Talk:Nuclear waste management

Risk of Leaking Canisters

From the San Onofre Safety Website: https://sanonofresafety.org/holtec-hi-storm-umax-nuclear-waste-dry-storage-system/
“Holtec HI-STORM UMAX canister storage systems and all other thin-wall nuclear waste canister storage systems are vulnerable to short-term cracking, radioactive leaks and potential explosions and criticalities.“
“Holtec Umax lids at San Onofre - Radioactivity at air vent (e.g., carbon-14) was 324 CPMs”
“A canister breach in Texas or New Mexico can impact the water supply for eight states (the Ogallala aquifer), the breadbasket of the U.S.”
Holtec canisters:
Cannot be inspected inside or out
Cannot be repaired
Cannot be monitored or maintained to PREVENT radioactive leaks
No plan for failing canisters

From Holtec website: https://holtecinternational.com/products-and-services/hi-store-cis/overview/
“The life expectancy of the stainless-steel canister, which is the primary containment of the spent nuclear fuel, varies based on the environment. Conservative estimates put the life expectancy of the canister at hundreds of years. As part of the aging management program, there are regular inspections of canisters that will check the entire surface of a single canister, or part of the surface of multiple canisters. If these inspections would ever indicate an imperfection or crack, canisters would be re-packaged before a crack could propagate and a leak occur. There is sufficient time to re-package the canister since it would take many years for a crack to develop into a leak.”
“There are no liquid effluents or radioactive gas produced by the HI-STORE CIS facility. Therefore, there is no risk to the local groundwater or the quality of air at the site.”
“The HI-STORE CIS facility occupies less than the top 30 feet of the earth’s crust. Industrial activities such as mining of potash or extraction of hydrocarbons from the land, which occurs >1000 feet below-the-surface, will be entirely unaffected by the HI-STORE installation.“

What about non-fuel waste

Question in the FaceBook group Renewable vs Nuclear
"all the stuff on the primary loop. Pipes, pumps, wiring, blah blah. Obviously there is going to be mechanical and chemical wear on parts and they will need to be replaced like any power plant relying on heat -> steam -> turbine -> generator process. Parts will be be additionally exposed to neutrons and presumably undergo nuclear reactions and I assume some of those reactions will compromise their mechanical properties... eventually. How big of a deal is this? Is it slow, fast? What is the balance of fuel waste to non-fuel waste? Where do these parts go?"

Answer from Captain Roger Blomquist, United States Navy (retired) 8 Feb 2022:
"There are small concentrations of activated structural elements like cobalt. These typically have half-lives of years, not multiple decades. If they are recycled, then the workers doing the recycling will need to take (sometimes expensive) precautions to minimize their radiation exposure. I doubt that any such exposures would be harmful, although some might be. The precautions are quite likely far in excess of what is needed to prevent actual health effects."

Question on Quora.com

How big a problem is irradiated steel and other non-fuel waste from a nuclear power plant?

Add image caption here.

Answer from Lyle McElhaney 30 March 2022:
Iron is an element that is difficult to make radioactive.

This table shows that iron-56, which is almost 92% of all naturally occurring iron, requires three neutron absorptions before it becomes radioactive, and two absorptions for another 2% of the material. A single absorption is a low probability event for any given iron nucleus; absorbing three is a low probability to the third power. If it does happen, it results in iron-59 which beta decays to cobalt-59 (stable) with a half-life of 45 days.

Of course, it also shows that about 6% of iron will become unstable with the absorption of a single neutron. The resulting isotope decays by electron capture, which does not emit a particle other than a neutrino, and results in manganese-55, which is stable. So, no harm done by that other than possibly some gamma-rays.

The cobalt-59 resulting from a triple neutron capture could catch another neutron, becoming the dreaded cobalt-60, nemesis of the cobalt bomb. Cobalt-60 has a powerful gamma-ray emission as it beta decays with a half-life of around 5 years. This requires, as noted, 4 successive neutron captures with an intervening beta decay after the third. It is a very small probability event in concept; I don’t know what it is in practice.

Other materials - some do become radioactive when drenched with neutrons for an extended time. One would need to know what materials to analyze what happens.