Does temperature affect nuclear decay? I'm wondering if the temperature could affect the half-life in an element. For example, Carbon 14 has a half-life of 5,730 years. Is this always true or only true for standard conditions of temperature and pressure? Also, if that does affect, how does it affect?
 A: Temperature affects the half-life via time dilation. If the half-life of a nucleus as observed in its rest frame is $\tau(0)$, then in some other frame in which it moves at a speed of $v$, it will be:
$$\tau(v) =\frac{\tau(0)}{\sqrt{1-\dfrac{v^2}{c^2}}}$$
Because the typical thermal speeds of atoms at room temperature are much smaller than the speed of light, we may expand the above expression to leading order. This yields:
$$\tau(v) =\tau(0)\left[1 + \frac{v^2}{2c^2}+\cdots \right]$$
The average of the square of the speed over the velocity distribution of atoms at temperature $T$ follows from the equipartition theorem. The average energy in each degree of freedom of a gas is $\frac{1}{2} k T$, this means that the average of the kinetic energy is $\frac{3}{2} k T$, it then follows that:
$$\left\langle v^2\right\rangle = \frac{3 k T}{m}$$ 
Therefore, the leading temperature dependence of the half-life is given by:
$$\tau =\tau(0)\left[1 + \frac{3 k T}{2mc^2}+\cdots \right]$$
For carbon-14 at $25 ^{\circ}$ C the term $ \dfrac{3 k T}{2mc^2}$ is $2.95\times 10^{-12}$. Since the experimental error in the half life is about 0.7% this effect is too small to be observed.
A: Pierre Curie checked this out in 1913 by cooling radium in liquid hydrogen and found that the half life was the same as room temperature...radioactive decay is independent of temperature. I am seeing other answers that provide more detail, but this I would say is the simple answer.
