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Saturday, September 18, 2021

N.S. Savannah

 "Death smiles at us all; all we can do is smile back." - Marcus Aurelius

This post is not just about a ship.  It's also about a happier era in the US.  A time when anything seemed possible, and major improvements in life were reasonably common - things like a cure for polio, widespread public jet travel, and manned spaceflight.  A time long ago, back when supermarket shelves were fully stocked.

The image above is N.S. Savannah (N.S. stands for "Nuclear Ship").  She was ordered in 1955, completed December 1961, had her maiden voyage in August 1962.  After a mere 10 years of operation, she was taken out of service, in January 1972.

There is a really great Wikipedia Page about N.S. Savannah, where I gathered most of the information about this post.  I encourage curious readers to visit the wiki, because this is a brief blog post, and not a comprehensive article.

Savannah was the world's first nuclear-powered merchant ship.  In reality, she wasn't intended to be a practical money-making ship for transporting goods.  Instead she was built as a goodwill ambassador for the peaceful use of nuclear power.  To understand how Savannah came to be built, it is important to understand the geopolitical situation of that era.

The Cold War was ongoing at the time, and tension between the Soviet Union and the United States had been building for well over a decade.  Mutual distrust, and the apparent need for massive stockpiling of nuclear weapons led to President Eisenhower's carefully-crafted PR campaign called "Operation Candor".  Operation Candor was a project to inform the public of the danger to the US that Soviet nuclear weapons posed.  

The project also explained and informed the public about why there was such highly unusual peacetime weapons stock-piling.  This massive spending on weapon systems was unheard of before the cold war.   Operation Candor served to justify the unusual expense of nuclear weapons research and development, the deployment of ballistic missiles, supersonic aircraft, warships, and research into even more deadly biological, chemical and nuclear weapons. 

In addition to Operation Candor, there was another bit of propaganda that was aimed both at the US and the rest of the world, and this was called "Atoms for Peace".  The "Atoms for Peace" program was aimed at easing the public's *fears* about nuclear weapons, by highlighting the peaceful use of nuclear energy - research, power plants, and naval transportation.  "Atoms for Peace" actually provided several nations with highly enriched Uranium, in exchange for oaths that they would use it for peaceful purposes only.

It is important to realize that while the world was happy to have World War II over with, the images of half-incinerated Japanese civilians from Hiroshima and Nagasaki also shocked the world.  Atoms for Peace was intended as a PR counter to the actual horrors of a potential nuclear war.

NS Savannah was funded through the "Atoms for Peace" program.  Although the US Navy had already developed nuclear reactors for military use, the decision was made to separately engineer a completely different reactor for civilian use.  This decision was an attempt to underscore the peaceful intent, even though the operation of each design was nearly identical.  In fact the contractors who built the reactor and steam propulsion plants for military ships were the same ones who manufactured them for NS Savannah.

Now that the deep-dive explaining why the ship was built is finished, we can now take a look at the incredibly cool features of this one-of-a-kind public relations showpiece.  We will start with the reactor and steam propulsion plants.

Below:  A cutaway showing the reactor plant and containment (forward of the bridge), and the steam propulsion plant underneath the bridge. 

Below:  A slightly enlarged image of the reactor containment, to visualize the details a little better.  The reactor was rated at 74 MW (thermal).  The active core region was about 5ft tall and 5-1/2ft across, with a 14ft tall reactor vessel.

Below is a top-down diagram of the physical arrangement.  I'll point out the items I recognize.  

  • #3 are the boilers (steam generators)
  • #6 is the pressurizer, which prevents boiling in the reactor core
  • #8 are reactor coolant pumps, two for each coolant loop
  • #7 are coolant pump discharge check valves - these keep coolant from flowing backwards when one pump is shut down.
  • #9 are shut-off valves for the coolant loops.  They operate in pairs to isolate one loop, should a major reactor coolant leak develop.
  • #4 and #5 are probably storage tanks for coolant make-up and discharge, but that's a guess.

Below is a iso-drawing of the reactor and steam plant, showing the flow paths of coolant and steam  I find it interesting that the primary heat exchangers are well below the steam drums in this system.  I'm more familiar with U-tube heat exchangers and once-through heat exchangers.


Below: One of the interesting steam generators on Savannah, showing the primary heat exchanger below, with risers, downcomers, and an upper steam drum.

Below:  A cutaway of the reactor vessel, followed by a top-down view of the fuel elements during refueling.  The "+" shaped control rods can be seen in between the fuel elements in the bottom image.


Below: The support structure for the control rod drive motors.  This is at the very top of the reactor in the first cutaway images.

 
Below:  A few views of the containment access points.  Not as pretty as the outside and passenger areas of the ship, to be sure!




Now we can look at a couple of pictures of the propulsion control room and steam propulsion turbines and reduction gears.  I like how everything is color-coded.  Steam turbines are the large red objects, and the reduction gears are painted yellow.  I would expect that 100% of the insulation contains asbestos.





Below: The reactor and steam plant control room, back when she was an operating vessel.

Below:  A few current photos of the propulsion control room.





Onward now to some of the really cool design features that were incorporated into the ship - again keeping in mind that she was built for public relations!  She not only carried cargo, but she also carried passengers for a certain length of time.

Below:  Passenger stateroom.   Very clean atomic-age design look.

A few pictures of the common areas.




 

Maybe you didn't notice the overhead light fixtures in the above images.  Pretty freaking cool.

Below:  The bridge and exterior of the ship are as stunning and beautiful as the passenger areas.  




I would say she was a success as a nuclear PR ship, and much less successful as a way to transport freight.  And of course like most things in the US these days, she is in need of TLC as a museum ship.













2 comments:

Johnnywoods said...

An interesting article Spud. What did you think of the recent story of the new Chinese Nuclear reactor. Is it a march on the west?

Mark said...

Johnny,
That's a great question! I don't have an answer, because I've not been paying much attention - although I should have been.

Tell you what, since you asked that question, and I'm going to have to learn what's going on with that reactor, I'll do a post about it and the tech in a post very soon. And that will be a huge contribution from you to this blog. Thanks for asking the question! Answer coming shortly!