APR: your source for nuclear news and analysis since April 16, 2010

Friday, December 2, 2011

December 2, 2011 - An anniversary piece.

Last week, faithful reader and commenter (on this and many other nuclear blogs) James Greenidge made the note to me that December 2 was an important anniversary - the anniversary of the very first criticality of the first nuclear reactor - Enrico Fermi's "atomic pile" near Chicago. At that time I decided to make a post with some details.

However, I saw earlier today that the American Nuclear Society's blog had declared today to be "Atomic Power Day" since - as it rightly points out - the Shippingport Atomic Power Station, our first commercial station, went to full power in 1957 on the same December 2 date. There's also the first electric power generation at EBR at NRTS, in December 1951. In rough addition in the atomic power timeline, I add that General Electric first announced the construction of its Vallecitos Atomic Power Laboratory in December 1955; it was later to be the first atomic station to commercially deliver useful power*. Also in December.. but December 1961.. the nuclear powered ship N.S. Savannah's reactor first achieved criticality. So we can make a really good case for nuclear energy in a number of ways for the month of December... and next month we'll have the National Nuclear Science Week.

This day is also important to Atomic Power Review, because it's the day that this blog's page views will pass the 200,000 page views mark.

Anyway... let's get to the presentation.

Much is available online about Enrico Fermi and his first "atomic pile," which really was the first nuclear reactor. Here are some technical details about that first pile.

The reactor was originally not given any sort of designation but later came to be known as CP-1 for Chicago Pile 1.

The core size was 24.5 feet by 24.5 feet square, by 19 feet high. It contained 385 tons of graphite in the form of blocks.

The fuel for the pile consisted of 12,400 lbs of uranium contained in 80,590 lbs of uranium oxide (both UO2 and U3O8.) There was no coolant employed of any sort; there was also no shielding although a one foot thick graphite reflector surrounded the core. The core had a maximum power rating of 100 to 200 watts, although at first it only operated at one half of one watt.

The reactor gave off enough radiation that the whole concept was reengineered to include shielding. The core was totally disassembled and later reassembled in another location with shielding and some considerable alteration as CP-2.

Of course, Enrico Fermi was at the lead of the men who built this first reactor and while he achieved very much more in his career, we may all today also remember most vividly the nuclear power plant which bears his name - the Enrico Fermi Atomic Power Plant, which originally included an experimental sodium cooled breeder reactor and which today houses a single GE boiling water reactor plant (although another BWR was under consideration, but stopped.) Let's take a look now at some rare illustrations from our collection here.

Above, an artist's conception of how the Enrico Fermi Atomic Power Plant would appear when completed. This is from an APDA/PRDC publication, which is the 1955 project progress report published March 1956.

Above, Fermi-1 as completed, from the other side and with the visitor information center in the foreground. Post card in APRA collection.

The reactor vessel for this plant was unusually complicated and was said to be the most difficult vessel fabrication ever attempted (not just including nuclear reactor pressure vessels.) The vessel was fabricated at Combustion Engineering's vessel shop in Chattanooga, Tennessee. Below is an illustration of part of the vessel under construction at C-E's shop, from the 1958 Atoms For Peace / Geneva pictorial illustration book assembled by the AEC.

The complicated shape of the vessel coupled with the requirements for metallurgical stability and strength in a high radiation flux are what made this piece so difficult. Here we see the vessel installed in the reactor building at Fermi-1. This illustration is from publication APDA-124, published January 1959 by APDA to act as a detailed technical description of the entire power plant.

To give a perspective of this installation we offer the following illustration, also from the same volume.

And also from the same volume, a view of the entire atomic power station. Item: Close inspection by sharp eyed viewers may reveal the installation of a "centerline at floor level" turbine generator set, a design then still new as a product of Allis-Chalmers Manufacturing Company. A-C was one of the many members of the APDA consortium.

Fermi-1 was as we all know a breeder reactor; without getting into technical details, I offer (also from APDA-124) the following illustration showing the core arrangement. This drawing blows up very large to allow reading of the legend. All of the illustrations on today's post are actually fairly large.

We can see the different zones in the core here at Fermi 1... an odd parallel to our next and final subject, suggested by ANS Nuclear Cafe's post today. That subject is the Shippingport Atomic Power Station. Shippingport (often called the PWR project) was unusual in many ways... two of them were the use of a seed and blanket core (highly enriched seed elements with control rods cause fission in unenriched blanket elements without control rods) and the fact that the plant was constructed mostly below grade.

Let's take a look first, briefly, at the plant arrangement. The next two illustrations are from the PWR Simplified System Schematics binder in the APRA collection.

Above, we see the reactor plant and the support buildings.. the turbine generator was actually located outside, in open air (much like San Onofre 1) and is not shown. Note that the reactor plant containment is almost totally below the grade. Below, we can see overhead and cross section views. The center chamber, mostly spherical, housed the reactor. Two identically sized chambers housed the four coolant loops with one main coolant pump and one steam generator each. The large auxiliary chamber housed the pressurizer and other primary equipment such as coolant cleanup and sampling.

Next, we look at the core from above to see the arrangement of seed elements and blanket elements. This is taken from our complete press release package which was sent out by Westinghouse / Duquesne Light at the time the plant went into full operation.

Let's now get into some very rare illustrations, acquired from the estate of the late James Vadeboncouer, who worked for both Westinghouse Atomic Power Division and later Sylvania-Corning Nuclear. Mr. Vadeboncouer was working at Westinghouse when the PWR core (Shippingport) was developed and there is much rare material in the many boxes on this core. First, let's see a cross section of one of the highly enriched seed elements. This is Westinghouse Atomic Power Div. negative number 13688.

We move over from a selection of WAPD photos to the "PWR Core 1 Core Assembly Engineering Tool Operational Manual," WAPD-NCE-5215 (July 1957) to see one of the seed elements in complete view.

This manual really was meant to cover the tools and fixtures needed to fully assemble the core prior to installation in the plant. Below is a complete view of the assembly stand developed by WAPD.

The blanket assemblies used not plates but fuel rods. Let's return to the group of photos in the folder labeled "PWR Specifications" for a couple of rare views. These are actually fully labeled so they need no explanation from me.

The support plate for this core was complicated, because the core was so highly instrumented and because it contained a FEDAL system (Failed Element Detection And Location.) Here are a couple of views to finish us off for today from this same folder which show the core support plate in the process of fabrication.

Without getting into detail, I will add as a final note that the FEDAL system contained a complex valve that sequentially ported water from a wide number of tubes in order that they could be sampled for detection of fuel element failure; this rotating valve was driven remotely by a then-standard commutator-inverter continuously unless a particular sample line were desired in which case it could of course be stopped.

That about covers our little photographic walk down the path of yesterdays in honor of "Atomic Power Day." Thanks to ANS Nuclear Cafe for declaring it and for giving me the idea to expand upon my original post idea to include Shippingport.

7:40 PM Eastern Friday December 2, 2011

* - General Electric essentially continued to try to one-up Westinghouse at all times following Westinghouse's success with the STR (S1W/S2W) PWR plant developed for USS Nautilus and after announcement of the PWR (Shippingport) project. So while Shippingport was the first commercial station to be planned, designed and ordered, GE beat them to the punch by a couple months (in terms of commercial sale of nuclear generated electricity) with the small experimental Vallecitos plant. GE had tried to make hay earlier with a big to-do at the S1G plant, Kesselring Site, West Milton, New York onto which it tacked a roughly 10 MW turbine generator and tried to sell power to Niagara Mohawk. This PR stunt did little in retrospect. GE redeemed itself fully however with the totally privately funded Dresden-1 plant only a couple years after Shippingport went on line.


1 comment:

  1. This is a very informative memory lane piece, especially seeing how the plant was partially underground and the turbines outside. I hope to Google up whatever drawbacks of the seed and blanket core design being that it's not in more common use unless it was experimental, would that be right? I also wonder what drawbacks kick in when you try to upgrade the tested and rugged sub nuke plant designs to a commercial plant scale. I once wondered whether it'd be an advantage to house nuclear plants about ships off-shore or in bays or even lakes which would render them immune to earthquakes and resolves a lot of citing and decommissioning headaches. Imagine many/large floating Savannah-type plants (larger than sub types?) lighting a city.

    James Greenidge