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Comment: Re:Fuck it - everyone for themselves. (Score 2) 357

by Mr.CRC (#49133913) Attached to: The Groups Behind Making Distributed Solar Power Harder To Adopt


Nearly all power transfer in the electrical grid is via completely passive transformers. There is no "one way" capability to AC transformers. If you are delivering power then it is being distributed proportionally to all other users, minus link losses. The only exception may be HVDC systems, in which power transfer may be unidirectional or bidirectional depending on the design.

Comment: Re:A precaution when done ahead of time. (Score 1) 311

by Mr.CRC (#49069147) Attached to: Nuclear Plant Taken Down In Anticipation of Snowstorm

I don't buy this The generators have electrically excited field windings. Take down the exciter fields, and there is no electrical power output.

Generator fields can be taken down in milliseconds. A resistor to dump the inductive energy stored is of manageable size, vs. a resistor to load the entire generator output for a long period. Once you drop the exciter fields, you have a mechanically unloaded steam turbine, which still presents a risk of over speed.

SCRAM takes a few seconds, so the thermal output of the reaction can be halted in this time. But there is stored heat from the reaction left in the core. Plus, there is still power output, equivalent to the initial value of the decay heat release rate, typically about 7% of total thermal power output.

It may take a few minutes, or at best a few 10s of seconds to actuate a steam valve of the massive size which controls the turbine feed. Presumably there is an alternate path to divert this steam, such as to additional heat exchangers in the cooling towers, right?

What I anticipate would be done if the grid tie were severed, is that instead of completely cutting generation, within a few milliseconds the exciter field may be ramped down to reduce power output to 10-20% or so, while a resistor (of more manageable size vs. one able to take full power) is switched in. Mechanical braking can also be applied, to consume another 10-20% of the turbine power. Now you are not completely unloaded, but still under-loaded 60-80%.

The problem now consists of a transient turbine speed rise then decay to stop, based on the competing dynamics of combined partial braking and power dumping working against the time it takes to divert the steam. I would expect that this control problem has been designed and validation tested to death for any plant. But I am speculating a bit here (not about the generator field, but about how the power take down is accomplished. So, since you asserted that:

"power that gets generated has to go somewhere, which is the power grid. If the nuclear power plant's connection to the grid gets severed (by bad weather, in this case), the power still has to go somewhere, or else it melts down the connecting infrastructure, and eventually triggers a nuclear meltdown situation."

Then please explain why the situation as I anticipate it is incorrect, and things will go all to hell anyway?

Comment: Re:What it means: (Score 1) 254

by Mr.CRC (#49045369) Attached to: What Intel's $300 Million Diversity Pledge Really Means

Bingo. While I work at a .gov lab, I've attended numerous courses and events at semiconductor and photonics companies in Si Valley. At one course (Xilinx), while helping the foreign instructor get his points across, I noticed that the class was composed predominantly of Asians, and Indians, and a few white folks. At least 2:1 non-white to white. In engineering/tech firms in Si Valley, Asian and Indian women and men are present in no obviously differing amounts. The only missing species is white females.

The dominant ethnic feature of the landscape, at least btw. the valley and S. SF, is that the hills of the West Bay are neighborhoods dominated by Chinese, Indians, and other Asians. I'm talking about the most expensive houses with the views.

Comment: Re:Somethig wrong with that (Score 3, Interesting) 254

by Mr.CRC (#49045303) Attached to: What Intel's $300 Million Diversity Pledge Really Means

Who is doing this "guidance counceling" anyway? Is guidance counceling dominated by white males (not in my experience)? Or are the people so concerned about diversity the ones doing the discouraging--to create a self-fulfilling prophesy which can only be solved by... Guess?

No one should be telling kids what they should do or be interested in anyway. And if the kids are so weak of self respect and awareness that they need someone to tell them what to do, this is a profound endictment of the entire public school system. It simply needs to be abolished.

Guidance councelors should only be providing kids with the honest truth about what needs to be done to accomplish what the kids say they want to do. The only exception might be to show an objective comparison of effort vs. probability of payoff for special cases of very hard to enter fields, such as movie star or NFL player. But even still, if someone wants to be an NFL player and falls short, maybe they can leverage their extensive training experience into a career in physical education, research, etc.

Failures rarely have to be total.

When the weight of the paperwork equals the weight of the plane, the plane will fly. -- Donald Douglas