Goofs

Prior to the test, Dr. Rodell states it was 'the most powerful weapon yet developed'. The film makers might not have been aware of this, but the most powerful device up to that time was the 'George' test of Operation Greenhouse, a boosted fission device with a yield of 225 kt, about ten times the yield of the Nagasaki bomb. Even with much lower yields, like the 15 kt of the Hiroshima bomb, it would not make sense to put up a house made of 'regular brick and shingle' at a distance of a mere 200 feet from ground zero for weapons effects testing, because no remains would be found to examine afterwards. That house would hardly be out of the fireball radius, experience more than 25 psi overpressure and wind speeds upwards of 2500 mph. It goes without saying that the detonation would not have been survivable at that range in such a structure.

The scientist mentions the bomb they are about to test is the most powerful one yet developed. The most powerful weapons were never tested on the Nevada Test Site (NTS) nor anywhere else within the continental USA to avoid creating excessive fallout. To the contrary, devices were frequently "detuned" for atmospheric tests in Nevada to minimize fallout problems. The most powerful atmospheric test in Nevada was the "Hood" shot of Operation Plumbob in 1957, three years after the release of this film, at 74 kt of yield. The USA had already started testing thermonuclear devices in 1952 on the Pacific Proving Ground, some of which released about 200 times more energy.