Characterization of particles formed during laser cutting of simulated fuel-containing materials from the Fukushima-Daiichi NPP and of SNF samples

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Abstract

Fragmentation of massive debris of the fuel and fuel-containing materials (FCMs) is one of important steps in the final decommissioning of the Fukushima Daiichi NPP. The generation and dissemination of radioactive microparticles in the course of the fragmentation largely depend on the cutting technology used. A previous study [1] dealt with the experimental cutting of simulated FCM and spent nuclear fuel (SNF) samples to justify the optimum configuration and operation conditions of the gas treatment system. To understand the properties of particles generated in the course of cutting FCM and SNF samples and to justify the methods for their localization, it is necessary to study in more detail the size, shape, and composition of the structures formed. We used in this study the microparticles formed by laser cutting of simulated FCMs from the Fukushima Daiichi NPP and of SNF samples. The microparticles formed were examined with a laser particle size analyzer and with a scanning electron microscope equipped with wave- and energy-dispersive spectrometers. The formation of particles of different size and morphology was noted. The laser cutting generates separate particles of submicron size and different morphology, which form agglomerates. Up to 35 wt % of particles formed by laser cutting of the simulated FDM passed into the vapor–gas phase. For the VVER (water-cooled water-moderated energy reactor) SNF, this fraction was 25 wt %. The major components of all kinds of particles formed by laser cutting of SNF are uranium, oxygen, and zirconium; their total fraction is in the range from 97.9 to 98.4%. The plutonium content ranges from 0.7 to 1.3%.

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About the authors

А. O. Makarov

State Scientific Center Research Institute of Atomic Reactors

Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

V. N. Momotov

State Scientific Center Research Institute of Atomic Reactors

Author for correspondence.
Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

S. D. Semin

AO TVEL

Email: SDmSemin@tvel.ru
Russian Federation, Kashirskoe shosse, 49, Moscow, 115409

O. N. Nikitin

State Scientific Center Research Institute of Atomic Reactors

Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

P. V. Lakeev

State Scientific Center Research Institute of Atomic Reactors

Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

V. A. Efimov

State Scientific Center Research Institute of Atomic Reactors

Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

V. А. Reztsova

State Scientific Center Research Institute of Atomic Reactors

Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

D. E. Tikhonova

State Scientific Center Research Institute of Atomic Reactors

Email: momotov@niiar.ru
Russian Federation, Zapadnoe shosse, 9, Dimitrovgrad, Ulyanovsk oblast, 433510

References

  1. Makarov A., Momotov V., Lakeev P., Sivkova V., Nezgovorov N., Semin S. et al. // Ann. Nucl. Energy. 2022. Vol. 173. Article 109103.
  2. Kitagaki T., Yano K., Ogino H., Washiya T. // J. Nucl. Mater. 2017. Vol. 486. P. 206–215.
  3. International Research Institute for Nuclear Decommissioning (IRID), Upgrading of Fundamental Technology for Retrieval of Fuel Debris and Internal Structures, FY2018 Final Report, July 2019. https://irid.or.jp/wp-content/uploads/2020/09/fy2018retrievaloffueldebrisandinternalstructures.pdf
  4. International Research Institute for Nuclear Decommissioning (IRID), Upgrading of Approach and Systems for Retrieval of Fuel Debris and Internal Structures, Accomplishment Report for FY 2017, April 2018/ https://irid.or.jp/_pdf/5_Upgrading%20of%20Approach%20and%20Systems%20for%20Retrieval%20of%20Fuel%20Debris%20and%20Internal%20Structures_IRID_2019.pdf
  5. Ohnuki T., Nakase M., Liu J., Dotsuta Y., Satou Y., Kitagaki T., Kozai N. // J. Nucl. Sci. Technol. 2024. Vol. 61. N 3. P. 384–396.
  6. Yano K., Kitagaki T., Ikeuchi H., Wakui R., Higuchi H., Kaji N., Koizumi K. Direction on characterization of fuel debris for defueling process in Fukushima Daiichi Nuclear Power Station // Proc. GLOBAL 2013, Salt Lake City, Sept. 29−Oct. 1, 2013. Am. Nucl. Soc., 2013 (CD-ROM).
  7. Kitagaki T., Yano K., Washiya T. Research approach of MCCI products characterization for debris removal // IEM on Strengthening Research and Development Effectiveness in the Light of the Accident at the Fukushima Daiichi Nuclear Power Plant. Vienna, Austria: IAEA Headquarters, Febr. 16–20, 2015. Poster ID Number: IAEA-CN-235–85.
  8. Journeau C., Roulet D., Porcheron E., Piluso P., Chagnot C. // J. Nucl. Sci. Technol. 2018. Vol. 55. P. 985–995.
  9. Tokyo Electric Power Company, Data of Abnormal Events Including Alarm Records–Unit 1 (June 23, 2011) (in Japanese). http://www.tepco.co.jp/en/nu/fukushima-np/plant-data/f1_3_Keihou1.pdf
  10. Tokyo Electric Power Company, Data of Abnormal Events Including Alarm Records–Unit 3 (June 23, 2011) (in Japanese). http://www.tepco.co.jp/en/nu/fukushima-np/plant-data/f1_3_Keihou3.pdf
  11. Colle J.-Y., Stohr S., Cremer B., Van Winckel S., Rasmussen G., Blanco O.D. et al. // J. Aerosol Sci. 2020. Vol. 148. Article 105588. https://doi.org/10.1016/j.jaerosci.2020.105588

Supplementary files

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2. Fig. 1. Schematic representation of the laser sample cutting installation. 1 – laser head, 2 – cutting chamber, 3 – gas cleaning line nozzle, 4 – removable tray, 5 – sampling line nozzle, 6 – digital video camera.

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3. Fig. 2. Image of the laser cutting setup in a radiation protection chamber.

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4. Fig. 3. Schematic representation and photograph of the radiation protection chamber of a sampling device with cartridge filter elements (1 – cartridge filter elements).

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5. Fig. 4. Particles from the cutting chamber tray after laser cutting of a TCM simulator sample, the size of which is more than 2 mm.

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6. Fig. 5. Results of granulometric analysis of particles from the cutting chamber tray after laser cutting of a TCM simulator sample in air.

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7. Fig. 6. Image of the surface of the mesh from the first cartridge filter element after laser cutting of the TSM simulator sample.

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8. Fig. 7. Electron microscopic image of conductive tape in secondary electrons (the area of microstructure study is indicated).

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9. Fig. 8. Electron microscopic images of dust particles in region 1 (Fig. 7) with different magnifications in secondary electrons. a – region 1, indicated in Fig. 7, with higher magnification; b–i, 1–7 – see comments in the text and explanations in Table 3.

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10. Fig. 9. Particles from the cutting chamber tray after laser cutting of a VVER SNF sample.

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11. Fig. 10. Images of a particle from the bottom of the cutting chamber after laser cutting of a VVER SNF sample, obtained using a stereomicroscope. a, b – see text for explanations.

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12. Fig. 11. Results of granulometric analysis of particles from the cutting chamber tray after laser cutting in air of a VVER SNF sample.

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13. Fig. 12. Electron microscopic image of the macrostructure of conductive tape in secondary electrons (areas of microstructure study are indicated).

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14. Fig. 13. Electron microscopic images in secondary electrons of dust particles in region 1 with different magnifications. a–e – see comments in text.

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