An assorted mix of posts, some original, some favourites previously published in other Al Fin blogs.
Wednesday, July 14, 2010
If You Build It, They Will Come
The builder of this 8,000 square foot treehouse was told in a vision that if he built it, he would never run out of materials. So he did, and he didn't, and yes, they do come -- 400-500 a week come to visit this rustic record-setting treehouse near Crossville, Tennessee.
Although he never bothered to measure Minister’s House (he estimates it must be about 8,000 to 10,000 square feet), he did count the nails he had to hammer into it, 258,000. It cost the 56-year-old landscape architect around $12,000 to construct the world’s biggest treehouse.
400-500 people visit Minister’s House every week, most of them tourists from out of state who heard about a 10-story-treehouse somewhere in Tennessee. _Oddity
Built to provide 20 years of power per fueling, the ARC 100 is perfect for your underground survival compound, to give you time to get back on your feet after an EMP or similar catastrophic event. Sometimes it is best to lay low for a decade or two, until things cool down.More from Idaho Samizdat Nuke Notes (from an entry in the 7th Carnival of Nuclear Energy):
Getting power out of the reactor
The inlet temperature, according to a specification sheet, is 355 degrees C. The outlet temperature is 510 degrees C. The outlet temperature is what is made available to the balance of plant. The reactor immersed in ambient pressure liquid sodium. The intermediate loop is also liquid sodium.
Transfer of heat to a turbine is being developed to use to Brayton Cycle which uses liquid CO2 yielding an expected 40% efficiency rate for heat transfer. However, Ali said the company is also working with turbine manufacturers to develop steam applications.
Answer on nonproliferation issues
In an answer to critics of nuclear energy who worry about bomb makers, Ali points out the fuel for the ARC-100 is sealed in the reactor, used for 20 years, and then returned to the factor, or a regional fuel center, for reprocessing. The customer doesn’t touch the fuel, stores any on-site, or manages the used materials.
“The customer never has access to the fuel.” Ali said.
According to the first phase design information provided by the company, the “fuel cartridge” is inserted in an underground portion of the reactor. There are no safety-related systems in the balance of plant. The reactor vessel installed underground and is 15 meters high with a diameter of about 7 meters. See conceptual image left.
The fuel itself is enriched to an average of 14% depending on customer requirements. The specifications for the fuel are found in a database developed for the EBR-II reactor which means extensive first-of-a-kind fuel testing required for some of the other fast reactor SMRs won’t be needed for the ARC-100.
“It is a proven metal-alloy fuel,” Ali said.
On the reprocessing side of the fuel cycle, creating new fuel for the ARC-100 does not involve separating pure plutonium that could be used in nuclear weapons. Instead, it keeps the plutonium mixed with other long-lived radioisotopes so that it cannot be used in making bombs.
Ali said the company is now holding “pre-application discussions” with the NRC ahead of formally submitting the reactor for design certification. Ali did not indicate a date when the firm would formally submit a package to the NRC. _ISNN
A pre-loaded nuclear fuel cartridge that provides reliable power for 20 years between cartridge changes goes a long way toward providing optimal safety and confidence in a power source.
This article from Idaho Samizdat was featured in the 7th Carnival of Nuclear Energy. Another article featured in the same carnival which is a very useful expansion of the above Idaho Samizdat article can be found at Capacity Factor. The Capacity Factor article also looks at competing designs for liquid metal fast reactors.
The Lifespan of These Homes is Measured in Centuries
Well-made monolithic domes, as described in the video, are expected to last for centuries. As described at the dometech.com website:
With the exterior protection of polyurethane insulation and the waterproof roof membrane, the steel reinforced concrete dome will not weather or decay. The life span of these buildings will be measured in centuries. Strength
The monolithic concrete dome is probably the strongest building that can be built with a specific amount of time and materials. This means it has very high resistance to the natural forces of earthquakes, hurricanes, tornadoes, and floods. _dometech
Monolithic domes are also relatively safe in a wildfire, due to the fireproof internal thin-shell construction. The external foam is apt to melt or burn unless protected by layers of fireproof material, but you should be safe inside the shell.
Another type of long-lived concrete home is built by Formworks, an example of which is pictured above.
The Formworks structural life-span is rated at 200-1000 years. That is five to ten times the structural life span of most homes. Plus - depending on what external features are chosen, the Formworks homeowner can reasonably expect a reduction of ninety-percent (90%) or more of the maintenance that is required on a conventional home of the same size. _formworks
Here is yet another type of concrete home from Conrad'sCastles:
With poured-in-place concrete walls, there are no worries about rotting wood, termites, or settling problems that can cause a lot of interior damage. This means you have fewer headaches, more money, and more enjoyable weekends! Strength and safety for your family.
Because of the concrete structure, these homes survive fires, tornadoes, hurricanes, and even earthquakes. What more could you want for your family? This also means cheaper homeowner’s insurance. Peace and quiet.
You won’t believe how little outside noise you will hear in a concrete home! Noise from traffic or the neighbors’ barking dogs is practically gone. _Conradscastles
An arched or domed shape provides strength and uninterrupted interior space. Earth sheltering on top of the concrete provides further protection from fire and weather, as long as proper water-proofing is used. Monolithic domes, for example, are strong enough to be buried beneath about 30 feet of earth.
Homes that can last up to 1,000 years may seem like overkill. Of course if you plan to live in a house the rest of your life, you may wish it to be practically indestructible.