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Erick's avatar

Hi Jason, thanks for writing this article. I appreciate your effort in digging into the topic beyond a surface level. I agree with you that the change from AEC to NRC/ERDA was mostly irrelevant to the level of regulation. And I love your way of explaining ALARA. Your analysis of cost drivers is also pretty convincing. Unfortunately, while your thesis is partially correct, some of your arguments are factually shaky. Please allow me to offer a few corrections and criticisms, in the spirit of trying to better understand the problems and possible solutions.

First a couple of minor things, not really important to the main argument:

- "The Automatic Depressurization System will open automatically in the event that the pressure in the reactor vessel is too high, and vent some gas outside."

The ADS isn't for pressure relief, it's for rapid emergency depressurization to near-atmospheric pressure so that you can inject cooling water with low-pressure pumps.

- "The Reactor Protection System is a piece of control software that will continuously monitor measurements and then automatically order the shutdown of the reactor if necessary."

The RPS is very much not a piece of control software, at least not at current power plants. It's a complicated physical system with arrays of pneumatic tubes and electrical buses and big mechanical relays and circuit breakers that will get stuck if you don't grease them properly. Relevant story: https://blog.ucsusa.org/dlochbaum/fission-stories-106-lightning-strikes-twice

More important is this paragraph:

- "Probabilistic Risk Assessment is the heart and soul of the NRC’s, and in fact the entire World’s, approach to regulating nuclear power plant safety. It controls all of the key decisions that really matter, and crucially, all of the decisions about what sort of expensive safety features are necessary."

I regret to inform you that this is wishful (okay let's say "aspirational") thinking. PRA is used now more than it used to be, and more in the US than most other places, but it's still basically treated as icing on the safety cake. You design a reactor to follow all the old prescriptive rules, and then you do a PRA, and if it turns out well then it might help you argue for an exemption to some specific rule. It's used in many cases to figure out how long you can take to fix a broken piece of safety equipment - but there's still a 30 day maximum, no matter what your risk calculation says.

The Regulatory Analysis Guidelines you pointed to are for cost-benefit analysis, which probably should be done for all NRC rules (most federal agencies are required to do this). But the NRC only has to do it for "backfit" rules that require changes to already-completed power plants. The rest of the time, it's optional.

Maybe these limitations will change over time. The idea that the NRC should be "risk-informed" was only coined in the late 1990s, though the actual process started a bit earlier. Progress has been bumpy. Part 53, the NRC's proposed set of rules for licensing advanced reactors, is a good example. It was originally a framework completely based on PRA. But some in the nuclear industry complained, because doing a PRA is pretty expensive, especially if you're just building a little micro-reactor. So then the NRC added a second option that uses prescriptive rules kind of like the old ones, but applicable to lots of types of reactor instead of just light water reactors. A lot of nuclear industry people don't like that one either, plus now the whole rule is 1300 pages long too. (Fingers crossed it will improve before it's finalized.)

But even if every regulation on nuclear power is someday based on rigorous cost-benefit analysis, that isn't the same as rationally pricing externalities. The marginal cost of increasing safety/decreasing pollution enough to prevent a death could be exactly the same for a coal plant and a nuclear plant, but the coal plant remains cheaper in most cases, largely because the pollution it is not paying for is so much more harmful. Unless we can get our act together and just charge for polluting, changes to NRC regulations are unlikely to fix the problem. A carbon tax is the obvious way, if politically unappealing. But taxing other types of air pollution would do a lot to help get rid of coal.

In other words, even if we are doing cost-benefit analysis to optimize trade-offs for each type of power plant, we are not optimizing the societal cost overall. Proper application of cost-benefit to a coal plant would show that you could dramatically reduce health effects at a modest increase in cost… by replacing it with something different. As far as I know, this is never required and there is no proposal to require it.

Some people have suggested that to even the playing field, we should loosen nuclear regulations until it is just as harmful as coal. Aside from the practical problems with this, you have elegantly explained why it would be fundamentally dumb.

- "I’d also like to reiterate that the amount of money spent on controlling low-level radiation is a very very small fraction of the cost of producing nuclear power. The normal, non-emergency operation of nuclear reactors pose a real but small threat to employees and the public. Yes, the government has a regulatory framework that says that that threat has to be addressed within a rubric of cost-benefit analysis. The amount of money spent on that threat is small for precisely the reason that the threat is small to begin with, and it’s cheap to contain."

Low-level radiation comes up in two different ways. One is normal operation, as you mention, where most exposure is to the employees. The other is after a severe accident spreads radioactive material over a wide area. In most such accidents, large doses can be easily avoiding by evacuating. But for people to return to their homes a few weeks later, or continue farming the land, etc, our society has to be willing to tolerate some small ongoing radiation dose that might (or might not) increase their risk of cancer. In theory this is just another application of ALARA, but I think people kind of confuse it with LNT.

- "The NRC doesn’t demand any design changes during construction."

This is sort of true, now, but it wasn't always. Vogtle 3 and 4 were licensed under Part 52, which means they got a combined Construction and Operating License before they started construction. Their design was supposed to be finalized at that point. When they ended up making changes, it added to the cost, partly because they had to get their license amended for many of those changes and that caused delays. Also some other things had to be redone was because they didn't meet the very strict quality standards required by the design they licensed. I think it's fair to blame that stuff on the builders, not the NRC, but it's still ultimately a cost of regulation.

But Part 52 was introduced in 1989. Most nuclear plants in the US were built under the requirements of Part 50, where they would get a construction permit based on a preliminary design, and then once it was finished they'd go back for an operating license. That meant no expensive amendments during the construction process. But it also meant that in order to get the operating license, they had to comply with rule changes made while the reactor was under construction. In the 1970s, when many of those reactors were under construction, there were lots of rule changes, some related to TMI and some not. You see the problem.

These days Part 50 is still an option - the NRC just recently issued a construction permit under Part 50 for the Kairos Hermes test reactor. It's a little safer now because the rules have mostly stabilized, and I think a lot of companies building first-of-a-kind reactors actually should be more worried about the problems of Vogtle 3 than the problems of reactors in the late 1970s, so applying for a construction permit instead of a combined license could make sense.

You mentioned backfits, but it's worth noting that they don't always have to be justified with a cost-benefit analysis (there's an exception if the change is required for "adequate protection" of public health and safety, whatever that means). And they certainly didn't stop shortly after TMI. Substantial backfits were required in the 1980s (the ATWS rule), after 9/11, and probably the most costly set was after Fukushima, when all plants were required to reevaluate seismic and flood risks and a bunch of BWRs were required to install hardened vent systems.

I think the appropriate conclusion is neither "nuclear only failed because of regulation" nor "the problems are unrelated to regulation". There's a big difference between how competitive nuclear power would be tomorrow if we relaxed regulation today, and how competitive it would be today if those regulations had been relaxed from 1960 on. The latter could be a huge difference, but the specifics are very difficult to guess. The former is just probably not very dramatic. The truth is that any change in regulations now will take many years, if not many decades, to filter through to its maximum effect on the US energy landscape.

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Dave Catlin's avatar

Great article, I have some questions we can discuss next time we talk.

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