Neat: Aircraft carrier U.S.S. Carl Vinson to produce 200,000 gallons/day for Haitians

[GroundedSailor]

That is some seriously awesome tech. But I wonder what do they do with the salts (plural on purpose) left behind? Dump it back in the ocean?

I do salt water reef aquariums and there is a LOT of salt(s) in the water with Ca and Mg also being pretty abundant. In all honesty the best thing they could do with what's left behind is to just dump it in the ocean at a constant rate.

All the salt left over can be dumped back if it is not contaminated on board in any way. Usually gets back flushed out of the desalination plant and pumped overboard. At least thats how it used to be.

Having said that newer garbage regulations may require that the salt be retained onboard and sent ashore with regular garbage. I've been out of touch for a few years.

 

[Hacp]

If they're docked, they should dump it on shore. The reason is that if the osmolarity of the water is too high, microorganisms might shrivel, thus killing a large portion of the marine food supply in the area. You would probably be ending up doing more harm than good, especially if the local population relies on fish as a staple.

 

[hal2kilo]

All the salt left over can be dumped back if it is not contaminated on board in any way. Usually gets back flushed out of the desalination plant and pumped overboard. At least thats how it used to be.

Having said that newer garbage regulations may require that the salt be retained onboard and sent ashore with regular garbage. I've been out of touch for a few years.

Used to be 12 miles. Now 200 miles, otherwise you got to haul out the TDU's and pump the sans to the land facility.

 

[PricklyPete]

cool stuff.

 

[dainthomas]

I was on a nuclear cruiser during the gulf war, and it was sure nice being able to stand aft lookout without choking on diesel fumes. It's decommed now, I believe it was the last CGN.

 

[GroundedSailor]

Used to be 12 miles. Now 200 miles, otherwise you got to haul out the TDU's and pump the sans to the land facility.

Pump out? When you open the evap plates the salt comes out caked to the plates. Its almost dry.

Does the 200 miles apply to galley waste as well? Salt was never considered garbage. All the ships I've been on used to back flush the evaps to clean out the salt. But that was a while ago.

 

[lothar]

There's only a few yards that are certified to do Refueling Overhauls. Notice the word overhaul in there. If you ever seen what encompasses refueling a nuclear reactor on a Navy vessel (only subs and aircraft carriers now), it's an extremely complex and expensive operation. When they are done with the reactors (ship decomissioned), the fuel is removed for reprocessing and the reactor core is prepared for burial in Hanford Washington. But let's not worry about that little tidbit. I sure hope when civilization comes back after the asteroid hit that they don't accidentally uncover any of that stuff. Some of that stuff has half lives of 250,000 years.

How often do Nuclear submarines get refueled?
Once every 6 months?

The words I quoted were those of a US military official.
I'm sure he knows much more about nuclear reprosessing than you or I put together.

The half lives can be reduced by lifting the ban on nuclear reprocessing.

 

[werepossum]

I've always wondered about that, why they don't build massive desalination plants on platforms out on the ocean and then pipe the water to the mainland. No more dependence on rivers etc for irrigation or drinking water etc. Seems like a good idea, but I'm sure there are problems with it or it would have been done already.

I've wondered about that too. I read not too long ago that California's grid manufactures so much electricity that at night they pay Nevada to take their excess production. If that's true - and I read it in an engineering magazine, but I haven't checked it out to see if it's really true or merely some accounting gimmick to make California's bizarre two-tiered electrical cost regulation a profitable business - then that excess electricity could be used to desalinate sea water and/or split hydrogen for use in peak plants. That would help solve one or both of California's persistent problems. (I don't think it can cure liberalism though.)

For those unfamiliar with power generation, generators must be synchronous generators exactly synchronized in phase with the existing power grid. Some generators (like in nuclear plants) don't like daily changes in their output levels. Other generators (like hydro) can be fairly easily shut down or throttled back, especially natural gas-fired motor-generators (as opposed to gas-fired steam boilers-generators) which are less efficient and usually used only for peak generation. And still other generators fall in between, with the very large oil-fired generators disliking varying output and natural gas- or coal-fired steam generators being fairly responsive to reducing load - to a point. There are economic limits (such as the cost in energy to restart a very large generator being more than is saved by shutting it down) and operational limits (such as boilers that, if allowed to drop to a certain temperature, must be shut down and cleaned before restarting) and I'm not conversant enough with generation in general or California's generation in particular to know if they are truly paying Nevada to take excess power or if that's merely another Enron-type accounting move for ulterior motives, but it's certainly possible that there exists enough free energy off-peak to do significant desalination or hydrogen splitting. Or at least, nearly free, once the new equipment is amortized.

 

[Minjin]

The Vinson is my old ship. Bravo Zulu, guys.

And to answer some comments above, I will guarantee that they are rationing water. If wouldn't be the first time either. Keep in mind that water usage is very dependent on whether or not you have the air crew on board (I didn't read the article). With the air crew on board, you are looking at a little over 6,000 people. Without the air crew, i.e. the quiet times, you're at about 1,500.

 

[keird]

Biosand filter

Essentially, it's a concrete encased filter using stratified layers of microorganisms and sand to create acceptable drinking water. What's neat about it is that you can create a small, local industry making these without a nuclear fuel source.

Also, the MoneyMaker pump and the Hippo Water Roller

I think that we lose sight of self-sustainment despite our best intentions.

 

[Linflas]

They have four distilleries that produce 100,000 per day each. They state in the article a couple times it is excess water. Also, the Vinson doesn't need much steam power right now.

Having been on a carrier and having dealt with water rationing it does not mean that water is not available. What it means is you do not stand in the shower with it running while you wash yourself. You turn it on for 15 secs to get wet, then wash yourself, then turn it on for another 15 secs to rinse yourself off. They designate times when the water will be on for that purpose and you shower accordingly.

 

[K1052]

The military gave up on nuclear powered surface ships (except for aircraft carriers) a while back because it costs huge $$$. They keep using it on submarines, but that's because of a nuke plant's rather unique ability to run without needing oxygen. I agree with you that there's been an irrational fear of nukes since Three Mile Island, however nuclear power is anything but cheap. I'd like to see more nuke plants in the US but let's not pretend it's a silver bullet to easily solve all of our energy problems.

The navy is actually considering nuclear power for the upcoming CG(X) program because of the power requirements of the future radar systems and new weapons.

 

[hal2kilo]

Having been on a carrier and having dealt with water rationing it does not mean that water is not available. What it means is you do not stand in the shower with it running while you wash yourself. You turn it on for 15 secs to get wet, then wash yourself, then turn it on for another 15 secs to rinse yourself off. They designate times when the water will be on for that purpose and you shower accordingly.

Does the phrase "No Hollywood showers" ring a bell.

 

[hal2kilo]

How often do Nuclear submarines get refueled?
Once every 6 months?

The words I quoted were those of a US military official.
I'm sure he knows much more about nuclear reprosessing than you or I put together.

The half lives can be reduced by lifting the ban on nuclear reprocessing.

The current Trident design can theoretically go 30 years without refueling. That never happens for a number of reasons. One has gone almost 2 decades.

Some people might get the impression that I'm anti-nuke. For the Strategic Navy it's a essential element to national security. What I object to is all this loose talk by people who are probably going to benefit from a revitalize nuclear industry that say that all the new stuff is going to be like magic and we don't have to worry about nuclear waste. We'll that is the whole problem with nuclear, and until one of you clowns volunteer your property, or state to be the nuclear waste dump of the nation then your just pissing in the wind.