Abstract: An apparatus for electrically simulating a nuclear reactor fuel assembly. It includes a heater assembly having a top end and a bottom end and a plurality of concentric heater tubes having electrical circuitry connected to a power source, and radially spaced from each other. An outer target tube and an inner target tube is concentric with the heater tubes and with each other, and the outer target tube surrounds and is radially spaced from the heater tubes. The inner target tube is surrounded by and radially spaced from the heater tubes and outer target tube. The top of the assembly is generally open to allow for the electrical power connection to the heater tubes, and the bottom of the assembly includes means for completing the electrical circuitry in the heater tubes to provide electrical resistance heating to simulate the power profile in a nuclear reactor.

Abstract: A suffocant in the form of a heavier-than-air gas is directed into the subterranean tunnel network of a burrowing air-breathing animal so as to replace the air from such tunnels and suffocate the animals therein. The heavier-than-air gas is preferably odorless, tasteless, colorless and substantially chemically inert, and injected at conditions approximately standard temperature and pressure, so as not to provide a warning to the burrowing animals. The heavier-than-air gas is preferably CO.sub.2, and is injected at a rate of from about 2 to about 10 L/minute. The heavier-than-air gas is injected into a cover member which overlies at least one tunnel outlet in the case of mammals (e.g. gophers) or a plurality of tunnel outlets in the case of insects (e.g. fire ants).