Department of Energy Hanford Site

An innovative solution to a somewhat routine request resulted in a relocatable structure for Department of Energy (DOE) contractor Fluor Hanford. The 150-foot structure is designed to cover a section of trenches housing low-level and transuranic waste buried in trenches during Cold War weapons production.

Located in southeastern Washington State, the Hanford Site includes approximately 25 million cubic feet of buried or stored solid waste throughout its 1,700 waste sites and 500 contaminated facilities, all spread over 80 square miles. A variety of cleanup options are being considered for the buried waste. In cases where retrieval is the selected cleanup option, shelter systems are being used to avoid lost production days due to inclement weather. Fluor Hanford turned to ASFI to develop the weather-resistant, movable structure to shield workers, equipment and waste from varying conditions in Washington.

ASFI’s 150- by 100-foot wide design incorporated a tension fabric structure made of aluminum and a white translucent roof membrane with acrylic topcoat cladding that sits on 2’ X 2’ X 6’ ecology blocks. The lightweight materials allow for a caterpillar-like tracking system for moving the structure as cleanup work progresses along the 450-foot trench. The track design requires only 7,000 pounds of energy force, so relocation is accomplished by use of small 120-volt electrical powered winches.

The 15,000 square foot enclosed workspace provides adequate space for machines and workers to safely remove the waste materials. In addition to two personnel doors on each side and one on each end, the structure is equipped with four 14’ X 14’ vehicle doors – two on each end – making drum removal effortless. Although the doors are electric, they are designed for manual use during a power outage.

Lighting is rated at 40 foot candles and is constructed in three phases. Egress lighting for illuminations during loss of normal electrical power were provided at each personnel door and comply with NFPA 101 Life Safety Codes.

With worker safety in mind, ASFI designed the structure with two air-handling units to change out the air four times an hour. In addition, an air inlet ensures the designed air exhaust flow rate does not result in excessive differential pressure.

ASFI designed, fabricated, and supplied the structure and its components. Fluor Hanford installed the structure. All materials used in the structure meet rigorous fire safety (NFPA), electrical (NCA) and OSHA requirements enforced at the site.

Client:
Fluor Hanford
Richland, WA 99352