Nuclear Power and Climate Change

I’m a lifelong nuke. I joined the navy at 17, was trained in their naval nuclear power schools, served as a reactor operator on a ballistic missile submarine, and then had a career in the commercial nuclear power industry as an instrument technician and an electrical/I&C engineer. I count myself fairly well versed in most things nuclear (including nuclear weapons but considerably less so).

All through my career in the civilian world, I would often reply to someone asking what I did for a living by saying “I keep the world safe from the evils of nuclear power.” Which was not entirely facetious. My specialty as an engineer was preparing a type of safety analysis calculation which examined the efficacy of plant safety systems. In other words, I demonstrated that they would work (to a specific degree of certainty) when they were most needed. Or I demonstrated they wouldn’t (again, to a specific degree of certainty), in which case the plant would have to modify something in order to ‘pass’ my calculation. Earlier on as an instrument technician, I ensured that the safety systems were in proper working order. I wrote a blog post on that subject.

Many aspects of my career were unpleasant (particularly the navy part) but I really never had any doubts that nuclear power was a great technological achievement for the benefit of society. Now that scientists (virtually ALL scientists in relevant fields) have concluded quite authoritatively that we’re in the midst of human-caused rapid climate change, I see nuclear power not only as a great thing but vitally necessary. We need nuclear power electrical generation and we need a lot of it. I’m not alone in this opinion.

But wait, what about all those nasty bad things – radiation, nuclear waste, Chernobyl? Fukushima, for chrissakes!? How can nuclear power be not only good but necessary with all that?

The long answer follows but the short answer is: because all other forms of base-load power generation are worse and we need electricity or society will collapse. Conservation, wind, solar, geothermal, etc. are all good things – technologies we should embrace and expand – but none can come close to powering industry, which uses the bulk of electricity in industrialized countries. Until we develop fusion power, only nuclear, coal, oil, natural gas and hydro can supply sufficient electrical power to satisfy our industrial demands. Putting solar panels on our roofs and driving EVs isn’t going to get it done (note that your Tesla still needs to be charged and that electricity comes from power plants). Coal, oil and natural gas have brought us to the present dire situation with climate change and hydro is played out. We can build no more dams, or at least not many.

Great. So we’re all doomed to either a planet-wide climate crisis or radioactive poisoning. Well, no. I don’t know if climate change has progressed to the point of being unstoppable but it certainly will be if we continue on the same path. Some scientists say we’re there already but I’m not sure that stance has a strong consensus. But I can address the radioactive poisoning bit. The short answer to that is: none of those nasty bad things I mentioned earlier are really anything to get worked up about. They’re all solvable with today’s technology and some are not really problems anyway.

Lets take them one at a time.

Radiation. I’m sure you’ve all heard about how bananas are radioactive, so too are granite buildings, how a flight across the country exposes you to a higher dose than nuclear plant workers receive (on average), how living in Denver will too. Not sure why Denver is always the city that gets mentioned – it’s not all that high in elevation – but there you are. Maybe you’ve seen graphs and charts that show how little radiation gets emitted from nuclear power plants as compared to, say, cosmic rays. All that is true so why is it that these facts don’t seem to matter to people? Why doesn’t it sink in? Why do you keep eating bananas, traveling across country by air to visit the relatives during the holidays, keep working in granite buildings while dreaming of a nice retirement cabin on a lake in the Colorado Rockies? Yet you recoil in fear at the thought of living in the same state as a nuclear power plant. It’s irrational.

Radiation scares people more than it should. I hear that it’s because radiation is ‘invisible’ but so are other hazards. Can you tell if your food is contaminated by e-coli or salmonella? Can you smell or taste COVID-19? No, you can’t, at least not without equipment you’re unlikely to have at hand. Detecting radiation also requires specialized equipment but it is very, very easy to do so with simple, cheap instruments. You’ve seen the sci-fi movies where someone is holding a radiation detector which starts clicking like mad. OMG! We’re all going to die! That’s the message. It’s wrong. Detectors designed to measure low-level background radiation will happily click away no matter where you are on Earth. We can detect individual radioactive decay events. A single atom emitting radiation. You’ve heard it before – “The dose makes the poison.” Almost anything is deadly to humans if the dose is too high. Radiation is no exception. It’s around us all the time but you really only need to get concerned when the dose rate (the amount of radiation per time) exceeds a certain level, which varies depending on the type of radiation. Speaking of which, a gamma ray, an x-ray, a beta or alpha particle, are all the same no matter where it came from. The radiation associated with nuclear power plants is not somehow more deadly to humans. For the more technically astute, you may have raised an eyebrow at that statement. I’m not saying all gamma rays are the same. They aren’t. Higher energy gammas, for example, are more hazardous to biological processes. But a 1 Mev gamma from a ‘natural’ source is exactly the same as a 1 Mev gamma from a nuclear power plant.

Being easily detected, radiation is quite manageable. It’s a simple matter to monitor, segregate and isolate radioactive materials to lessen exposure risks. Far easier than other hazards, in fact. When a salmonella outbreak is discovered, do grocery stores check to see which bags of romaine lettuce are contaminated? No, because there’s no easy, cheap way to do that. So it all gets thrown away.

Nevertheless, most folks, even if they’ve just read what I wrote, will become alarmed if the local news reports a tritium leak from the neighborhood nuclear plant. They won’t bother to find out if it was a leak sufficient to cause a health hazard. And the news folks are in the business of scaring you so they won’t say anything to dispel your concerns. Nope. It’s radiation and all radiation is deadly.

Fact is, nuclear plants emit very little radiation outside their perimeters during normal operations. That which does escape is dwarfed by natural background radiation. We’ll discuss abnormal operations in a bit. When it comes to radiation from power plants, it’s not that from the plant that is of concern. Rather, it’s the nuclear waste the plant generates that needs to be discussed.

Nuclear waste. This topic engenders so many misconceptions, it’s hard to know where to start. Let’s break it down into three subtopics: radioactive half-life, amount of waste, long-term storage. Before discussing the first one, a nuclear physics refresher might be of benefit.

Radioactive half-life refers to the time (on average but when you have trillions of atoms, the average is essentially exact) it takes for one-half of a given amount of radioactive isotope to decay, to emit radiation of some form in a process that transforms the isotope into a different isotope.

An isotope is a subset of an element. Uranium, for example, has several known isotopes: U-234, U-235, U-236, etc. The number (e.g. 235) refers to the sum of the isotope’s neutrons and protons. All isotopes of a particular element have the same number of protons but they vary by the number of neutrons. So U-235 has the same number of protons as U-234 (92) but has one more neutron. All elements, from hydrogen (one proton) to oganesson (118 protons) have isotopes. [I had to look up oganesson on the latest chart of the nuclides] All elements have more than one isotope; some have many. Lead, if I counted correctly, has over forty isotopes. Physicists are continually discovering new elements and extending the periodic table. If you’re interested in the subject, check out this link: or just search on ‘chart of the nuclides.’

Isotopes can be further divided into two groups: those that are stable and those that are radioactive. A stable isotope is one that has essentially an infinite half-life. A radioactive isotope is one that will emit some form of radiation and in the process transform into a different isotope, on a schedule according to its half-life. It is the latter group that concerns us here. Some half lives are quite short. Oganesson 294 (Og-294) has a half-life of 5.8E-4 seconds. That’s 0.00058 seconds – it doesn’t hang around very long. U-235 is quite long-lived with a half-life of 2.22E16 seconds, or a little over 700 million years. So if you had a gram of U-235 in your hand, in 700 million years you’d now have half a gram. The other half would be something else, probably mostly lead. In other words, U-235 is not exactly stable but it’s pretty close. That chunk of uranium in your hand just isn’t very radioactive – you could hold onto it for a long time without any noticeable health effects.

The U-235 decay process – termed the ‘decay chain’ – doesn’t go directly from U-235 to Pb-207. Rather, the decay chain involves several steps, each with its own half life and therefore, each with an associated level of radioactivity. In the case of U-235:Pb-207, there is an additional 34,000 years worth of half-life along the chain.

So what’s the point? If you read a news article about nuclear waste and it stated that some of the radioactive material had a half-life of 700 million years, what would your reaction be? If you’re like many people, you’d think “No way! We can’t keep waste safe for that long!” and might jump on the anti-nuke bandwagon just over that. But consider, we just reasoned that U-235 is almost stable, effectively non-radioactive. So why would you worry about burying it in a nuclear waste repository anyway? You could just bury it in your backyard for all the harm it would do. Or maybe you had a chunk of that Og-294. Would you worry about properly disposing it? Of course not. With its half-life, before you could even load it on a truck bound for Yucca Mountain, it would be essentially gone, decayed away (Disclaimer: I don’t know the decay chain for Og-294, so I don’t know the half lives of the downstream isotopes. Maybe nobody does because it just got discovered. But my point stands).

Of course, U-235 and Og-294 are not the components of nuclear waste – and we’re mainly talking spent nuclear fuel here – that need to get buried in Yucca Mountain. There are other far more harmful elements with half-lives somewhere between 700 million years and 0.00058 seconds. I used those two to illustrate a concept, which is that we really only need to consider medium-long half-lives, those in the hundreds or thousands of years. All of the short-lived isotopes will have mostly decayed away to stable isotopes while the spent nuclear fuel is still stored at the nuclear plant, and the longer ones aren’t much of a health hazard anyway.

Our second sub-topic is the amount of waste. How much spent nuclear fuel are we dealing with? I mentioned the old adage about dose making the poison, so it stands to reason that if we bury tons of waste in every local landfill, we’ll have a problem, right? We don’t have that much. In fact, very little. The volume of spent nuclear fuel generated in the US since the beginning of nuclear power plants would fit in one football field at a depth of ten feet (Americans demand their measurements be related to football fields). All of the fuel from all of the power plants for all of the years – one football field. Of course, burying nuclear waste in a football field-sized repository isn’t good engineering so we’d require something a bit bigger, practically speaking. A repository the size of, say, Yucca Mountain in Nevada. Not the whole mountain – just part of it. Wrap your head around that. Or better yet, go to Google Maps, find Yucca Mountain (just north of Las Vegas), zoom in to see the mountain (more like a big hill) and then zoom out to the whole US. That’s the scale we’re talking about to store every bit of spent fuel ever generated in this country. It’s really not an issue. If you’re enthusiastic, now look up how much coal ash is generated in this country. Coal ash is radioactive, by the way.

The third sub-topic is long term storage. Recalling the half-life discussion, it’s clear a nuclear waste repository, such as Yucca Mountain, requires a stable geologic environment on the order of maybe a few tens of thousand years, well within the realm of current geologic knowledge. We might not need even that long – there’s quite a bit of geologic evidence and research relating to heavy isotope migration that strongly suggests that even if the spent fuel storage containers ‘leaked’, the dangerous isotopes aren’t going very far, maybe tens of meters. Finally, repositories such as Yucca Mountain are not ‘bury it and forget it’ installations. There’s no reason why we can’t periodically check up on things – the spent fuel would not actually be buried. More like securely stored with provisions for access. Spent nuclear fuel is a valuable commodity anyway – it can be used in breeder reactors after some reprocessing – so we’d probably be hauling it out again before too long anyway. So don’t pay attention to the folks who scream about million year half-lives.

If you’re up for another Google Maps exercise, find your local nuclear power plant – doesn’t matter which. If you zoom in, somewhere on the site you’ll find a parking lot-sized area that appears to be somewhat segregated from the rest of the plant that seems to contain a bunch of circular objects. You’re looking at the ISFSI – the Independent Spent Fuel Storage Installation. Because of the delay in opening Yucca Mountain, all US nuclear plants have had to devise methods to store spent fuel onsite. Those circular objects are actually cylinders of concrete and steel – casks – that hold several spent fuel assemblies each. Note that the fuel is not transferred into the casks right away after being removed from the reactor but rather sits in the plant’s spent fuel pool for a number of years while the short to medium-short isotopes decay and the assembly ‘cools.’ Once cooled, the spent fuel assemblies are easily encapsulated in the casks, which are then welded shut. The external radiation from the fuel isn’t all that high because it’s shielded by the cask. Engineers and technicians can safely approach the cask to do whatever is needed in terms of monitoring cask condition. It is these casks that will be ‘buried’ at Yucca Mountain when it finally becomes operational. You can also see that the idea of casks ‘leaking’ is not realistic – they’re composed of metal and concrete and the spent fuel itself is entirely metallic.

Anti-nuke advocates sometimes toss out figures on how much waste is generated by nuclear power plants but they usually lump in all the low level radioactive material to get a bigger, more scary number. They’re including waste such as rags, used anti-contamination clothing and other stuff that really could be buried in the local landfill if people weren’t so paranoid about radiation but has to be segregated because of NRC regulations. Note that I’m not dissing the regulations – they’re a good thing but to understand the issue of nuclear waste, it’s important to understand there’s a lot of regulatory overkill. Focus on the real issue: spent nuclear fuel. For further info:

OK, but that’s radiation from nuclear power plants that aren’t currently melting down or from spent fuel. What about Chernobyl, Fukushima, Three Mile Island? Don’t those accidents prove that nuclear power is not safe? How can we be safe knowing the local plant might melt down and emit far greater amounts of radiation? While there have been other, less known nuclear incidents, let’s very briefly examine those three infamous nuclear accidents. With all, the causes and lessons are quite complex but an overview is easily at hand. For those who want the whole, detailed picture of each event, the information is available online.

Three Mile Island. I worked there as a technician, just after the Unit 2 meltdown had occurred in 1979. Talk about a weird workplace! TMI was an accident that had several causes. There were equipment failures (stuck relief valve), procedural failures (cooling valves erroneously locked shut), training failures (operators not believing their instruments), bad design (the control alarm systems inundated the operators and then fell hours behind in recording significant events), insufficient understanding of some aspects of pressurized water reactors (experts did not anticipate a hydrogen bubble) and industry and regulation failures (another plant with a similar relief valve had issues but that wasn’t communicated to the other utilities that operated the same type of plant and the NRC had no regulatory mechanism to compel them to do so). In a nutshell, a relief valve stuck open, much of the water in the core was expelled, a key automatic safety system had been disabled, a hydrogen bubble formed in the core which caused anomalous readings on some control room instruments, the operators did not believe their instruments so they shut down the emergency water supply to the core. The core became uncovered and with safety systems compromised, it partially melted.

Eventually, over days, reactor experts figured out what had happened and efforts to supply water to the core were successful. But not before a significant portion of the core had melted and not before some very anxious hours wondering if the hydrogen in the vessel would explode, as hydrogen has a propensity to do.

What were the immediate ramifications? Well, the reactor was destroyed of course and the effort to relieve the reactor building (the containment) of dangerous conditions mandated venting some radioactive gas to the atmosphere. Radioactive water was released into the auxiliary building but not beyond that. Two things didn’t happen. First and most importantly, the primary defense against an unacceptable release of radioactivity to the public did not fail. The containment building held. Inside the containment, it was radioactive hell. Outside, not so much. And by ‘outside’ I mean immediately adjacent to the exterior of the building. It was still safe for workers outside to do what they needed to do. Secondly, no significant radioactive material or radiation escaped the plant boundary. Yes, there was some venting and the radiation level at the plant boundary fence rose, but never to a level remotely dangerous to the public. I know there are scare stories of radioactive cow milk and increased cancer rates but they’re bullshit. Utter (udder?) bullshit.

Long-term, the ramifications of the TMI accident, other than the utility going bankrupt and nuclear construction across the country stalling, were enormously positive. The industry and the NRC responded in several significant ways: plant operating procedures were modified, existing equipment was upgraded, new equipment was installed, a whole industry watchdog came into being, the NRC became more assertive with regard to plant safety. I personally built half a career on installing extensive modifications to several nuclear plants in the country. It was a veritable boom time for workers like me. You know those safety analysis calculations I mentioned? That was part of it. World-wide, the nuclear power industry is much more safety conscious and much better equipped to handle accidents because of the lessons learned from TMI.

Chernobyl. No discussion of the accident at Chernobyl 4 can be valid if the political situation is ignored. Chernobyl is located not too far from Kiev in the Ukraine – at the time a republic of the USSR – and was tightly controlled by the Soviet Union. It has been thirty years since the collapse of that regime so maybe people have forgotten how dysfunctional it was. With regards to what we’re discussing here, the USSR designed, built and operated some very inferior nuclear power plants. Safety systems were minimal and unreliable; the plant operators were cowed into compliance even when they knew things were not right. The basic design of the four Chernobyl units – the RBMK reactor – is notoriously unstable. Chernobyl Unit 4 was as unlike a western nuclear power plant as you could imagine and still be an electric generating station.

I am not nearly as familiar with the events surrounding the Chernobyl disaster as I am with TMI, or as with Fukushima. That’s largely due to the secrecy imposed in the aftermath by the Soviets, which was not relaxed all that much by Yeltsin’s Russia after the USSR’s demise. And good luck getting anything out of Putin. I wouldn’t be surprised if officials of the now independent Ukraine aren’t privy to the details. I did find the HBO show Chernobyl to be illuminating, however. Worth a view.

Briefly, for whatever reason, the agencies responsible for nuclear plant operations in the USSR ordered a test to be performed at the Unit 4 reactor which would demonstrate whether the latent heat of the reactor after an emergency shutdown could supply the turbine with enough steam to power the reactor coolant pumps until backup generators could come online. It was ill-advised because it required disabling safety systems designed to shut the plant down when key plant parameters were exceeded. It also involved operating the plant in a manner outside its design limits. The reactor responded badly to the test, power increased at a rate far beyond limits and entered an operating region that was uncontrollable. A steam explosion occurred due to the excessive power level and the reactor essentially blew its top. A fire ensued. The fire is key because the RBMK used graphite as part of its core design and the graphite caught fire, resulting in an inferno that was extremely difficult to put out. The heat plume from the raging fire sent highly radioactive material into the atmosphere where it was carried by winds to neighboring regions.

But bad as it was, it wasn’t as bad as some nuclear doom-sayers said it would be. Many people died trying control the fire and plenty more died in the local region due to radiation poisoning, cancers. Certainly, this was the worst nuclear disaster we have experienced. However, predictions of enormous swaths of land uninhabitable for centuries have not borne out. The area surrounding Chernobyl is still abnormally radioactive but wildlife is flourishing. It isn’t the post-nuclear wasteland many predicted. The Ukraine, including Kiev, are fine and countries further away that were in the path of the plume have no significant residual contamination. I should mention that the other three units at Chernobyl eventually resumed operation. They probably shouldn’t have.

Fukushima. Fukushima teaches a lesson and that lesson is that TMI already taught the lesson. Ignore it at your peril. The Japanese nuclear regulatory agencies were lax in their oversight and failed to insist the plants adopt newly-developed safety measures, as is routinely done in the US.

The six-unit Fukushima Daiichi plant, located about 250 km from Tokyo on the Pacific coast, was inundated by a tsunami generated by a large earthquake centered offshore which caused massive damage to the country. The plant’s seawall was inadequate to hold back the rising water which subsequently flooded most of the plant, including vital safety equipment. Units 1 – 4 were most affected, with the newer units 5 and 6 being better protected. Of the four affected units, 1 – 3 were operating; Unit 4 was shutdown for refueling. Units 1 – 3 each suffered substantial core meltdown.

The details are not as involved as at TMI, which had in my opinion more numerous sub-failures, but briefly the floodwaters disabled the emergency diesel generators, located at low elevation (i.e., below the level of the seawall). Without the diesels, the plant safety systems were left with only the emergency batteries, which were not designed to last very long. The four reactors eventually lost electric power and injection of core cooling water terminated. Without continual cooling water, the cores in 1 – 3 overheated and melted. The core for unit 4 had been removed to the spent fuel pool. There was some concern with the spent fuel pool conditions post-accident but they turned out to be unfounded.

Fukushima has become a major economic disaster not only for the utility that operated the plant but for Japan as a whole. Regulators and government officials shut down the entire Japanese nuclear industry in the aftermath and it still hasn’t fully recovered. Prior to Fukushima, the country relied on nuclear power for some 30% of its electricity, all of which had to be replaced by non-renewable power during the shutdown. In the years since, many of the reactors have either restarted or are gaining approval to do so. Meanwhile, the cleanup effort at the Fukushima plant and the Fukushima prefecture is ongoing and very, very expensive.

It’s not my intent to minimize the extent of the Fukushima disaster. It surely was the worst accident to occur with Western built reactors (Fukushima’s reactors were designed by General Electric, one of the four reactor suppliers in the US). The only points I will offer are: one, such failures are very rare and should be evaluated in context of the industry’s record as a whole, particularly in comparison to that of competing industries. An examination of the coal, gas and oil industries will quickly expose far greater environmental and economic damage, damage that includes worsening climate change. Moreover, far more people have died and are dying from fossil fuel use than can be attributed to radiation exposures. My second point is that the recovery from the disaster has been a bit of a disaster itself, mainly due to unreasonable fears of radioactive contamination preventing engineers from doing what needs to be done: use the Pacific Ocean as a heat sink and a source of dilution. Rather than build hundreds of storage tanks to hold the radioactive water used to cool the disabled cores, a pipeline could be constructed to carry the water far out to sea where it would mix with ocean currents. The resultant increase in ocean radioactivity would be extremely minimal due to the enormous dilution factor, and would be localized at that. Such is the state nuclear power today – even reasonable recovery and mitigation efforts are thwarted by ignorance.

Current Regulatory Environment. The USNRC has long set a good standard for safety and has in my estimation has properly directed efforts to learn from Fukushima as we did with TMI (Chernobyl was irrelevant – the RBMK reactor design and Soviet regulatory practices were so far afield from western reactors and regulations that no real lessons could be learned, other than to do what you can to keep nuclear technology from countries like the USSR). Not long after regulators and industry experts determined what exactly had gone wrong to allow the Fukushima accident to happen, the NRC developed a two-phase plan. Phase I was guidelines (some were mandatory actions) for the industry to use to determine if similar vulnerabilities existed at US plants. Phase II comprised regulations implemented to address the vulnerabilities with utilities having a certain period of time to make physical and procedural changes that would assure Fukushima-like accidents would not occur. Unfortunately, the NRC now has three Trump-appointed commissioners and they voted to shelve Phase II of the Fukushima effort.  How far Trump’s commissioners have degraded the NRC’s history of safety consciousness in favor of a ‘good for business’ regulatory atmosphere remains to be seen (think of the cozy relationship Boeing has/had to FAA regulators, resulting in the 737 Max 8 mess).

With a few exceptions (Davis Besse, Grand Gulf, Diablo Canyon), nuclear utility operators have always been very safety-conscious. They want nothing to do with a potential accident – it’s bad for business. Even those plants that have skirted too close to the safety line (such as the three I just listed) still operated well above Fukushima levels of safety compliance and have had increased regulatory scrutiny. Moreover, as mentioned above, after TMI an industry watchdog group – the Institute for Nuclear Power Operations (INPO) – was created to monitor individual plant safety performance and to provide a vehicle for sharing important technical information between utilities. Recall that knowledge of a the faulty relief valve design was never shared with other plants, including TMI. INPO now has in place a repository of data regarding equipment and procedural issues available to all utilities. Indeed, plants are committed to inform INPO of any such issues as they come up. In terms of monitoring operations, all plants are subjected to periodic inspections by INPO, inspections that comprise audits of past operations as well as monitoring current operations.

My Stance. I no longer work in the nuclear industry and I derive no source of income from when I did. As the saying goes, I have no horse in this race. If every nuclear plant in this country was shutdown tomorrow, I would lose nothing. But I do still have a considerable amount of knowledge from my decades of work in the industry. So here’s what I think should be done:

  • Shutdown vulnerable plants. I’m not in favor of shutting down good nuclear plants before their design life expires but as they come up on that milestone, strict scrutiny and application of the latest data and protocols need to be employed to determine whether a license extension should be granted. For sure, if any existing GE designed BWR’s are still operating with Fukushima vulnerabilities, maybe we should pull the plug on them.
  • Accelerate construction of new generation reactors. Several good, improved designs are out there. The new Westinghouse reactors coming online as Units 3 & 4 of the Vogtle plant in Georgia are an example of a large-scale design but there are also a few small-reactor designs that have passed various regulatory approval stages and are eligible for preliminary licensing. Smaller plants are cheaper and have greater inherent safety with respect to major disasters (they are much less likely to suffer core meltdown). Smaller plants are easier to site, both from a local regulatory and public resistance stance as well as not needing as large a heat sink for cooling. And being new designs, they benefit from the latest technology and innovations.
  • Strengthen NRC independence (not sure how but certainly we need scientific experts not lobbyists). The NRC is already an independent agency (like the EPA) so is not under the president’s authority. As we have see with Trump, that doesn’t mean the president can’t set their agenda. We need the NRC to do their job, as they have done for most of the agency’s existence.

I don’t expect the long-anticipated nuclear renaissance will come about in my lifetime, if ever. What with the alarming increase in not only ignorance but vilification of science and scientific expertise in the last decade or so, I can’t imagine the country will accept large scale nuclear power as a solution to climate change. Indeed, many progressive elements in the country who are working to stem the climate crisis still can’t seem to get past their long-held, irrational fears of radiation and radioactive waste. And if Trump gets elected again, all bets are off.

Some truths*

* As I see them.

  • There is no god. Not yours, not his, not hers. People would do better coming to grips with that fact and live their one life as best they can. Mostly, religious people need to stop screwing things up for the rest of us just because we don’t believe in your particular flavor of god. Be kind to one another. That’s the only rule that counts.
  • There are too many people on this planet. Overpopulation is the root cause of virtually all the really bad things that have happened and are happening to humans. Wars, famine, plagues, pollution, religion. I do not automatically think it a ‘blessing’ when people have children. We could use more child-less couples. Or adoptions.
  • Evidence-based decisions are the only way to decide policy. And by evidence-based, I mean supported by peer-reviewed, testable science. Sure, we don’t know how everything works, but we know a hell of a lot more than that moron you follow on Facebook or Twitter does. For example:
  • Vaccines are safe and they save people from horrible diseases and death. The body of evidence for this is so fucking huge that it’s mind-boggling that people believe otherwise.
  • GMOs are safe and provide enormous value towards supplying the world with nutritional food. Yes, there are issues with seed patents and corporate greed but the actual product is very beneficial.
  • Nuclear power is safe and is the only base-load generation technology we currently have that will make a dent in climate change. Yes, I know about Fukushima, Chernobyl and Three Mile Island. In fact, I know a hell of a lot more about those disasters than you probably do. They were bad but not as bad as what literally every other base-load power generation technology has wrought. If you don’t know what base-load means, find out. It’s important.
  • Speaking of human-caused climate change, yeah, it’s real. It’s happening and it’s not the same thing as what happened on Earth 12,000 years ago, or whenever. Human civilization has spread across the entire world and it really isn’t going to be a good thing when the various farm belts that feed the population go too dry, or too wet, or too cold. It’s already happening and future generations will be left with a far less sustainable planet if we don’t stop doing what we’re doing now. We have options.

That’s it. There are more truths out there of course but these are some of the important, pressing truths.

Oh, yeah, we landed men on the moon. It happened.

Keeping the World Safe From the Evils of Nuclear Power

When people ask me what I do at work, I often pause to consider who’s asking the question. I have a selection of answers.

  • I’m an engineer
  • I’m an engineer in the electric power industry
  • I’m a nuclear engineer
  • I’m a control systems engineer in the nuclear industry
  • I work on safety analysis calculations in the nuclear industry
  • I do setpoint and uncertainty calculations for nuclear power plants
  • I keep the world safe from the evils of nuclear power

first two are accurate; the third one isn’t but serves a purpose. A nuclear engineer is someone with a nuclear engineering degree and I don’t have one of those. The fourth one is accurate; the fifth isn’t but few people would know that. While the sixth is an accurate description of what I do, it’s not very accessible to most people. The last is also accurate, if a bit flippant. My work helps ensure a nuclear plant is operated safely.

Nuclear power plants have an array of automatic and semi-automatic control systems designed to sense abnormal and potentially unsafe conditions and initiate actions to put the plant in a safe mode. These systems are separate from those that control the plant during normal power operation.

Every nuclear power plant also has a comprehensive array of analyses and calculations that demonstrate the plant can be safely shut down without releasing significant amounts of radiation to the public during postulated ‘accidents.’ In this context, an accident is a critical system failure, whether from equipment malfunction, design error or natural occurrences such as earthquakes. All credible accidents are analyzed with the results published in the plant’s Final Safety Analysis Report, a document that is submitted to the Nuclear Regulatory Commission as part of the requirements necessary to secure a license to operate the plant. The FSAR, along with other engineering documents, details the design basis of the plant. In other words, the design features that allow it to operate safely. As long as the evolving design of the plant remains within the design basis, the safety analyses remain valid. The FSAR is a living document – it’s continually updated as upgrades and modifications are made.

A license issued by the NRC is not simply a go-ahead to operate. It’s not a piece of paper. Rather, it’s a lot of paper. The most significant part of the license is the Technical Specifications, a document that provides, in considerable detail, exactly how the plant must be operated, particularly what safety equipment must be operable. The Tech Specs, as they’re commonly referred to, also contains dozens of limiting conditions for various parameters.

For example, the primary system pressure must be maintained within specific limits – not too high and not too low – when the reactor is at power. There are instruments (electronic measuring and control devices) that monitor primary pressure and initiate actions if it goes too high or too low. How high or low? Well, that’s where I come in. It would not do to set the instruments to actuate right at the limits provided in the Tech Specs. All measurements contain some amount of uncertainty and that uncertainty must be calculated and accounted for in the actual plant setpoint. So, if the Tech Spec limit is 2250 psia increasing, the actual setpoint might need to be 2230 psi or lower after determining that there might be 20 psi uncertainty. The 20 psi figure would come out of one of my setpoint and uncertainty calculations.

Because some of the uncertainties inherent in a measurement aren’t in play when instrument setpoints are periodically checked by technicians, the Tech Spec limits themselves incorporate a certain amount of margin with respect to what the safety analysis calculation assumed in concluding the plant could be safely shutdown. To determine a safe setpoint, we start with the safety analysis assumption and work backwards, accounting for all uncertainties that might influence the measurement during any postulated plant conditions, including accidents. That ends up validating both the Tech Spec limit and the actual setpoint.

So, that’s what I do. But as you might imagine, the details are complicated. Determining instrument inaccuracies is a matter of skill and art, as one of my engineering managers once described it. I have to agree. After doing this for a couple of decades – and before that I was an instrument technician, one of the people charged with actually ‘setting’ the setpoints in the field – I’ve come to know a bit about how to apply skill and art to the matter.

We (setpoint calc people) don’t work in an unregulated vacuum. I can’t just apply my experience, add a bit of art, and come up with what I think the setpoint should be. As with all nuclear safety-related activities, there are procedures and regulations to follow. Every plant has a specific engineering procedure that details in varying degrees how to determine setpoints. Most derive from what the original reactor vendor provided as a basis for operating the plant. Some plants have kept a version of that methodology in place over the years while others have made changes to come up with their own, unique methodology.

In every case, the methodology must be approved by the NRC. To determine whether to grant approval, the NRC relies on the controlling federal regulations (found in 10CFR50) and on industry standards that have been previously endorsed by the agency. The prevailing industry standard for determining setpoints is the International Society of Automation’s (formerly the Instrument Society of America) 67.04 publication, which has been revised over the years. ISA 67.04 and its implementing standard, RP67.04, discuss in great detail what effects on instruments must be considered and provides the basis for statistically combining the effects to come up with an overall uncertainty that accounts for all required factors with the level of confidence mandated by the NRC.

In the course of my career, I’ve prepared setpoint calcs for dozens of plants. That experience has been wildly mixed in terms of personal and professional satisfaction. Frankly, most clients can be utter assholes. They demand results that cannot be achieved and schedules that cannot be met. They demand error-free calculations despite providing ambiguous, error-ridden design documents to me as inputs to the calcs and despite allowing much faultier calculations from their own engineers. Their comments are often pedantic, irrelevant, or mind-bogglingly stupid. I’ve had discussions with clients that left me speechless. I’ve many times just wanted to say “You have no idea what you’re talking about, so why don’t you do the rest of us a favor and just shut the fuck up.”

On the other hand, when you get a client who understands the process, understands the challenges and respects you as a professional and as someone whose goal is to help their plant with whatever engineering difficulty they’re currently involved with, it can almost be rewarding. Almost.

All through my career as a setpoint calc engineer, my focus has been client-oriented. I’ve tried to find a way to allow the plant to do whatever it is they had in mind, be it a power uprate, a switch to 24-month fuel or simply (often not so simple) responding to a directive from the NRC, all while maintaining the prime directive: protect the design basis of the plant. Sometimes, it just doesn’t work out so well.

Recently, I was asked to come into a project that had experienced some difficulties because the engineers my company had doing the calcs were inexperienced and were getting hard questions from the client they couldn’t answer. I agreed, but after re-doing the calculations, I had to conclude that the plant couldn’t do what they wanted to do. The numbers just weren’t working out. No one is happy with that outcome.

Perhaps the darkest time for me was after years of working calculations with a big client that was planning not one, but two major plant modifications in back-to-back refueling outages. My partner (whom I’ve worked with for almost two decades and who is awesome) and I just kept running into issues making a set of very critical calculations come out right. And by right, I mean they would demonstrate that the plant’s design basis would be protected even after the two modifications were performed. Our results kept coming out negative. The client grew increasingly unhappy and eventually said they would take over the calculations themselves if we didn’t agree to incorporate changes that we didn’t think were proper. Changes that would make the calcs work but weren’t supported by available data.

I’m not going to name the plant and I’m not going to discuss how it all finally resolved itself. But I will say that for the first and only time in my career, I felt obliged to inform the NRC of a significant safety concern. In other words, I blew the whistle. There’s a process for doing this and as with other whistleblowing involving the federal government, there are some protections. I gave them all my files and my analyses and told them that, in my expert opinion, the plant was planning on violating their license and that the NRC should step in.

As I said, my primary focus is maintaining the design basis and I will not compromise that principle. You know how we’ve prevented Fukushima here in the US? By vigilantly maintaining the design basis. That’s also why Three Mile Island wasn’t Fukushima – the plant’s defense-in-depth safety systems worked. The containment building held.

So, yeah, I keep the world safe from the evils of nuclear power.

In the final analysis (no pun intended), I’ve hated this job. I wanted to be a geologist with the  US Geological Survey. Or a tennis pro.