Swedish Nuclear Fuel and Waste Management Co (SKB)
Radioactive waste facilities
Complying with wide-ranging safety regulations
SKB manages and disposes of all radioactive waste from every nuclear power plant in Sweden. Our client needed to make sure this is done in such a way as to secure maximum safety for people’s lives and the environment.
To handle collected waste, SKB’s system of facilities included: a central interim storage facility for spent nuclear fuel (Clab), near Oskarshamn; a final repository for short-lived radioactive waste (SFR) in Forsmark; and sea transport using the vessel M/S Sigrid. Our client was also constructing/had plans to construct an encapsulation plant, where spent nuclear fuel would be sealed in copper casks before being placed in a geological repository.
SKB wanted our independent help in meeting two major requirements:
- renewing the Safety Analysis Report (SAR) on the Clab facility
- producing a preliminary SAR, supporting the construction of a new encapsulation plant.
Detailed analyses had to show how nuclear safety would be established and maintained for the facilities during normal operation and in the case of disturbances. Any failings would mean not complying with the regulations of the Swedish Radiation Safety Authority (SSM), posing a threat to continued operation, development of the facilities and the safe disposal of nuclear waste.
How we helped
Our support covered the development of our client’s analysis methodologies (design and review) and then carrying out the analyses. The project’s scope was comprehensive, considering internal and external events that could pose threats to the facilities. Such events encompassed equipment issues and operating aspects, such as the cooling of spent nuclear fuel, through to natural or manmade phenomena, including flooding. We also conducted a Probabilistic Safety Analysis (PSA) study on the overall plant response to possible accident sequences. For the new encapsulation plant, we helped to develop the technical concept in parallel with analyses, adapting to evolving conditions.
Ten of our experts from three locations in Sweden supported the project. To ensure quality and consistency of work, internal reviewers were appointed. All deliverables, including review findings, were discussed and addressed before final issue of documents to our client.
- Establish methodologies for the identification and classification of internal and external events that could lead to radiological accidents.
- Identify, classify and analyse possible internal events, using the established methodologies.
- Conduct a detailed survey on possible types of external events, and combinations of external events, that could lead to radiological accidents, analyse the facility’s response, and perform a screening analysis.
- Establish a methodology for a Probabilistic Safety Analysis (PSA).
- Conduct a PSA study to characterise possible accident sequences and to quantify the likelihood of accidents.
- Perform flooding analyses.
- Perform analyses on the cooling of spent nuclear fuel.
- Contribute to the Safety Analysis Reports (SARs), showing how nuclear safety is established for the facilities (using the above analyses).
Our methodologies, analyses and contributions to the Safety Analysis Reports (SARs) formed a critical part of SKB’s presentation of safety concepts to the regulator. Beyond meeting this objective, the project introduced valuable new knowledge across the organisation.