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Frederick Kuhnow

Management & Design

Mr. Kuhnow is a Professional Engineer with over 20 years of multidisciplinary experience with a focus in geo-structural engineering, seismic design of nuclear facilities, drill & blast engineering, surface and underground construction. His project experience includes detailed engineering design of civil infrastructure projects, demolition projects, earth retaining structures, foundation engineering, slope stability investigations, geohazard evaluations, underground and surface mining engineering, and construction management.

Mr. Kuhnow graduated from the University of Utah in Civil Engineering. He has a Master of Sciences (MS) degree in Civil Engineering and a MS in Mining and Mineral Engineering also from the University of Utah. He is a licensed Professional Engineer (PE) in the states of Arizona, California, Florida, Nevada, New York, Pennsylvania, and Utah. Mr. Kuhnow also has a Master certificate in Project Management from George Washington School of Business.

In his current role, Mr. Kuhnow is responsible for the management, design, support, the direction of technical staff and construction contractors for the execution of multiple projects.

Mr. Kuhnow has published several technical journals and has peer-reviewed articles for industry professional societies.

Frederick Kuhnow
Harmonic energetic delamination of T2 building is being considered for demolition at a formerly known atomic power lab. The T2 building is within a containment structure that is currently enclosed by a containment structure that is under negative pressure of -49 Pa (-0.2 inches of WC), so that no remaining radioactive material is leaked out to the environment. The T2 containment enclosure is a portal frame-type system that spans east/west over 35.05 m (114′-11 7/8″) and spaced 2.9 m (9′-6″) apart. The west side of the portal frames is supported by a 64 cm (2′-1 “) thick concrete wall which is backfilled to the west and open to the T2 basement to the east. The east side of the portal frames is supported by a 61 cm (2′-0”) thick concrete wall that is backfilled to the east and open to the tank farm vaults to the west. A concrete slab-type footing supports both the east and west walls. Transverse walls provide lateral support for the walls as part of the original design. The west wall has an elevated slab that provides further stiffening of the concrete wall between the transverse walls.

Previously, delamination had been considered for the neighboring S2 building, but plans to do so were aborted. During the review period for S2, several issues were brought up by authorities, most notably Air Overpressure (AOP). Most typical demolition projects using blasting methods are performed in open air, under atmospheric pressure. Using these methods within the containment enclosure led to failure to prove success to the level of certainty authorities were expecting. At T2, the AOP concern also exists, although there were portions of T2 that were more favorable to gaining client’s approval. Unfortunately, the most challenging of the T2 delamination involves a 2.4 m (8′) thick concrete reinforced wall. This challenge is founded on the fact that the wall is located approximately 7.6 m (25′) from the containment boundary. A preliminary calculation suggests that AOPs at this distance will exceed the operational pressure transient that the containment is designed to absorb.
The production of expansive gases during detonation events produce increases in the base air pressure values due to compression of the existing volume of air within the facilities. The effects of this phenomenon are not generally considered in open-air AOP operations and will be considered in the demolition of the T2 building given that delamination activities involving the detonation of explosives will take place within a fixed volume, under negative pressure.

A theory has been proposed to phase the demolition such that the blast burden and AOP relieve to the pipe tunnel side. In theory, this would use the remaining portion of the 8′ wall to shield the containment boundary from the AOP from the blast, relying on the ventilation system to exhaust explosive- generated gas expanding volume. Due to the lack of AOP data when blasting under sub­atmospheric (negative) pressure, a sound pressure wave survey was conducted inside the T2 building to investigate what the attenuation would be when under negative pressure. These results were used to develop site-specific attenuation curves that led to a blast design that would ensure pressure levels would not exceed the pressure transient that the containment was designed to withstand, keeping all radioactive material from leaking out to the environment.