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Comment Re:Economics? (Score 1) 297

A few quibbles with your math:

At a U.S. average rate of 12 cents/kWh = $120/MWh

That may be the average retail rate paid by you and me. But as for what the generator can sell the electricity at, you need to look at the wholesale rates. Squinting at this graphic from the EIA, you can see the wholesale rates tend to hover at around $50/MWh, or a bit less than half the figure you were using. Because nuclear tends to supply baseload, rather than peaking, power, it may even be less than that. So you should figure only about $400 million of power generated per year.

Secondly, you have neglected operating costs: those nuclear engineers don't come cheap, and neither does enriched uranium. This table from the EIA tabulates the operating cost of various power plants, priced in $/1000 ("mils") per kWh generated, which is the same as $/MWh. Operation and maintenance for a nuke plant in 2014 ran about $18/MWh, and from the table seems to be increasing pretty quickly. For the 1 GW plant you hypothesize, the operating costs end up at about $140 million / yr.

So the net revenue for the plant may only be about $250 million/year, not $947 million/year. Over the lifetime of the plant, that gets you maybe $10 billion of net revenue. That's perhaps 2x the initial investment and doesn't take into consideration things like Net Present Value, etc. All in all, it doesn't look so rosy from an investment standpoint.

There's also the cost of decommissioning, which is a number that's hard to pin down, since very few plants have been fully decommissioned. Some poking around gave me figures anywhere from 10%-100% of the initial cost. Nuke plants are supposed to be setting aside that decommissioning cost during the life of the plant, so it may be baked into the operating cost numbers already. On the other hand, those decommissioning funds, like public pensions, are generally believed to be vastly underfunded. Leaving aside the externality of sticking the cost to the public, one should assume that, in year 40 (or 60), you'll need to cough up another $500 million to $5,000 million.

Comment Re:6.8 Billion (Score 1) 297

A chunk of land nobody can be allowed to enter, no trees or animals can be allowed to inhabit.. just imagine it all.

There are a variety of prime places in the American southwest that come to mind. The former nuclear test site in Nevada would be a decent start: it's not going to be turned into casinos and golf courses anytime soon.

Comment Re:6.8 Billion (Score 1) 297

With hydro, we lose huge amounts of land (although we at least get a lake out of the deal) but imagine if we could have covered that land with solar cells instead of a lake

considering that the lake used to be a deep river valley, I'd say it would be a terrible idea. But, now that we do have a lake there, and the river valley is filled in, I suppose we could deploy floating rafts of solar panels.

Comment Re:Calling BS on some points (Score 1) 254

the SLS program. That program's pace, however, is set by NASA,

Correction: That program's pace is set by Congress. Congress set the milestones in the appropriations. Congress at the same time appropriated only a fraction of the money needed to make those milestones. If people are whinging about how SLS will take longer to get off the ground than Mercury, Gemini, and Apollo combined, one can start by examining the amount of money devoted to each of those programs.

Comment Re:Space tourism a plague (Score 1) 254

95% of hydrogen gas currently produced in the United States is made using natural gas reforming: stripping the hydrogen atoms off methane (CH4) in the presence of a catalyst and water steam. As a waste product, you get mostly CO. CO can be further reacted with steam to liberate hydrogen from the water, resulting in more CO2.

some hydrogen is created via electrolysis of water, but the electricity used for that mostly comes from burning fossil fuels. Can you point to a large scale hydrogen production facility that is run entirely on wind and solar?

Comment Re:Y'know... Actually... (Score 1) 680

That rather depends on what temperature readings you choose to use in the last 100 years ;-). But, everyone loves a graph that goes up at the end, whatever that might happen to mean.

Is there a data set for global temperatures for the last 100 years that doesn't show a sharp rise at the end? Is there one that would have continued the rather prosaic rate of change displayed in the rest of the XKCD comic?

Comment I am so proud (Score 1) 105

As a member of the human race, I am so proud that centuries of technological and culinary progress has brought us to this. What a lovely day! I can't think of anything more useful for drone (or burrito) technology. All praise to our glorious overlords!

(perhaps the sarcasm was a little thick. The chip in my skull must be getting some crosstalk from North Korean propaganda - they've got that turned to full blast today.)

Comment Re:Great firefighters (Score 1) 243

Actually, the construction of the Tesla battery pack is designed with per-cell fusing. One of the patents that Tesla made available describes how each Li-Ion cell in the pack is wire-bonded to the bus bars. In a high acceleration crash, some of those internal wire bonds will break. (The wire bonds primarily act as conventional electrical fuses, breaking in the event of overcurrent.) Really you only need one bond in each series string to break in order to open-circuit the battery.

Comment Re:Why haven't we done Voyager 3 and 4? (Score 2) 61

Meanwhile, New Horizons just buzzed Pluto, and is now heading into the Kuiper Belt.

What is more, New Horizons did a flyby of Jupiter on its way to the outer solar system - quite similar to Voyager. However, this was not in the prime science mission, so they didn't gather all the data they could, it was really more a system test to make sure that they could take useful data.

Comment Boolean Logic (Score 1) 133

A hands-on demonstration of boolean logic: starting with two switches in series to show A AND B, then two switches in parallel to show A OR B. A more advanced portion of it might have a large plugboard (like from the old Ma Bell days), and a collection of gates and switches, with flashcards showing how to build up common circuits - a 1-bit adder, XOR, a 1-bit flip-flop, etc.

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