Hanford was the last destination of my 2024 eastern Washington road trip. I stayed in Richland for a night and took the tour the next morning.
The Manhattan Project National Historical Park operates tours of the remarkable first plutonium reactor that was built at Site B on the Hanford site. Hanford was one of the top secret sites operated in World War II to build the first atomic bombs. One of the critical materials for a bomb was plutonium, which occurs only in the most minute trace amounts on earth. Therefore, scientists had to devise a means of making plutonium from a reaction using Uranium-238. The Hanford area was well-suited for these pioneering experiments because it was far from major metropolitan areas, had access to cool water from the Columbia River, and had access to ample electrical supply, thanks to the hydroelectric projects on the Columbia River. I will not try to summarize the pioneering engineering and scientific achievements that went on during and after the war. You may or may not approve of the atomic weapons program, but it happened and is part of our scientific history.
The National Park Service offers (or offered) tours of the plutonium reactor in the summer months. A bus takes visitors across the broad scrublands of the Hanford site. Tour guides describe the setting and the background of the immense project. I was very impressed how well the entire tour operated. One of the guides was a nuclear engineer and was able to answer questions of every level. He told us that the first part of his career was creating radioactive materials. For the second part, he is cleaning up the waste.
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| 105-B reactor containment building, Site B, Hanford, Washington |
This severe and ominous concrete building houses the first plutonium reactor ever built. Workers began construction in October 1943, and the reactor was ready to load fuel in September 1944. This is remarkable productivity considering how long it takes to complete any major project today in the USA. The tall chimney was for ventilation. The construction of the B Reactor and the Hanford complex was one of the largest engineering and construction projects in the United States during World War II.
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| Reactor charge (front) face with elevator gantry near the bottom |
This is the front face of the reactor. About 2000 aluminum tubes penetrate through the graphite core. Each of the plugs in the photograph above is a cap and water valve over the end of an aluminum tube. To fuel the reactor, workers removed the end cap/plug and inserted aluminum slugs containing U-238. When the reactor was operating, cooling water came through each cap and flushed through the aluminum tubes and around the uranium slugs at a rate of 75,000 US gal. per minute. Highly skilled workers built the graphite pile, intricate piping, complex sensors, and the support equipment.
Cooling water came from the Columbia River via large water pumps. Electricity was supplied via the grid from hydroelectric plants, but a coal-fired generating plant operated and was on-line in case an emergency disrupted of the electric supply. Our tour guide (a retired employee) told us that once in 1944 or 1945, the electric supply was partly disrupted. The electric grid operators were told to stop all power to the city of Portland immediately to ensure that the Hanford water pumps continued to have full power.
After the water passed through the reactor, it was discharged into basins to allow short-lived radioactive materials to decay. Then, it was pumped back into the Columbia River downstream (yes, really!).
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| Sump below the back face of the reactor |
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| Safety signage |
When the physicists on duty computed that a certain set of U-328 slugs had been partly transformed and contained suitable plutonium, reactor technicians stopped the reactor and pushed the spent slugs out the back. The slugs fell into a water-filled sump and rested while short-lived isotopes decayed.
After some time, workers picked up the slugs by hand with long tongs and placed them into a water-filled cask. Later, a train took the cask to a plant that separated the P-239 from other materials in the spent slug.
The separation plants are not on the tour, and most (or all?) have been demolished. These were complex and experimental facilities that generated vast amounts of toxic waste. Much of the cleanup that is ongoing, and will last well into the next century, relates to the decaying storage tanks that contain hazardous and radioactive sludge. This cleanup will cost between $300 and $600 billion (which realistically means a $ trillion) and take 70 years (translate: a century).
The current plan is to mix low level waste into glass, to be buried elsewhere. The Hanford Vitrification Plant, also known as the Waste Treatment and Immobilization Plant, has been in construction for 21 years. It has cost an estimated $17 billion, but the budget has grown over time and may exceed $30 billion. You can see where this is going......
The entire reactor was manual. Humans operated everything. I love the precise mechanical gauges, controls, and valves. Highly-skilled craftsmen built everything with meticulous precision.
This was the train that carried the water casks to the processing/separation plant. I wonder if the locomotive engineer knew what he was carrying?
After the War ended, B Reactor was initially shut down at the end of 1946. But with the paranoia of the Cold War and growing tension between the United States and the Soviet Union, B Reactor restarted in 1948 to produce more plutonium. It operated until 1967. The U.S. Atomic Energy Commission shut down B Reactor permanently in 1968.
The other plutonium production reactors at Hanford have been closed and encapsulated with protective covers. I do not know if the remnants will sit for years or centuries. But because of its historic significance, B was preserved and became a tour site.
The Park Service tour is a fascinating historical visit to another era. Do go. And no, plutonium will not jump out of the graphite and irradiate you.
I took these photographs on Kodak Tri-X film with my Hasselblad 501CM camera and 80mm ƒ/2.8 Planar-CB lens.
