Spoiler alert: No! They Aren't!
You've been living in your little town for over a decade, and your favorite part about it is the crystal clean, spring-fed river that runs by just out of town. It's great for fishing, canoeing, swimming, or any combination of the three. You read the local paper one day to find out the clearing a few miles up river has been bought by a power company, and they're going to build a nuclear power plant there. You know enough about the power industry to look forward to your power bill going down, but the next time you talk to your neighbor he mentions he's worried, because the power plant plans to use the river for its runoff! Is your clean river in danger of being polluted by nuclear waste?
It really isn't. Unlike farms, chemical processing plants, metal foundries, and other man-made things that pollute local surface and groundwater [1], a nuclear power plant puts nothing back into its water source other than regular, clean water--albeit a little bit warmer.
Yes, a nuclear power plant uses water as its primary coolant, and that water is exposed to and activated by the radiation in the nuclear core. But even in a boiling water reactor (BWR) where the water across the core is turned directly into steam for turning the turbines, that water is not put into the environment. It's cooled off, chemically treated, and placed back into the core. The "cooled-off" part is accomplished through a closed secondary cycle, where "closed" means that the two never come into direct contact with each other; the water on the cold side is never exposed to the radiation from the core or held within the primary water coolant. [2] It's this secondary-cycle water that is drawn from and returned to the local river, lake, ground reservoir, or other source of water in order to maintain the temperatures of the reactor. As mentioned, due to the basic principles of thermodynamics this water is returned to its source a little warmer than it was found, but new reactors always have extensive environmental studies performed to ensure that the net temperature change in the water source will have negligible effects on the surrounding ecosystem.
If the reactor is a pressurized water reactor (PWR), the concern is even less. The primary-cycle water is never brought to a boil, the closed secondary-cycle performing steam generation and running turbines. This puts the cold cycle in a tertiary position, even more removed from the radiation of the core. Your hypothetical self can rest easy knowing that the plant will cause no effect to the river.
[1]http://floridaswater.com/waterbodies/pollutionsources.html
[2]http://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-power-reactors/nuclear-power-reactors.aspx
This is a great post and I think it squashes a lot of claims that nuclear power plants are bad for the environment. Honestly, I feel like the opening story could be made into a commercial to start enlightening people about nuclear.
ReplyDeleteBecause of requirements for putting water back into local rivers and the nuclear process as a whole, water can be even cleaner than it was originally since contaminants have to be removed for operation and for release into the river.
DeleteI hadn't even thought about it to that level! Obviously no-net-change is a requirement, but the possibility of the river being even cleaner from the presence of a power plant almost funny given some of the stigmas they face.
DeleteReally enjoyed reading this. I agree that this was a great opening and paints a great picture of nuclear energy. Do you have any data from a study that shows the near to no radionuclide dispersion in the runoff. I personally agree with your findings but seeing the study is always good...
ReplyDeleteGood point, I forgot to reference anything for those claims. Here's one of the reports from the NRC that I came across, it has a bit more of a meta-analysis on the theoretical limits and practical results of actual power plants.
Deletehttp://www.nrc.gov/reading-rm/doc-collections/commission/secys/2011/2011-0019scy.pdf
This was a great read. In many cases people would probably assume that a power plant will contaminate the environment where it is located. This is a great approach to showing how the nuclear industry is very clean especially if you compare to other industries out there that do contaminate their surrounding environment.
ReplyDeleteThanks! It's not scientific, but I've found it's hard to get people to listen to your point when you keep everything technical, especially with a "scary" industry like nuclear.
DeleteYou mean to say the fish I catch (or don't) from these rivers aren't radioactive? And here I thought I was going to get super powers. The gullibility of people is amazing. The amount of specifics on safety such as site approvals, spent fuel disposals, etc. is one of the most rigorous in the nuclear industry.
ReplyDeleteVery interesting post. You can tell people a million times that the power plant is not contaminating the water but until you explain it in terms that they can understand, they still may not ever believe you. It's also important that you don't just say "no they are not running into the river" but instead saying that they are in fact running water used in the plant to the river, but that it is perfectly clean.
ReplyDeleteYou did a great job of explaining the way primary and secondary sides of nuclear plants work in a simple but accurate manner. I think it's an important part of being in the nuclear industry to be able to quell popular myths and misconceptions about nuclear, and you're doing a great job of doing so.
ReplyDeleteThis is a great post. It is all too common that the population of the US is skeptical of nuclear power, but sometimes it's just absurd to think that a nuclear reactor would actually dump nuclear waste in a river.
ReplyDeleteExactly, a lot of people make jokes about it and it seems that by playing jokes off suspicions has had an even worse effect. Like, as funny as the Simpsons is, there's probably more than a few people that believe fish with 3 eyes will actually appear in lakes or the Homer Simpson reactor operator image.
DeleteThis is an interesting post as I do know people are persuaded by the media that any waste from a nuclear plant is bad but it is good to know that there is truth in saying that there may be no contaminants. I do wonder though whether the increase in water temperature may have long term negative effects on the ecosystem.
ReplyDelete