The computation for the half-life of this is:
Tritium, which decays at a rate of 5.471% per year
1/2 = 1 *e ^ (-0.05471 h), where h is the half-life
ln (1/2) = -0.05471 h
h = -ln (1/2)/0.05471= 0.693147181 / 0.05471≈ 12.6694787 yearswhich in actual has a half-life of 12.32 years.
