TA-55 More Details

March 1998 2 0 2 TA and Facilities Descriptions Facility Hazard Categories
Table 4-28 identifies the facilities at TA-55 that fall into a facility hazard category because of the
type of operations performed in the facility.
March 1998 2 0 3 TA and Facilities Descriptions Nuclear Facility Hazard Categories
The Plutonium Building (Building 4) is categorized as a Hazard Category 2 nuclear facility. Although not currently operational, the Nuclear Materials Storage Facility will also be a Hazard Category 2 nuclear facility and is shown as such on the accompanying maps. Plutonium Building
Plutonium processing is performed in the Plutonium Building (Building 4, Figure 4-32, Sheet 1),
which is a two-story laboratory of approximately 151,000 ft2 (46,025 m2). The exterior walls and
roof are of reinforced concrete. A concrete fire wall divides the building into two halves, each of
which contains its own ventilation systems and electrical substations. One half of the process
floor is divided by a central corridor into Areas 100 and 200. This half contains the plutonium research and development laboratories, the 238Pu operations, and the personnel decontamination area. The other half is divided into Areas 300 and 400 by another corridor. This half houses plutonium recovery, metal preparation and fabrication, and nondestructive analysis laboratories.

Each of the processing areas is further divided into a number of rooms that contain the gloveboxes for plutonium work. The ventilation systems that service the gloveboxes and all other utilities are located in the basement of the facility. The basement also houses critical support equipment, including all other ventilation equipment, the packing/unpacking room, waste-handling areas, the isopress laboratory, and the plutonium storage vault.

Three levels of containment are provided for plutonium processing. The primary confinement
system includes gloveboxes, hoods, vessels, tanks, piping, and the glovebox ventilation exhaust
system. The secondary confinement system includes the walls, floors, ceiling, and doors of the
laboratories containing the gloveboxes, as well as the laboratory recirculation and bleed-off exhaust system. The exterior walls, floor, roof, and doors of the structure, along with the basement exhaust system, provide the tertiary confinement system.

The ventilation system in the facility has four zones, all of which are maintained at a lower pressure than that of the outside air. Air enters the two halves of the facility through an intake stack that has four ducts. Two ducts supply air to each half of the building. The ventilation system is designed so that each zone operates as a separate building with its own filtered exhaust stack. Exhaust from each confinement area is sent through at least two stages of HEPA filtration to prevent radioactive particles from being discharged to the environment.

The conveyor system in the facility transports contaminated material and equipment to almost any point on the first floor. Elevated stainless steel tunnels equipped with a trolley hoist system connect the gloveboxes. The vertical portions of the tunnels connect the overhead system to the
gloveboxes at drop boxes located on the first floor. These drop boxes are the transfer points in
which items are hoisted up to the trolley in the overhead tunnel system for eventual offsite waste

The criticality detection system monitors operations on the main processing floor of the Plutonium Facility and in the basement vault to detect gamma energy released from fission of SNM. The system is designed to detect conditions that could lead to a criticality accident in this facility and to sound an audible alarm. The alarm initiates immediate evacuation to minimize personnel exposure.

This system consists of 20 Geiger-Mueller detector heads and associated circuitry located
throughout the first-floor process areas and basement vault.

A continuous air-monitoring system is used to sample and analyze air from multiple points
throughout the laboratory areas, basement, ductwork, and exhaust stacks. A continuous stream
of sample air is drawn to a solid-state alpha detector, whose data are used for man/machine interface (lights, meter, squealer) and for monitoring by the operations center .

Other supporting systems include fire detection and suppression systems, a chilled-water system, an instrument air system, electrical power, water distribution systems, and a vacuum system.

Voice communication is provided by a paging system and a telephone system. The emergency
system provides paging throughout the TA-55 area and sounds the criticality and fire alarms. Nuclear Materials Storage Facility
The Nuclear Materials Storage Facility (Building 41, Figure 4-32, Sheet 1) will eventually contain a significant amount of stored nuclear material. This facility is primarily intended for intermediate and long-term storage of SNM. Although completed in 1987, the Nuclear Materials Storage Facility has never operated because of design and construction deficiencies. A major renovation project is being planned to correct those deficiencies so that the facility can operate. The renovation project is expected to be completed by 2001. Non-Nuclear Facility Hazard Categories
Two facilities, Buildings 3 and 5, are categorized L/CHEM, and one facility, Building 7, is L/ENS.
Building 3 (the Support Building) contains some laboratories that use chemicals. Building 5 (the
Warehouse) is used to store chemicals. Building 7 (the Calcium Building) is used to store calcium (Figure 4-32, Sheet 1). Nonhazardous Facilities
Approximately 55 other facilities exist at TA-55, all of which have been categorized nonhazardous.

These buildings are administrative, technical, and general storage buildings; passageways; and
pump stations.

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