24100 years
You can easily convert from decay constant to half-life by using the relationship:
H = ln(2)/D where
H = half life D = decay constant
ln(2) = natural logarithm of 2.
So
H = ln(2)/D
H = 0.693147181/2.88x10^-5 1/year H = 2.41x10^4 year
H = 24100 year
