Which of the following is NOT an indication of nuclear radiation presence?

The presence of nuclear radiation is typically indicated by various signs, while the absence of such signs indicates that radiation is not present. Among the options, "normal room temperature" reflects what can be considered typical environmental conditions where no radiation is detected.

Conversely, a green glow is often associated with certain types of radioactive materials, particularly when they are interacting with fluorescent materials; it can indicate radiation presence. Intense heat may occur due to the decay of radioactive materials or through interactions that produce heat, thus suggesting the presence of radiation. A crackling sound can be emitted from detectors designed to pick up ionizing radiation, indicating that radiation is present.

Thus, "normal room temperature" stands out as the only option that does not provide any evidence of radiation, supporting the idea that radiation is absent in that scenario.