#: locale=en
## Media
### Title
photo_51597A51_4264_5429_41BD_186C8D634444.label = 12566-NEG-E (1954) PUREX CANYON AND CRANE, DAMEAGED SLUGS 100-DR - CANYON CRANE CONTROLS AND VIEW
photo_501CF7F5_4264_5BD3_412F_6C6380C07364.label = 12656-NEG-B (1955) DR PARKER AND TECH GRADS
photo_509343F7_4264_5BE8_41C3_AFD62C61DC9B.label = 13688-neg-l5 (1956) Hanford Operations - Cask Car (color tran
photo_5044FA35_426C_7452_41A2_C1C9DE851244.label = 3316-neg (1944) 221-T, Gallery Level Under Construction
photo_56C614D2_426C_BC22_41D0_93621B3EDAE3.label = 3495-neg (1944) construction of 241-T tank farm - looking nor
photo_51C7B5E9_4265_FFE5_41B0_8CCADE6334D0.label = 3504-neg (1944) construction of 221-B building - looking nort
photo_5075D831_426C_5452_41AA_479FD5BC17DC.label = 3710-neg ( 1944) construction of 221-T ( canyon building ) -
photo_50A309D5_4264_B7D3_41C8_D8FAE0E73D5F.label = 4155-neg (1944) process canyon cell cover blocks construction
photo_50AF8591_4264_BC25_41BF_0867C4BD331F.label = 4975-neg 221-U Canyon Section 19 Interconnecting Piping
photo_5649A1DE_426C_D421_41BE_42410C1425FF.label = 6198-1-neg-(1953) 221-T Operating Gallery
photo_50FCC871_4267_D4D3_41C4_141333526309.label = 7203-1-NEG-E (1953) 221-U BUILDING CANYON - 200 WEST
photo_510D8354_4264_D42C_41B7_9EE656A652F2.label = 7649-1-NEG-S (1954) RADIATION MONITORING AT 200 WEST AREA
photo_514C5A26_4264_546D_41C2_ADC06A2AC14B.label = 7651-NEG-E (1954) RADIATION MONITORING - 202-S BUILDING - REDOX - 200 WEST AREA
photo_577CAEB8_426C_6C6E_41A7_EB1DF2FF7624.label = 7729-neg 231-z cell 1
photo_50EC21A6_4264_547E_4144_8934B138BE60.label = 8411-neg plant electrical gallery
photo_511888FB_426C_75E3_41B9_9B7048E05660.label = 8430-neg separations pipe gallery
photo_564FBCF8_4263_EDE2_4174_A0329AAB1F08.label = HP-163-Photo-(1953) 221-T Operating Gallery-Bismuth Phosphate Chemical Separations
photo_50031925_426C_D472_41D0_890EF7B361F2.label = Laboratory_-_New_Chemistry_Building
photo_561C30AB_426D_B460_41C8_2F65E46E30C6.label = M-2355-Neg-(Circa 1944) Smoke Stack Atmospheric Testing
panorama_E1BA112B_ED20_5117_41C7_252014E27F7E.label = R0010316
panorama_E668FE58_ED21_D331_41B4_E8ECD814F775.label = R0010318
panorama_E665F63D_ED21_F372_41AA_89B7443029BE.label = R0010320
panorama_E665FE2A_ED21_F311_41E9_C5171DF77590.label = R0010322
panorama_E665A704_ED21_D111_41E8_2EF0B1C11C0D.label = R0010324
panorama_E665CF8C_ED21_D111_41B1_4CDD1CBFE814.label = R0010325
panorama_E66597E1_ED21_B113_41BD_E619C00F801C.label = R0010326
panorama_E6643058_ED20_4F31_41E8_6FA264313DA3.label = R0010327
panorama_E664885A_ED20_5F36_41E1_E942C8EECC3B.label = R0010329
panorama_02F08338_114A_EC08_4183_D870EC931FF6.label = R0010330
panorama_01FA5944_114A_DC78_4189_BA01CF6DE68D.label = R0010331
panorama_01E59199_114A_2C08_41AC_262B88F39A6D.label = R0010332
panorama_01E45A0F_114A_3C08_41B0_23C68768332C.label = R0010333
panorama_01E4727B_114A_2C08_417B_82EA20BB4D6C.label = R0010334
panorama_01E45A8F_114A_5C08_417D_7C2B2BF9CF97.label = R0010339
panorama_01E442DD_114A_6C08_4188_2335450A30B5.label = R0010340
panorama_01E47B75_114A_7C18_41A0_82F00E214083.label = R0010341
panorama_1F3189DF_114A_3C0E_41A7_4DF3B69F987C.label = R0010342
panorama_1DB03562_1149_F431_41A3_C38CC230EA44.label = R0010343
panorama_1DB458D0_1149_DC11_4170_319BB4FD618A.label = R0010346
panorama_1DABB166_1156_2C3E_4178_45EB95A5A2F7.label = R0010347
panorama_1DABF985_1156_3CF3_419B_16C466B5B11E.label = R0010349
panorama_1DACD1BE_1156_2C11_41AB_84E54C082FFE.label = R0010350
panorama_1DACEA34_1156_5C12_41A1_7FF5C67F8A71.label = R0010352
panorama_1DACD262_1156_6C36_41B0_F4AE5AFF7E7E.label = R0010353
panorama_1DACFACE_1156_7C0E_417C_58A0176A02A3.label = R0010354
panorama_1DAD3355_1156_6C12_4193_A9CEC37067B0.label = R0010355
photo_506593FD_4264_5BD3_41C7_279319E3680D.label = RG1D_4A_0028
photo_53DD5036_4263_F45E_41B6_476DCAE0B5D2.label = Shinkolobwe
photo_53909C22_426C_EC71_41C0_F442351BC3BB.label = T-plant_construction_HS_4
photo_5065F364_426C_54F2_41C9_C046251FCB4E.label = T_plant_image_HS_3
photo_5614FFF8_426C_EBEF_41CD_89911E51FE52.label = green_run_map_HS_22
## Popup
### Body
htmlText_22B67EEF_3824_7B8C_41C4_3A55CE07317A.html = Administrative and engineering controls use time, distance, and shielding to protect workers from radiation exposure. Managing or limiting the amount of time workers are exposed to a radiation source is an example of administrative control and is one of the easiest controls to manage.
The above photo shows a recording of exposure for a particular task. During the early startup periods at Hanford the exposures were based on a 40-hour week, with limits for exposure for a week, a month, and a year. Timekeeping was a minimum of a two-person task. The primary individual was the “radiation monitor” who continually performed the task of evaluating radiation exposure to the worker. The second individual involved was typically an operation staff member who recorded the radiation levels provided by the monitor. Workers were limited to 300 mRem radiation dose per week to keep employees below the annual exposure limit of 5 Rem. If an employee worked on a high exposure job during the week, he was then limited to the amount of exposure he could receive for the remainder of the recording time frame.
Image Credit: US Department of Energy
As the distance from a radioactive source increases (i.e., move farther away from the source), the measured dose drops off rather quickly, inversely proportional to the square of the distance from the source. In other words, if the radiation measures X at 1 foot (.30 m) from the source, at 5 feet (1.5 m) it would measure only 1/25 or 4 percent of the original dose.
Putting distance between people and the source of radiation can be a simple procedure. In the case of the levels of radiation handled at T Plant, just maintaining a safe distance as the only control would have made the operation of the plant virtually impossible because the “safe” distance from a batch of irradiated slugs would have been measured not in feet, but in miles. In fact, the distances between the separations plants, reactors, and the public were, indeed, measured in miles, so that an accident at one plant might not force the abandonment of the others.
Image Credit: US Department of Energy
At the conclusion of the process in the T Plant canyon, the material was piped to a nearby building, named 224-T, for further concentrating. The fuel was originally processed in “batches” to limit the possibility of a buildup of plutonium and the possibility of a chain reaction (nuclear criticality). The “batch” of irradiated fuel from the reactors had now been reduced to about 325 gallons (1230 l) of plutonium baring solution. The separations process also removed much of the mixed fission product waste from the solution, which significantly reduced the radiation levels. This solution was then further processed to remove additional waste materials and reduce the volume to about 8 gallons (30.28 l) of plutonium concentrated solution.
The product solution from the 224-T building was stored in a special container and transported to the 231-Z building (pictured) by motor vehicle. At this stage of the process, the radioactivity of the solution was only a small consideration. Of greater concern was the product itself, plutonium, which is quite deadly when inhaled or absorbed through the skin. The plutonium was pulled from the solution in the form of plutonium nitrate, which was reduced in volume by evaporation, transferred to a special container for shipment, and then evaporated still more until it was thick and paste-like material.
On February 5, 1945, first small batch of plutonium nitrate was ready for shipment to the Manhattan Project laboratory in Los Alamos, New Mexico where the plutonium was fabricated into the core of atomic weapons.
Image Credit: US Department of Energy
Built during the Manhattan Project, Hanford’s T Plant was the first separations plant in the world constructed to chemically separate radioactive materials. Much of the separations work was done remotely to protect workers from the tremendous amount of radiation given off by the irradiated uranium fuel slugs. While humans had separated base and rare metals using heat and chemical processes for millennia, separating a man-made material from a highly radioactive fuel slug at an industrial scale had never been done before.
T Plant was designed to chemically separate about a half-pound (250 g) of plutonium metal from one ton (907 kg) of irradiated uranium each day. That is like separating the weight of a hamster from a mass that weighed as much as an average automobile! The chemical separations process that enabled Manhattan Project personnel to recover miniscule amounts of plutonium from the irradiated uranium were developed by University of California chemist Glenn Seaborg. His original experiments were conducted with micrograms of plutonium. T Plant’s separations processes used a billion times the amount of chemicals that Seaborg used in the lab.
Image Credit: US Department of Energy
DuPont used two types of optical devices for the crane operator to “see” inside the canyon: a periscope mounted on the crane bridge to see the canyon deck and a television camera mounted on a crane hook that focused on the crane hooks. These devices provided a broad field of view in the canyon, as well as a closeup view of the cell equipment and crane hook or impact wrench. The remote television CCV that was used on the T Plant crane represents one of the earliest uses of television in an industrial setting.
Learning how to use the crane and its optics to remotely work in the canyon required a bit of a learning curve. The following is from an oral history describing this process:
"So, I got two or three of the top operators into the cab, of course there was no radiation yet, and I said, “Gentlemen, I’m not a cane operator. You are. I think we have to get together and learn how to use what we’ve got.” Oh, they thought that would be terrible. The first thing you know they were getting the biggest kick out of looking through the periscope, with this great big hook going down and hooking on to a wheelbarrow or something down there in the cell area, picking it up and gently putting it down. They had a ball. They were fantastic. The crane operators learned in 10 hours or so."
- T Plant Worker NAME REQUIRED
Role at T Plant Dates
Image Credit: US Department of Energy
During the design of the separations building a major concern was the level of radiation that workers could be exposed to during separations activities. To reduce this hazard the canyon was designed to be operated remotely. To accomplish that task, it was necessary to design and build equipment that could operate without direct hands-on manipulation by individuals. The result was a crane with multiple hooks and multiple capacities and equipment that could be operated using air or electrical connections such as impact wrenches and piping equipment that had impact wrench connections to open and close the valves.
The crane spanned 58 feet (17.67 m) across the canyon (pictured). The bridge, the side-to-side transport that carried the hooks for lifting equipment, across the canyon’s width, had a range of 32 feet (9.75 m), covering the working area of the canyon. The canyon is to your right as you move through the electrical gallery. There were multiple lifting hooks and hoists available that provided the crane operator with the ability to raise the cover blocks, lift equipment into and out of each cell, and remotely add and remove liquid and electrical jumpers in the cell.
Protecting workers in the crane from the radiation in the gallery was critical. The first line of shielding for the cab (and its occupants) was the cabway in which the crane rode. The cabway was 5 feet (1.52 m) thick concrete wall that separated the galleries from the canyon and ran the length of the building. This put the cab in a three-sided channel, surrounded by heavy concrete walls on both sides and below. The roof and upper walls of the crane were 4.5 inches (11.43 m) thick. The lower walls were 3 inches (7.62) thick, and the crane floor was 1.5 inches (3.81 cm) thick.
Image Credit: US Department of Energy
Engineering a building for safe chemical separation of plutonium required an enormous structure. T Plant is 875 feet (266.7 m) long, which is the length of almost three American football fields. It is referred to as the “canyon.” T Plant also earned the nickname “Queen Mary” since it is long and narrow like the well-known ocean liner, and much of the building is located below ground.
The T Plant building is a concrete box measuring 875 feet (266.7 m) long, 65 feet (19.8 m) wide, and 85 (26 m) feet tall. Along one side, there are three rectangular galleries: electrical gallery, pipe gallery, and the operations gallery. These galleries are stacked on top of one another and run the entire length of the building. Adjacent to and running alongside the three galleries is the canyon portion of the building, composed of 40 individual concrete cells. The chemical separations process took place in the canyon portion of the building.
This huge fortress of a building required a lot of building materials:
• 1,880 tons (1705 mt) of reinforcing steel, which equates to about 10% of the steel used to build the Eifel Tower.
• 27,000 square feet (3,000 sq m) of reinforcing mesh, which is enough mesh to cover every square foot of an American football field.
• 90,473 cubic yards (69,172 m3) of concrete, which is enough concrete to build a two-lane road from Seattle, Washington to Salt Lake City, Utah.
• 59,500 square feet (6,000 sq m) of roofing material, which is enough to cover nearly three American football fields.
Image Credit: US Department of Energy (modified)
Gardner C. Blackburn worked as a carpenter foreman in the T Plant starting in 1943. He described a typical workday in the T Plant:
"We were going all the time with several batches; once we got one going, another one would be right behind it. I had an operator on each of the boards (one for each section). Before there was any movement of the process materials from one tank to another, I had to go unlock the board. The steam went to them for jetting, and then the air blew them out to cool them off, and then we locked them up again. So I had a lot of walking up and down the gallery.
I had a supervisor who sat in the office most of the time. Of course, he would talk to the operators, but I did all the running on my shift (there were four shifts and four of us chief operators).
I had the keys and had to write in the book at the end of a shift; we always had a log, and I was responsible for filling it out. The pages in the log told the operators just how long to settle, how much and what type of chemical to put in. And then the operator had to put in that he did this, and he did that, and he did this. That’s the way we ran it." Gardner C. Blackburn, 17-Nov-1999
Image Credit: US Department of Energy
Hanford was the first industrial-scale plutonium factory in the world, and for safety reasons, it was situated in a remote area of eastern Washington and isolated from major cities and highways. Workers recruited from more populated areas of the country often felt in the middle of nowhere and were struck with an immediate case of homesickness after arriving at the Hanford Site.
One of the biggest challenges managers faced was finding and keeping workers. Finding tens of thousands of skilled and unskilled workers was a feat. A high rate of turnover among the workforce compounded this problem. Throughout the life of the project, DuPont conducted more than a million interviews in 47 states, resulting in 90,500 hires, of which 72,500 employees actually showed up for work. The above image shows several of the Hanford construction working building operating gallery.
Due to extensive aircraft and ship building that was taking place on the West Coast, the shortage of skilled labor required DuPont to provide specialized training and transfer many craftsmen from other DuPont plants and projects.
Image Credit: US Department of Energy
Hanford’s role in the Manhattan Project was to produce plutonium on an industrial scale to be used in the world’s first atomic weapons. This story begins at the Shinkolobwe mine (pictured) in present-day Democratic Republic of the Congo, known as the Belgian Congo during World War II. Miners extracted some of the world’s richest uranium ore from this mine and shipped it to Canada for refining. After refining, the ore arrived at one of several plants in the United States that processed the uranium ore into pure uranium metal and shaped the uranium into billets.
Workers loaded the billets onto railcars and shipped the billets to Hanford where they arrived at the fuel fabrication site, also known as the 300 Area. Here, machines milled the uranium billets into cylinders and sealed the uranium cylinders in aluminum jackets creating fuel slugs for the nuclear reactors.
Workers drove the fuel slugs across the Hanford Site to the B Reactor and its two siblings, D and F reactors, for irradiation. After irradiation in a nuclear reactor, workers carefully loaded the highly radioactive fuel slugs into shielded, water-filled casks on train cars for transportation to the T Plant.
At T Plant, the fuel went through a series of complex chemical processes to separate plutonium from uranium and other radioactive byproducts. Scientists in Los Alamos, New Mexico, assembled the core of the Trinity Test device and the Fat Man atomic bomb using Hanford’s plutonium. The chemical separation process created millions of gallons of toxic waste that is stored in underground tanks. Safe management and disposal of this waste is the biggest challenge at Hanford today.
Image Credit: Public Domain
Irradiated fuel slugs were transported from the B Reactor to the T Plant by rail car in water-filed and shielded cask cars (pictured). When the train arrived at T Plant, the cask car would be backed into the train tunnel at the east (head) end of T Plant, straight ahead of you, through a roll up door. If you were to continue the direction you are going, you would eventually encounter the railroad tunnel. The railroad personnel and the operations staff would disconnect the cask car from the train engine, evacuate the tunnel area, and then close the roll up door. Once all was clear, the crane operator removed the cover blocks from cell 3. Then the operator would position the crane above the cask car and use the crane hooks to remove the transport basket from the cask car and move the basket with the fuel slugs to cell 3 where and dump the fuel into one of the dissolvers in the cell to begin the separations process. Once the fuel slugs were dumped into the dissolver, the crane operator would replace the cover blocks for the cell.
The operations staff in the operating gallery would start the first step in the plutonium removal process by dissolving the aluminum cladding on the outside of the fuel elements. All of this was done remotely with the cover blocks in place to reduce the tremendous amount of radiation being released at this point in the process.
Image Credit: US Department of Energy
Misadventures with radium and X-rays in the early 20th century, some deadly, provided a starting point for dealing with the new problem of radiation in an industrial workplace like the T Plant.
Herbert Parker reviewed the recommendations of the 1934 National Committee on X-Ray and
Radium Protection and introduced controls for working with radiation in 1944, including the Special Work Permit (SWP).
An SWP is a standardized list that instructs employees on how to conduct a specific task in a radiological zone. A health physicist developed an SWP for the task and workers reviewed them prior to starting the assignment, typically during a pre-job planning meeting. This form of standardized procedure became the basis of many of the nuclear safety protocols still used today. These instructions included the task to be performed, the appropriate protective devices to be worn including clothing, respiratory requirements, training requirements for the workers, special equipment needed, estimates of exposures, time keeping requirements, and necessary approvals to perform the work.
Image Credit: US Department of Energy
On December 2, 1949, the Atomic Energy Commission and the United States Air Force conducted an experiment known as “Green Run” at the T Plant. It was the largest single release of radioactive iodine-131 in Hanford’s history, covering vegetation as far north as Kettle Falls, WA and as far south as Klamath Falls, OR.
During the Cold War, plutonium production at Hanford increased dramatically, as did the production in the Soviet Union as they conducted atomic bomb testing in August 1949. The United States feared that the Soviet Union would build a nuclear arsenal, thus, they needed a way to monitor Soviet nuclear weapons production.
U.S. Government officials, hoping to develop better methods for detecting Soviet nuclear weapons production, initiated what is known as the Green Run. Its purpose was to test by tracking and measuring a large volume of particles released into the air at Hanford. In the experiment, fission products from Hanford’s reactors were processed after only 16 days of cooling, rather than the normal 90 to 125 days, to replicate the Soviets’ process. This “green,” highly radioactive fuel was then processed, intentionally releasing high quantities of iodine-131 and other radioactive gases, unfiltered, from Hanford’s Chemical Separations “T Plant."
Key to the success of the Green Run was favorable weather. The Health Instrument Division of the General Electric Company established five conditions that had to be met. First was a layer of cold air close to the ground. The Division believed that this inversion would protect the ground from stack emissions. There also could not be any precipitation that would hinder measurements from the air. Wind speeds above 200 feet (60.96 m) had to be less than 15 miles per hour (24.14 kph) and come from the west or southwest. Lastly, all conditions had to remain stable long enough for the emissions to be measured.
From the outset, the experiment did not go as planned. Scientists predicted that 4,000 curies of iodine would be released. Analysis after the experiment proved that roughly twice the predicted amount was emitted. Wind directions on the test day went mainly northwest to southeast which dispersed the radioactive material around the state of Washington. Radioactive iodine ended up on the ground in vegetation and water. Vegetation contamination readings by Hanford’s environmental monitoring staff showed 600 times the tolerable amount in Kennewick, WA. Adverse weather on the day of the test doomed its success. Rain caused significant concentrations of radioactive material to fall on Spokane, WA and Walla Walla, WA. Winds throughout the experiment’s run changed direction and scientists lost track of the radioactive release. The map above shows the of dispesion of materials from the Green Run.
The amount of iodine-131 released during the Green Run is estimated to be around 8,000 curies. Compare this to the approximately 15 curies of radiation released from the Three Mile Island accident in Pennsylvania in 1979. The people affected from the Green Run and other radiation releases due to accidents or negligence are known as the Downwinders. The Green Run experiment resulted in long-term health problems for many of the Downwinders, such as increased cancer rates and lymphatic illnesses.
Image Credit: Technical Steering Panel of the Hanford Environmental Dose Reconstruction Project, “The Green Run” (Fact Sheet #12, Mar. 1992)
Once the plutonium was extracted, the chemically separated uranium, unwanted radionuclides, and chemicals used to dissolve the fuel slugs became liquid waste and was put into underground waste storage tanks at Hanford. The system for handling wastes from the separations process at T Plant was never meant to be a long-term solution. The scientists and engineers who designed the Hanford plant were aware of the waste disposal problem. Given the burdens and limitations brought on by the war, they were not able to address the problem other than in the short-term. Therefore, the issues associated with waste were kicked down the road to a later time.
The ventilation system and stack removed noxious gases from the cells and canyon, diluted them, and dispersed them into the atmosphere. The removal of liquid wastes from the chemical separations process was handled by the 241-T tank farm, a system of large-scale storage tanks, and drainage fields. At the heart of the tank farm were 12 large storage tanks each was 75 feet (22.86 m) in diameter and could hold about 530,000 gallons (2,006,268 l) with a depth of 16 feet (4.87 m). They were constructed underground of concrete with a welded steel liner and buried under 9 feet (2.74 m) of earth for shielding.
Each series of three tanks were linked together in a cascade, so that as the first tank filled, it would spill into the second tank, which would eventually spill into the third tank. Liquid waste coming to the tank farm could be sent to one group of tanks or another by means of diversion boxes.
Today the waste legacy left by the Manhattan Project and the Cold War plutonium production is about 56,000,000 gallons (211,983,060 l) of highly radioactive liquid waste that in many cases has been stored for nearly 80 years and continues to be managed by the Hanford contractors under contract with the Department of Energy.
Plutonium produced at Hanford was in the Trinity test on July 16, 1945, and in the Fat Man atomic bomb dropped on Nagasaki, Japan, on August 9, 1945. T plant continued operating as a Cold War facility and is still in operation. Its current mission is radioactive sludge storage.
Learn more about the Manhattan Project and its many legacies.
Image Credit: US Department of Energy
Protecting people and other living things from a source of radioactivity is not unlike protecting them from a source of high heat or even sound. Different types of materials provide different levels of protection. For example, a 10-fold reduction in gamma radiation can be made with any one of the following: about 1.7 inches (4 cm) of lead, 8.5 inches (21.5 cm) of concrete, 8 inches (20 cm) of aluminum, or 20 inches (50 cm) of water. It takes about 1,300 feet (40 m) of air to provide the same shielding as the above-described materials provide.
The design of the T Plant included barriers to protect workers from radiation. Thick concrete walls and concrete cover blocks (pictured are cover blocks under construction) are two examples of engineered barriers deployed to protect workers from the high levels of radiation within the canyon. The walls ranged in thickness from 5 feet (1.52 m) to 9 feet (2.74 m).
There are 40 cells within the canyon. A typical cell was covered by four cover blocks: three C1 blocks that weighed about 32 tons (29 mt) each, and a single C2 block that weighed about 26 tons (24 mt) and served as the keystone block. The C1 block measured 6 feet (1.82 m) and 4.75 inches (12 cm) wide by 15 feet (4.57 m) and 11.5 inches (29.21 cm) long and was 6 feet (1.82 m) thick. The C2 block was 5 feet (1.52 m) and 10.5 inches (26.67 cm) wide but otherwise the same as a C1 block. There were 328 cover blocks used in the T Plant.
Image Credit: US Department of Energy
Research and experimentation to develop the chemical process to separate plutonium from irradiated uranium was carried out at University of Chicago’s Met Lab (pictured) and the Clinton Engineer Works in Tennessee. Several suggested methods for the separation of the plutonium from the uranium were evaluated. The bismuth phosphate process was selected based on simplicity and use of less volatile chemicals in the process.
The bismuth phosphate process involved multiple steps:
1. Remove aluminum cladding from the irradiated uranium fuel slugs by dumping the slugs into a dissolver and covering them with a basic caustic such as sodium hydroxide or sodium nitrate solution. The solution was then brought to a boil.
2. The next step was the slow addition of sodium hydroxide to the solution to remove the liquified aluminum from the waste stream and bonding agents that enclosed the slugs.
3. Next the slugs were washed with nitric acid to dissolve the irradiated uranium. Bismuth nitrate and phosphoric acid were then added to separate the plutonium from the uranium and the mixed fission products.
4. Following removal of the uranium and mixed fission products, the solution ran through a centrifuge to separate out the heavier plutonium material from the lighter mixed fission products, namely cesium and strontium. In the process nearly 90 percent of the gamma radiation was removed from the remaining plutonium material. The resulting product was a plutonium-containing paste that was dissolved in nitric acid.
5. The plutonium paste was then further reduced by repeating the previous steps and using additional chemicals. The result was a plutonium nitrate solution with a higher concentration of plutonium. This material was then transferred to the 224-T building where it was further purified and reduced. At this stage, the radioactivity was reduced to the point where it could be handled without heavy shielding. It was then delivered to the 231-Z building for final processing before being shipped to Los Alamos to be incorporated into atomic weapons.
Image Credit: Public Domain
T Plant was the first industrial scale building designed to separate highly radioactive materials. Protecting workers was the upmost concern when designing the facility and implementing operations. Herbert Parker (pictured), a prominent medical physicist, established the Health Instruments Section and initiated a radiological monitoring and control program at Hanford, the first program of its kind. His goal was to develop formal procedures and controls for the protection of workers, citizens, and the environment from excessive radiation exposure. His innovations led to a better understanding of the effects of radiation on human health, enhanced protections for workers, and the emergence of a field that continued to protect lives long after the Manhattan Project ended.
Herbert Parker created administrative and engineered controls to protect workers from radiation exposure. Engineered controls included shielding, locked access doors, and long handles for equipment. Administrative controls such as documented work procedures, well-defined zones, and special badges to monitor worker exposure to radiation were also implemented.
Gamma, beta, alpha, and neutron radiation pose different risks to workers, and workers at Hanford had to contend with all the different types of radiation. Depending on the radiation type emitted from a source, workers use a specific recipe of time, distance, and shielding to protect themselves. Alpha radiation cannot penetrate a piece of paper. Even the outer layer of our skin can stop it, but alpha radiation is very dangerous inside the body. Gamma radiation is the most penetrating form of radiation and is the greatest concern externally. Thick shielding such as six or more feet of concrete or more than a foot of lead is required to stop gamma radiation.
Image Credit: US Department of Energy
The canyon was normally unoccupied but needed a constant flow of air to exhaust the radioactive fumes from the separations process going on in the cells. Air flowed into the canyon through 11 filtering and washing units in the outside wall above the crane cabway. The air circulated throughout the canyon and into the cells through slots in their concrete covers. The air then moved into the canyon’s main ventilation exhaust tunnel that ran the entire length of the building. The air finally exited the building through the 291-T exhaust stack. Airflow was always maintained from lowest potential for contamination to highest potential to keep the air as clean as possible where most workers performed their tasks.
Sampling for releases of radioactive material began even before the plant went online. The photos above shows a “smoke testing” events prior to processing activities in T Plant for the purposes of determining the distribution of gaseous and particulate material that might be released from the 200-foot (60.96 m) exhaust stack during separations processing.
During the early operation of T Plant and other separations buildings, it was easy to determine if the plant was operating as you approached your work area. One witness to the first step, dissolving the irradiated fuel slugs in nitric acid, said, “Brown fumes blossomed above the concrete canyons, climbed thousands of feet into the air, and drifted sideways as they cooled.” A typical sight at T Plant during operations.
Image Credit: US Department of Energy
The canyon within T Plant was designed with remote handling as an integral part of its design. This provided for the elimination of direct hands-on activities to install, remove, or adjust the flow of material from one cell to the next. This was accomplished by the development of what is called a “jumper,” which is a piece of pipe shaped for a particular purpose that can be installed and connected by an air operated impact wrench suspended from the crane by the crane operator about 40 feet (12 m) away in a shielded crane cab. Additionally, all pipe penetrations through the walls of the cells and into the galleries were installed as shown in the above photo with a “bend” in the pipe to prevent radiation passing through the pipe to the operations staff on the other side of the wall. Radiation travels in straight lines; therefore, the bend in the pipe would not allow radiation to travel through the pipe.
Image Credit: US Department of Energy
The picture above is a view of the west end of T Plant under construction. Note the thick concrete walls that protected workers from the intense radiation given off by the irradiated fuel slugs processed in the building. In the lower left is the electrical gallery, which is underground. Stacked on top of the electrical gallery is the pipe gallery. On top of the pipe gallery is the operating gallery. The space in the upper left is the “crane way” for a massive 75-ton (68 mt) capacity crane that was suspended over the canyon. The crane cab traveled the length of the building using the crane way with the actual crane sitting atop the large space in the right portion of the photo. T Plant also has an office complex and facilities where workers mixed the chemical used in the separations process.
Image Credit: US Department of Energy
The tremendous amount of radiation given off by the irradiated uranium fuel slugs required protecting workers with up to 9 feet (2.74 m) of concrete shielding between them and the equipment. These extreme conditions pushed engineers to create a chemical separations building that had never been built before—an amazing feat accomplished in about 18 months.
The timeline for construction of T Plant:
01-16-1943 General Leslie Groves approves the site selection for the Hanford Engineer Works (HEW) in eastern Washington state
02-08-1943 Directive by the U.S. Secretary of War authorizing acquisition of land for Hanford
03-22-1943 DuPont officially starts construction activities at Hanford
06-08-1943 DuPont chooses the bismuth phosphate method for the separations process
06-26-1943 Construction begins on T Plant.
09-22-1944 Construction department turns over T Plant to the Operations Department
09-26-1944 Startup of the B Reactor, plutonium production at Hanford begins
10-09-1944 Construction crews leave T Plant and testing for operations begin
12-26-1944 The first production batch of hot fuel slugs is processed at T Plant
02-05-1945 First shipment of plutonium leaves Hanford for Los Alamos
Image Credit: US Department of Energy
We are now in the operations gallery (pictured). Here operators remotely monitored and control the separations process in the canyon as there are no openings between the galleries and the canyon.
The T Plant operations crew was made up of several disciplines.
• A radiation monitor measured radiation levels and conducted surveys for radioactive contamination in the T Plant.
• The nuclear/chemical operator manipulated the chemical batch processes for separations of the plutonium and operations of all supporting equipment (e.g., pumps, dissolvers, centrifuges, and other canyon equipment).
• The vent and balance operator was responsible for maintaining heat and cooling for the buildings and control of ventilation airflow.
• The shift engineer provided technical support to the operations staff.
• The shift manager was responsible for the overall operation of the facility.
• A craft person (e.g., carpenter, sheet metal worker, iron worker, pipe fitter, painter) to make repairs as needed.
• A janitorial crew for housekeeping duties.
In the photo above, two nuclear/chemical operators monitor process gauges for work that is being conducted within the cells in the canyon. One of the operators controls a valve for introduction of additional materials into the process stream.
Image Credit: US Department of Energy
We are now in the pipe gallery (pictured). The steam, water, and various chemicals that were used in the separations process were brought into T Plant through the pipe gallery. No special shielding or procedures were required for normal operation in the pipe gallery because radioactive solutions did not pass through the pipe gallery. Radioactive materials were all contained in the canyon side of the building.
Image Credit: US Department of Energy
We just passed through the electrical gallery (pictured). The electrical gallery is the lowest level of the manned portions of the processing building. This gallery runs the length of the building adjacent to the canyon and contains all electrical circuitry for the operation of the building. Since T Plant has been in continuous operation since 1944, much of the electrical circuitry has been upgraded, as is obvious by the newer electrical panels you see in the virtual tour. Many of the original panels are still in use today.
Image Credit: US Department of Energy