KORAD - Low and intermediate level waste (LILW) consultation

Case description

Fortum and TVO Nuclear Services (TVONS) were contacted to assist KORAD in the process of drafting a PSR, seeing as both companies have extensive expertise in this task and generally in the field of nuclear waste management. Both Fortum and TVO own and operate LILW repositories at their respective NPP sites, at Loviisa and Olkiluoto. Through the operation of these repositories, both companies have gained plentiful experience in the area of radioactive waste management and disposal. Furthermore, Posiva Oy – a waste management organization co-owned by Fortum and TVO - is currently preparing for the spent nuclear fuel disposal in Olkiluoto, in a facility called ONKALO® as the first operator in the world. In the consultation for KORAD, Fortum and TVO were able to draw inspiration from their own facilities, both when it comes to PSRs, as well as with general operation of said facilities.

The licensee has the responsibility to manage the radioactive waste in a safe manner. This includes handling, storing and the final disposal of the waste. In order to do this, the waste has to be identified, classified and categorized by the radioactive content and managed accordingly. The service provided by Fortum and TVO for KORAD consisted of two different tasks. Firstly, the consultation about drafting of a PSR for the LILW repositories, and secondly KORAD needed assistance regarding the formulation of waste acceptance criteria. 

Consultation on drafting a PSR

Fortum & TVONS delivered the PSR-related consultation by describing what they had taken into account and done when compiling PSRs for their own LILW repositories. The purpose of a PSR for a disposal facility is to evaluate operational experiences, aging management and effects of aging, new technological developments, as well as compliance with the regulatory requirements considering the disposal facility as a whole.

Generally, a PSR includes an assessment of plant design and operation against applicable current safety standards and operating practices, and has the objective of ensuring a high level of safety throughout the plant’s operating lifetime. It is complementary to the routine and special safety reviews conducted at NPPs, however does not replace them. A PSR provides an effective way to obtain an overall view of the actual plant safety, the quality of safety documentation, and to determine reasonable and practical modifications to ensure safety or improve safety to an appropriate high level (IAEA).

Because the PSR was compiled for the Loviisa LILW repository rather than for a NPP, resulted in a slight deviation from the general principles. For instance, some items were combined, and a separate report was dedicated for some items, such as the monitoring programmes.

General lessons that Fortum and TVO have learned from PSRs, that were further delivered to KORAD, often related to the workforce needs. For instance, the fact that a PSR for a disposal facility can be successfully done without previous expertise, although knowledge assists in the procedure substantially. Expert support helps in planning the scope and therefore reducing required overall costs. Furthermore, Fortum & TVO stated the importance of the use of own personnel in the drafting of PSR documents, since it contributes to internal knowledge transfer, which is quite valuable. Additionally, communication and collaboration with third parties, such as the authorities and external contractors needs to be done well in order to ensure a smooth progress in the project. Moreover, the long-term safety case is a major part of the PSR, and needs a lot of focus. This involves reserving correct schedule and resource planning to enable a qualitative & up-to-date case study. Lastly, both companies defined the project management, resource, budget and schedule planning as being of utmost importance. This of course applies to all projects, but PSRs are no exceptions. 

LILW criteria consulation

As was the case with the PSR consultation, Fortum and TVONS delivered the consultation on waste acceptance criteria (WAC) from the perspective of their own LILW repositories. The breakdown of the criteria consultation touched upon the LILW of both companies, the inventory of the waste to be disposed of, and an explanation on how waste acceptance criteria relates to the Finnish regulatory requirements.

WAC is often based on international recommendations agreed upon, such as those of IAEA, however details vary between countries. Nuclide-specific activity limits introduced into a repository are part of the waste acceptance criteria. Meeting the waste acceptance criteria and activity limits defined therein helps to ensure a safe disposal, both during the operational and the post-closure phases of the repository.

Some final conclusions that Fortum and TVONS drew after analysing their respective WAC, was how the activity limits varied between the two companies. When it comes to Fortum, the limits where focused on long-term safety considerations. Meanwhile for TVO the limits were mostly based on the operational safety (i.e., radiation dose received by personnel and transport safety). This difference can be attributed to the difference in the waste treatment and disposal concepts between the two organisations. TVO solidifies relatively fresh liquid waste, which results in relatively high external dose rates, whereas at Loviisa the liquid waste to be solidified is older and packaged into concrete containers, which reduces the external dose rate. The Finnish regulations regarding WAC are not very prescriptive and leaves room to derive the activity limits.

Lastly, it is important to note that the Finnish acceptance criteria function differently than in other countries. The reason behind this is that nuclear operators produce and dispose their own waste in Finland, whereas nuclear waste disposal is often carried out in centralized manner in other nations. The differences between Fortum and TVONS activity limit derivation offers KORAD a wider approach to waste criteria management. In fact, the approach to derive waste acceptance criteria from long-term safety point of view combined with consideration of operational safety perspective provides basis for clear and transparent criterion for stakeholders’ communication.

Our approach

As prior mentioned, Fortum and TVO have significant expertise in nuclear waste management, including disposal as well as in the drafting of PSRs. This portfolio of knowledge was utilized when consulting KORAD on how nuclear waste is managed in a safe and optimized manner. The concrete practical know-how from owning and operating an own disposal facility, something that is not the norm globally, was particularly useful in assisting the client.

The fact that Fortum and TVO both produce and manage their own waste gives the Finnish nuclear companies a clear edge on the market through their in-house waste management expertise. Additionally, the disparities between the companies offered KORAD a broader approach to nuclear waste management.

Value added

Fortum and TVO were able to provide consultation on drafting of PSRs and how to manage nuclear waste in accordance with waste acceptance criteria. The customer was pleased with the gained expertise in the areas of LILW management.

In order to safely pursue the generation of nuclear energy, one must also have a safe plan on how and where to store and dispose the waste that is produced throughout the power plant’s life-cycle and after its closure. Seeing as KORAD needed assistance in the regulatory documenting and general know-how of safely disposing LILW, Fortum and TVO were able to contribute to the safe generation of carbon-free nuclear power in South Korea.