|MadSci Network: Engineering|
A complicated question about a complicated subject probably best covered face to face, however, that is not an option here. First, an outage is a controlled blackout. You are questioning the recent repeat of the 1965 "Northeast Blackout." First, most plants do not have "Black Start" capability - they depend on grid power to start the fans, pumps, and controls needed to fire up the boilers, roll the turbines, and synchronize the generators to the grid. Steam may or may not be available at the proper pressures for a restart, but that is only part of the problem with an areawide grid outage. Each plant can only supply a portion of the load, and as you say, they should be able to supply a small "island" if it can be assured that a. the required transmission lines are intact, and b. the generator won't be overloaded the second it is synced to the local grid. That takes a verification by Distribution Engineering that the total connected load for the circuits to be recovered is less than the capacity of the generator(s) to be reconnected. Then it must be verified that ONLY those circuits are connected and NOT any others - sometimes that requires a visual inspection of the breakers at the local substation. Somebody has to go out and look. Usually, this happens in foul weather, so that isn't the easiest thing to do. Since all of this is far from routine operation, even if the utility has procedures for performing the required actions, the rule is that the first time you do something it takes five times longer than if it is something you do every day. Since the last time this happened was 38 years ago, I would assume that anyone involved in the recover from that blackout has retired, so this is all being done by a "green" crew who will proceed cautiously. Plants and systems along the edge of the blackout area usually are the first to recover as they can connect to an operating system on the other side of that edge to borrow power to start those pumps and fans required for boiler/turbine restart. Of course, that's once the necessary transmission lines have been verified as operable. Most of the nuclear plants are capable of Black Start, but are restricted from doing so by a license requirement specifying the amount and type of off-site power they need to begin to startup. Plus they suffer from a "paper interlock" that requires extensive forms and checklists to be completed and verified, and one of the obvious requirement of those forms is to identify the cause of the shutdown. A fact that nobody knows as of this writing. I have been involved in one plant blackout caused by a heavy, wet snowstorm. That plant had 11 transmission lines connected to it's sub station, and they all came down as a result of icing. In places those lines were covered with ice a foot in diameter. This particular plant was old enough to have black start capability, and plenty of steam. The only person there who had ever participated in a black start was the plant superintendent. He operated the auxiliary equipment necessary. He had one main turbine almost up to speed to be able to carry "House Load," and to start the auxiliaries for the other boilers and turbines when the line crews finished repairing one transmission line and power was supplied from off-site. The remainder of the restart was then routine, and the crisis was over. From what I saw in satellite photos, there were "islands" of light visible within the blackout area a few hours after sunset, so some of the plants and systems were more easily restored than others.
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