Author: Kiersten Sundell
Something we are frequently asked on TikTok is: “If nuclear waste decays over time, how many years until it’s safe again?”
This is a tricky question because technically, used nuclear fuel remains radioactive forever. Uranium’s half-life is 4.5 billion years. The good news is that it doesn’t remain equally radioactive the entire time.
Let’s preface by explaining that spent fuel emits three forms of radiation: alpha rays, beta rays, and gamma rays. Alpha rays cannot penetrate through the skin, while beta rays can travel a few feet in the air and can pass through the skin, but they are absorbed by a few centimeters of body tissue or blocked by a few millimeters of aluminum. In general, the only real hazard to human health is the high-powered gamma ray.
After less than 600 years, spent fuel has decayed to the point where 99.999% of gamma rays have completely disappeared, leaving behind mostly Uranium-238, which is an alpha emitter. At this point, it has returned to about the radiation level of uranium that you can find in the ground, and you can safely handle it with your bare hands.
In fact, the radiation really wouldn’t affect you at all unless you ate it.
If you were to eat it, for some reason, you would most definitely die of kidney failure before you developed any form of cancer. Consequently, there are a lot of things that you shouldn’t eat due to the risk of kidney failure. These include things like pure copper, agricultural pesticides, arsenic, and most household cleaning products.
Just don’t do it.
But in all seriousness, the spent fuel will be “safe” in 600 years. Of course, the word “safe” is relative, but I hope this helps.
Head to our TikTok to watch the full video, and check out the source article, written by Jack Devanney!
