Nuclear Safety: Sophistication vs. Capability, A Metaphor.

So I’ve found that talking about nuclear safety doesn’t really resonate with people. Whether it’s because they think that it’s far too complicated and immediately file it under “too much work” or because they might actually recognize how much work goes into it, thus putting it in the “it will just work” folder of their brain. Or maybe they have a dislike of nuclear and think that there’s no way it could actually be as safe as we keep saying it is.

But I really like metaphors, and plus, this is a golden opportunity to touch on an event that has been at the forefront of Albertan’s minds for an annoyingly long time recently. The Trans Mountain Expansion pipeline. Not actually that one in particular though, more like pipelines in general. I know most people might not think it, but pipelines are actually a very sophisticated technology. The work that goes into each one, the planning and design is actually astoundingly thorough. Here, have some pipeline design basics if you don’t believe me.

Most modern pipelines carrying liquids that have any potential to cause corrosion are generally a variation of a triple layer design. The middle layer is the basic structural pipe and can be up to 5 cm thick in cases of very large diameter pipelines. Then there is an inner layer made of a material resistant to either chemical or physical damage most common with whatever material is being transported. In the case of really awful stuff like hot bitumen from Alberta’s Oil Sands, it can be a very expensive technical ceramic coating like tungsten carbide simply to give the pipe any measurable lifespan at all. Then finally there is an external layer, generally of a woven polymer wrap designed to keep liquids and oxygen from coming into contact with the surface of the pipe. This is simply to prevent scratches from dust, rocks, or animals which could become nucleation sites for corrosion and a possible weak spot that could become a failure point in the future.

This is what I mean by sophisticated. It’s a technology that has started brushing up against the absolute limits of what it can do in its current iteration. It has accounted for near every possible regular deviation from normal. Mapped out each of their effects and magnitudes, and have reduced them to numbers detailing how long they reduce the life of the pipeline. The only thing that causes pipeline failures now are unforeseeable circumstances, operator error, or willful neglect of maintenance. It’s at this point where I can finally start crafting my metaphor, and my opening statement might be a little contentious.

Right now pipeline technology is basically in the same place as nuclear technology was with the design and construction of the RMBK reactor. And if that sounds familiar, that’s because this is what the most famous RMBK reactor looks like:

Here’s why I say that. The RMBK reactor was in fact a sophisticated design, fine tuning many aspects into things that Should have helped the operators maintain the plant (like graphite lubricated control rod tips to prevent sticking of control rods so they can operate smoothly and reliably). You don’t build a working nuclear reactor without a sophisticated understanding of nuclear science. It just wasn’t a very capable design. It relied almost entirely on constant maintenance and oversight to stay within operational parameters, it had no passive safety systems worth mentioning or containment in case of worst case scenarios. And it was ultimately able to be completely trashed by operator failure.

So, let’s try and figure out what a pipeline would look like if it followed the scale of nuclear regulations for safety. A Gen IV pipeline if you will.

Well first stage is replicating the containment that is required for nuclear plants by building the pipeline as a double walled pipe. This is already done for some places but most companies argue against doing it for long distance oil pipelines due to costs. Basically, the same arguments that the nuclear industry used before governments said they had to do it anyways. But oil or gas can’t contaminate the environment if it can’t Get to the environment, even if it gets out of the main pipe. Now, all that does is catch the leak, it doesn’t actually stop the pumping or alert anyone that a breach has occurred so all that fluid is just pouring into the containment vessel. Some sort of sensor is needed to detect leaks and shut off the pipeline to minimize loss and alert repair and containment crews

We could use normal digital sensors to detect but we would require huge numbers of them all throughout the pipeline to ensure rapid and accurate detection of any leak. Instead we need a way to cause an effect on the pipeline that will always function regardless of how or where the leak occurs and that doesn’t use up huge portions of the energy budget of the pipeline. So let’s take a page out of Gen IV reactor designs and use some basic physics to ensure our system works. By pressurizing the space between the two pipes at 2 atmospheres with nitrogen (or any inert gas) and using a mechanical pressure sensor to detect changes of say more than 20%, we can tell when the pipe has been breached either in the inner pipe, or outer pipe and hopefully not have false positives due to hot or cold days.

But that only works if the pipe isn’t in enormous multi-dozen kilometer long sections between pump stations, otherwise you would never be able to localize where the leak was without inspecting the entire pipeline. By the time you did you could have huge volumes of lost product in the gap between pipe walls. So this means we need regular valve stations on the pipeline, say every kilometer (or whatever distance makes most sense depending on circumstances) where the sections of pipe are sealed to measure the air pressure and automatically shut if the pressure sensors are tripped. Maybe it would even possible to have the valves turned by the pressure change in the gap between walls, which would remove the point of failure of an electric actuation system. Now not only is any leak or damage immediately contained, but also owners of the pipeline don’t even have to know exactly where the fault is, they can simply pull the whole section out and put in a new run of line and then inspect the failed section at their leisure and recycle what they can.

Although, this would mean that while these repairs were happening that no product would be reaching the end of the line. Granted that is what currently happens when there is a major pipe repair, but we are holding pipelines to the standards that the nuclear industry is, so lets open the SMR playbook for some inspiration. There are two possible methods to solve this. Either split the single large pipeline into several smaller pipelines and run them at less than max capacity, or build a complete second pipeline that only gets used when the primary pipeline is damaged and needs to be replaced. Now while the array of smaller pipes would probably work for things like natural gas assuming it it kept as a gas, it wouldn’t work for oil or other incompressable liquids. So, with this change, now the valve stations also have act as switching stations to shunt the flow between lines. This is in case one is damaged and has to be closed off so the flow can be rerouted without interruption. These stations could be powered by a nice little solar panels and capacitor banks capable of powering the shunts between lines since running electrical lines along the entire length of the pipeline would be impractical and frankly, pretty unsafe.

And finally, in the case of something truly unpredictable like a rock slide, mudslide, earthquake, or other event that is able to damage both lines and cause an actual leak that the double wall is unable to contain. My suggestion would be a bit of landscaping, build a couple of berms on either side of the pipeline and bury some kind of absorbent fabric material under the topsoil. That way if the transported material does make it out into the environment, the amount will be restricted to the volume of pipe between unaffected valve stations, contained in close proximity to the spill and, hopefully, finally contained by the fabric which can be easily pulled up with its absorbed material. Sure if it’s natural gas it will escape into the air, but it would only be an immediately finite amount, unlike the unrestricted emission that occurred in Los Angeles in 2015.

So now, we have not only two completely separate pipelines for a single pipelines worth of material. Each line is also double walled and has a huge number of extra valve check stations over a current modern pipeline. Add in the landscaping for the berms and we have probably added an extra zero to any major pipeline project. A frankly ridiculous amount of money oil companies would say, but this is what is required to approach the same level of redundancy and safety of nuclear facilities. And honestly this though experiment probably still falls short as there is no 24/7 guard presence or walls capable of withstanding the impact of a jet fighter at 500 mph. Maybe if the entire thing was built underground in a serviceable, traversable, waterproof tunnel I would say that pipelines would be as safe and disaster resistant as a nuclear power plant, but it would still be only tentatively.

For all the extra cost, theoretically we now have a much more capable design instead of only a sophisticated one. A pipeline able to withstand and self regulate damages while protecting the environment as it’s first priority While minimizing product loss for the investors who paid for it. This is what spending the money to do things right pays for, and the level that the nuclear industry operates on. Nice, quiet, dependable nuclear power.

Edit: A big thank you to Rick Maltese of Energy Reality Project for help with the edits. I really need to stop writing these things at 3 AM.