https://www.eia.gov/todayinenergy/detail.php?id=33792 https://www.eia.gov/todayinenergy/detail.php?id=33792 DECON takes at least 7 years, SAFSTOR 50+ years. 50

https://www.eia.gov/todayinenergy/detail.php?id=33792 https://www.eia.gov/todayinenergy/detail.php?id=33792 DECON takes at least 7 years, SAFSTOR 50+ years. 50% of the decommionings in the US are the slow kind. If you are going for the quick kind, you have to take everything off site somewhere and stick it in a hole in the ground (or probably store it on another nuclear plant site) - and then that hole in the ground is radioactive. Its likely when they decommission Diablo Canyon, they will turn off the power and post a guard at the gate for 50 years and not touch anything.