I've had a fascination with nuclear
power for about 40 years. As a teenager, I watched the construction
progress of a small nuclear power plant about 20 minutes from home; that reactor, built in the 1970s, has since been shut down after
several extensions of its license by the Nuclear Regulatory
Commission (NRC). Normal licenses are for a 25-year lifespan, but
because of the safety record and design of this particular plant,
they were able to get it extended until 2033. The flooding of 2011
showed that it was in a poor location (it had been shut down for
refueling before the flood and was in no danger) and the operator
decided to cease operations in 2016. Cleanup and decommissioning is
still going on, and the old fuel rods are stored on-site so it will
be a secured area for a long time.
Having grown up in the shadow of
a nuclear power plant, we dealt with a lot of emergency planning and
notification information coming from the operator of the plant, FEMA,
and the Nuclear Regulatory Commission (NRC). A network of warning sirens was placed about 15 miles in every direction around the plant. Testing every month became just another part of life, kind of like the Emergency Alert System tests on the radio.
Our house was far enough away that we were not in any of the
emergency zones, but we still got an annual map of evacuation routes.
Growing up during the Cold War, a lot of what we now call prepping was
just everyday life back then.
All of this came to mind this week because of the announcement that the founder of Microsoft is funding a company that wants to build a new nuclear power plant in Wyoming. This is notable because the newest nuclear plant we have in the US was commissioned in 2016, and the second newest is 20 years older than that. Construction of conventional nuclear plants has been rare and slow for a generation because of an attitude whereby people want electricity, and agree that nuclear power is the cleanest source, but don't want a plant built near them -- aka Not In My Back Yard (NIMBY). Lawfare from various environmental groups has also slowed or stopped the construction of pretty much anything nuclear. We'll see if huge piles of money can make a difference this time.
Pressurized Water Reactors
Nuclear power plants, if
built by good workers and designed by competent engineers are as safe
as a coal-fired plant and don't produce as many by-products. If you
happen to live near one, learn as much as you can about it from
reliable sources and pay attention to the NRC-required informational
packets. They aren't nuclear bombs waiting to go off; instead, the major
threat is a steam explosion or release of radioactive materials. Erin and I have covered the basics of
radioactivity in the past.
This new reactor, however, is of a new design.
The older nuclear reactors used a (barely) sub-critical mass of
Uranium to heat water under pressure (superheating)*, transferred
heat from that very hot water to a secondary system at lower pressure
where it would create steam that could spin a turbine connected to a
generator. Called a “light-water reactor” (LWR) or Pressurized
Water Reactor (PWR), this has been the only design approved for power
generation since the 1950s in the USA. (Other countries have other
designs, and they don't always have the same safety record.) LWRs have
the major problem of containing the superheated water, which leads to
huge containment vessels and redundant pumps, adding to the cost of
construction and operation.
* Just like water will boil at less than 100°C/212°F on a mountain top where the air pressure is low, you can keep it from boiling and changing to steam (which takes up 17,000 times more space than the liquid) by increasing the pressure. If you're interested in the exact numbers, look up “steam tables” for boiler operations.
Liquid Sodium Reactors
This new design is called a Natrium or
Liquid Sodium Reactor (LSR). Selected by our Department of Energy (DOE) as
a promising technology, it has been funded and tested extensively in
the last decade or so. Instead of super-heating water, the Natrium
system uses the heat from a nuclear reaction to melt a giant tank of
salt. That liquid salt is at a much higher temperature than you can
reasonably get water, and it doesn't require the high pressures that
super-heating water does, which leads to a safer and simpler
construction. That heat is used to create steam and drive a turbine
like any other generation station.
Molten salt is a bit corrosive, so
they've been researching materials that are safe to use. Natrium uses
a modular approach to their design, making power plants more flexible
in their output. The liquid salt can also be used to store heat
(several solar-thermal systems use it as a “heat battery”) for
boosting generating capacity when needed instead of relying on
natural gas-fired peaking generators.
The nuclear side of the reactor will
still work the same and will still have some of the same issues. We
don't yet have a good way or place to store spent fuel rods, so they'll
be a sore spot. Reprocessing those rods tends to generate Plutonium
(Pu), and our current needs for that have already been met. Certain
groups get very vocal when you start talking about stockpiling the
makings of nuclear weapons, so Pu is a no-no.
We'll have to wait and see what happens
with this project. The design is much safer than a LWR, but the
current political and social atmosphere is not friendly to new
sources of energy, and pipelines, new oil well drilling permits, and new
refineries are all on hold or canceled. Building anything will take
years to get all of the permits and settle all of the lawsuits, but
we need to have something making the electricity for all of those new
electric vehicles that are being sold.
