Fort St. Vrain in Pictures: 1

Fort St Vrain concept art B

by Will Davis

What became the Fort St. Vrain Nuclear Generating Station began as a study almost two decades before the plant was completed and led to years of effort to construct a commercial high-temperature gas-cooled nuclear power plant. While the effort did not ultimately lead to a successfully competitive alternative to light water designs, it did add considerably to the knowledge and experience base of gas-cooled reactors specifically and nuclear power generally. We will chronicle the effort in images – mostly using those from an incredible press package in the author’s collection.  (Photos will enlarge when clicked.)

New headquarters for General Atomic under construction at Torrey Pines, California, late 1950's.  See next photo for details.

New headquarters for General Atomic under construction at Torrey Pines, California, late 1950’s. See next photo for details.  This company championed gas cooled reactors and, after several changes of ownership, still does today.

Public Service Company of Colorado (PSCo) – the company that would eventually own and operate the Fort St. Vrain Station – became involved with nuclear energy in 1954 when it and eight other utility and corporate partners formed the Rocky Mountain Nuclear Power Study Group for the purpose of determining approaches to utilize nuclear energy in the wake of the amendment to the Atomic Energy Act allowing private groups access to such technology.

PSCo became connected with the General Atomic Division of the General Dynamics Corporation just four years later in 1958 when it and seven utility companies formed the (separate) Rocky Mountain – Pacific Nuclear Power Study Group. This arrangement focused on the study of high temperature gas cooled reactors using a graphite moderator.  In that same year, some of the members of this new group (including PSCo) joined a large 53-member group that also pushed for a gas-cooled reactor; this wider effort would lead to the construction of the Peach Bottom Atomic Power Station in Pennsylvania. Peach Bottom differed considerably from what later became Fort St. Vrain, but its construction and operation was pivotal to, and integral with, the path that led to Fort St. Vrain.  Without going into detail on the Peach Bottom effort, it cannot be understated how important Peach Bottom was to PSCo’s continuing effort. PSCo’s effort was in fact contingent upon operational success of the Peach Bottom plant. Naturally, that held reactor vendor’s (General Atomic) future in the field of gas-cooled reactors, in the balance as well.

General Atomic Headquarters.

Headquarters of the General Atomic Division of General Dynamics was this impressive facility at Torrey Pines, California – the John Jay Hopkins Center for Pure and Applied Science, which was dedicated in 1959.  At the left are offices and a high-bay building used for experiments, while at lower left is the fusion energy laboratory.  At lower right is a technical office building; at the upper right are a critical test facility, a linear accelerator, the TRIGA training / research reactor center, a hot cell facility and a tower for testing reactor components.  Upper far right top (just visible) is the nuclear fuel fabrication facility.  Dominating the view are, at center, the library and technical information building and, surrounding it in a semicircle, a building housing 150 laboratories.

Following the launch of the project to build Peach Bottom the U.S. Atomic Energy Commission (AEC) promulgated a request for a follow-on plant which would be larger and hopefully much more like a competitive commercially viable design.  While there were other proposals offered to the AEC (notably, one by Rochester Gas & Electric in New York) the AEC selected PSCo for the construction of a 330 MWe gas-cooled, graphite-moderated plant.  The project to build this plant was announced to the public on March 13, 1965.

The project moved along at the rapid pace common to many of the early nuclear plants. On November 1, 1965, PSCo,  AEC, and General Atomic signed a contract for the construction of the plant although a location had not yet been determined.  However, on November 23, PSCo announced that it had selected a site in Weld County, Colorado, about four miles northwest of Platteville.

This map shows the selected location for PSCo's new nuclear plant, November 1965, at a location between Cheyenne and Denver and just to the northwest of Platteville.

This map shows the selected location for PSCo’s new nuclear plant, November 1965, at a location between Cheyenne and Denver and just to the northwest of Platteville, Co.

In January 1966, at the first meeting of the Platteville Improvement Association, PSCo announced that the new nuclear plant would be known as the Fort St. Vrain Nuclear Generating Station. The origin of the name is explained in a booklet published by PSCo and is reproduced here:

Fort St Vrain original fort nearby

“How did Public Service Co. of Colorado happen to select ‘Fort St. Vrain’ as the name for Colorado’s first nuclear electric generating station?

There really was a Fort St. Vrain, located about two miles northeast of the location of the power plant.  The first Fort St. Vrain was built in 1837 by Ceran St. Vrain, a French trapper.  It was one of several active trading posts in the area in those days.

When the fur trade was near collapse in 1844, Fort St. Vrain was abandoned, but sometime after 1846 it was reopened as a general store.  It also served as the County Seat of Weld County when the Territory of Colorado was formed in 1861.  A U.S. Post Office was located at the Fort until 1870, when it was moved to Platteville to be on a railroad line.”

It is probably no accident that the Fort St. Vrain Public Information Center built across from the nuclear plant and the sketch of the original Fort appear so similar.  This center still stands today, amazingly.

It is probably no accident that the Fort St. Vrain Public Information Center built across from the nuclear plant and the sketch of the original Fort appear so similar. This center still stands.

While critically important developmental testing was beginning at the now-completed Peach Bottom plant in Pennsylvania, design work went ahead on Fort St. Vrain.  This new plant would be radically different, in that it would attempt to make the primary or Nuclear Steam Supply System (NSSS) of the plant more compact.  To do this it would use a new fuel design and, for the first time in the United States, would employ a prestressed concrete containment vessel.

This sketch from a 1965 General Atomic report shows the planned layout of the plant, with the large concrete containment vessel enclosed in the tall structure and the turbine generator in the long projecting structure.  While not 100 per cent accurate this design sketch did come out to be close.

This sketch from a 1965 General Atomic report shows the planned layout of the plant, with the large concrete containment vessel enclosed in the tall structure and the turbine generator in the building to the right.  This sketch only roughly represents the plant as built.

While low-power testing was underway at Peach Bottom, PSCo began construction of a small facility at its Valmont station to test helium circulators that would be used at the new nuclear plant.  The company also built a 204 foot tall weather tower at the Fort St. Vrain site to gather weather data which would be used in its application to the AEC.  On October 20, 1966, PSCo officially filed its application for a construction permit with the AEC.  Not too long after that, in January 1967, Peach Bottom was able to generate electricity – a major accomplishment and a good sign for PSCo that its project would move along.

In June 1967, just as Peach Bottom reached its full-rated power on the grid, the planned Fort St. Vrain site was inspected by members of the Advisory Committee on Reactor Safeguards.  This was a very important time, as PSCo had hinged its decision to proceed any further with the new power plant until Peach Bottom had completed a nine month power run and performance review.  As it would happen, Peach Bottom hit the required marks early in the run (including 1000 hours of continuous operation) which ensured PSCo would approve continuing its own project.  What stood in the way now was the permitting process.

Two approvals were needed – that of the AEC, and also that of the Colorado Public Utilities Commission (not too different from today’s process in many states).  The PUC hearings began in November 1967.  By April 1968, the PUC had heard enough from all sides to determine that the project was viable and safe, and granted PSCo a “Certificate of Convenience and Necessity” for the Fort St. Vrain Nuclear Generating Station.  It was only at this point that actual, preliminary site preparation work was begun.

In July, PSCo was ready to go before the Atomic Safety and Licensing Board which met in Greeley, Colorado.  Two days worth of public hearings took place at this time, a necessary part of the licensing process set up to allow all stakeholders to have an input.  On September 16, 1968, the AEC’s Atomic Licensing and Safety Board authorized the issuance of a construction permit for the Fort St. Vrain station to PSCo, and this was in fact issued two days later on September 18.  General Atomic, acting as the prime contractor for the project, immediately began construction.  Although the company had design capability, internally it hired Sargent & Lundy as architect-engineer. Construction of the plant was contracted to EBASCO.  Interestingly, during this time period, General Dynamics decided to sell General Atomic to the Gulf Oil Corporation.  While this caused somewhat of a stir in the industry, it did not interrupt the effort to construct Fort St. Vrain or, for that matter, to operate Peach Bottom.  What mattered was that in just three and a half years (since announcing the project) Public Service of Colorado had a permit to build its first nuclear power plant.

Aerial photo showing site preparation underway for the Fort St. Vrain Nuclear Generating Station.

Aerial photo showing site preparation underway for the Fort St. Vrain Nuclear Generating Station.

The actual design used for the plant was not wholly dissimilar from the concept sketch shared earlier, although dimensions were considerably changed.  The prestressed concrete containment would be enclosed by a reactor building with a refueling floor atop it – not too different from BWR plants being designed then.  A turbine building, with the turbine axis radial to the reactor building, would extend outward and be flanked by offices and work spaces.  The straight lines employed in the design gave the concept a modern, yet imposing, appearance.

This rare artist's concept illustration of Fort St. Vrain comes from the October 1967 "News Briefs" brochure included in a Fort St. Vrain press package.  This concept drawing is very close to the design actually built, which is shown in the artist's concept at the top of this article.

This rare artist’s concept illustration of Fort St. Vrain comes from the October 1967 “News Briefs” brochure included in a Fort St. Vrain press package. This concept drawing is very close to the design actually built, which is shown in the artist’s concept at the top of this article.

COMING SOON:  Novel design of the prestressed concrete containment; design of the NSSS; construction photos on-site, and much more in future installments.

Farming within sight of the Fort St. Vrain Nuclear Generating Station; note tractor at far left of photo.

Farming within sight of the Fort St. Vrain Nuclear Generating Station; note tractor at far left of photo.



Will DavisWill Davis is a member of the Board of Directors for the N/S Savannah Association, Inc. He is a consultant to the Global America Business Institute, a contributing author for Fuel Cycle Week, and he writes his own popular blog Atomic Power Review. Davis is also a consultant and writer for the American Nuclear Society, and serves on the ANS Communications Committee and the Book Publishing Committee. He is a former U.S. Navy reactor operator and served on SSBN-641, USS Simon Bolivar.  His popular Twitter account is @atomicnews.

8 thoughts on “Fort St. Vrain in Pictures: 1

  1. Michael Allard

    I was employed by General Atomic in 1972 and sent to Ft. St. Vrain to help with startup testing. My specific job was as a computer engineer manning the startup testing data logging processes by a computer system installed under the control room floor. Much of my time was spent inspecting data extraction devices, sensors, and points throughout the facility. The data that was collected was enormous – monitoring temperatures, valve positions, and numerous other critical pieces of data. My critical time occurred the moment control rods were pulled to slowly bring up power, run tests, then move on to the next power level. I was fortunate to witness the first-ever spin-up of the main turbines after having been on turning gear for years. It was indeed exciting but short lived. Testing of backup systems control logic exposed a problem which caused a shutdown of the main cooling loop. This wasn’t the worst event. Moments later when the backup cooling was supposed to come online, it did not and the reactor was without cooling for several minutes – a failure that was deemed impossible to occur! So, of course, temperatures rapidly increased causing a pressure overload resulting in a very loud bang from safety valve exhaust stacks above the facility. I was told it could be heard for miles around. It scared me enough to send me running from the plant as quick as my legs would carry me. All things considered, it was an exciting tour as a General Atomic employee. I wish I could have been there when the plant went into commercial production years later. I still believe in the technology and hope to see it brought to full maturity soon with other HTGR plants coming online in my lifetime.

  2. JK August

    I have mixed feelings about the Fort, having burned up around ten years of my adult life at the site. One of the comments above, I agree with in full. I think it is unfortunate that more experienced production engineers had not reviewed the design critically. Aspects of that design varied from brilliant to stupid, frankly, from design of the PCRV, for example, to the Core Support Floor inside it. I personally believe virtually all the concepts worked out in principle, and that the original design was proven out as a prototype. The naiveté came from the assumption that they (e.g., “we” — PSCo) could “blow off” maintenance; it wouldn’t be required. There was this notion that Helium was inert, and corrosion control considerations wouldn’t be required. Or that it was just a fancy boiler, unlike our other coal-fired plants. That and some incredibly silly notions about operations (“Only” operators do that), such as not having integrated startup/shutdown procedures until ~1985 (Don Hood, myself and others developed the first ones then, mostly Don and Operations I admit) led to unfortunate circumstances like overstressed SG tubes from excessive heatup/cooldown rates. Oh well!!! That and a few Magic Marker “pen-masters” who documented management’s oversights as they saw it all over the concrete in the plant helped to leave the lasting notion that FSV management didn’t have a clue. In reality, I believe we did a great job, overall. You can’t believe now that a utility could run its own refueling crews (no one else does still), redesign its own refueling software (we did — emulating the old PDP-8S operating system on a PC), and numerous other significant redesigns that were needed to maintain the operating license to the plant. It was a valiant effort for which all employees can be very proud. The legacy at FSV lives on now, and will continue, until the next generation MHRs are designed, built and operated on the Fort’s experience base. I predict that another MHR (aka HTGR) will be built in the not very distant future. In the meantime, all you old-timers, take time to pat yourselves on the back for a job well-done working on a difficult design!

  3. Tom Donaghy

    I read your article concerning Peach Bottom. I went to Peach Bottom in 1963. I went from a Reactor Operator to Shift Supervisor in Unit 1. When I went to Unit 2 & 3 (BWR) it was as a Shift Superintendent. I supervised startups of Unit 2 & Unit 3. I retired in February of 1985 (before the sleeping problem at PB). To most of us from Unit 1 there was no comparison between the two different reactors. Unit 1 was only 40 MWE, but the concept of the HTGR and BWR were so much different PB Unit 1 was super clean. I went to Oyster Creek in New Jersey and picked up more of a dose of radiation than I had at PB 1 in over three years of operation. When we found out that General Atomic was going to build an HTGR in Colorado we thought that this would be the beginning of larger HTGR’s and bring Nuclear Power to great advantage. Unfortunately General Atomic (or Gulf) decided to do some design changes on the Helium Compressors which doomed HTGR’s probably forever. I am just putting my little bit of history into Fort St Vrain.

  4. Philip Bearly

    I transferred to FSV in 1971 as a maintenance helper. All reactor maintenance was through the mechanical maintenance dept. The fuel handlers had to acquire an NRC Special Senior Operator License, but were Journeyman Mechanics specializing in reactor maintenance, such as inspecting, loading, refueling, spent fuel shipping, control rod maintenance, and support system maintenance. I was helper, apprentice, plant mechanic, journeyman welder, then licensed fuel handler. Initial core loading was done from the inside, hand placing the fuel elements a layer at a time. I inspected elements, loaded burnable poison, worked the top head, loaded elements in core, refuelled, shipped spent fuel, and was on shift during unloading to the Independent Spent Fuel Storage Installation after plant was closed for decommissioning due to stress cracking of steam piping ring headers. My last 11 years was as a Nuclear Training Specialist training fuel handlers and operators all aspects or reactor maintenance. FSV was, in my opinion, the cleanest, safest, most efficient nuke plant in the country. We did refueling or shipping mostly in plastic gloves and booties only. We were limited to 70 percent for the life of the plant due to an overpressure of the core support floor cooling imbedded tubes during initial testing. When at 70 percent, it was rather noisy, due to throttling everything. One time, we were allowed to go to 100+ percent for 26 hours, to allow license approval with NRC. During that short run, the plant was fantastically smooth and quiet, with 1000 degree, 2500 pound main steam, and reheat working per design. The fuel particle, type, and loading design was amazing. This nation needs to rethink and go to HTGR reactors, for efficiency, fuel design, recycling conversion, and overall quality. I was glad to be asmall part of this historic era for Colorado. Former and current employees and contractors still meet monthly at the visitor center. We need to get the visitor center designated as historic landmark due to the displays, and photos there. Hopefully someday, before XCEL decides to do away with it. FSV is now repowered with gas turbines, and still a great sight standing out in the farmland.

  5. George Silvestri

    The problem with the HTGCR is that the scientists saw no need for engineering input and paid dearly for their misjudgement

  6. David R. Lawson

    Will, this I a very informative article. as usual. However, since I grew up in the area, I have to quibble with your use of the name Peach Bottom Atomic Power Station. Although originally there was only one unit, the one that you’re referencing that used graphite and helium, two BWR generating stations were also built there. Unlike Unit 1, Units 2 and 3 were standard (as far as that term has meaning) General Electric BWRs. Unit 1 was always considered to be experimental, and was shut down in 1974. The Peach Bottom site is notable in nuclear power history for being shut down by the NRC for “operator misconduct, corporate malfeasance and blatant disregard for the health and safety of the area,” (Wikipedia) This eventually led to major efforts in Conduct of Operations and Human Performance Improvement efforts throughout the industry. The shutdown was ordered not just for operator malfeasance but for management and corporate malfeasance, which eventually led to extensive industry efforts to improve the safety culture of companies operating nuclear power plants. I may be a bit biased, but I think that mentioning Peach Bottom without linking to later problems doesn’t create the right picture. Although corporate ownership changed quite a bit over the years, the experimental Unit 1 was successfully operated by this same dysfunctional corporate culture and operator (using a broad interpretation) malfeasance. The achievement is larger than your article would imply. The two BWRs remain I operation, mostly owned and operated by Exelon Energy. Peach Bottom’s story as it connects to Fort St. Vrain is limited to the experimental reactor, but the site’s impact on the entire nuclear industry is worth at least a footnote. Thanks for the great article, as usual.

  7. Steve Bump

    I worked at Ft. St Vrain while it was in operation. It was a really great place to work from a radiological standpoint. Too bad it was shutdown early and the technology not replicated elsewhere.

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