Existing Structural Studies

DOE-HDBK-3010-94

Appendix B; Plutonium Recovery Facility

Nitrogen is supplied from outside the building to inert the metal reduction line. Inerting is

specifically intended to prevent excessive oxidation of the product metal, not to preclude

plutonium metal buttons from burning (a highly unlikely event). However, the inerting

system provides residual fire prevention benefit as well. Nitrogen is recycled through

Plenum D, which has two HEPA filter banks in series, and is regularly bled off the system

to join production exhaust at the inlet to Plenum C. Nitrogen can also be diverted from this

system to inert the feed preparation glovebox if desired.

The final flowpath in the building is associated with the vessel vent system. Offgases vented

from liquid-bearing vessels in gloveboxes and process rooms are drawn to this system. The

vessel vent system contains a scrubber that uses 15% potassium hydroxide to neutralize

entrained nitric acid vapors. The scrubbed gases are then transferred back to the main

process exhaust plenum by two small centrifugal blowers.

For the production areas, negative pressure at specific supply and exhaust inlet points is

controlled by pneumatically operated dampers. These units respond to signals from

differential pressure detectors. Typical differential pressures maintained between areas and

atmosphere are listed below:

Clean Areas

- 0.1" WG

Secondary Air Locks

- 0.15" WG

Regulated Production Areas- 0.2" WG

Primary Air Locks

- 0.25" WG

Operating Rooms

- 0.3 " WG

Maintenance Rooms

- 0.4 " WG

Gloveboxes

- 0.9 " WG

Differential pressure readout and low-level alarms are available in the facility control room.

Local gage indications of differential pressure are available at each glovebox as well. An

automatic mechanical sequencer controls restart of fans following loss of ventilation to

prevent overpressurizing the facility. This unit will also trip supply fans if an exhaust fan

fails and the standby unit does not come on.

2.1.4

E xistin g S tru ctu ral S tu d ies

The PRF was designed and built in accordance with standards of the M&O contractor at the

time of construction. These standards were based on the Uniform Building Code. The PRF

was considered to be a Class 1 structure capable of withstanding a static live load of 1000 psf

acting simultaneously on the whole outer surface. However, complete design drawings do

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