Update from Beach from San Juan


#61

I’m home…! Hopped the Samaritan’s Purse DC-8 Combi (first time ever in one of those) and would have left at noon but for Hurricane Trump which shut down all of San Juan for about 5 hours. This DC-8 came off the assembly line on Christmas Eve, 1969 - two years before I was born…!


#62

Funny little side note on that DC-8…the crew consciously try to avoid a digital ITT readout of 666 in cruise. I laughed when I realized that’s what they were talking about…


#63

It’s like the opposite of the Air Force and 69.


#64

Glad to hear you got home safely!


#65

DC-8s have always had a place in my heart. One of my first memories of flying in an airliner was in a DC-8…back when they were new and Delta flew them probably about the 1967-68 time frame.

Welcome home. Glad you are back safely.


#66

Yeah…I’m thinking I wouldn’t. Turns out that a lot of civilian nuclear power plants are Boiling Water Reactors (BWR) vs the Pressurized Water Reactor (PWR ) that you and I are familiar with.

For those playing at home who may not be nuclear power trained or a mechanical engineer, a picture:

The key sentence here, “Water that is turned to steam never mixes with the water in the first loop.”

The US Navy uses PWRs…why? Probably because they are a lot safer. A submariner friend of mine once explained it this way “We like to keep the radioactivity in the radiation tank and out of the people tank.”

OK, technically in a BWR it’s a closed loop and the pipes are all shielded once they leave the containment vessel…but why chance it…

Fukushima’s reactors were BWRs. Those “closed” loops at Fukushima NPP rapidly became a very open loops once the H2 explosions started and blew things up.

I’ve seen a couple of years on ships with PWRs with narry a worry. But when a doctor hands you a couple of Iodine tablets saying, “You may need these…we’ll tell you when.”, it gives you a gut-level distrust of BWRs…just say’n.


#67

I’d actually like to spend an afternoon going through business decisions for commercial reactor types, especially in the fallout (ha, pun), of the failed second nuclear renaissance at the end of the last decade. If I had to guess, I’d concur about monetary motivations. There’s probably a smaller investment and quicker ROI in a BWP type plant.


#68

I’d say you are correct - its money. The Fukushima disaster was bound to happen. I had a civilian expert–top of his field–say that those reactors all have an achilles heel–“station power outage”

When the earthquake hit, the plant scrammed which stopped the fission. But the reactors were still incredibly hot. You need big coolant water pumps to cool them down. The pumps are electric and run off the power grid, which also went down with the earthquake. The backup diesel generators were insufficiently protected from the follow-on tsunami and they were permanently taken off line. The battery back up to run the pumps was only good for something like 10-12 hours because “Surely that is enough time to reestablish the power grid or fix the diesels.”

It wasn’t.

They experienced a complete station power outage that lasted well beyond the battery life–the known achilles heel of the design.

The pumps stopped when the batteries were drained. The reactors got hot enough to start a chemical reaction generating hydrogen gas–trapped inside the reactor buildings-no way to vent it–that eventually blew up. After that…we know the rest.

You can probably count the different “cost saving” measures that contributed to the disaster


#69

Eh, it’s not a matter of safer per se, unless you’re talking about containment or potential for damage control, since it provides another layer of shielding and physical separation at the expense of increased complexity and slightly reduced efficiency, and honestly, the extended lack of decay heat removal would’ve had similar reasons in a PWR as well - it’s just possible that the pressurizer would either go first or lift a relief first, but the end result would still be steam being vented into the containment building, where H2 would’ve been stripped or if solution.

Newer plants have much, much more in the way of passive cooling systems to help with decay heat removal in the event of a loss of power (decay heat is the heat generated by the fission products in the fuel elements continuing to undergo radioactive decay after the reactor is shut down. This varies with the power level the reactor was operated at prior to shut down, and decreases the longer the reactor is shut down).


#70

Bruce Dickinson probably calls it optimal cruising ITT on Ed Force One. :metal:


#71

Yep - thats exactly what I am talking about. The H2/Air explosions did some damage to the reactor vessels, however is was the severe damage to the the single-loop piping which gave the reactors’ cooling water a direct path into the environment.

Copy all about the same thing happening to a PWR suffering an extended lack of decay heat removal. The question is, would damage to the secondary loop release much radiation? I would think it wouldn’t…but I’m not ready to put that to the test.

…anyway Beech is back safely …which was the theme of this thread until I went down the nuclear habit hole…and his experiences have given me a great sim flight idea for my JustFlight DC-8. All is good n the world…as long as I stay away from 666 ITT on my sim DC-8.


#72

Oh god no, all the 50’ and 60’ designs need to die out in a painful death. Such a shame we are not innovating with functional reactors a lot these days!


#73

Well…Chernobyl’s RBMK “High Power Channel-type” graphite-moderated nuclear power reactors were innovative for their day…probably not the best example…but it did spawn the whole S.T.A.L.K.E.R. series of games…which are pretty cool…so its got that going for it.:sunglasses:


#74

We are, they’re just not getting built - that’s the problem. Or, they’re starting construction, then not finishing - about a dozen of my friends were among the roughly five thousand who lost their jobs when SCE&G stopped construction on the AP-1000 at Summer NGS.

Also, General Atomics has been doing some really cool things with modular fast reactors, but in the current regulatory and economic climate, they’ll never be built.


#75

That was my point, the research is there but not the practical applications around us. I should have worded that a little better :smile:


#76

Well… since were already pretty derailed… What are your thoughts on molten salt reactors? I’ve heard some pretty interesting concepts in the last few years for small ones on everything from space craft to the backs of trucks.


#77

since we’re derailed, I’m playing doi @Andrew116


#78

Wait. Don’t you DoI peeps have a ‘join me’ thread?


#79


#80

You’re dangerous.