Decontaminating Radioactive Materials

[brianempson]

Is there a way or process to neutralize the radioactive properties of a material (i.e. Make a radioactive substance stop ionizing it's surroundings?)

Alternatively, since the gamma radiation penetrates through materials the most, is there a way of "slowing down" the frequency (lowering the energy) of the particles/photons to such a degree that they are no longer capable of ionizing and stripping off electrons?

Apologies if my question has errors in my assumptions above, I'm generally curious.

 

[brianempson]

Oops, I think I put this question in the wrong forum, sorry!

 

[Drakkith]

Oops, I think I put this question in the wrong forum, sorry!

I've moved this to the Nuclear Engineering forum.

 

[brianempson]

I've moved this to the Nuclear Engineering forum.

Thanks, nothing like making a mistake on your first post. :P

 

[Astronuc]

Is there a way or process to neutralize the radioactive properties of a material (i.e. Make a radioactive substance stop ionizing it's surroundings?)

Alternatively, since the gamma radiation penetrates through materials the most, is there a way of "slowing down" the frequency (lowering the energy) of the particles/photons to such a degree that they are no longer capable of ionizing and stripping off electrons?

Apologies if my question has errors in my assumptions above, I'm generally curious.

There is no way to stop a radionuclide from decaying, which is the source of the radiation. The radiation (α, β^-, β⁺, γ) leave the nucleus with energies in keV to MeV range, which is well above the eV ionization energies. This is why we put 'shielding' around radioactive materials.

Gamma rays lose energy by interacting with electrons in atoms. Some gamma rays can be completely absorbed in a process call the photoelectric effect, some gamma will scatter off electrons losing energy in the so-called Compton effect, and other gammas (E > 1.022 MeV) may interact with nuclei producing positron-electrons pairs. The positron will find an electron and annihilate into a pair of 0.511 MeV gamma rays. High energy gamma rays can also cause some nuclei to emit neutrons (photoneutrons). Gamma rays eventually lose energy and are absorbed by electrons. In metals subject to gamma radiation, we refer to gamma heating.

Alpha particles occur in decay of a number of radionuclides heavier than Bismuth, or in some nuclear reactions in light nuclei, for example d+t fusion, which produces n and α).

 

[Hiddencamper]

As Astronuc said, you can't stop something from being radioactive. If we could, then we would use that method to cause all our spent nuclear fuel to become safe and solve the nuclear waste challenge.

What we can do, is in some cases you can further irradiate a material to change it to an isotope which decays faster to a stable product or has more stable daughter products overall.

 

[brianempson]

Thank you for the great replies. Is there any active research on this topic or is it pretty much an unsolvable problem we have to live with?

 

[Astronuc]

Thank you for the great replies. Is there any active research on this topic or is it pretty much an unsolvable problem we have to live with?

There is no practical way to influence a particular radionuclide to neutralize its radioactivity. In most cases, e.g., a nuclear reactor, there are a large number of different radionuclides present. We might recover the unused uranium and plutonium, and recycle/reprocess it for further use. The fission products may be oxidized, calcined and vitrified, and even made into synthetic rock with characteristics similar to geologically stable minerals. It is not economical/practical to partition fission products or sort them by element and half-life.

For transuranics, there is the possibility of transmuting longer-lived radionuclides into shorter-lived radionuclides, or consume them in a so-called actinide burner.

 

This reminds me of the latest diehard movie with their radioactivity neutralizing spray, that scene made me chuckle.