Zirconium-95 (Zr-95) is a radioactive isotope of zirconium with a half-life of approximately 64 days. It decays by beta emission, producing niobium-95, which itself is radioactive. During its decay, Zr-95 emits gamma radiation, making it detectable through gamma spectrometry. Zr-95 is a fission product of uranium and plutonium in nuclear reactors and is commonly associated with nuclear waste and fallout from nuclear weapons testing or reactor accidents.

Zr-95 is primarily used in scientific research and nuclear monitoring. It serves as a tracer to study the behavior of fission products in reactor systems and the environment. Its gamma emissions are also utilized to calibrate radiation detection equipment. In environmental studies, Zr-95 helps in understanding the dispersion and impact of radioactive materials following nuclear accidents.

Zr-95 is not naturally occurring and is found only as a byproduct of nuclear fission. It is encountered in nuclear reactors, spent nuclear fuel, and areas affected by nuclear contamination. Due to its relatively short half-life, the presence of Zr-95 in the environment decreases over time, but it is closely monitored in the context of nuclear safety and environmental protection.