reading questions to me and inputing my answers on my behalf. (EDIT: This is also being posted from my son-in-law's account, as I do not have a Reddit account of my own.) Ask me anything.

Proof: https://i.imgur.com/fG1d9NV.jpg

EDIT 1: After about 3 hours we are now wrapping up.  This was fun. I've enjoyed it thoroughly!  It's nice to be asked the questions and I hope I can provide useful information to people. I love to just share what I know and help the field if I can do it.

EDIT 2: Son-in-law and AMA assistant here! I notice many questions about nuclear waste disposal. I will highlight this answer that includes thoughts on the topic.

EDIT 3: Answered one more batch of questions today (Monday afternoon). Thank you all for your questions!

Comments: 3986 • Responses: 24  • Date: 

TheWinStore2263 karma

With construction costs for large scale plants becoming prohibitive (at least in the U.S.), are small modular reactors the future of nuclear?

jhogan2726 karma

Interesting question.

There is a large nuclear power plant being built today in spite of the so-called incredibly high prices (and I’m talking about in America). So I’m not convinced that it is priced out of reach.

Small reactors still have a higher cost per kilowatt hour. They are a more expensive source of energy than large reactors. However they have one virtue which really attracts people: They can be built in increments and get online sooner. Big reactors can get delayed and delayed and the whole time you’re paying ongoing construction costs. There’s no question that being able to get online and get some income while doing increments, that is an advantage. In the long run that may turn out to be an overwhelming advantage that gives small-scale reactors a better bet.

lardbeetle262 karma

What I've seen as a genuine advantage is the possibility of mass manufacturing these small reactors and delivering them pre-assembled to a prepared construction site on the back of a truck. Do you think that will help SMR's outcompete larger designs which must be assembled on site?

jhogan643 karma

Well, we have yet to build even one SMR (small module reactor).   It's a vision for the future.  Technically it's doable.  But at the moment, economically, it's not a strong argument because the factories don't exist.  

In the long run, it's an attractive concept.  Any system where you create a design, where that specific design has been judged to be safe, and then reproduce the same design over and over, has big advantages.

Incidentally this is one of the attractive things about France's nuclear program.  They have multiple nuclear power sites that all have basically the same design.

Umber0010893 karma

What's the dumbest reason you've seen someone give for why we shouldn't go nuclear?

Bonus points if it's not the standard mutants/wasteland/cancer shtick

jhogan1339 karma

The argument that we don’t have a way of disposing of the waste.

People use the argument that we don’t have a good way of waste disposal to say “don’t go down that pathway.” But we do! It is being done today in Finland, and it is being done under conditions that are similar to ours.

It's an opinion and there are going to be other opinions. But that's mine.

frako40485 karma

I'm curious about this, can you elaborate of the good way being used currently? I was in the impression that we were always stuck with useless waste for 100's of years, but I might just be uneducated, would love to know where I'm wrong.

jhogan1050 karma

OK. In Finland, they're about to start deep geologic disposal. The question of "is deep geologic disposal safe?" has been argued for generations. The consensus of the scientific community is that it is safe. I talked more in another answer here about some of the safety details of that approach.

In the US there is a good deal of power in the hands of the states. So there's a question of whether you can do something safely in America, where there might be a national commitment but the states might be resistant, even to transport waste to the site. But that issue does not exist in Finland. They do not have provinces which have almost veto power (which is what really happened in Nevada, with the Yucca Mountain project I talked about in the link above).

Also, suppose a baby is born, and for their whole lifetime the only power they use is nuclear. It turns out the amount of nuclear waste they would generate over their entire lifetime is just two Coca-Cola cans! So the question is, can you safely dispose of something like that? The answer is, yes, with deep geologic disposal.

hexjunki127 karma

I think part of the problem is that people don't trust companies to dispose of the waste safely even if it is possible as most companies will cut corners to turn a profit as long as they know they wont get caught or if they do the fine will be less than the cost of safe disposal.

So what would you change to ensure that companies do do the right thing in respects to disposal and safety?

jhogan119 karma

In the US, I would require that they get approval from the Nuclear Regulatory Commission before they dispose of the wate.  And I would require that nuclear waste be *routinely checked* by an independent organization.

And this exists today!  Nobody handles nuclear waste today independently (and we have a lot -- we have 70,000 or 80,000 tons).  The handling is all checked by the Nuclear Regulatory Commission for whom I have a great deal of respect. And they not only *check* things, if there are errors, the companies pay for it!

akaemre822 karma

In your opinion, what are the biggest downsides of nuclear energy? As a layperson I know it costs a ton, but what else?

jhogan1567 karma

Costs a ton! Haha.

Until we actually demonstrate the will — and I won’t say what kind of will, I just mean the actual backbone — to actually dispose permanently (for the next thousand years) the nuclear waste in the country (we now have in excess of 70,000, probably 80,000 tons of spent/used fuel) — it’s the biggest drawback.

Until we have a functioning disposal system it’s going to continue to be a negative for nuclear power in America. Quite frankly the Yucca Mountain project was killed because of lack of political strength. It was said to be safe by the Nuclear Regulatory Commission and yet at this point we have put off solving that problem.

akaemre171 karma

Thank you for answering!

Regarding the waste problem, how viable is recycling?

jhogan248 karma

Recycling is, in the long run, a very interesting and attractive approach. It does *not* eliminate the waste — it concentrates it. It separates the fuel that remains in the waste from the fission products, mostly which simply need to be disposed of safely. But the recycling is something I’ve been interested in for decades. Ultimately, it allows virtually all of the uranium to be used (both U-235, and U-238).

Right now there are economic issues. In order to recycle economically you need to do it at a very large scale. France and Russia actually each have a plant that does at least one round of recycling. India has an experimental program around this. China is leading the pack in terms of future plans. The US does not currently do any recycling.

ITeachAll89 karma

I'm generally curious. Can't we package the waste and launch that shit off into space to never return?

jhogan316 karma

Having the nuclear waste in outer space is safe. But getting it into space is dangerous (for example if the rocket explodes). From a safety standpoint it is much more predictable to use deep geologic disposal.

Sending it into space is also expensive.  The energy required to put it into space is close to, or more than, the original power generated by the waste!

BedsideTiger773 karma

In your opinion which country is leading the charge in nuclear energy and which country do you think will pull ahead in the future?

jhogan1441 karma

The answer for both of these is China.  China is definitely leading the charge at the moment -- they are leading the commitments to design, build, and operate reactors.  And I see no slackening of interest in that country for continued expansion.

When my wife and I were there last, the air pollution problem in Shanghai was serious. And ultimately I think what China realizes is the sooner they can expand their nuclear power, the better the environment will be, especially in the larger cities.

Obviously their economy is growing rapidly, and any growing economy requires a growth in electrical energy.  Most of China's power currently comes from coal, but nuclear can step in and take some of that burden.

Moist_Wet_Socks504 karma

What were the obstacles you faced when Chernobyl happened? Also, were your own beliefs affected by Chernobyl?

jhogan849 karma

I was personally not impacted professionally.  I was saddened because a preventable accident, and that particular reactor didn't have the kind of containment that *all* of our nuclear power plants have in the US (and that's true of almost everywhere, including Russia now).

nemo69_1999441 karma

Are you one of those liquid thorium salt reactor guys?

jhogan706 karma

I am not a guy associated with any particular reactor design but I happen to know a little bit about liquid thorium. A long time ago, when I was at Oak Ridge National Laboratory, there was an effort to develop a molten salt reactor. A long time ago! I left there in 1972.

In these experimental efforts, the reactor actually operated successfully, and it actually involved thorium. But there are many problems to be solved, and it did not prove a commercial feasibility, and there is a lot of work to do improving materials of construction that will withstand the environment, and long-term stabilizing of the system. It’s a longer shot than other approaches, but is still feasible.

snowteenager346 karma

Can nuclear energy power cars and trucks? What’s your thoughts on that? And what do you think, how many years it takes roughly estimating if you it’s possible?

jhogan596 karma

Oh, ok. That's a good question! The answer is yes, but they do it by creating the energy in central stations and using it to charge batteries.

There is no question that electricity can drive vehicles. We already know that, we're doing it. It's the source! An electric-transported vehicle, broadly speaking, depends on the source! If you get the electricity from a gasoline engine that's mounted in the car, ultimately the energy is based upon gasoline. If you operate a car with a plug-in that allows you to go two or three hundred miles… it's the source of that electricity!

In DC we have 2 or 3 nuclear power plants that produce maybe 30% of the electricity. People that plug in their electric car are taking electricity from the grid and 30% of that in the DC area is nuclear.

The_Mann_In_Black307 karma

What happens to a nuclear plant in the event of no humans to maintain it? Would it meltdown and leak radiation like Chernobyl? When humans are gone will nuclear plants have long term, adverse effects on wildlife?

jhogan682 karma

In my judgment, no. But that requires some advance work. You have to plan for the cooling process to be done without humans.

Right now the plants we design do require maintenance after shutdown. But we do have plants, for example one I visited in Dresden, which have been shutdown and are safe, with no additional work required to keep them from melting. They still have guards to prevent anyone from tampering with it, but do not otherwise require additional maintenance.

Also, this is important! 1.8 billion years ago there was a natural nuclear reactor that operated in what is now the country of Gabon in Western Africa. It operated for hundreds of thousands of years, shut down itself, produced a ton of plutonium, and life has since done pretty well!

Nicynodle2198 karma

Do you have an solutions for nuclear waste?

jhogan533 karma

Yes, I worked for 16 years on the Yucca Mountain project in Nevada, which I’m convinced is a safe location to dispose of nuclear waste.

At the Office of Civilian Radioactive Waste Management (OCRWM) we did a site study and identified Yucca Mountain in Nevada as a site for nuclear waste disposal. This was right next to a nuclear test site where 900 nuclear tests had been done with no containment. So a well-contained waste disposal site should have been very safe.

Our research included a performance assessment showing it would handle waste safely for at least 50,000 years. Not only should that should be perfectly safe, but as a backup there could be test wells in the nearby land to monitor the aquifer (1000 feet below the repository site anyway) that would detect if there was any radioactivity present in the aquifer, and if it *were* detected, that could be removed using ion exchange.

But the most important thing about this site, from a long-term perspective, is that the aquifer drained into Death Valley. It didn’t drain into the Colorado River or any other water source that would cause any problems 100,000 years from now.

payne747198 karma

Theoritcaly, how small do you imagine reactors could become?

jhogan363 karma

Well, there's some effort now to develop what is called a microreactor.  It's principally for defense use, for locations that might require a power source that can operate several years without having to rely on external supplies like a power grid or flying in diesel fuel. That's under study at Idaho National Laboratory.  

But what most intrigues me is the idea that you could provide power in a location and then remove it. There are plenty of places, particularly in Africa, that do not have electricity. It could be supplied nicely in a concept of a transportable system, but we’re looking at decades [for this to be developed]. 

small_h_hippy181 karma

How was the design of nuclear reactors changed through the years? Do you think it will ever be safe to use nuclear power where you might get an earthquake?

jhogan316 karma

Improved reactor containment is the most important change that has come about. Very, very good design of reactor containment systems, due to excellent independent analyses of the safety systems.  I'm very impressed with the great care the Nuclear Regulatory Commission puts into making nuclear operations more broadly safe (whether it’s nuclear medicine, storing fuel safely, reviewing long-term safety of waste disposal, etc.).

These containment practices include the analysis associated with an earthquake. There was a devastating earthquake on the western shore of Japan that caused the shutdown of many reactors. And those reactors were safely shut down. 

This was a good demonstration of the fact that if you design for such an occurrence, you can survive it.

quintessential17173 karma

Where do you see the future of nuclear energy going?

jhogan441 karma

It’s hard to tell. For example Germany has decided to abandon nuclear power even though they were one of the early adopters. But there are other countries — my favorite example is China — China thinks that nuclear power is going to be very important for them for a long time. They’re building more reactors than any other country in the world. And I think they’re building safe systems. Some parts of the world have essentially made a commitment that it’ll be an important part of their energy for a long time.

At the moment 75% of all power in France is nuclear. It’s an unusual situation. They don’t have as many reactors as the US but they decided decades ago to make that their primary source of energy. But it’s interesting that they’re shutting down old reactors, and have a commitment to REDUCE their dependence on nuclear power to 50%, whether it’s hydro or coal or natural gas. I don’t think they’re going to save money, and it doesn’t necessarily improve the environment, but much of their constituency feels 75% is just too high of an amount.

thesnapening119 karma

Did you considering leaving the field after Chernobyl, three mile island or fukushima?

jhogan371 karma

No, no! What I felt was chagrin and unhappiness that the design features of those reactors contributed to the accidents. For example, in the case of Fukushima, it saddened me that they lost their auxiliary power, when if they had put their auxiliary power up on a hill behind the plant, with simple wire connections, the disaster would have been prevented. But it was located in the basement, and there was a flood.

Japan now has an independent safety review organization, and have 50 shut down reactors that are very very slowly being put back online.

In the US, in 1975 it was decided the Atomic Energy Commission should NOT be both the developer and reviewer of nuclear power plants. And as a result, since then, there have been no deaths of any Americans as a result of our nuclear power grid. That includes all the power that has been generated on submarines and aircraft carriers.

Candle_Jacqueline71 karma

Most people I encounter are extremely antagonistic or terrified of nuclear power. What do you think can be done to improve public understanding and acceptance of it?

jhogan112 karma

I suppose in the long run it would help if the education system we had treated nuclear power in an objective manner.  I think it'd be nice if even if the grade school or high school level there was better information available to allow people to understand what's involved in the generation of the power, what the safety issues are, and how to treat them as you do anything else.

Every bit of engineering we do in the country, in any field, involves an understanding of the hazards and a way to address them. It's possible to do that with nuclear.

hellochase51 karma

It seems like the biggest obstacle to widespread nuclear power adoption is the public image after accidents, and we seemed to be doing better for a long stretch since Three Mike Island and Chernobyl… until Fukushima Daiichi. What needs to happen to reactor design or engineering to assure the public that nuclear power is safe, or is it really a matter of PR? What about issues surrounding spent fuel isolation and WIPP?

jhogan64 karma

I don't know what WIPP is.  Regarding the engineering, current designs in America, France, and China are good, safe design.  Take Three Mile Island.  There was no significant release of radioactivity, and no one was hurt.  It's because it was a good containment system.  

The current design of reactors, which is *different* from Chernobyl, and *different* from Fukushima, is safe!  I don't want to get involved in public relations issues, but I'm just telling you what the facts are today.

Rosiebelleann43 karma

I am 62 and am thinking of retiring later than my cohorts because retirement doesn't look all that interesting. I work in a newer field and know that opportunities will continue to present themselves for many years to come. What has helped you to continue and flourish both physically and mentally in a world that sometimes sees older people as bothersome as opposed to wise? Edit: should not matter but female, business continuity and resilience.

jhogan12 karma

I can only speak from experience.  I found working increasingly interesting with age.  New opportunities and new interesting topics kept emerging. Since the federal government, at least, has a policy of not discriminating on the basis of age, I elected to continue, and I was glad I did. Right up to my 92nd birthday, I was still enjoying going to work and working with others on new and interesting subject matter.

If this present work-from-home would continue indefinitely, I'm not sure I'd be quite as enthusiastic.  Because it was the physical interaction with people of all ages and the sharing of their ideas that continued to make it so interesting and exciting.

So I'm hoping that that type of physical interaction will re-emerge, perhaps after the vaccine, and we can go back to things which I found most interesting, namely technical interaction with individuals and groups on a personal basis.

colorduels23 karma

In my country, Italy, we chose to ban nuclear energy with a referendum, just after the Chernobyl disaster. Do you think energy, given the state of the world, should be managed by an entity that supersede governments and politics? Thank you.

jhogan92 karma

laughter Do I think that countries shouldn't be allowed to make a political decision like that? Of course not! That's a potato I would never pick up.

Some countries will make this decision and that's fine. That's a national decision. It's their decision to make.

saoirseshibhialta8 karma

How proud are your daughter and son-in-law of you as they do an AMA with you?

jhogan13 karma

(Daughter and son-in-law here) Very proud :)