Nuclear Physics and Atomic Energy

ßäåðíà ô³çèêà òà åíåðãåòèêà
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, Russian
  Periodicity: 4 times per year

  Open access peer reviewed journal


 Home page   About 
Nucl. Phys. At. Energy 2019, volume 20, issue 4, pages 381-387.
Section: Atomic Energy.
Received: 29.07.2019; Accepted: 04.12.2019; Published online: 12.03.2020.
PDF Full text (en)
https://doi.org/10.15407/jnpae2019.04.381

Improving the accuracy of thermal power determination of VVER

V. I. Borysenko1,*, D. V. Budyk2, V. V. Goranchuk1

1 Institute for Safety Problems of Nuclear Power Plants, National Academy of Sciences of Ukraine, Kyiv, Ukraine
2 Private Joint-Stock Company "Severodonetsk Research and Production Association "Impulse"", Severodonetsk, Ukraine


*Corresponding author. E-mail address: vborysenko@ispnpp.kiev.ua

Abstract: In most algorithms for forming control signals, locks and protection of VVER, the value of the reactor’s thermal power (RTP) is used. This article is dedicated to the analysis of the problem of determining the RTP of VVER-1000. The article suggests ways to improve the accuracy of the determination of RTP based on the signals of the neutron flux parameters control system at VVER-1000. The thermal power of the reactor is one of the important safety parameters of VVER-1000, and also this parameter determines the technical and economic parameters of the power unit. The task of increasing the accuracy of RTP determination is especially relevant considering plans to increase RTP of VVER-1000: in the first stage to 101.5 % of the nominal value, and later to 104 - 107 % of the nominal value, which equals to 3000 MW according to the project. In the article, the main factors influencing the errors of determination of RTP in different ways are considered: according to the thermal parameters of the 1st and 2nd contours and the parameters of the neutron flux in the Neutron Flux Monitoring System (NFMS) and In-core Monitoring System (ICMS). In order to improve the accuracy of determination of RTP in the NFMS, we propose a model that considers the influence on the signal of the ionization chamber of the following parameters: temperature and concentration of boric acid in the coolant, the position of the control rods, burning of fuel, etc. The results of the analysis of the change in RTP during the fuel campaign of VVER-1000 are given, which is determined in different ways.

Keywords: reactor thermal power, thermal engineering parameters, neutron flux parameters, correction model, linear heat generation rate, weight coefficients.

References:

1. Neutron Flux Control Equipment. Specifications. TU U 30.0-31393258-010-2003 A. (Rus)

2. V.A. Bragin et al. In-core Monitoring Systems of NPP with VVER (Moskva: Energoatomizdat, 1987) 128 p. (Rus)

3. A.N. Dobrotvorskii. Development and substantiation of methods of determination of weighted mean power of NPP units with VVER-1000. The thesis of the Candidate of Technical Sciences. (Novovoronezh, 2017) 191 p. (Rus)

4. Yu.V. Saunin, A.N. Dobrotvorskii, A.V. Semenikhin. Methods of Estimation of Weight Coefficient when Determining Weighted Mean Thermal Power of VVER Reactors. Tyazheloe Mashinostroenie (August 2008). (Rus)

5. J. Taylor. An Introduction to Error Analysis: The Study of Uncertainties in Physical Measurements. 2nd ed. (United States, Sausalito: University Science Books, 1997) 327 p. Google books

6. V.F. Bai et al. State of in-core thermal control and analysis of the main thermal and physical characteristics of RP of Kalinin NP. In: Book of Abstracts of the 7th Intern. Sci. and Technical Conf. “Safety, Effectiveness, and Economics of Nuclear Power Engineering”, Moskva, Russia, 2010, p. 228. (Rus)

7. M.P. Vukalovich. Thermophysical Properties of Water and Steam (Moskva: Mashinostroenie, 1967) 160 p. (Rus)

8. A.A. Aleksandrov, B.A. Grigor’ev. Tables of Thermophysical Properties of Water and Steam (Moskva: Publishing house of MEI, 1999) 168 p. (Rus)

9. Yu.V. Saunin et al. Possibilities of operative evaluations of weight coefficients of weighted mean thermal power of VVER reactors. In: Proc. of the Conf. "Safety Assurance at NPP with VVER", OKB "Gidropress", May 26 - 29, 2009. (Rus)

10. V.I. Borysenko. Enhancement of methods and means for operational control and diagnostics of neutronic parameters of nuclear installations. The thesis of Doctor of Technical Sciences (Kyiv, 2018) 400 p. (Ukr)

11. Standard operating procedure of Rivne NPP 4th unit safe operation. 4-RNPP. (Rus)

12. V.I. Borysenko, Yu. F. Piontkovskyi, V.V. Goranchuk. An investigation of models of rhodium emitter used in a self-powered neutron detector. Problemy Bezpeky Atomnykh Elektrostantsiy i Chornobylya (Problems of Nuclear Power Plants' Safety and of Chornobyl) 28 (2017) 25. (Rus) http://www.ispnpp.kiev.ua/wp-content/uploads/2017/2017_28/c25.pdf

13. D.V. Vorob’eva et al. Calculation of RP capacity on parameters of in-core detectors. Analysis of operation experience. In: Book of Abstracts of 10th Intern. Sci. and Technical Conf. "Safety Assurance at NPP with VVER", Podolsk, 2017. (Rus)