NIKET & UNIKET sorbents - Technical Report of Experimental Results in SevAcc project
Issued: 6th August 2018
Technical Report of Experimental Results in SevAcc project
Martin Skala, +420 266 172 147, e-mail: firstname.lastname@example.org
Centrum vyzkumu Rez, Husinec-Rez 130, 250 68
The following document serves as a feedback for sorption materials providers. The materials were provided for use in the project "Sorption module for nuclear power plant severe accident mitigation" supported by the Ministry of Industry and Trade of the Czech Republic under the TRIO program (hereinafter referred to as the "Project").
Project: Sorption module for nuclear power plant severe accident mitigation
Programme: FV – TRIO
The aim of the project is development of verified modular technology, altogether with testing of its individual parts (sorbent module, related membrane processes) that could be used for effective treatment of large volumes of radioactive wastes, originating from potential VVER 440/1000 NPP severe accident. The technology would also aim to minimize the final radioactive wastes when ensuring radiation safety during waste management (transport and storage).
Material provider: Renecol limited (Eksorb)
• NIKET (E112)
• NIKET-K (E116) - F kompozit
• NIKET-K (E116) - S kompozit
• NIKET-K (E516) kompozit
• UNIKET (E212)
• UNIKET (E213) kompozit
• UNIKET (E214) kompozit
Analysis and experiments:
• Sorption efficiency Cs, determination of distribution coefficient Kd,
• Sorption efficiency Sr, determination of distribution coefficient Kd,
• Influence of model solution matrix on material integrity.
(the full material is available at the link: /UPLOAD/user/stati/sevacc_2018_08_06_results_report_eksorb.pdf)
CONCLUSIONS AND REMARKS
The sorbent samples exhibit higher affinity towards Cs than to Sr. All samples (NIKET-K (E516) kompozit, NIKET (E112), NIKET-K (E116) - F kompozit, NIKET-K (E116) - S kompozit, UNIKET (E214) kompozit, UNIKET (E212), UNIKET (E213) kompozit) perform excellent separation efficiency - Kd higher than 10,000. Moreover, NIKET-K (E116) kompozit and UNIKET (E212) scored within top 4% of all tested material with respect to Kd value for Cs (more in Fig 1). UNIKET (E212) scored value of Kd higher than 100,000 (more in Table 1).
In terms of a stability in the model solution (based on the UV-vis spectroscopic measurement of treated solution) the sorbents samples follow the decreasing stability trend NIKET-K (E516) kompozit, NIKET (E112), NIKET-K (E116) - F kompozit, NIKET-K (E116) - S kompozit, UNIKET (E214) kompozit, UNIKET (E212), UNIKET (E213) kompozit (more in Fig 17). The sorbents NIKET (E112) and NIKET-K (E516) kompozit show very little leaching to the treated solution observed visually (Fig 3, 6) and on UV-vis. spectra (Fig 10, 13). However, samples of UNIKET (E214) kompozit, UNIKET (E212), UNIKET (E213) kompozit and NIKET-K (E116) - S kompozit suffered strong decomposition in the model solution which can be seen both on visual observation (Figure 5, 7, 8, 9) and UV-vis spectra (Fig 12, 14, 15, 16).
During the experiments with UNIKET (E212) and UNIKET (E214) kompozit the gas release has been observed. The nature of the gas hasn’t been identified.