Nuclear Physics and Atomic Energy

Ядерна фізика та енергетика
Nuclear Physics and Atomic Energy

  ISSN: 1818-331X (Print), 2074-0565 (Online)
  Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine
  Languages: Ukrainian, English
  Periodicity: 4 times per year

  Open access peer reviewed journal


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Nucl. Phys. At. Energy 2026, volume 27, issue 1, pages 38-47.
Section: Atomic Energy.
Received: 25.08.2025; Accepted: 02.03.2026; Published online: 31.03.2026.
PDF Full text (en)
https://doi.org/10.15407/jnpae2026.01.038

Radiological impact assessment for possible accidents during the decommissioning of the WWR-M reactor

S. Yu. Lobach1,*, Yu. M. Lobach2

1 Nuclear and INdustrial Engineering (N.IN.E.) S.R.L., Lucca, Italy
2 Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, Ukraine


*Corresponding author. E-mail address: s.lobach@nineeng.com

Abstract: The WWR-M research reactor is planned for decommissioning. An essential component of the safety analysis report is the analysis and assessment of potential accident scenarios during decommissioning. This article presents an approach to identifying hazards and possible radiological consequences of the most dangerous initial event. The assessment results show that the radiological consequences will be significantly lower than the established standards.

Keywords: WWR-type research reactor, decommissioning, accident, exposure, release.

References:

1. Safety Assessment for Decommissioning. Safety Reports Series. No. 77 (Vienna: IAEA, 2013) 151 p. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1604_web.pdf

2. Decommissioning of Facilities. General Safety Requirements. No. GSR Part 6. IAEA Safety Standards (Vienna: IAEA, 2014) 44 p. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1652web-83896570.pdf

3. Accident Analysis for Nuclear Power Plants. Safety Reports Series. No. 23 (Vienna: IAEA, 2002) 129 p. https://www-pub.iaea.org/MTCD/publications/PDF/Pub1131_scr.pdf

4. Safety Assessment for the Decommissioning of Facilities Using Radioactive Material. IAEA Safety Standards. Safety Guide. No. WS-G-5.2 (Vienna: IAEA, 2008) 79 p. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1372_web.pdf

5. Safety Assessment for Research Reactors and Preparation of the Safety Analysis Report. IAEA Safety Standards. Specific Safety Guide. No. SSG 20 (Rev. 1) (Vienna: IAEA, 2022) 150 p. https://www-pub.iaea.org/MTCD/Publications/PDF/PUB1981_web.pdf

6. General Safety Provisions for the Decommissioning of Nuclear Installations. NP 306.2.230-2020. Registered with the Ministry of Justice of Ukraine on 30.12.2020 for No. 1311/35594 (Ukr) https://zakon.rada.gov.ua/laws/main/z1311-20?utm_source=chatgpt.com#Text

7. Yu.M. Lobach et al. Preliminary safety analysis at the decommissioning of the WWR-M research reactor. Nucl. Phys. At. Energy 23(2) (2022) 107. https://doi.org/10.15407/jnpae2022.02.107

8. On Use of Nuclear Energy and Radiation Safety. Law of Ukraine of 08 February 1995 No. 39/95 VR. (Ukr) https://zakon.rada.gov.ua/laws/show/39/95-%D0%B2%D1%80#Text

9. Radiation Safety Standards of Ukraine NRBU 97. State Hygienic Norms DHN 6.6.1 6.5.001-98 (Kyiv: Ministry of Health of Ukraine, 1998). (Ukr) https://zakon.rada.gov.ua/rada/show/v0062282-97#Text

10. Terminology Used in Nuclear Safety and Radiation Protection. IAEA Safety Glossary (Vienna, IAEA, 2009) 261 p. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1290_web.pdf

11. INES: The International Nuclear and Radiological Event Scale. User's manual. 2008 Edition (Vienna, IAEA, 2013) 206 p. User's manual

12. Preparation of Nonreactor Nuclear Facility Documented Safety Analysis. DOE Standard. DOE-STD-3009-2014 (Washington: U.S. Department of Energy, 2014) 92 p. DOE-STD-3009-2014

13. M. Laraia (Ed.). Nuclear Decommissioning Case Studies. Vol. 1: Accidental Impacts on Workers, the Environment and Society (Academic Press, 2021) 464 p. https://shop.elsevier.com/books/nuclear-decommissioning-case-studies/laraia/978-0-12-823700-7

14. B. Park, J.Y. Kim, C.L. Kim. Suggestion of risk assessment methodology for decommissioning of Nuclear Power Plant. J. Nucl. Fuel Cycle Waste Technol. 17(1) (2019) 95. https://dx.doi.org/doi.org/10.7733/jnfcwt.2019.17.1.95

15. Yu.M. Lobach et al. Principal provisions of the decommissioning concept for the WWR-M research reactor. Nucl. Phys. At. Energy 22(4) (2021) 348. https://doi.org/10.15407/jnpae2021.04.348

16. K.S. Jeong et al. A qualitative identification and analysis of hazards, risks and operating procedures for a decommissioning safety assessment of a nuclear research reactor. Ann. Nucl. Energy 35(10) (2008) 1954. https://doi.org/10.1016/j.anucene.2008.05.008

17. Yu.N. Lobach, G. Toth. Design for the WWR-M reactor vessel removal. Nucl. Eng. Des. 258 (2013) 184. https://doi.org/10.1016/j.nucengdes.2013.01.032

18. Yu.N. Lobach, M.T. Cross. Dismantling design for a reference research reactor of the WWR type. Nucl. Eng. Des. 266 (2014) 155. https://doi.org/10.1016/j.nucengdes.2013.11.041

19. Yu.M. Lobach et al. Assessment of the dose load during dismantling of the WWR-M reactor. Nucl. Phys. At. Energy 23(4) (2022) 234. https://doi.org/10.15407/jnpae2022.04.234

20. Technical substantiation of the operational safety for the WWR-M reactor. No. ÒÎÁ. 02-136-15/16/17. Approved by the State Nuclear Regulatory Inspection of Ukraine, letter No. 15-15/7-3620 dated 06.16.17. (Kyiv, Institute for Nuclear Research, 2017) 302 p. (Ukr)

21. Derivation of the Source Term and Analysis of the Radiological Consequences of Research Reactor Accidents. Safety Reports Series. No. 53 (Vienna: IAEA, 2008) 178 p. https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1308_web.pdf

22. K. Eckerman et al. Compendium of dose coefficients based on ICRP publication 60. ICRP Publication 119. Annals of the ICRP 42(4) (2013). https://doi.org/10.1016/j.icrp.2013.05.003

23. Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities. Vol. 1: Analysis of Experimental Data. DOE-HDBK 3010-94 (Washington: U.S. Department of Energy, 1994) 359 p. https://www.osti.gov/biblio/10113350?utm_source=chatgpt.com

24. Hazard and Accident Analysis. Handbook. DOE-HDBK-1224-2024 (Washington: U.S. Department of Energy, 2024) 374 p. https://www.standards.doe.gov/standards-documents/1200/1224-bhdbk-2024/@@images/file

25. B.A. Napier, J.G. Droppo Jr., J.P. Rishel. Air Dispersion Modeling of Radioactive Releases During Proposed PFP Complex Demolition Activities. Report to CH2M HILL Plateau Remediation Company. PNNL-20173 (Richland, Washington, Pacific Northwest National Laboratory, 2011) 118 p. https://www.pnnl.gov/main/publications/external/technical_reports/pnnl-20173.pdf

26. Authorized gaseous-aerosol emission for the nuclear installations of the Institute for Nuclear Research (Kyiv, Institute for Nuclear Research, 2021) 6 p. (Ukr)