New crack at Crystal River nuclear plant casts doubt on repair plan (FL)

[jpak]

http://www.tampabay.com/news/business/energy/article1202505.ece

On July 26, monitors detected something amiss in the already crippled building that shields the reactor at Progress Energy's nuclear plant. The pile of shattered concrete outside meant the utility faced a new problem.

The building was still falling apart — a development Progress was in no hurry to reveal to state regulators.

The incident marked the third time since 2009 that the containment building at the Crystal River plant had suffered major structural damage.

Within the nuclear power industry, Progress' fumbling efforts to fix the plant raise crucial questions: Can the building be safely repaired? Or, as critics maintain, should it be torn down and replaced?

<more>

[diane in sf]

1. Dumb to put a nuke plant in Florida. How much of the state is going to be under water

in the next century? Why not use solar power and work on tidal power as well?

[PamW]

2. Limited amount.

Why not use solar power and work on tidal power as well?
==============================================

Former San Francisco Mayor Gavin Newsom wanted to put submerged water turbines
under the Golden Gate bridge and power all of San Francisco with the electricity.

He had engineers do an assessment of how much energy is in the daily tidal flow
into and out of San Francisco Bay.

The engineer's answer was about 2 Megawatts.

The volume of water that goes into and out of the bay daily is large, but the
pressure head is virtually nonexistent. When you have a hydro dam, the vertical
drop of the water flowing through the dam gives you the pressure head which is
cited in units of length - so many "feet" of pressure head. The head cited in
feet can be converted to give you the pressure at the inlet of the turbines.

The power output of the turbines is given by the product of the pressure drop
across the turbine, and the volumetric flow rate. Turbines placed under the
Golden Gate Bridge would have a substantial flow rate, but essentially no pressure
head. Unlike a hydro dam, the water is not falling a large distance giving you
a large pressure.

The product of this pressure and the volumetric flow rate is the total energy that
is in the flow, and in the case of the Golden Gate, the energy in the tidal flow
was 2 Megawatt-Days. Therefore, a set of turbines under the Golden Gate can
AT MOST give a power output that average about 2 Megawatts.

Following the engineer's report, the whole idea was scuttled.

PamW

[kristopher]

3. The Gulf Stream between Florida and the Bahamas isn't San Francisco Bay.

[jpak]

4. WRONG, the Electric Power Reseach Institute estimates 10% of US demand could be met with tidal

http://www.time.com/time/specials/packages/article/0,28804,1872110_1872133_1872147,00.html

<snip>

— a study by the Electric Power Research Institute estimated that as much as 10% of U.S. electricity could eventually be supplied by tidal, a potential equaled in Britain and surpassed in powerful coastal sites like Canada's Bay of Fundy.

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The Bay of Fundy - the Canadian portion alone - has the potential for 300 MW of usable tidal power...

http://www.albertaoilmagazine.com/2007/07/will-the-bay-of-fundy-wash-ashore-nova-scotia’s-hidden-energy-potential/

Furthermore - the study you cite is for a tidal barrage at the Golden Gate - and did not consider tidal turbine technologies currently under late development....

http://theenergycollective.com/tbhurst/31050/15-mw-tidal-power-turbine-coming-canada’s-bay-fundy

<snip>

The SeaGen turbines to be installed use similar principles found in wind generator technology. The tidal turbines generate power from sea currents using a pair of axial flow turbines that drive generators throughgearboxes. However, the high density of seawater compared to wind allows a much smaller system. The capture of kinetic energy from a water current, much like with wind energy or solar energy, depends on how many square meters of flow cross-section can be addressed by the system.

With water current turbines, the rotor swept area that dictates energy capture capability, because it is the cross section of flow that is intercepted which matters. SeaGen has over 400 square meters of rotor area which is why it can develop its full rated power of 1.2MW in a flow of 2.4m/s (5 knots).

<snip>

pathetic fail

again

yup

[PamW]

5. You need a dictionary

Evidently you don't understand the word "limited"

PamW

[jpak]

6. You are wrong

wrong

wrong

wrong

yup

:rofl:

[intaglio]

8. Yep, selecting your sources can be so informative

Who said anything about only San Francisco Bay - apart from you?

Tidal can apply to many geographical areas, as can ocean current generation, wave generation, wind, solar (centralised thermal), solar (photo thermal), solar (photo voltaic) and geothermal. Now let me dispose of your arguments against these and in favour of the dinosaur option of nuclear.

First; the problem is storage, not capacity. With the exception of geothermal (hot rock generation) the sustainable sources of electricity are intermittent. Even today renewables often produce far too much power, there have been recent cases where renewable industries have produced so much power the pricing has had to be negative because the producers did not have storage capabilities. But storage can be cheap; pumped storage (either hydraulic in mountainous areas or pneumatic in salt mines or dead oilfields where available), gyroscopic storage and hydrogen production also viable. Personally I have gone off the idea of flow batteries - too many noxious chemical compounds - but they and advanced metal ion batteries might play some part as well.

Second; the source of your current has to be tailored to the geographical area. Photo thermal and photo voltaic are not currently suitable sources for Alaska but geothermal, wave, wind, tidal and ocean current generation are very appropriate. Similarly wind and the solar alternatives would be preferred in Kansas.

Third; some areas will not be able to produce sufficient power for themselves all the time. True, but (even without storage options) that is what a national distribution system is supposed to solve. The problem is that the US grid is aging and is not capable of accommodating the large number of "low volume" sources of power that a renewables based grid will involve. The system needs to be remodeled on the lines of a high connectivity network, similar to the internet.

[BeFree]

7. F'N crack-heads

They are gonna milk these cracks for all they can get out of their pipes.

[madokie]

9. A containment building that has cracked concrete is not a containment building

At present there is no way to repair a crack in concrete. The only option is to tear it down and build it new. I spent the last 15 years of my work life in the concrete world.