The events of the past weak in Japan have sparked a number of discussions. Some have been rather good but when it pertains to the events at the
Fukushima Dai-ichi nuclear power plant most have been based on either ignorance or fear or a combination of the two. While I am not a "nuclear
engineer" or a "nuclear physicist" or an “expert” per say, I am a licensed engineer and have worked in the power and petrochemical industry for
over a decade, including a relatively lengthy project at a nuclear power plant.
This post will attempt to clarify some of what I feel are the key issues. It’s a mix of opinion, facts and speculation based on these facts.
1.Why build a nuclear power plant in such an area with known hazards like Fukushima?
When siting a plant several things, aside from NIMBY considerations, are taken into account: how is your fuel going to be delivered, how are major
components going to be shipped, how to interconnect with the grid, where is your water coming from for steam condensation and makeup water, and what
site specific issues are present.
While time and money solve all problems there is always an optimal site based on these considerations when finalizing a location. One site may provide
easy access to fuel and a grid interconnect, but it might be dry with little water for steam condensing. Another site might proved excellent access to
all three but be in a hurricane or seismic zone.
All thermal power plants utilize the Rankine cycle to generate electricity. Water is pressurized, boils, expands through a turbine and the steam is
condensed so the cycle can repeat. When we think of nuclear power we almost automatically associate the big natural draft cooling towers we see on the
Simpsons. The fact is very few nuclear plants use natural draft cooling towers for steam condensation. Most, like Fukushima, DC Cook, San Onofre, Quad
Cities, Indian Point etcetera .. use some natural body of water for their supplies of condensing water. It’s the simplest, least expensive, and
safest way to do this. Simpler is always safer.
Fukushima was built where it was because the site met all the key siting criteria at the lowest cost. Fact is you cannot build anything in Japan in an
area without some kind of seismic hazard. The plant was designed for an 8.0 earthquake and withstood the effects of a 9.0 … or thirty times as
powerful as it was designed to withstand, without significant damage! All backup systems performed precisely as designed until the tsunami hot. If
anything is to be said, this is a testament to the people who designed and built the facility.
The tsunami is ultimately what led to the cascading series of events seen at Fukushima. While the plant was built with this event in consideration,
the wave was just slightly taller than the sea wall.
I would also add the nuclear plant at Fukushima performed much better than the hundreds of chemical plants, refineries, fuel storage depots and the
like that were in the quake and tsunami effected zone, but since they don’t have the word “nuclear” in them little attention is being given to
the release of millions of pounds of toluenes, furans, PCB’s, dioxins, aldehydes, heavy metals and the like.
2.Shouldn’t these plants be designed for all possible contingencies regardless of their probability of occurrence?
With all things your design is based off of what level of comfort you have with the probability of a failure and the consequences of that failure.
This principle is true whether you are talking about aircraft, cars, dams, or nuclear power plants. An event that will kill 1,000,000 people and/or
cause $100,000,000,000 in damage is serious but should it be considered and planned for in your design basis if the frequency of occurrence is 1 in
People think that risk assessment and cost benefit analysis is just TBTB’s way of doing things on the cheap but in a world with limited resources
and manpower it’s the only way to efficiently allocate scarce resources and whether you know it or not, everyone does it on an individual basis
For example: did you shower today … did you know there is a quantifiable risk of death or serious injury from showering … on some level you do
even if you cannot quantify it but you deem the risk is small enough and the positive outcome (getting all clean) far outweighs the risk. Did you
exceed the speed limit by 10mph … did you know there is a quantifiable risk of death or serious injury from exceeding the posted speed limit … and
You could certainly make the case that you don’t share the risk assessment the professionals have come up with for nuclear power but if that is your
position you’d better be damn well able to explain what the numbers are and why you don’t agree with them. Ignorant posturing makes for good bar
talk, but not serious debate.
3.How serious is the “meltdown”?
As I have stated in other posts, the term “meltdown” doesn’t have any agreed upon definition. One man might think a meltdown is a “china
syndrome” event while another might think any damage to the fuel rod is a meltdown.
A “meltdown”, broadly speaking, takes place in several steps: fuel is exposed to air/steam, fuel rods heats, fuel rods swell, fuel rod begins to
break apart, fuel rod fragments fall to bottom of reactor, fuel rod fragments get even hotter, fuel rod fragments melt through bottom of reactor, fuel
rod fragments now sit on concrete pad under reactor. So far whats happened at Fukushima is fuel rod swelling and perhaps some breaking but because the
rods are at least partially submerged, most of the fuel has not yet broken apart but some of it most certainly has.
The fragments of the fuel do manage to melt through the reactor vessel will most likely disperse and cool from that dispersal and will not have enough
heat to melt through the concrete in the basement of the unit. This is not just my opinion, but is based on an individual who has performed these
kinds of simulations on the GE Mark 1 reactor and is far more knowledgeable than I.
4.What about the spent fuel pools?
This, in my opinion is currently the most serious issue at Fukushima and the one that authorities have under control the least. The water that is
being boiled off in these pools is responsible for the vast majority of the radiation releases seen on site.
5.What kind of idiot keeps spent fuel on the roof?
Every try and move a spent fuel bundle? Not easy to say the least. Ideally, you want to move it as short a distance as possible. The best way to
minimize handling is to put the spent fuel storage as close to the reactor opening as possible. Since the reactor opens from the top it makes most
sense to place the spent fuel storage pool as near to that location as possible.
6.What about the radiation?
What about it? A lot has been said about radiation exposure in general the radiation readings taken around the plant. My advice is to keep it all in
perspective. A sievert (what is most commonly being reported) is a “dose equivalent” value and is meaningless without some time reference. If a
report says “a high reading of 200 microsieverts/hr was reported” you would need to know the following to determine the dose: how long was the
peak for what was the background (non-peak) reading? If you received a 200 microsieverts/hr does for 10 hours, you’d probably be dead. If, however,
you received a 200 microsieverts/hr does for 1 seconds, it would be like smoking a cigarettes.
7.Aren’t we all being lied to about Fukushima by TPTB?
I would refer you to Hanlon’s razor: “Never attribute to malice that which is adequately explained by stupidity”. Most of the reporters have
little if any science background and know about as much about radiation as they do about the Hilbert's Nullstellensatz theorem. Combine this with
many slick anti-nuclear experts (at least this is who I see being cited the most in the news) who feed them all their talking points and it’s a
combination ripe for hysteria and misinformation. Unfortunately the US NRC chairman Gregory Jaczko is an antinuclear zealot who cut his teeth working
for congresses most antinuclear member: Ed Markey.
8.Werent the GE Mark I’s dangers know about almost 40 years ago?
Old story … the individual who initially made the complaint had his concerns addressed in the 1980’s when all Mark 1 reactors including those in
Japan were retrofitted with additional PRV’s. Why this story which was resolved 25 years ago, is news today is beyond me.
9 Why even take the risks of using nuclear power especially when risk free sources like solar and wind exist?
Systems like nuclear, fossil thermal and hydro have a benefit which is critical to our power supply: we control the fuel supply therefore we control
the output. Renewable like wind and solar are out of our control .. we cant control the wind or the sun and the more we integrate them into our
existing electric supply, the more we have to rely on spinning reserve in our natural gas fleet to make up for sudden unannounced changes in wind
speed. For the time being, these are rather small and manageable but will grow exponentially as more wind and solar comes on line.
Basically if you like electricity on demand, water on demand, sewage on demand and all the perks of electricity, you have to be willing to accept some
of the consequences.
And just another tidbit for you … particulate matter from the burning of fossil fuels leads to the premature deaths of what … 10,000 people a year
in the US (or something on that order of magnitude) … how many premature deaths has nuclear caused in the US to date? One, maybe two?
10.Isnt your real mission here just to do the bidding of TBTB and divert this conversation in the direction they want it to go?
But of course! That’s why this post is so long … I get paid by the word!