Nuclear Physics and Atomic Energy

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

 Home page   About 
Nucl. Phys. At. Energy 2021, volume 22, issue 1, pages 48-55.
Section: Atomic Energy.
Received: 01.06.2020; Accepted: 02.04.2021; Published online: 19.06.2021.
PDF Full text (ua)

Analysis of the influence of nuclear fuel burnup on the 16N formation rate in the primary coolant of the WWER-1000 reactor

Yu. Fylonych*, V. Zaporozhan, O. Balashevskyi, K. Merkotan

Department of the Scientific and Technical Support, Odesa SS "Scientific and Technical Support" of SE NNEGC "Energoatom", Odesa, Ukraine

*Corresponding author. E-mail address:

Abstract: The developed model of the WWER-1000 reactor using MCNP6.2 (Monte Carlo N-Particle Transport Code) includes the detailed core taking into account the design of the fuel assemblies, as well as the baffle, the lower plenum, the fuel support columns, the core barrel, a downcomer, and the reactor pressure vessel. It allows implementing multifunctional calculations such as recriticality with various fuel configurations, the critical concentration of boric acid, determination of the axial and radial peaking factor in the reactor core, etc. For obtaining the more precise result of the cumulation nitrogen-16 formation rate, the contribution from different water volumes was taken into account: in the core, above the fuel and the top nozzle, in the top nozzle of the fuel assembly, in the bottom nozzle, between the fuel and the bottom nozzle, in the axial channels of the baffle, in the reflector. In order to obtain the realistic boundary conditions, the change of the isotopic composition in the fuel assemblies during one fuel cycle was calculated using the ORIGEN-ARP of SCALE software. Therefore, the influence of the nuclear fuel depletion of fuel assemblies in the WWER-1000 reactor on the change of the basic neutron-physical characteristics was determined such as the distribution of the neutron flux density with the energies necessary to initiate the 16O(n,p)16N reaction, the average number of neutrons per fission, the neutron spectrum and average fission energy. As a result, the dependence of the nitrogen-16 formation rate in the primary coolant system on the nuclear fuel burnup is obtained.

Keywords: WWER-1000, coolant activation, nitrogen-16, MCNP code, reaction rate, ORIGEN-ARP, burnup.


1. H. Mattsson, F. Owrang, A. Nordlund. Utilisation of 16N in Nuclear Power Plants (Goteborg, Sweden, Chalmers University of Technology, 2003) 28 p.

2. V.B. Gayko, Yu.V. Kryukov, T.V. Sitnikova. Analysis and justification of the possibility of automated estimation of the leakage rate of steam generators at nuclear power plants with VVER-1000 according to information from ASRK (on the example of the Tianwan NPP in China). Proc. of the 7-th Interbranch Scie. and Tech. Conf. Problems and Prospects for the Development of Chemical and Radiochemical Control in Nuclear Energy Atomenergoanalytics 2014, Sosnovy Bor, Sept. 16 - 18, 2014. A. A. Efimov (ed.) (St. Petersburg: VVM, 2014) p. 43. (Rus)

3. S.G. Tsypin et al. 16N γ-Ray Diagnostics of a Nuclear Reactor in a Nuclear Power Plant. Atomic Energy 95(3) (2003) 609.

4. K.F. Graham. N-16 power measuring system. Report WCAP-9191 (Pittsburgh, USA, Westinghouse Atomic Power Division, 1977).

5. V.I. Boyko et al. Physical Calculation of a Nuclear Reactor on Thermal Neutrons: Tutorial (Tomsk: Publishing House of Tomsk Polytechnic University, 2009) p. 504. (Rus)

6. J.R. Lamarsh, A.J. Baratta. Introduction to Nuclear Engineering. Third edition (New Jersey: Prentice Hall, 2001) 783 p. Google books

7. M. Matijevic, D. Pevec, K. Trontl. Dose rates mode-ling of pressurized water reactor primary loop components with SCALE6.0. Nuclear Engineering and Design 283 (2015) 175.

8. B. Babcsany, Sz. Czifrus, S. Feher. Methodology and conclusions of activation calculations of WWER-440 type nuclear power plants. Nuclear Engineering and Design 284 (2015) 228.

9. C.J. Werner et al. MCNP6.2 Release Notes. LA-UR-18-20808 (Los Alamos National Laboratory, 2018) 41 p.

10. E.D. Blakeman et al. PWR facility dose modeling using MCNP5 and the CADIS/ADVANTG variance-reduction methodology. ORNL/TM-2007/133 (Oak Ridge National Laboratory, 2007) 97 p.

11. A. Zohar. Activation of Water in Nuclear Reactors. Seminar presented at Univerza v Ljubljani, Fakulteta za Matematiko in Fiziko (Ljubljana, 2016) p. 12.

12. R.A. Forrest et al. Handbook of Activation Data Calculated using EASY-2007. UKAEA FUS 552 (EURATOM/UKAEA Fusion Association, 2009) 670 p. Researchgate

13. M.B. Chadwick et al. ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology. UCRL-JRNL-225066. Nuclear Data Sheets 107(12) (2006) 2931.

14. P. Garcés. Activation Neutronics for the Swiss Nuclear Power Plants. Doctoral Thesis (Zurich, Eidgenossische Technische Hochschule, 2013) 188 p.

15. J.W. Sterbentz. Q-value (MeV/fission) Determination for the Advanced Test Reactor. VHTR Program. INL/EXT-13-29256 (Idaho National Laboratory, 2013) 33 p.

16. J.T. Goorley, M.R. James, T.E. Booth. Initial MCNP6 Release Overview - MCNP6 version 1.0. LA-UR-13-22934 (Los Alamos National Laboratory, 2013) 43 p.

17. V.O. Tarasov et al. Development of the WWER-1000 Reactor Geometric Model in the Neutron-Physical Code MCNP6.1. Proc. of the VI Intern. Research and Practical Conf. "Safety and Efficiency of Nuclear Energy", Odessa, Sept. 4 - 6, 2018. (Odessa, 2018). (Ukr)

18. Yu.P. Kovbasenko, Ye.I. Bilodid. Analysis of criticality of melt during severe accidents in reactor vessel. Nuclear and Radiation Safety 2(78) (2018) 3. (Ukr)

19. D.B. Pelowitz, J.T. Goorley, M.R. James et al. MCNP6TM Users Manual - Version 1.0. LA-CP-13-00634 (Los Alamos, Los Alamos National Laboratory, 2013).

20. R.C. Little, R.E. Seamon. Dosimetry/Activation Cross Sections for MCNP (Los Alamos, Los Alamos National Laboratory, 1984) 37 p.

21. R. Kinsey. ENDF-102 Data Formats and Procedures for the Evaluated Nuclear Data File. ENDF/B-V, BNL-NCS-50496. 2-nd edition (Brookhaven National Laboratory, 1979) 587 p.

22. SCALE: A Modular Code System for Performing Standardized Computer Analyses for Licensing Evaluations. Version 5, Vols. I - III. CCC-725, ORNL/TM-2005/39 (Radiation Safety Information Computational Center, Oak Ridge National Laboratory, 2005).

23. I.C. Gauld et al. ORIGEN-ARP: Automatic Rapid Processing for Spent Fuel Depletion, Decay, and Source Term Analysis. Vol. 1, Rev. 7. NUREG/CR-0200 (Oak Ridge National Laboratory, 2004).

24. S.M. Bowman, I.C. Gauld. OrigenArp Primer: How to Perform Isotopic Depletion and Decay Calculations with SCALE/ORIGEN. ORNL/TM-2010/43 (Oak Ridge National Laboratory, 2010) 110 p.

25. V.G. Rudychev et al. Optimization of the detection system for 16N registration along with coolant leaks in the WWER-1000 steam generator. Problems of Atomic Science and Technology 3(85), Ser.: Nuclear Physics Investigations 60 (2013) 259.