Waste package quality control

To ensure safety, the radioactive waste is subjected to several examination procedures before it is disposed of. A combined control of conditioning (packaging in a manner meeting the requirements for disposal) and random sampling has proven their worth.

A phase of product assurance

In the scope of this procedure it is verified that the waste has been packaged in compliance with the waste acceptance requirements for the Konrad repository. Independent experts perform this verification on behalf of the Federal Office for Radiation Protection (BfS). The waste package quality control can be carried out in two different ways. Either

• by applying procedures for the production of radioactive waste packages that have been qualified by the BfS and have, thus, been cleared, or
• through random sampling of already produced waste packages.

Qualified procedure for the production of waste packages meeting the requirements for disposal

"Procedures have to be used for the treatment and packaging of radioactive waste for the production of waste packages meeting the requirements for disposal, whose usage has been approved by the Federal Office for Radiation Protection" (StrlSchV § 74, para. 2).

In principle, the applicant must prove that the waste forms meet the requirements demanded by the waste acceptance requirements for the Konrad repository before such a procedure for the treatment and packaging of radioactive waste can be used. The procedure itself is accompanied by independent experts. This will ensure that the treatment and packaging (conditioning) of the waste meets the requirements for disposal and that all relevant data is documented.

Random sampling of already produced waste packages

The data on the features of the radioactive waste given by the waste producer is random verified through independent examinations. Up to twelve per cent of the waste packages are random checked in this process. The waste primarily consists of old waste for whose conditioning no accompanying controls have been carried out by independent experts.

As to the techniques to be used, a distinction is made between non-destructive and destructive measures.

• When using non-destructive techniques, the waste package is examined from the outside using various methods. They include, among others, measurements of the dose rate at the surface of the container, computer tomography, and taking gas samples and analysing them.
• Using non-destructive measures includes the opening of the container, for example to take and examine a core.

Tasks of the experts

The experts commissioned in the scope of waste package quality control need to have the expertise and independence required for their task. Among others, their tasks include:

• verifying the description of the characteristics of the waste forms and packaging,
• examining and assessing conditioning procedures with respect to the waste form features including the examination of used containers and packaging,
• control of samples from the conditioning process,
• carrying out accompanying inspections with respect to the waste form features in facilities where radioactive waste is conditioned with qualified procedures,
• carrying out control measures in the production of containers and/or packaging with respect to the used materials and compliance with the quality assurance measures, and
• taking random samples of waste packages with respect to the waste package features.