Pool Reactors 3: Building a Reactor Facility

by Will Davis

In this final installment of the series on pool reactors we’ll take a look at some remarkable images found in a 1956 brochure which shows some of the steps of the process in constructing the Ford Nuclear Reactor and attendant facilities at the University of Michigan.  Under the leadership of Babcock & Wilcox (today, BWXT) this 1000 KWt facility was constructed in about 19 months.  Reviewing the previous article in this series will be helpful in relating the construction photos.

Build 1 Ford Pool Foundation

In our first photo, construction of the Ford Reactor facility is well underway. Here, the roughly horseshoe shaped foundation for the reactor pool can be made out; normal operating position for the core will be at the left or rounded end of the pool. In this photo the lab and administration building would be to the right.

Build 2 Reactor Building

In this view the construction of the reactor building itself, comprising the left portion of the photo, continues while the adjoining building appears virtually complete. The reactor building had foot-thick reinforced concrete walls. Perhaps “has” would be better since this facility is still standing today, although without an operational reactor.

Build 4 Tubes and Thermal Column

In this mostly straight down view, a variety of beam tubes (the pipes in a half circle) can be seen converging at the location of the core when in operation. The large structure dominating the upper portion of the photograph is the thermal column, comprised of a 9 ton shell and 12.5 tons of graphite bricks. The purpose of this structure is to thermalize, or slow down, neutrons for research purposes outside the pool structure. This column was protected on the outward side by a large, heavy shielded door. However, this column could not be used with the core in the position at the bottom of the picuture; the core had to be beside the column, and in that location further beam tubes can be seen directed at the gap between the thermal column structure and the pool wall. For thermal neutron research the core would be moved to this position by the mobile bridge and operated here.

Build 5 Heat ExchangerThe Ford Nuclear Reactor had what we might call more than one operating mode.  As can be seen from the above picture, the core could be positioned by the bridge crane and operated at the convergence of a large number of beam tubes in order to maximize research potential; a pneumatic rabbit tube system was also installed for quick experiments.  However the core could also be moved beside the thermal column for thermal neutron work.  There were also two modes of cooling; the reactor could be cooled just by convection at low power, but a forced cooling system using a heat exchanger in the basement of the structure (shown at left) and outdoor cooling tower could handle power outputs up to 1000 kilowatts.  These considerations made the Ford Nuclear Reactor facility versatile, and advanced for its day.

Build 7 Bridge Crane

As with all pool reactors the core of the Ford Nuclear Reactor was suspended in the pool water by a rolling bridge crane and attendant core support structure.  Above, we can see the bridge crane in the final stages of assembly; one of the rails on which it rides just protrudes into the left of the picture, while the arms to support the core can be seen dropping through the wooden scaffold platform near the center of the photo.  In the photo below we see the lower end of those arms which are holding the core support plate, or “grid plate.”  The plate, at this point with no other equipment installed on it, is sitting at the normal full power operating position by the majority of the beam tubes.

Build 9 Core Frame In Position

 

Build 6 Core SupportWhile plain training reactors were built and intended to operate with just a single core configuration, most pool type research reactors were built with a flexible arrangement in mind; that is to say, they were set up to allow a variety of core / fuel and experiment configurations, and versatile instrumentation in and near the core.  All of the instrumentation for monitoring and controlling the reactor as well as the control rod drives were suspended from the bridge crane.  At left we see the brand-new grid plate for the Ford Reactor in close-up.  This plate had 80 locations which could accept fuel elements, graphite reflector elements, or instrumentation.  According to the brochure, unused openings were plugged to force coolant to the fuel elements; additionally the plate had another 63 small openings which allowed smaller amounts of water to pass through for cooling the fuel element exterior.

Ford Nuclear Reactor Core Detail

This beautiful illustration from the same material shows a core assembled in operating configuration on the grid plate, complete with fuel elements (note the grapple fixture or “handle” at the top of each square-section element) as well as control rods and nuclear instruments.

Build 11 Ceramic Pool Tile

Here’s a job most of us can relate to – applying grout to ceramic tile! The entire interior of the Ford Nuclear Reactor’s pool was covered with a durable ceramic tile capable of enduring the abuse of a high radiation environment. The light-reflecting tile was also intended to be easily decontaminated.

Build 12 Ford Reactor Nears Completion

The Ford Nuclear Reactor facility nears total completion in this view. The reactor facility was not in an entirely unpopulated area and was not surrounded by any sort of restricted zone – so it had to be designed as a gas-tight structure. Doors into the reactor building as well as ventilation dampers were all designed to seal tightly when closed.

I hope you’ve enjoyed this three-part look back at a very humble, but very necessary part of the nuclear technology history of the United States and, for that matter, much of the world.  The pool reactor, made inexpensive by design and through the use of then-available off the shelf critical components such as fuel and instrumentation, was the training and research tool that opened careers for thousands and thousands of professionals in the field.  It’s worth noting again, as at the start of this series, that the pool reactor isn’t just a thing of the past, either; it may come back, this time as a district heating machine in cold climes.  Certainly the advantages of simplicity and ease of construction so clearly shown during the 1950’s and 1960’s have not been forgotten, and we may yet see the pool reactor make a triumphant return to a stage widely, and noisily, occupied by much newer, more advanced and more exotic actors.  Perhaps in a way that return would be fitting, and welcome.

(Illustrations in this installment come from the remarkable brochure, “The Babcock & Wilcox Company Builds a Research Reactor,” published late 1956.)

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, @atomicnews is mostly devoted to nuclear energy.

Feel free to leave a constructive remark or question for the author in the comment section below.

 

3 thoughts on “Pool Reactors 3: Building a Reactor Facility

  1. Charles S. Barnett

    I enjoyed your sequence of articles on Pool Reactors. Perhaps some additional information from a geriatric physicist might entertain you.

    From Fall 1956 to Fall 1957, I was one of about 30 or so students at the Oak Ridge School of Reactor Technology (ORSORT). I recall some reactor training exercises at the Low Intensity Training Reactor (LITR). It was, I think, a pool type reactor.

    The year at ORSORT was one of the most intense study periods of my graduate-study days. One student commented, when told that we were being scheduled for sessions at the LITR: “I am ready for some low-intensity training.”

    In those early days it seemed that all sizable nuclear laboratories had to have a reactor of some sort, and the pool type seemed to fit the bill. Most of my career was spent at the Lawrence Livermore Nuclear Laboratory (LLNL); in those days it was called Lawrence Radiation Laboratory (LRL). And sure enough LRL built the Livermore Pool Type Reactor (LPTR). I did not work at the reactor, but I was periodically recruited to test the operators when their certificates required updating. The LPTR ceased operations years, perhaps decades, ago. I retired from LLNL in 1993.

  2. Ed Klevans

    Will,
    Since I got my PhD at Michigan in Nuclear Engineering in 1962 and have a photo of me sitting at the controls, I appreciated seeing all the photos related to the U. Michigan Ford Nuclear Reactor. I personally think they made a mistake to shut it down. Here at Penn State – I was on the faculty from 1966-1998 and Department Head from 1987 to 1998 – we took a very different direction by upgrading the reactor, rebuilding the bridge to move anywhere in the pool, putting in a digital control system and now realigning the beam tubes to enhance the research capability, we, with the first license of an operating reactor, are still going strong and have a lot of industry support. Indeed, the building with the reactor is being expanded to put in a cold neutron source and increase the research capabilities. Kenan Unlu, as the Director of the Nuclear Science and Engineering Center, is in charge of this effort. He also got his PhD at Michigan. Now that I am retired I organize tours of the reactor every few years and usually get a number of retirees who are interested in seeing it. You probably know Candice Davison, who conducts the tours. I get a lot of positive feedback from these tours.

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