Idaho National Laboratory Cultural Resource Management Plan

The plant buildings were contained mostly within the rectangular perimeter boundaries of a security
fence. By no means did these consume the entire 82 acres; the designers planned for growth and
expansion. Today the perimeter fence encloses 210 acres, and an additional 55 acres lie outside the
fence. 251
One way to identify the main features of the site is to follow a shipment of fuel as it arrived at the
ICPP gate. The fuel arrived packed in heavily shielded transport casks carried in specially equipped
carrier trucks or by rail. After passing through the main guard gate at the west side of the plant, the truck
headed south about a third of a mile away to CPP-603, the Fuel Storage Facility, isolated from the main
activity area for safety. The truck entered special bays for the transfer operation. Unloading of the fuel to
one of two transfer basins was handled remotely. The fuel elements were placed in stainless-steel buckets,
suspended from overhead racks, and the whole apparatus placed in a water-filled basin. At least 15 ft of
water was above the submerged fuel at all times. This water was recirculated and refreshed daily, the
overflow going to a percolation pond just to the south of CPP-603 and on the outside of the perimeter
fence. The Fuel Storage Facility had its own heating and air cleaning system and its own generator for
emergency power supply. Water came from the main plant source, but was metered and filtered with
separate equipment. The structural-steel building was covered with Transite siding. Before arriving at the
ICPP, the fuel typically had had at least 90 days of cooling time. Here it cooled off for another 120 days
or more.
When the proper time had elapsed and the operators had accumulated sufficient fuel to “run” the
extraction process at the Fuel Processing Complex (CPP-601), a “straddle carrier” transferred the fuel to
the “head end” (south end) of CPP-601. The first step was to dump the fuel element into a vessel of nitric
acid to dissolve it — cladding, fuel, and all. From there it went via a complex system of piping from one
process cell to another, each step producing various waste products. Each product in this waste stream
required treatment before it could be released to the atmosphere or stored. All vessels and piping were
sized (small) to prevent the accidental accumulation of a critical mass of fissionable fuel.
The process complex was designed for direct maintenance. This meant that during periodic
shutdowns, workers could decontaminate work areas and perform maintenance tasks on the equipment. A
minimum of moving parts made for simplicity, although essential items such as transfer jets, valves, and
pumps were installed in pairs, one being a spare. High-maintenance equipment was placed in
crew-accessible lead-shielded cubicles outside the hot process cells. Cleaning solutions were sprayed into
the cells, flushed out, and then entered by maintenance personnel via ladders.
The portion of the building above grade contained no uranium-processing equipment. It was
constructed of steel framing and insulated with Transite siding. Chemicals added to the process feed were
stored in tanks on this level. 252
Waste products left the process building in underground pipes eastward to the Waste Treatment
Complex, which included three main waste processing buildings and a tank farm. One of the buildings
(CPP-604) housed the equipment necessary to recover Krypton-85 gas and generally reduce the volume
of waste. Another (CPP-605) housed blowers which provided vacuum to process cells and exhausted
filtered off-gases to the 250-ft-tall main stack (CPP-708). The Complex recovered all of the nitrogen and
oxygen needed at the ICPP and other parts of the NRTS site. Further east of the Waste Complex—
downwind of operations—was the 250-ft stack. 253
251. “Land Use Information, www.inel.gov/resources/flup/icpp.html.
252. The progress of fuel to be reprocessed is extracted from “Chemical Processing of Reactor Fuel Elements at the Idaho Chemical
Processing Plant,” Proceedings of the Geneva Conference (New York: United Nations, 1955), reprint pages 14-23.
253. R.D. Logan, INEL Building Study, Idaho Chemical Processing Plant (Idaho Falls: INEL Energy Management, 1990), p. 33-36.
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