Rocky Flats Plant,
Uranium Rolling and Forming Operations
HAER No. CO-83-R (Rocky Flats Plant, Building 883)
Rocky Flats Environmental Technology Site, Highway 93. Building 883 is
located in the southeastern section of the Rocky Flats Plant, in the southeast
quadrant of the intersection of Central Avenue and Eighth Street.
Date of Construction: 1957.
Present Owner: U.S. Department of Energy (DOE).
Present Use: Uranium Rolling and Forming Operations.
This building is a primary contributor to the Rocky Flats Plant
historic district, associated with the U.S. strategy of nuclear military
deterrence during the Cold War, a strategy considered of major importance in preventing
Soviet nuclear attack. As production of nuclear weapons increased, space in Buildings 881
and 444, (enriched uranium and depleted uranium parts manufacturing) became inadequate.
Building 883 was constructed to handle additional uranium rolling and forming operations.
In 1995, an inventory and an evaluation was conducted of facilities at the Rocky Flats
Plant for their potential eligibility for listing in the National Register of Historic
Places. The primary goal of this investigation was to determine the significance of the
Cold War era facilities at the plant in order to assess potential effects of the long-term
goals and objectives of DOE. These goals and objectives have not yet been
formalized, but include waste cleanup and demolition activities. Recommendations regarding
National Register of Historic Places eligibility were developed to allow DOE to
submit a formal determination of significance to the Colorado State Historic Preservation
Officer for review and concurrence and to provide for management of historic properties at
From this determination and negotiations with the Colorado State Historic Preservation
Officer, the Advisory Council, and the National Park Service, a Historic American
Engineering Record project began in 1997 to document the plants resources prior to
their demolition. The plant was listed on the National Register of Historic Places in
1997. The archives for the Historic American Engineering Record project are located in the
Library of Congress in Washington, D.C.
The plant is one of 13 DOE facilities that constitute the Nuclear Weapons
Complex, which designed, manufactured, tested, and maintained nuclear weapons for the U.S.
arsenal. The plant was established in 1951 to manufacture triggers for use in nuclear
weapons and to purify plutonium recovered from retired weapons. Each trigger consisted of
a first-stage fission bomb that set off a second-stage fusion reaction in a hydrogen bomb.
Parts were formed from plutonium, uranium, beryllium, stainless steel, and other
A tense political atmosphere both at home and abroad during the Cold War years drove
U.S. weapons research and development. By the 1970s, both the U.S. and the Soviet Union
maintained thousands of nuclear weapons aimed at each other. These weapons were staged on
submarines, aircraft, and intercontinental ballistic missiles. Both the North Atlantic
Treaty Organization and Warsaw Pact countries in Europe had small nuclear warheads, known
as theater weapons, used as part of the Mutually Assured Destruction program. (The
Mutually Assured Destruction program acted as a deterrent in that if one side attacked
with nuclear weapons, the other would retaliate and both sides would perish.) The final
nuclear weapons program at the plant was the W-88 nuclear warhead for the Trident II
missile. This mission ended in 1992, when President Bush canceled production of the
Trident II missile.
The plant was a top-secret weapons production plant, and employees worked with a
recently man-made substance, plutonium, about which little was known concerning its
chemistry, interactions with other materials, and shelf-life. The Historic American
Engineering Record documentation effort focused on four aspects of the plant and its role
in the Nuclear Weapons Complex: manufacturing operations, research and development, health
and safety of workers, and security.
|Chronology of Building 883:
||Building 883 was constructed. Depleted uranium was handled in Side A; enriched
uranium in Side B. Other metals such as aluminum, titanium, stainless steel, and cadmium
were machined in Side A.
||An addition was constructed to house uranium component manufacturing and to
provide additional storage space.
||Beryllium forming operations began in Side A.
Enriched uranium operations were transferred to Oak Ridge Reservation; Side B
remained idle until 1977.
|| Most beryllium operations in Building 882 ceased.
|| Foundry operations in Building 444 ceased.
||Manufacturing of calorimeter plates using depleted uranium began. Depleted uranium
calorimeter plates were manufactured and rolled in Side A.
||Pilot-scale operations were conducted using depleted uranium to manufacture
armor plates for M1A1 tanks.
||Construction began on the Side C addition which was to house armor plate manufacturing
for the M1A1 tank.
||Construction of Side C was completed; full-scale manufacturing of armor plates
using depleted uranium began.
Building 883 was a nonreactor nuclear facility. It was constructed in 1956 to
accommodate fabrication of enriched and depleted uranium parts used in weapons. The
sealed, hollow shape of the weapon components required a significant amount of rolling and
forming of both types of uranium. Because space in Buildings 881 and 444 (enriched
uranium and depleted uranium parts manufacturing) was inadequate, Building 883 was
constructed to handle some of the uranium rolling and forming operations.
Additions to Building 883 began in 1958 with the construction of storage and uranium
component manufacturing spaces. In 1972, a valve room was added. From 1983 to 1985,
additions were constructed to support the manufacturing of armor plates for M1A1 tanks.
Enriched uranium was processed in Building 883 from 1957 to 1964. These operations were
moved from the building to Oak Ridge Reservation between 1964 and 1966. After 1967,
metalworking operations in the building primarily involved depleted uranium (U-238) and
binary metal (U-238 alloyed). Some stainless steel and aluminum work also occurred in the
building on a fairly routine basis. Beryllium, copper, and other metals and alloys were
occasionally worked on in the building. Projects included rolling, pressing, and spinning
classified blanks for trigger contingency and special order work; bending tubes for weapon
body parts; and swaging reservoir stems.
Building 883 is a high-bay, single-story building with a 38-foot-high ceiling. The structure has
a partial basement and a small second floor on the north and south ends. The facility is
constructed of steel framing with corrugated asbestos cement exterior panels and concrete
exterior walls. The floors are concrete; limited areas are covered with asbestos tile or
carpet. Ceilings in the office areas are suspended acoustical tile; ceilings in the
process areas are the exposed undersides of the roof. The roofs are built-up over steel
decking and supported by structural steel. The entrance to the structure is along the
southern end. Office areas are located on the southern end of the building, on both the
first and second floors. The majority of the buildings area, encompassing
approximately 76,500 square feet, is contained in a high-bay metal working area. This area
contains 2,000-ton presses, rolling mills, furnaces, hot salt baths, and shearing
machines. Eighty percent of the area of the building has been used for metal processing.
The three processing areas on the first floor are referred to as Sides A, B, and C. The
building was originally designed with two functional areas (Sides A and B) to prevent
cross-contamination of radioactive enriched uranium with non-fissile depleted uranium. In
1985, the third area, Side C, was added to support depleted uranium armor plate
production and acid scrubbing operations for cleaning depleted uranium components.
The second floor contains the inlet air plenum, associated blowers, heat exchangers,
and coolers. The basement area includes a utility room, process waste storage and
maintenance areas, and the entrance to an underground tunnel leading to Building 881.
Building 883 is associated with manufacturing processes in Buildings 440, 444, and 460.
There is one support building and a tunnel associated with Building 883. Building 879
houses the filter plenum for Sides A and B of Building 883. A reinforced concrete tunnel
connects the northwest corner of the second floor of Building 881 to the southwest corner
basement of Building 883. Originally, the tunnel was used to transport enriched uranium
parts and other materials between the two buildings. The tunnel is 192 by 8 by 10 feet with a
15-inch-thick floor slab (total floor area 1,536 square feet).
Historical operations within Building 883 included manufacturing of parts from uranium
and beryllium, and a series of special projects involving various metalworking operations.
Manufacturing processes included rolling and forming of enriched uranium, depleted
uranium, uranium-niobium alloys (binary metal), and beryllium into parts for weapons
production. Actual manufacturing processes depended on the type of metal used and the
desired final form.
Operations included rolling, shearing, forging, pressing, roller leveling, grinding,
punching, bending, welding, heating, annealing, and cleaning. Metal was annealed in salt
baths or in furnaces with argon atmospheres. Vapor degreasing, grit blasting, water
washing, and nitric acid etching were used during the cleaning process. Other processes
conducted in Building 883 included inspection; nondestructive testing; weighing; shipping
of fabricated parts; and receipt of raw materials used to fabricate, inspect, and clean the
The flow of materials into, within, and from Building 883 varied according to the type
of material. Enriched uranium was cast in Building 881, sent to Side B of Building 883 for
rolling and forming, and returned to Building 881 for machining and inspection. Depleted
uranium was cast in ingots in Building 444, sent to Side A of Building 883 for rolling and
forming, and returned to Building 444 for machining and inspection. Depleted uranium
products manufactured in Building 883 were shipped to Building 444 for subsequent
Depleted and Enriched Uranium Component Manufacturing: Building 883 received depleted uranium (U-238) that consisted of either virgin stock
from off-site vendors or recycled scrap generated from site processes. The U-238 ingots or
billets were hot-rolled and formed into various weapons parts or electrode strips, or were
combined with niobium to form binary metal that was subsequently formed into weapon
components. Virgin U-238 ingots were weighed, immersed in a salt bath, rolled into a sheet,
then sheared to length. The sheets were annealed in a second salt bath, cooled, and
cleaned in water. These flat plates were either shaped into weapon components or were
sheared a second time and trimmed to form electrode strips and electrode filler strips. The
electrode strips were bent, cleaned in acid, and welded in a box configuration. The
electrode filler strips were rolled, punched for boltholes, and cleaned in acid. The
electrode strips and electrode filler strips were then transferred to Building 444.
Recycled U-238 ingots were weighed, cropped, re-weighed, and heated in a salt bath. The
ingots were rolled into sheets and sheared to length; the sheets were annealed, cooled,
and cleaned in water. They were then sheared, cut into discs, heated, and formed into
parts. A second forming, called a re-strike, was done to ensure proper size. These parts
were vapor degreased (cleaned using a hot solvent vapor process to remove contaminants)
and sent to Building 444.
Manufacture of weapon parts from enriched uranium occurred in Building 883 from 1957 to
1964, at which time enriched uranium part manufacturing operations were transferred from
the plant to the Oak Ridge Reservation in Tennessee. Enriched uranium was cast in Building
881, then sent to Side B of Building 883 for rolling and forming. The formed enriched
uranium parts were then transferred back to Building 881 for machining into final shape.
Binary Metals Parts Manufacturing: Binary metals (depleted uranium alloys) were delivered to Building 883 as recycled
ingots and non-recycled rolling pucks (slices off a cylindrical ingot). The binary ingots
were heated in an argon atmosphere and rolled into sheets. The sheets were either formed
into shapes to make weapon components or cut into electrode filler strips. The electrode
filler strips were stamped with batch identification marks and boltholes were punched in
one end. The strips were then annealed in an argon atmosphere and quenched in water. The
strips were strengthened in the roller leveler, cut to final length, and transferred to
Building 444. The binary pucks were also heated in an argon atmosphere, rolled into
sheets, annealed, and water quenched. The sheets were then straightened in a roller
leveler and cut into discs for forming into parts. After inspection, the parts were sent
to Building 444.
Beryllium Component Manufacturing: Beryllium-forming operations, which took place in Side A from 1962 to the mid-1980s,
required the development of special techniques to compensate for the brittle nature of
beryllium. Beryllium ingots, measuring 9 by 9 inches, were cast in Building 444 and
encased in stainless steel in Building 881. The stainless steel and beryllium sandwich was
heated and rolled into sheets; stainless steel forms were cut away after the beryllium was
rolled to the specified thickness. The beryllium sheets were heat-treated and pressed into
the desired shapes in Building 883, then returned to Building 444 for further machining.
Operations Since 1989:
Starting in 1989, Building 883 operations began to diminish. By 1993, Building 883
operations focused on rolling and pressing of classified blanks for trigger contingency
(war reserve) and special order work; bending tubes for weapon body parts; and swaging
reservoir stems to meet production requirements.
In 1994, Building 883 operations ceased and the building was closed.
Colorado Department of Health. Project Tasks 3 & 4 Final Draft
Report. Reconstruction of Historical Rocky Flats Operations and Identification of Release
Points (1992), by ChemRisk. Rocky Flats Repository. Golden, Colorado.
Padron, Henry, employed at the plant by the site contractor since 1969. Personal
communication, December 1997.
United States Department of Energy. Public Affairs. n.d. Tour Information: Rocky
Flats Facilities. Golden, Colorado:
U.S. Department of Energy, Office of
Communications and Economic Development.
United States Department of Energy. Historical Release Report (HRR) (1994), by
EG&G. Rocky Flats Plant Repository. Golden, Colorado, 1994.
United States Department of Energy. Final Cultural Resources Survey Report (1995), by Science Applications International Corporation. Rocky Flats Repository. Golden,
D. Jayne Aaron, Environmental Designer,
engineering-environmental Management, Inc. (e²M), 1997. Judith Berryman, PhD.,
Archaeologist, e²M, 1997.
Index to Photographs
Located in the southeastern section of the plant, in the southeast quadrant of the
intersection of Central Avenue and Eighth Street, Golden Vicinity, Jefferson County, Colorado.
Photographs CO-83-R-1 through CO-83-R-19 were taken by various site photography
contractors, dates indicated in parentheses.
CO-83-R-1 – View of Building 883 exterior, looking southeast. Ventilation equipment is visible. (11/27/56)
CO-83-R-2 – View of interior, east side (Side A) of Building 883 during installation of rolling mills and molten salt bath equipment for depleted uranium fabrication. The crane near the ceiling was used to install the equipment. Boxes on the floor contained equipment to be installed. (1/23/57)
CO-83-R-3 – View of interior, east side (Side A) of Building 883 during installation of equipment for the molten salt baths and rolling mills processes. (4/25/57)
CO-83-R-4 – Detail view (Side A) of a handmade steel box associated with the depleted uranium alloy development and component fabrication process. The box was used to transfer heated blocks of metal (shown in the opened door) from the molten salt bath to the roller lines. (4/28/62)
CO-83-R-5 – View of beryllium processing area, rolling mill. Beryllium forming began in Side A of the building in 1962. (11/5/73)
CO-83-R-6 – Detail view of spin form furnace for stainless steel fabrication. Stainless steel was machined in Side A of the building, beginning in 1957. (4/24/78)
CO-83-R-7 – View of the hydraulic hammer stamping press on Side A of Building 883. This type of press was used for both stainless steel and for depleted uranium. (7/2/86)
CO-83-R-8 – View of the switchgear and electrical supply room between sides A and B of Building 883. Equipment within the building required an extensive amount of power. The electrical supply room is essentially an electrical substation. (1/23/57)
CO-83-R-9 – View of molten salt bath equipment and roller presses being installed on the west side (Side B) of Building 883. Side B of Building 883 was used to process enriched uranium from 1957 to 1966. (1/23/57)
CO-83-R-10 – View of the addition to Building 883, referred to as Side C. Armor plate made with depleted uranium was heated in a molten salt bath, then processed through the rolling mill to form large sheets. (9/16/85)
CO-83-R-11 – View of the manipulator and the parts-heating furnace. The parts or metals were heated prior to being pressed. The manipulator arm was used to insert and remove parts or metals from the furnace. (2/9/79)
CO-83-R-12 – View of the manipulator and the parts-heating furnace. The metals were heated prior to being pressed. The arm is draped with fire resistant material. (2/9/79)
CO-83-R-13 – View of the molten salt baths used to uniformly and quickly heat metals prior to working (rolling). (9/16/85)
CO-83-R-14 – View of metal-rolling operation. The metals are being prepared to be rolled into sheets of specific thickness. Component parts were fabricated from the metal sheets. (11/82)
CO-83-R-15 – View of rolling operation. Ingots and bar stock were rolled to a specified thickness in preparation for further processing. (11/82)
CO-83-R-16 – View of a rolling mill that was used to create a metal sheet (shown). (4/16/57)
CO-83-R-17 – View of forming equipment. Discs cut from metal sheets were formed into shapes. (7/2/86)
CO-83-R-18 – View of roller leveler used to straighten and flatten metal sheets. (7/2/86)
CO-83-R-19 – View of the bake-out furnace, where parts were heated under a vacuum to heat treat or to bake out any impurities. (9/19/72)
CO-83-R-20 – View of the basement floor plan. The basement area includes a utility room, process waste storage and maintenance areas, and the entrance to an underground tunnel leading to Building 881. The original drawing has been archived on microfilm. The drawing was reproduced at the best quality possible. Letters and numbers in the circles indicate footer and column locations.
CO-83-R-21 – View of the first floor plan. The first floor was used for depleted and enriched uranium fabrication. The original drawing has been archived on microfilm. The drawing was reproduced at the best quality possible. Letters and numbers in the circles indicate footer and column locations.
CO-83-R-22 – View of the second floor plan. The second floor contains the air plenum and some office space. The original drawing has been archived on microfilm. The drawing was reproduced at the best quality possible. Letters and numbers in the circles indicate footer and column locations.
CO-83-R-23 – View of section drawings. The section lines cut the building east-west. The original drawing has been archived on microfilm. The drawing was reproduced at the best quality possible. Letters and numbers in the circles indicate footer and column locations.