Really Tiny Reactors

Dome City Blog 4 - Welwyn Garden City and my proposals for a Dome City

I have looked at an old map of Welwyn Garden City and I estimate that this town is around 7.5 square kilometers.  The population according to Wikipedia is 43,000.  Welwyn Garden City is considered that classic example of a “Garden City”.  Recent proposals are to build 5 new Garden Cities in Southern Britain to help reduce the current chronic housing shortage.  The proposals that I have read suggest that each of these cities would house around 15,000 people.

Garden Cities are attractive to people and politicians because they are considered to be great communities and a very pleasant place to live.  If we accept that new Garden Cities are a good place to live what would that suggest about my proposals for a Dome City?

In a previous blog I worked out that the Geodesic dome I am proposing would have a area are within it of 25.3 square kilometres.  assuming 43,000 people per 7.5 square kilometers this would allow a population of 143,000 people.  As I have stated previously my goal wold be to have 100,000 people living in the city so the effective density of this dome city would actually be less than Welwyn Garden City.

I have visited Welwyn Garden City once to have lunch at my Prefessor's house when I was doing my MSc.  While this visit was a long time ago and I wasn't paying really close attention I do remember my Professor's house as being in a quiet cul-da-sac with lots of green space around.

Assuming when get get the lighting within the centre of the dome right this suggests to me that the dome city could provide a very comfortable environment for it's residents.

Reasons that I would like to live in a dome city are:

The ability to walk everywhere within the city.  There would certainly need to be elevators when one is going up or down more than a few levels but once on any level you would never be further than 500m from your destination.

I live in Scotland where it rains alot.  The dome city will provide a roof over my head at almost all times allow me to be outside of my house much more.  I would hope that this would encourage more "outdoor" activities like sport, walking, cafes, open air concerts etc.

I feel that since people would walk around more that they would come into contact with their neighbours on a more regular basis.  I would hope and expect that this would engender better feelings of community.

I wouldn't need to own a car for day to day living.

Given the high population density I would see that public services would be easier and less expensive to provide.  Examples are:

With a electrical power plant located very close to the city combined heat and power is a real possibility.  The energy provider would be able to supply district heating at relatively low cost.  

I imagine that garbage collection could be made more efficient since people could carry their waste and recyclables to larger bins.  

Schools could also share facilities much more easily.  In addition, parents would have a greater choice of schools for their children since every school is accessible on foot by any child.  

Waste could be disposed of in an incinerator located within the city providing additional district heating options and reducing the amount of waste going to landfill.

Sewers could be smaller since they would not have to deal with rainfall.

I am sure there are more examples that I haven't thought of yet but I hope these do show you how costs could be reduced and services improved.

I hope you have found this interesting.

Swam with Stacey from Rosneath Slip (1st slip) bang on high tide. There was a south east breeze creating a reasonable swell. Swam to the yellow pole and then back towards the beach. Stacey exited the water at Rosneath Slip (1200m 42m) and I continued to the Boat Club (1675m 53:33) Water Temperature 13.5 degC #esplanade #inverclyde #greenock #rwsabc #openwaterswimming (at Royal West of Scotland Amateur Boat Club)

First entry into Tumblr

This is my first post in Tumblr.  This seems a nice system for writing blogs.  I have sort of tried Wordpress but it doesn't lend itself to short posts.  I will move the blogs that I have created so far to here.  I'm not going to put any tags on this entry.  - Note to myself - Only one entry per day.  I was following a blog on Tumblr called "Today I learned (TIL)".  With a title like that you might expect to learn one new and hopefully important thing per day.  No he/she seems to put things out every hour and it completely clogged up things.  I got fed up and stopped following the blog.

Dome City Blog 3 - Energy production in the city

 In today's blog I plan to talk about energy production and use within a Dome City.

In general, residents of cities use less energy per capita, then people in rural areas.  Some reasons for this are:

Distances travelled can be less,

Mass transportation systems can work well,

Shared walls in housing lead to lower heating requirements,

If energy sources are located in the city then combined heat and power can be used, and

Less resources are used to provide infrastructure for high density populations compared to low density ones.

  A Dome City should have nearby power resources large enough to cover the needs of the population for electricity, heating, cooling and local transport within the city.  Transport away from the city would most probably provided in standard cars and trucks powered by gasoline and diesel.  

I would propose that the Dome City has a electricity power station sited just beside it. This power station would be located close enough to the Dome City to allow the waste heat, which arises from electricity production, to be used to provide hot water, heating and if required, cooling, to the city.  This is known as combined heat and power (CHP) or as cogeneration.  When a Dome City is sited in a tropical location then a "trigeneration" systems which includes refrigeration could be provided.  The typical efficiency of thermal power plants for electricity is 30% to 40%.   This waste heat represents a significant resource.  District heating would be feature of the Dome City.  This heat supplied to residents and business would form another source of income for the city.   

My preferred method of dealing with electricity production would be with Nuclear Power.  Nuclear Power is a low-carbon form of electricity production that is not so climate dependent compared to wind or solar.  Furthermore, while wind and solar can be excellent sources of low-carbon electricity at the right locations, these forms of energy production are intermittent.  This intermittentcy requires back up power sources to cover the times when these renewable sources cannot provide power.  

There are proposals for new smaller reactors  known as Small Modular Reactors (SMRs).  By definition these reactors have electricity outputs of less than 300 MWe (Megawatts electrical).  The suggested size of these reactors varies from 2 MWe for the UPower proposal to 130 MWe for the B&W MPower proposal.  The system that I would most want to see would be 3 number NuScale 45 MWe reactors to provide electricity and heat to the city.  A combined output of 135 MWe would generally provide more power than the city would require. I would estimate that the city will consume around 100MWe.  However, the additional supply could  be used to entice power hungry industries to move to the city.  Some energy intensive industries are data centres or heavy manufacturing.  Alternatively, the additional supply above the needs of the city would be a useful source of income for the city.

The NuScale reactors have a refueling cycle of around 2 years.  Refueling would be staggered such that no more than one reactor is off line at any one time.  In the UK, the city should be connected to the National Grid and any shortfall in power during a refueling shut-down could be supplied from the grid.

The use of 3 number SMR's has the advantage of "right-sizing" the plant to the population of the Dome City.  The Dome City will take several years to build.  Once the lower levels have been constructed I would expect that people would begin to move in.  However, to reach the full population of around 100,000 people will take a number of years.  Initially a single reactor would provided for power.  The second and third would follow in later years when the population as grown large enough to justify the additional generating capacity.

I would very much hope that the power station for the city be owned and operated by the municipality.  

I appreciate that there will be some reading this blog that are opposed to or afraid of nuclear power.  In addition, the NuScale SMR is still in the design and licensing phase.  We are still waiting for the first one to be constructed. An alternative to an SMR that would accomplish much the same ends is to have a Combined Cycle Gas Turbine (CCGT) power plant producing electrical power for the city.

This brief outline on the supply of electrical power and heat to a proposed Dome City has set out what I consider to be the "best" option. The compact nature of the Dome City would allow Combined Heat and Power to be feasible.  The power station would have 2 sources of income.  One comes from the Electricity produced and the second is the hot water and heat supplied.  This would increase it's financial performance and make it easier to find financing for this aspect of Dome City development.

Tonight was the first night of Open Water Swimming at RWSABC. A beautiful evening with sun, clear sky and no wind. We swam in the direction of the Battery Park. The tide was coming in so it was a hard swim out (35 min) but fast (15 min) coming back.😊

Europe: Carnivore Paradise?

Bears, wolves, lynx and wolverines are flourishing in Europe, largely in humanized landscapes and not in parks. Can North America learn from the “coexistence model” that characterizes the continent’s approach to conserving big carnivores?

Now that I am back from China I felt I needed an Open Water Swim. It was a lovely day. Stacey, Colin and I went in. Stacey and for a swim. Stacey and I did 1030m in 34m 22s . Water temperature was 11.3 degC. I was in too long and came out very chilled. #openwaterswimming #greenock #esplanade #rwsabc (at Royal West of Scotland Amateur Boat Club)

I had a nice swim with Colin and David tonight. It was high tide and very calm. I saw a few jellyfish. There was a rainbow at the start of the swim. I swam to the "yellow" pole. #inverclyde #openwaterswimming #Greenock #RWSABC #Scotland #esplanade (at The Royal West of Scotland Boat Club)

The Economist | Land-shackled economies: The paradox of soil via @theeconomist

We walked the Greenock Cut today. The weather was beautiful.