[p1mrx]

It's a single isotope, nickel-63, which decays into regular copper-63. The amount of nickel halves every 96 years.

If you throw it in a fire, you'll disperse nickel-63 into the environment, which isn't good, but the decay process is unaffected.

[Fatnino]

I've seen it said that it takes 10 halflives for something to decay all the way away.

So like 1000 years for this to flush itself.

[jbboehr]

> I've seen it said

You can estimate it yourself:

0.5 ^ 10 = 0.0009765625 (~0.1%)

https://en.wikipedia.org/wiki/Half-life#Probabilistic_nature

> When there are many identical atoms decaying, the law of large numbers suggests that it is a very good approximation to say that half of the atoms remain after one half-life