There are probabilistic models that NPPs use to account for random failures, and human interactions (e.g., valve left in wrong position after test and undetected).

The issue that the OP is referring to is that most stations only use the internal events model which has an initiating event that starts with a NPP system failure (e.g., coolant line failure), instead of the external events models. They are called external, but includes fire, flood, seismic and high wind events.

There's also the fact that part of Pioneer Pipe's work revolves around fabrication for specific industries. Industries with specific requirements and certifications. You can't just hire any guy off the street to do welding for something that is slated to be used in the primary side of a nuclear power plant.

You might want to look at what Pioneer Pipe actually does. They service a lot of different industries, including the nuclear industry.

It isn't simple welding. If you're pre-fabbing stuff that gets installed into a nuclear power plant, it's got some very specific requirements which includes radiography.

I wouldn't be surprised to hear that a lot of the nuclear industry is hurting for welders, or that their maintenance outage timelines are challenged because they can't find enough welders, or other specific tradepersons.

http://www.pioneergroup.us/fabrication-assembly/nuclear-fabrication.html

I would much rather see self-driving bikes than human-piloted ones. Every day, the human-piloted ones seem to weave in and out of traffic, and obey the rules of the road only when convenient.

Any time you can take the human out of the equation, you are making it safer.

Lots of things are designed not to fail. Arguably, everything is designed to not fail, however, everything that is designed well is designed to fail gracefully or in a predictable fashion (or at least, not catastrophically).

The reason you don't get invited to meetings is that you demonstrated arrogance (or misplaced humour) when asked a legitimate question.

Not that being in meetings is particularly pleasant, but there is sometimes value in being present.

There should never be accidental detonation of any munition on a bomber/fighter. The entire point is that they target something. Whether a country is at war, or flying a training exercise during peace time, you never want any weapon to detonate when the plane goes down shortly after takeoff.

Not sure how it works in the US, but in Ontario, there is the Feed-In-Tariff program (FIT). Otherwise known as a way to make money from renewable energy. Depending on the scale / method of electricity produced, you are guaranteed a different rate. Something like $0.13/kWh for wind, and $0.40/kWh for solar. And I think the term they use to describe them is 'non-dispatchable', in that, the grid must always accept the energy provided by these generators. Other generators (natural gas / hydro) are generally responsible for curbing output and maintaining adequate spinning reserves.

I assume it is somewhat similar in the US but don't know the details.

Nuclear plants aren't usually asked to reduce power, as they provide baseload generation. It is simpler to ask a fossil plant to shutdown.

FRAND doesn't mean that the price of licensing the patent should be near zero. Just that it should not be discriminatory. If Samsung's typical price is in the range of 2.4% of the handset, then why would it be different for Apple? Just because they chose to produce a more expensive shiny trinket? If that's the case, then everyone else would say that they were discriminated against (I paid 2.4% and Apple only paid 0.3%).

Also, if Apple really didn't want to pay the appropriate licensing fee, then they could have just used technology that did not violate any of the patents. After all, they do place a very high priority on IP.

Maybe you should help subsidize them because you want to buy meat, bread and gas. You don't think the farmers live in the city, do you? What about the oil refineries? Obviously, they drill and refine oil in your city specifically for you, and could not possibly be doing this in an area that is unattractive (except for the oil refineries).

You strike me as one of those city hipsters that doesn't actually know what goes into making their life possible.

I recently went to see "The Purge", and prior to the start time (8:35), there was a pre-show consisting of entertainment trivia, product placement spots, and such.

At 8:35, the commercials started. I timed it. There was a full 10 minutes of commercials.

Then there were previews. 10 minutes of previews. I don't mind the previews usually, but after sitting through 10 minutes of commercials, I just wanted to see the movie.

For an 86 minute movie, there was 20 minutes of stuff before the movie started, and the movie ended up starting at 8:55 instead of 8:35.

I won't be going to the theatre again any time soon.

Reveal codes was such a great feature for making sure the formatting did everything as expected.

I always fight with Word at work to make sure everything is formatted properly.

Answering your phone and leaving the theater means it was probably important.

However, checking your texts and responding??? Texts are never important. If they were that important, it wouldn't have been a text (no guaranteed delivery time, and no feedback that it was received). It would have been a phone call, and taken care of by the above scenario.

The fact that you see people checking their phones and texting (here and there...) during the movie does not mean that you live in a more polite region, it just means that your definition of polite has shifted dramatically during the years.

You know, I am sure that the Red Cross does many good things, like you mentioned, however I am often conflicted about large humanitarian / philanthropic organizations. They just seem like they have many layers of management.

I am always glad to hear about the 'normal' folk who provide immense value to these organizations.

In the case of any thermal station (nuclear, coal, etc.), this is not good, because they are suddenly producing vast amounts of waste heat that must be quenched. The sudden changes in temperature cause the heat exchangers can go into thermal shock. Also, once cooled, any brick refractory material must be checked. This process takes days, especially in the case of nuclear generating stations where numerous rigorous safety checks must be completed. Thus, once the grid has been destabilized, it cannot restart quickly.

The heat exchangers (e.g., boilers / steam generators) at a nuclear plant don't go into a 'thermal shock' when a plant is forced to shutdown unexpectedly. The plants are designed to reduce power rapidly (~2% per second, in some cases) to vent steam to maintain the temperature / pressure in the steam generators and primary heat transport system. This is called 'zero power hot' by many utilities. You're producing basically zero power, but the systems are still hot.

The reason it takes longer for a nuclear plant to restart after reducing power rapidly is the xenon transient. At full power, there is a baseload of neutron absorbing xenon-135, which is daughter product of iodine-135. When power is reduced, xenon-135 is no longer being 'burned,' only produced by the decay of iodine. The result is that there is a large amount of negative reactivity that the control systems cannot counteract. Depending on the exact fuel makeup, it can take about 30-36 hours for the xenon to decay down far enough such that you achieve criticality again.

Page 11 of 14 for a nice graph

I was thinking along these lines too. For any issued report / calc (either internally or externally), it should be very simple to reproduce for one of two reasons:

1. It is a 'simple' problem with only one real solution.

2. The report / calc is issued with the exact instructions and/or files to reproduce the results.

It is much harder to do #2 when you're trying to follow along what someone else has done in the GUI vs. a flat text file where errors can be very readily apparent, or at least checked programmatically.