Follow-Up Interview with my Dad, a Nuclear Engineer, about the Fukushima Daiichi Nuclear Power Plant Disaster in Japan

A recent photo of my Dad and one of his favorite trains– he is a high speed train buff.

Cross-posted on my geology blog Georneys.

I just conducted a follow-up interview with my dad– Commander Mark L. Mervine, a nuclear expert– about the Fukushima Daiichi Nuclear Power Plant Disaster. If you haven’t already, I encourage you to listen to the first interview I conducted yesterday. The full interview– with transcript– is available here:

First Interview with my Dad

For some reason, I was having problems with Simkl today. So, I recorded the Skype calls as .mp3 files and uploaded them to Kiwi6. If anyone has a better suggestion about how to host the .mp3 files, I would appreciate your help.

Today’s interview is broken up into two files:

Part I: Follow-Up Interview with my Dad

Part II: My Dad Answers Questions from Listeners

Update: thanks to Brad Go, the interviews with my dad are now up on YouTube:


Evelyn is a geologist, writer, traveler, and skeptic residing in Cape Town, South Africa with frequent trips back to the US for work. She has two adorable cats; enjoys hiking, rock climbing, and kayaking; and has a very large rock collection. You can follow her on twitter @GeoEvelyn. She also writes a geology blog called Georneys.

Related Articles


  1. Thanks to you both for another great interview, it answered a lot of questions I had.

    It’s very interesting to know how much damage might be done if the worst happens so we can judge the relative merits and dangers of Nuclear and Fossil power generation.

    When the restraining dams failed at a US coal plant in 2008 enormous harm was done to the local environment. I’d be interested to know how much worse a Nuclear Plant failing in a Tsunami and Earthquake would be compared to a Tsunami washing tons of coal ash into the environment.

    It’s great to hear a real expert, like kittynh said. The news is just interviewing industry stooges on one side or anti-nuclear campaigners on the other, having someone who knows the risks and is willing to talk about them seriously is proper journalism.

  2. @Akheloios: I’m a journalist? Yes, I guess I (and my dad) have become a citizen journalist.

    I’m so glad this is able to answer some questions for people. The mainstream media really isn’t doing a good job of covering the nuclear disaster in Japan.

  3. First off, I would like to thank you for posting this, as it was very informative, and your father explained things very well.

    However, when you asked your father for the best case and worst case scenario, he only answered the question for the former, and not the latter.

    Would still like to very much hear what is the worst case scenario.

  4. @kittynh: What’s wrong with Bill Nye? I tried googling what he had to say about nuclear power, and couldn’t find anything directly by him. I did find a summary of episodes of his TV show, and one of them was about this subject, but I couldn’t find the show itself. The summary seemed perfectly reasonable, explaining how it works and what the pros and cons are (including long-term storage and/or disposal of waste.)

    My own view is that all forms of energy use and consumption have effects on people and the environment, and there are way too many people using way too much energy to just ignore these effects. So all forms of energy production require careful analysis of the costs (economic, environmental, and human.) Oil and gas are depleting rapidly and create CO2. Drilling and transportation are risky. Coal is abundant but mining is filthy and destructive and dangerous, and burning it produces vastly more CO2 than oil or gas. Nuclear is clean when running properly (just produces waste heat, which can be an environmental problem sometimes), but is enormously expensive and mining and disposal and accidents are big problems. Solar is inefficient and only works in the daytime. Hydro and wind are limited, and hydro silts up (i.e. stops working eventually) and disrupts river ecologies.

    I used to think nukes were an unnecessary can of worms (except for things like submarines and outer-solar-system spacecraft), but have in recent years accepted that sometimes, especially if some of the issues can be reduced or remediated, nuclear could be a viable option. But the current situation in Japan doesn’t help, and will be politically disastrous for the pro-nuke people unless they can prevent any further release of radiation and make it obvious very soon (in the next few days) that they have the situation under control and know how to prevent it in the future.

    Secondary backup generators on nearby high ground or on boats or barges that can be activated quickly if needed, or maybe a passive cooling design that doesn’t require powered pumps to work while the reactor is shutting down.

    I think all energy intensive and polluting industries should be moved to asteroids (and solar powered), but that is obviously centuries if not millennia away. And it does nothing for domestic power, heating and cooling.

  5. At the risk of sounding pedantic, may a one-time designer of radiation safety equipment clarify the difference between “radiation” and “radioactivity,” two words used interchangeably in the press and even by the esteemed Commander Mervine whom I’m sure knows better.
    A radioactive atom is one which has surplus energy which it will, sooner or later, release in the form of radiation. Once an atom has released that energy it is, in general, no longer radioactive. The radiation produced is traveling at or close to the speed of light and is eventually stopped by, for example, the atmosphere. It doesn’t stick around and, unless it passes through you on the way past, it won’t do you any harm.
    Each decaying atom produces one of two particles of radiation. If you have a large number of similar atoms, each decaying at random, the effect is to produce radiation continuously until the radioactive material is used up.
    The rate at which radioactive atoms decay (produce radiation) is specified by their “half-life.” This is the time it takes half of a batch of identical atoms to decay. It varies enormously from atom to atom, from billionths of seconds to billions of years.
    Short half-life atoms generate high levels of radiation for a short time, long half-life ones produce much less radiation but over a much longer period of time.

    With me so far?

    Each atom of uranium in a nuclear reactor produces a lot of heat as it splits. A wide variety of “fission fragments” are produced. These are all radioactive but have different half-lives. Some contribute immediately to the reactor’s power output, others are just a nuisance after the fuel rods are removed from the reactor. They continue to generate gradually falling levels of heat and radiation for weeks or months.
    That’s why, if you put the brakes on a nuclear reactor, you have to keep on cooling it for a long time after the reactor has shut down.
    The big distinction between radiation and radioactivity is that while radiation shoots out and soon stops, radioactivity is a material property. It can endanger people if these materials are released from a reactor’s containment shell and spread by the wind or in water.

  6. I have not seen anything by Bill Nye, but it sounds like he has succumbed to the all to frequent:
    “I used to be an engineer, so I am all smart about stuff like that. Even smarter than experts who are still working in the field.”

  7. Um, it’s pronounced NUK-ya-lur!

    Seriously though re: Nye. He is indeed kinda full of himself, like a lot of media personalities. I have met him and he just radiates (is radioactive?) charisma but also arrogance. Like most politicians or celebrities, really.

    However he does know that he’s not an expert on everything and is aware of his own limitations as a scientist. He makes a clear distinction on his shows between himself and “experts” on a given subject, and tends to find a good balance of opinion. He certainly does a laudable point-counterpoint and tends to fully disclose the biases and backgrounds of people he interviews. Good science journalism.

    His “Eyes Of Nye” episode about nuclear power was very good. His final conclusion was, “there is no clear answer” which is a ballsy and much-needed breath of reality. A grey area with no clearcut results? CRAZY I KNOW! MSN take note, please.

    It goes into the main points for and against nuclear power and talks about all the proposed ways to dispose of waste, which is the main problem with it even if things go swimmingly all the time w/ the reactors. Interviews Yucca Mt. personel and former personel. Good stuff.

    I would like to hear what he got wrong in interviews about the Japan situation because that’s very out of character. He does not typically talk about things he doesn’t have the facts about…maybe these interviews are off-the-cuff candid pieces where he didn’t have time to prepare and research?

  8. @kittynh: I found one two short clips of him on the CNN site. He makes two statements of fact in each and a lot of “this is scary and worrying” vague pronouncements. I the 1st clip, he first statement is that cesium is used as a moderator in nuclear reactors and as far as I can tell, is completely wrong. I search CNN and google for a retraction and did not find anything. The 2nd statement was that boron, specifically 10B, is used as a moderator, and they must have had a supply on hand to mix with the seawater. This is correct, as far as I can tell. According to Wikipedia, natural boron is about 80% 11B and 20% 10B, and the nuclear industry uses pure 10B as a moderator, since 11B is worthless for this purpose.

    In the 2nd clip, he repeats the bogus claim about cesium, then gets cut off because of a breaking news story (resulting in lots of conspiracy theories), but they return, and he finishes the stuff about cesium being a moderator, and then goes on to say that the only way for cesium to get into the atmosphere is if there was a meltdown, or a partial meltdown, or “that’s on the road to the science fiction meltdown”. The hosts immediately go on to ask explicitly about “What’s the worst case scenario?” Not “What’s the most likely scenario” or “what are the probabilities?” Later he backs up a bit and says it might be possible that the official explanation (which he appeared to be hearing live from the hosts) might be correct, that a small amount of cesium might have boiled off with the cooling water, but he still thinks the building explosion is was the containment vessel rupturing.

    I really, really wish he had not made the number one skeptical mistake, being afraid to say “I don’t know.”

    I hope he has time to do some googling and checking with friends and does the correct skeptical thing and admits he was wrong. More importantly, that he tells CNN that when future technical subjects arise, they actually seek out experts in the field and that they and he agree that when they ask him about something that he doesn’t know about, he will tell them so and help them find someone who does, rather than just winging it on live TV.

    P.S. I hope my isotope superscripts work; I searched for the right HTML tags, but they don’t look right in the preview pane.

  9. @unexplainedbacon: Thanks for summarizing the Eyes of Nye episode. I hope I’ve summarized the two CNN segments I could find adequately. It does sound exactly like you feared.

    And RATS, my HTML for the isotopes didn’t work. I used [sup] and [/sup] before and after the mass numbers, but the tags seem to have disappeared when I “view source” on the resulting comment.

    BTW, URL’s for the two Nye videos:
    first video and 2nd video.

  10. @Evelyn, congratulations to you and your Dad for (yet another) timely and educational piece.

    Outstanding communication skills and technical knowledge seem to run in your family.

    When all the dust has settled (no horrible pun intended) maybe you and your Dad could address in more detail the question of where we should go in the future with nuclear power, perhaps including more detail and pictures of various designs with an emphasis on safety features?

    I agree with everything Buzz Parsec said and the debate is a worldwide one. In Oz we have no nuclear power apart from a single small experimental unit. We are also very stable geologically. OTOH we are very subject to massive flooding – and so on, rah rah.

    Meantime, best wishes for your thesis, which is more important right now!

  11. @Buzz Parsec: #16
    Just to keep the record straight:
    To get a nuclear reactor to run requires inter alia a moderator that will slow down neutrons without absorbing any and an absolute minimum of any element that will absorb neutrons. The latter condition is why fuel rods are encased in zirconium and not something cheaper like stainless steel.
    Some elements such as boron and cadmium absorb so many neutrons that they make the chain reaction stop. Cadmium is therefore used to make reactor control rods. Boron, e.g. as a solution of borax, is what you dump into a reactor when you want to shut it down in a hurry and don’t care about ever starting it up again.
    The moderator is often pure graphite. Heavy water is also good. Plain water, as used in the Japanese reactors is OK but not ideal.
    Cesium is not a component of a reactor but is one of the more common radioactive end-products of fission.

  12. Buzz,

    about Bill Nye….

    I used to love watching his show. It was fun and moved along quickly. I wished that my teachers were like him.

    But it’s years later now. He has become an activist. He has, it seems, moved away from things he did well. And he continually advocates for an activists group called “Union of Concerned Scientists”. That organization is not comprised of all scientists, thought it is named like it is. I suppose they all mean well. But their science is not solid. They are more an environmental and political activist group than a scientific group. It was sad for me to see the change in his life. Part of me still likes him and hopes he’ll come back to true science.

  13. Here is a rough paraphrase of the 2nd interview, similar to the initial transcript posted by Ashlyn. I hope to do a more careful transcript later, as well as the 3rd interview, later. If anyone else wants to jump in, please do, just post a quick comment so we can avoid duplicating work. I’ll do the same. Evelyn, please let me know if I got anything substantially wrong in the paraphrase, or simply edit the comment to correct it.

    [explanation of interview, mention previous one, re-introduce the interview subject]

    Q: What’s happening at the plant?

    A: Relying on news reports, Internet, [unclear], IAEA, and of course, television; piece together, a serious problem, a partial failure of the fuel rods in that reactor. There was an explosion at the plant yesterday, destroying the auxiliary building. They were venting pressure from the reactor into that building, and that steam also contained a mixture of hydrogen, which exploded when mixed with atmospheric oxygen. Hydrogen came from: Fuel pellets are encased in zirconium fuel rods, which if it gets hot (2200 deg F) will interact with water to form Zirconium dioxide, releasing hydrogen. In order for there to be a significant amount of H, some of the fuel had to have reached that temperature. Also, in the environment, cesium and iodine have been detected. Previously mentioned, uranium fissions into smaller elements such as cesium and iodine. Normally, these would stay in the fuel rods, and only get out if there’s a failure of the fuel rods. Maybe not complete, but these two factors make it very likely to have some fuel failure.

    Q: Are we in a meltdown situation, and if so, explain what a meltdown is?

    A: Normally, a meltdown refers to a complete meltdown of the reactor core. That’s probably not happening. There must have been some water, we know they’ve in injecting boron-laden seawater, agree with prevailing opinion that a meltdown is unlikely at this point. However, probably the upper part of the fuel was exposed, and some damage has occurred, the release of iodine and cesium from those fuel rods has occurred.

    Q: What about the other reactors that are in trouble?

    A: There are six reactors at the site. Three were already shut down for normal maintenance. One, Two and Three were shut down automatically when the earthquake occurred. What’s occurred today is at Unit Three, a newer and slightly larger plant, they’ve lost the normal shutdown and emergency cooling systems. They’re also attempting to inject “firewater”, assumed to be boron-laced seawater, and will need to vent pressure from that reactor. Very similar to Unit One situation. Probably a partial uncover of the core, probably some fuel damage from that reactor as well.

    Q: Have they made progress, gotten batteries and generators in there?

    A: It does sound like they’ve gotten power at those sites, that’s what they’re using to pump the seawater and boron into both reactors.

    Q: There were reports that people were testing positive for radiation. Over and under reactions. Your thoughts?

    A: It wasn’t clear how many people, or whether they were plant workers or members of the public. Because of the radiation releases from the steam venting, there would be some small radioactivity, so it would be possible for a worker to pick up some contamination. And of course the particles travel up into atmosphere, prevailing winds taking it out to the ocean, but some member of the public, before the evacuation, may have had some of these particles fall on them.

    Q: Do you think this poses a serious exposure risk? Some experts said it wasn’t bad, so far. Will there be health problems?

    A: Hopefully not. Hard to know the exact details, and what the actual readings are. We know the Japanese government has evacuated people 20 kilometers from the plant, so I would say the concern for major health risks, if the reactors don’t get worse, is very very low.

    Q: Presumably, the workers have safety gear.

    A: That would be correct.

    Q: Also, distributing iodine tablets, to help reduce the exposure level, and the cancer response to that level.

    A: Let me explain that. Your thyroid will absorb iodine, and the purpose of the tablets is to fill up your thyroid with non-radioactive iodine. That’s important because your thyroid is one of your more active glands, and if you can prevent that from absorbing any radioactive iodine that’s a real health benefit.

    Q: Last question; you mentioned to me personally, that many of the nuclear officials are using so-called “safe language”, when describing the disaster. This was one of the keys to you that this situation might be more serious than at first they were revealing. What do you think this means, and you are not currently in the industry, do you think lets you speak more frankly?

    A: It’s really hard to determine if information is being withheld. First of all, some media reporting has been horrible. One media personality claimed that cesium is used to control the reactor. This is not true, control rods are used — boron can be used, but cesium is a byproduct of uranium fission, and normally should not be in the reactor water, and should not be in the atmosphere, but it’s not used to control the reactor. Also, the pictures shown on TV were the wrong type of reactor — a pressurized water reactor, not the actual boiling water reactor that it is. They are similar, but different. If you are going to be an “expert”, you need to get it right. In terms of public announcements, most important is that it is rated as a Category 4, one level less serious than TMI, in my opinion, if we’ve got a partial core melt, and any engineer or scientist, given all the data available, would conclude there has been a partial core failure, therefore this is at least equal to TMI, and the fact that we have multiple units at the same site involved, this is worse.

    Q: That’s good to know; people have been looking at that number and being relieved, but I think it’s too soon to feel relief in this situation, before it’s under control.

    A: This is not going to go away tomorrow, even if they get enough water in those containment buildings, it’s going to take days for these reactors to cool down.

    [discusses dividing the interview in half, due to technical recording issues, good-byes]

  14. TMI had a gigantic fraction of the core melt. There is no indication that anything like that is happening here.

    There may have been no “melting” of fuel here, there certainly is fuel damage, but fuel damage can occur without melting. The zirconium casing is susceptible to oxidation, and if it oxidizes it will then leak. That leakage can occur without any melting.

    I think there is confusion between “fuel damage” (which there has been), and “fuel melting” which is a specific type of damage which is much more serious. It is important to make the distinction because fuel melting can lead to the liquid fuel accumulating in the bottom of the reactor which is an enormous escalation in concern.

    If the fuel stays in its normal position, even if it is damaged, that is not so bad. In its normal position water can flow around it, it is in the right place relative to the control rods, the instrumentation they have can monitor it.

    Fuel melting can cause positive feedback because the first fuel to melt is at the top, as it drips down, it blocks cooling passages and adds its own heat to the hot fuel below. The heat generated per unit volume goes up, and the area for that heat to dissipate goes down.

Leave a Reply

You May Also Enjoy