Specification of waste forms to allow safe treatment, storage and disposal of problematic radioactive wastes held at Ukrainian nuclear energy facilities (U4.01/14 A)

Intermediate-level waste streams currently stored at the Ukrainian Nuclear Energy Facilities include radioactive wastes such as sludge’s, resins and salt-cake (sometimes known as fusion cake). At the present time these wastes are held in their raw state for lack of a defined processing route. The project will examine the characteristics of these waste streams and propose appropriate waste processing methods so that these waste streams may be transformed into packages that will be suitable for passive storage and eventual disposal. Furthermore the project should develop a Technical and Economic Analysis (TEA) for the selection of technologies for processing, safety related documentation, and technical specifications for equipment/systems required for implementation of optimised processing technologies for three selected problematic RAW streams into the forms acceptable for long-term storage and disposal.

The overall objective of the U4.01/14A INSC project was to contribute to a safe long-term storage and disposal of problematic radioactive waste (RAW) in Ukraine. A special focus should have been on a salt cake from evaporation facilities and ion-exchanging resins from water treatment stations of nuclear power plants (NPP), and on a perlite slurry from RBMK reactors.

The specific objectives of the contract has been to produce:

• Physical, chemical and radiological analysis of selected RAW streams,
• Generic Waste Acceptance Criteria (WAC) for the long-term storage,
• Technical and Economic Analysis (TEA) for the processing technologies,
• Detailed description of the optimised technologies for processing of the selected problematic RAW streams
• Technical Specifications for the required equipment/ systems and

The related safety documentation. It should include including a Preliminary Safety Analysis Report (PSAR) that would demonstrate operational safety of the proposed waste processing technologies. A regulatory approval of the PSAR was required.

The contractor for this project was a consortium of PLEJADES GmbH, NUKEM Technologies Engineering Services GmbH and Brenk Systemplanung GmbH. 

The 36-month project started on 1 November 2018 and ended on 31 October 2021.

In accordance with the contract Terms of Reference, the project was divided in the following tasks providing specific technical deliverables:

Task 1: Project Preparation and Inception Phase

The project kick-off meeting took place within the first month of the contract. Project working groups were established and an Inception Report was issued.

Task 2: Detailed analysis of problematic RAW streams

The contractor undertook several site visits. He collected available data relevant for the project and analysed the existing streams of radioactive waste in Ukraine. The contractor and beneficiary then agreed on the three problematic waste streams for further analysis: perlite from the Chernobyl NPP, spent ion-exchanging resins and salt cake from the operating Ukrainian NPPs. Task 2 workshop for presentation and discussion of Task 2 results took place and Task 2 Report was prepared.

Task 3: Characterization of selected problematic waste streams

The contractor developed a sampling methodology for the problematic waste and provided a practical demonstration/training of low-level radioactive waste (LRW). The contractor and beneficiary submitted a Sampling Methodology document and Analysis Methodology document for a regulatory approval. The sampling started at the beginning of 2020 with sampling at the Chernobyl NPP. The unexpected COVID-19 restrictions severely hampered the following samplings. Sample analyses finished in April 2021 and a final laboratory result report was prepared in May 2021. The Task 3 Report was issued in June 2021. All task 3 results were ready on time for Tasks 4 and 5.

Task 4: Technical and economic analysis of potential technologies for processing of problematic RAW

An initial technical analysis of possible waste processing technologies for the three problematic waste streams was prepared in 2020. The analysis was documented in a draft Task 4 report.. The contractor then performed detailed technical and economic analyses (TEA) for the selected waste streams. The following documents were prepared:

• TEA for Perlite from ChNPP,
• TEA for spent ion exchange resins from SUNPP,
• TEA for salt cake from RNPP.

A complementary document was prepared when all advanced TEA was completed:

• TEA for problematic wastes from other operating NPPs of NNEGC Energoatom.

A final Task 4 Report including the above deliverables as annexes appeared before 30 August 2021.

Task 5: Description of technologies, Technical Specifications for equipment and safety cases

The contractor prepared Safety Analysis Reports (SAR) and Technical Specifications (TS) for each of the selected waste streams. They have been submitted in the following documents:

• SAR for Perlite from ChNPP,
• SAR for spent ion exchanging resins from SUNPP,
• SAR for salt cake from RNPP.
• TS for Perlite from ChNPP,
• TS for spent ion exchanging resins from SUNPP,
• TS for salt cake from RNPP.

A Task 5 Report with the above documents as annexes was issued before 6 September 2021.

Task 6: Support to the Beneficiary/End User during Regulatory Review of Technical Specifications for the equipment/Systems, safety cases and expected characteristics of RAW packages

The contractor encouraged the beneficiary to invite representatives from the Ukrainian Regulatory Authority (URA) during the development of documents subject to regulatory review. Representatives of URA then participated on a regular basis in project workshops and project technical meetings. They provided comments prior to the actual document review. The official review started on 13 September 2021.

Task 7: Final Technical Report and project dissemination

The contractor presented project results at a dissemination workshop. It was combined with the final project meeting that took place on 12 October 2021. A Press release and Final Report were prepared.

The contractor provided possible technical solutions for processing the three main radioactive waste streams: perlite, spent ion exchangers and salt cake. The solutions were justified by safety assessments.

Although the COVID-19 restrictions considerably affected the project implementation, the contractor achieved all results expected in the contract Terms of Reference. The project was completed within the planned schedule and budget.