Posts by Fooman
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Hard News: Dreaming of a world without evidence, in reply to Steve Barnes,
I would be interested to know if Peter Dunne has any brewery shares.
Or some sort of involvement with Big Tobacco?
FM
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Cracker: Send in the Clowns, in reply to Russell Brown,
The country is bloody awash with overpriced Laphroiag. There are better whiskies you could spent $108 on, for serious.
It's not overpriced when the importer starts selling the 10 year for ~$50 bucks per 700 ml bottle every now and then - I'm quite happy to pick up a couple of bottles at that price.
A job which involves travel every now and then is good for the whisky shelf as well.
FM
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Hard News: Limping Onwards, in reply to Russell Brown,
Question: how many of you here are Usenet veterans, and is that where you learned your culture of internet argument?
Long-time lurker, some-time poster
#creepy "I like to read..."
1993/4 - started off with uoc.talk with Jane Gregg and Dave Frame arguing. rec.sport.cricket and s.c.n-z, and nz.general. That plus a.t. when I was bored.
FM
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Field Theory: Japan moves, in reply to recordari,
Has this been posted here yet? Turns out 'MIT Scientist' is in the same category as 'leading expert' and 'unqualified opinion'. At least I wasn't the first to link to it.
See this link discussing that in detail.
Precis:
What was an article about nuclear safety by a MIT risk analysis expert is now a joint article by a MIT risk analysis expert and MIT Department of Nuclear Science and Engineering experts.
Cheers,
FM -
Hard News: What Now?, in reply to ,
Charcoal-derived carbon iron reduction is iron age technology. Coking coal is 18th or 19th century technology. The only other large scale reduction process for steel that I can remember is using natural gas (methane) as the reducing agent. Which can be considered a bit of a waste of a useful resource (quick fact: 80% of the worlds nitrogen based fertilisers come from natural gas).
Cheers,
FM -
Hard News: What Now?, in reply to ,
Using coal to smelt steel is iron age technology.
Er, no its not. Coking coal is a essential ingredient in steel making, regardless of the process (basic oxygen, electric arc, reduction as per Glenbrook).
iron = iron ore - (oxygen removed by oxidation of carbon)
Steel = iron plus carbon (plus other additions to improve properties).
The coking coal is essentially the source of reasonably pure carbon in sufficient quantities for large scale production.
Cheers,
FM -
Hard News: What Now?, in reply to Sacha,
Aramoana uses 15% of our total generation. You’d need to expand it many times over to justify the cost of building nuclear power infrastructure and capability.
NZAS at Bluff (the Aramoana smelter was never built) uses around 600 to 700 MW operating at full capacity. A mid-size conventional nuke plant (e.g. 2x 500 MW units) could supply the power as required plus a bit for the grid. But it wouldn't. The Manapouri hydro plant was built specifically to power it and the capital cost of it was essentially gifted by the NZ govt at the time (was not operating in a commercial environment). The operating cost of Manapouri is low (rain is free), hence the price can be offered at the low rate NZAS gets. A few other aluminium smelters throughout the world do use hydro, but the majority use thermal generation (coal or gas), due to lower effective cost of supply compared to nuclear or hydro (if available).
Cheers,
FM -
Hard News: What Now?, in reply to Sacha,
Nuclear power is not a viable option for his country even just on economic grounds – we simply don’t have the scale of industry or population to justify building a nuclear capability.
Probably true for conventional nuclear power (generally >1000 MW units). People have been encouraged by the smaller pebble bed reactors (around 50 MW) which are supposedly inherently safer (in design, operation and fuel). Little development on them (more later). Nuclear power generally requires a base load (much like geothermal) as it is hard to turn off (as seen in Japan), and in NZ, there is no base load, especially at night, which can take up the demand.
It’s really expensive regardless of the poisonous and persistent safety and pollution issues.
Compared to coal fired generation, which I would consider as more insidious in terms of pollution (both chemical and radioactive - check the estimates on how much U235 goes up out the stack from coal fired plants world wide), nuclear is relatively clean. It is like comparing 400 deaths a year on the road ("meh") to maybe 500 deaths over the past 160 years from earthquakes ("OMFG!").
But you have hit the nail on the head when it comes to choice of generation technologies:
It’s really expensive
The reason for that expense is the capital cost in developing the technology (thanks US DoD for paying for the PWR and BWR designs that are prevalent) and applying it - the factors of safety in design are large (due to the OMFG! factor) and the standards for materials, inspection, operation are high. A former boss of mine worked in the UK nuclear industry, and told tales of the resources thrown at them to help maintain the technology - everything was brand new, in triplicate, again to mitigate the OMFG! factor.
Until the accountants came in.
Now, thanks to the idea that power generation needs to be a competitive, profit focused industry, the capital and operating costs of a technology are the prime drivers in development and usage of that technology.
A few years ago I was at a conference, and the key note speaker was the recently retired CEO (or president) of the american electrical power research institute (read mostly coal/gas/nuclear/little bit of renewable technology people). His summary, for the US at least, given the increasing resentment against conventional coal fired plant was:
- continue with coal (and live with pollution)
- rapidly deploy new nuclear generation (at the time there hadn't been a new nuke plant in the US for decades, because of cost and TMI:OMFG!)
- accept a decrease in the standard of living.Which choice is politically or commercially acceptable?
When in comes to the cost of technologies, gas fired combined cycle plants are cheapest per unit energy (e.g. MWh), followed by coal fired plant (conventional and super-critical), with nuke and hydro (very high capital costs) next. Then the renewables.
What is being built worldwide? gas fired combined cycle and coal fired plant. These represent the best return on investment in the short to medium term (accountants!) for commercial generation, in the absence of other drivers (e.g. carbon tax, public sentiment, regulatory requirements)
In the long term, of course, marginal operational costs (i.e. the price of fuel) will tip the balance. But how many businesses are willing to minimise profit now to get an advantage in the future.
NZ is rather unusual in it's generation profile - thermal generation is still held to be unusual (but look at the increasing market share since the power reforms - again comes back to return on investment).
Cheers,
FM -
Hard News: What Now?, in reply to Ross Mason,
Hi Ross,
NZS3404 (Steel Structures Standard), in discussing seismic loading do take that point:
"The design earthquake forces are derived from the 450 year return period damped uniform spectra...these spectra are indicative of the likely recurrence of the peak acceleration response..."
with the cavets of:
"a) The level of sustained shaking likely to cause damage within a building is approximately 60% of recorded peak response...
b) [experience] show that buildings perform better than can be predicted by calculation using simplified analysis..."
This suggests to me, that the current standards base seismic loadings on PGA. I recall, (admittedly with some levels of vagueness) that NZ4203 (loadings standard) loads are derived from the expected accelerations and the building mass. There are design details in 3404 to ensure a ductile response of the building if design loads are exceeded, or to make the response fully elastic, as well as appropriate damping response (types of connections etc).
So I would say the current building codes use PGA as the basis for loading in seismic design, but accommodate the duration and excitation response of the structure in the design. I guess Bill Robinson or Chris Gadd at RSL would be one to ask with regards to this.
Not being in Chch but I suspect witness accounts would say that the collapsing did not occur in the first second or so of the quake but seconds later.
Did peak acceleration occur in the first second? And if the initial response of the structure was inelastic (e.g. bending or initiating fractures) in that first second, that doesn't necessarily mean it has fallen down, but just severely weakened - and susceptible to smaller loads (further shaking and aftershocks). It is hard to say.
The top at the Heathcote School was 2.2g vertical. But it was so short that the buillding do not have the opportunity to be chucked up.
That doesn't mean it wasn't significantly loaded - the building could have been a light, flexible, well damped design (i.e. wooden frame building like most schools I know of).
But anyway, metaphorically, the gist of my initial post was to point out that the Japanese hurricane did not necessarily have stronger winds than the Chch tornado...
Cheers,
FM -
Hard News: What Now?, in reply to Ross Mason,
Re Japan: What has impressed me with the hand held footage of the insides of buildings especially is the lack of ceilings and floors crashing down around ears. Those buildings have withstood horrendous shaking and I suspect heritage buildings would truly be dust along with practically all of the city if this has occurred in Chch or Wgtn. There is a lesson there
Peak ground accelerations in Japan were much lower than in central/east/south Christchurch from the Feb 22 quake. The Japan quake was spread over a much wider area due to the comparative sizes of the two quakes. Shaking was longer in Japan. Infrastructure density in Japan is also likely to affect perception of (earthquake) related damage (no oil refineries in the south island!).
Compare Japan with Feb 22 Christchurch and Sept 4 Christchurch.