The Army Nuclear Power Program

[DMD]

Most people associate nuclear power with the Navy, but the US Army had a program from 1957 to 1975 with a few working power plants. This article gives a little history of this program.

 

A reactor operator qualification was required to operate the plant. Between 1965 and 1990, the Army authorized wear of four types of qualification badges for reactor operators: Basic, Second Class, First Class, and Shift Supervisor. The square on the badge is supposed to symbolize the reactor, and the two bars on each side are supposed to be the neutron-absorbing control rods inserted into the sides of the core. (It looks closer to the world’s first nuclear reactor at the University of Chicago during the Manhattan Project. Present day reactors general have the control rods entering at the top of the core).

 

This is an example of a Nuclear Reactor Operator, First Class, badge. The Shift Supervisor badge was the same design but gold colored.

[DMD]

There were 8 working reactors in the program, and the two letter designation describes the portability and power output:

 

First Letter: S – Stationary, M – Mobile, P – Portable

Second Letter: H – High, M – Medium, L - Low

[DMD]

SM-1 (1957 – 1973) was the Army's prototype nuclear plant, located at Fort Belvoir, VA. It served as the training facility and trained about 800 people, mostly Army but some Navy and Air Force personnel also. It had an electrical output of 2 Megawatts and achieved first criticality (reactor startup) in 1957. It was the first US nuclear power plant to be connected to an electrical grid and was shut down in 1973. The Shippingport plant in Pennsylvania was the first civilian nuclear plant to be on the grid, not long after SM-1 did.

[DMD]

Here is an old photo showing the SM-1 control room.

[DMD]

SL-1 (1958 – 1961) was an experimental nuclear power reactor at the National Reactor Testing Station in Idaho. The SL reactors were intended to be used at small, remote military facilities, such as radar sites near the Arctic Circle. The reactor was rated for 3 Megawatts thermal, and the plant could produce 200 kilowatts electricity and 400 kilowatts steam for space heating.

 

On January 3 1961, three operators died in an accident that caused a reactor power excursion and steam explosion. Reactors are controlled by the position of control rods that absorb the neutrons in the reactor, and the night shift was doing maintenance on the mechanisms that withdraw the rods to increase reactor power. One of the operators manually pulled one of the control rods out, and the output of the reactor increased to 20000 megawatts in a fraction of a second. The resulting steam explosion killed the three men (two were Navy) and melted the reactor core. Most of the radioactive material was contained within the plant, but the radiation dose was very high around the plant. This was the only fatal reactor accident in the United States. After this accident, all reactors were required to be designed so the core would not start up if only one control rod was withdrawn.

[DMD]

PM-2A (1960 – 1964). This reactor was located in Greenland at Camp Century, an army arctic research center built completely under the ice. Camp Century was used to learn how to operate in the arctic environment. The Arctic Engineer Task Force did experiments in storage and living conditions and the Army's Transportation Corps tested special Arctic vehicles. PM-2A was the world's first portable nuclear plant and produced 2 megawatts electrical plus 1 million Btu/hour steam heat. The reactor was removed and shipped home when Camp Century was closed in 1967 because of movement of the glacial ice.

[DMD]

ML-1 (1961 – 1963) was an experimental reactor at the National Reactor Testing Station in Idaho. The reactor was designed to be very compact and used a closed-circuit gas turbine. It never got out of the testing phase and was abandoned after only a few hundred hours of operation.

[DMD]

PM-1 (1962 – 1968) was used to provide electrical power to a remote Air Defense Command radar station near Sundance Wyoming. The plant generated 1250 kilowatts and was operated by the US Air Force, 731st Radar Squadron. The reactor was built underground.

[DMD]

PM-3A (1962 – 1972). This was the power plant for McMurdo Sound, Antarctica. It was an Army reactor operated by the Navy under direction from the Atomic Energy Commission, the predecessor of today’s NRC. The plant had maintenance problems and was eventually shutdown due to chloride stress corrosion.

[DMD]

SM-1A (1962 – 1972) was built at Fort Greely, Alaska. There’s not a lot of information about this plant and some controversy about its purpose. Apparently there is contamination around the plant, and the reactor was entombed on-site.

[DMD]

MH-1A (1967 – 1977) was the first floating nuclear power station. Mounted on the Sturgis, a converted liberty ship, it supplied 10 megawatts electricity to the Panama Canal Zone from 1968 to 1975.

[DMD]

Finally, one last photo that shows what the control room looks like. The training facility at Fort Belvoir had an electronic control room simulator for training the operators of MH-1A. This is the simulator.

 

There's not a lot of information available about the Army Nuclear Power Program (with the exception of the SL-1 accident). The photos are courtesy of Wikipedia, has a good article about the program. Hope you enjoyed!

[The Meatcan]

thanks DMD! that was truly educational. I had no idea the Army was so involved with reactors in that era. Thanks for posting

[Plant#4]

PM-2A (1960 – 1964). PM-2A was the world's first portable nuclear plant and produced 2 megawatts electrical plus 1 million Btu/hour steam heat.

The NB-36 first flew in 1955 and had an operating nuclear power plant onboard. Ergo, it was the first portable nuclear power plant, as that it did not power the aircraft. I have quite a bit of info on these reactors that Convair was using. Dave

[DMD]

The NB-36 first flew in 1955 and had an operating nuclear power plant onboard. Ergo, it was the first portable nuclear power plant, as that it did not power the aircraft. I have quite a bit of info on these reactors that Convair was using. Dave

 

The difference between portable and mobile is not really clear, but I believe a portable reactor was one that could be disassembled, moved, and reassembled in a new location. The NB-36 reactor should be considered mobile.

[El Bibliotecario]

What a revealing thread--I had no idea! And scary as hell--I can just see the old sarge saying, "Private, don't give me any crap about radiation--the general's coming tomorrow and I want every one of those damn control rods Brasso'd!"

 

As for nuclear propelled aircraft, the Nevada Test Site spent years working on such a program, but finally abandoned it. In a publication on Nevada ghost towns, the writer claimed the apparatus was dumped down an old mine shaft and sealed with concrete.

[evstringer]

……

As for nuclear propelled aircraft, the Nevada Test Site spent years working on such a program, but finally abandoned it. In a publication on Nevada ghost towns, the writer claimed the apparatus was dumped down an old mine shaft and sealed with concrete.

 

Testing of nuclear aircraft engines was also done at Test Area North (TAN) located at the present day Idaho Nuclear Engineering Laboratory site.

 

In about 1986 I went there as part of an independent engineering team to review the results of clean up efforts at the INEL TAN site.

 

I recall that as well as nuclear contamination there was still a large amount of mercury contamination. I was told that the mercury was used as a coolant in the engine. There was a huge hanger still there. I think the project was abandoned in the early 60s.

[hawkdriver]

There was some testing on nuclear powered rockets at the Nevada test site, but it was abandoned as to risky. The reason was that an accidental explosion on take-off wasn't worth the risk.

[evstringer]

SL-1 (1958 – 1961) ……….

 

On January 3 1961, three operators died in an accident that caused a reactor power excursion and steam explosion. Reactors are controlled by the position of control rods that absorb the neutrons in the reactor, and the night shift was doing maintenance on the mechanisms that withdraw the rods to increase reactor power. One of the operators manually pulled one of the control rods out, and the output of the reactor increased to 20000 megawatts in a fraction of a second. The resulting steam explosion killed the three men (two were Navy) and melted the reactor core……

 

The reports I saw indicated that two were Army (John Byrnes and Richard McKinley ) and one was Navy (Richard Legg). One was impaled and stuck to the ceiling with a control rod and the other two died from the intense radiation. All three were buried in lead lined caskets due to the large amount of long lasting radioactive material in their bodies.

 

Argonne National Laboratories was involved with the SL-1 site and when I worked for an Engineering Firm in Idaho Falls during the 1980s we did some work at the Argonne National Laboratories West site. The workers there still thought the incident was caused by irrational behavior resulting from a “love triangle” involving the wife of one of the men. There are others that think the incident was caused by inept engineering and management.

[DMD]

There are a few errors in this thread. First off, the badge pictured in #1 is actually a Second Class badge, not a First. You have a very short time to be able to edit a post, and I found I got the wrong picture too late. Moderators, it would be good if there was more time allowed to edit what you have posted.

 

I read that two Navy and one Army guy died, but I am not certain if that's right.

 

The two guys that died immediately were killed by the steam explosion, not by radiation. However, all three men received well over the fatal dose and would have certainly died within a few days.

 

I have heard the rumor about personal problems and suicide, but I don't think there's any truth to it. The design of the reactor was not tolerant of mistakes. The theory is that the operator pulled out the control rod by hand so he could get working room for the rod's drive mechanism on top of the reactor pressure vessel.

 

This reactor had two characteristics that made it dangerous. It was able to go "prompt critical" when only one control rod was withdrawn (there were 5 control rods total, with room for four more). Prompt critical means the fissions in the core can increase at enormous rates (2.7 times every 4 milliseconds for SL-1). Also, it used highly enriched uranium (U-235) for the fuel. If there was more U-238 in the fuel, the power increase would have been turned around as the fuel heated up, so the energy release could have been limited. For the SL-1, the energy increased to the point that it caused a huge steam explosion in rhe reactor's pressure vessel, pretty much like a boiler explosion.

[ehrentitle]

Great thread. Below are two Nuclear Reactor badges that I picked up at the Ft Benning in the early 1980s. That was the good old days before AAFES took it over when you could buy badges for less than a dollar. Any idea how hard these badges are to find now days. Not that the badge you show at the start of the thread is not a First Class badged but actually a Second Class badge. See the TIOH website at: http://www.tioh.hqda.pentagon.mil/Badges/n...or%20badges.htm

[evstringer]

I agree that I was mistaken about radiation being the cause of death of two of the men. That is what I get for trusting my memory of what I had heard a long time ago. I guess the impression of the extreme amount of radiation coming from the bodies stuck more than the rest of the story.

 

I found some old Atomic Energy Commission reports on the incident and they indicate that the men were killed by violent force rather than radiation.

 

However from the reports, I would say that the “explosion” was not “pretty much like a boiler explosion”. A boiler explosion is where the pressure inside the boiler can no longer be contained and the boiler comes apart in chunks that fly in all directions.

 

The reports state that a large amount of steam was produced underneath a 7-foot column of water and the column of water was pushed upwards striking the top of the reactor vessel, more like a water hammer than an explosion. The whole reactor vessel was thrown up about 9 feet as a result but it did not blow to pieces. Apparently being thrown about by the violent movement of the vessel killed two of the men.

 

Any way you look at it, it seems that this incident was the beginning of the end for the Army’s involvement with nuclear power.

[gwb123]

Testing of nuclear aircraft engines was also done at Test Area North (TAN) located at the present day Idaho Nuclear Engineering Laboratory site.

 

In about 1986 I went there as part of an independent engineering team to review the results of clean up efforts at the INEL TAN site.

 

I recall that as well as nuclear contamination there was still a large amount of mercury contamination. I was told that the mercury was used as a coolant in the engine. There was a huge hanger still there. I think the project was abandoned in the early 60s.

 

 

In typical military fashion, I believe they built the hanger, a runway, and an oversized towing tractor...before the airplane was ever built.

 

The project was abandoned after it was determined that the weight of the reactor plus the amount of shielding required to keep the crew safe precluded carrying any sizable weapons load.

[evstringer]

I think you are right about the hanger with no airplane to go with it.

 

Probably they knew for a long time that the engine was too big and heavy to be used in an aircraft. To me it had all the earmarks of a Pork Barrel Project.

 

I talked to one man who had worked there and he told me that one day when they showed up for work they were lined up at tables in the big hanger, paid off and told to go home and not come back. It was a big surprise to them, there had not even any rumors about it being shut down.

[Plant#4]

ASTR or Aircraft Shield Test Reactor. Here are a few pics from a Convair manual for the ASTR, this one was ment to be flown around just to show that it could be ported, they had another one that was not flown, but was used in testing. It was shielded by water, and the crew was also protected by a large lead baffle system. They had a lot of assets following this aircraft around when it flew, recovery equipment and a detachment of Marines as well.

Dave