Nuclear Waste Immobilization Network

Responsibility

At present, each country is legally and ethically responsible for their own nuclear waste storage. There are now over 50 countries that generate high level nuclear waste.

Immobilization

A highly effective way to store nuclear waste is through immobilization techniques. These methods are designed to encapsulate the waste in a material with the correct properties to deal with the residual temperatures involved.

This High-level waste (HLW) stems from the use of uranium fuel in a nuclear reactor. It contains the fission products as well as the transuranic elements generated within the reactor core. HLW is highly radioactive with high temperature concerns due to decay heat so it requires extensive cooling and shielding.

Encapsulation

After 40-50 years of temporary storage, the heat and radioactivity have fallen to one thousandth of the level at removal. At this time, the used fuel is ready for encapsulation or loading into casks ready for indefinite storage or permanent disposal underground.

Methods

Treatment and conditioning methods are used to convert radioactive waste materials into a form that is suitable for its transportation, storage and final disposal.

There is a variety of materials and methods to encapsulate the HLW including:

  • Cementation
  • Glass encapsulation
  • Ceramic encapsulation
  • Polymer encapsulation

Resources

 PPE worn while managing HLW or LLW

 

When dealing with HLW the choice of appropriate personal protective equipment (PPE) depends on

  • Worker’s role and specific tasks
  • Risk of contamination

PPE can protect against

  • External contamination
  • Internal contamination

PPE cannot protect against exposure from high energy, highly penetrating forms of ionizing radiation. Lead aprons do not provide sufficient shielding against these kinds of radiation.

In low level environments the recommended PPE include:

Eye protection: Safety glasses should always be worn at all times when handling radioactive material, even if working with a fume safety cabinet or shield. All about the Poly-carbonate material used in modern safety glasses applications can be found at NASA

Lab coat: A buttoned lab coat is recommended because you are more likely to get contamination from the front. Do not leave gaps and use extra covers. Make sure that your sleeves aren’t too loose which could allow them to drag across radioactive material and easily become contaminated. Consider elastic knit cuffs.

Double gloves: By wearing two pairs of gloves, you greatly reduce the risk of radioactive material coming in contact with your skin through a tear in the glove, or migrating through the glove.

In addition, other PPE should include long pants and extra shoes for the specific task.

Direct-reading personal radiation dosimeters are highly recommended to monitor radiation dose.

Respiratory protection: Higher levels require full-face piece air purifying respirator with a P-100 or High Efficiency Particulate Air (HEPA) filter3.