The article considers the computational model of the reactor VVER-1000 on the basis of the point neutron ki-netics including the feedback on the reactivity effects as well as variations in the basic parameters of the model from temperatures and pressures present in the fuel and coolant during the transient processes. Interest in the point model of a neutron reactor kinetics explained by the fact that modeling with the help of three-dimensional neutron codes of transient process in VVER-1000, caused by the tripping of accelerated unit unloading due to failure of the primary equipment of power generating unit is significantly different from those observed in practice for a number of important parameters such as on the rate of increase of the neutron power after falling of one group control rods. During the operation in design mode of accelerated unit unloading on several units with VVER-1000 occurred scrams over the period of the reactor, which has not previously been observed. The article represents results of simulation and comparison with real data obtained during the operation of accelerated unit unloading on VVER-1000 nuclear power plants of Ukraine at different fuel campaign moments. Conservative model parameters are defined for the analysis of reactivity accidents.
Keywords: VVER, interacting codes, kinetics model of neutrons in a reactor, accelerated unit unloading, reac-tivity accident.
1. Technical Report "Modernization design operation AUU on VVER-1000. SAR development to modernize the operation of AUU". "FIZAR". L.t.d., 2008. (Rus)
2. Bykov M.A., Alechin G.V., Petkevich I.G. Analysis of the statements of the neutron flux monitoring system with operation accelerated unit unloading for reactor units with VVER-1000 (The 6th Intern. Scientific and Technical Conf. "Safety Assurance on NPP with WWER."-6-29.05.2009. (OKB “GIDROPRESS”, Podolsk, Russia). (Rus)
3. Borysenko V.I., Kadenko I.M., Samoilenko D.V. WWER-1000 accelerated unit uploading activation transient features // Nuclear Physics and Power Engineering. - 2009 . - Vol. 10, № 2. – P. 157 - 164. (Ukr)
4. Technical Report "On the safety and stability of NPPs with VVER-1000 under dynamic conditions with operation of AUU." - ОАО «VNIIAES», 2008. (Rus)
5. Borysenko V.I., Krushynsky A.G., Mukoyd V.P. Standard problem validation code RELAP5 for WWER-440 // Problemy bezpeky atomnyh electrostantsiy i Chornobylya (Problems of nuclear power plants and of Chornobyl). - 2006. - Iss. 6. – P. 41 - 48. (Rus)
6. Computer code validation for transient analysis of VVER and RBMK reactors. Final RELAP5 validation plan for application to VVER. – Moskva, 1998. - 69 p. - (USINSC/RINSC joint project. WO 974066401).
7. Keepin G.R. Physics of nuclear kinetics. – Addison-Wesley Pub. Co., Inc. - 1965. – P. 435.
8. Kuznetzov I.A. Emergency and transitional processes in fast reactors. Library Plant Operator (t. 17). - Moskva: Energoatomizdat, 1987. – P. 171. (Rus)
9. Final Report. Safety Analysis Report. Analysis of beyond design basis accidents unit # 5 ZNPP. Zaporizhzhya NPP.21.5.59.ОБ.03, 2008. (Rus)
10. Alexandrov A.A., Grigorev B.A. Tables of thermophysical properties of water and steam. – Moskva: Publishing House of Moscow Power Engineering Institute, 1999. – 168 р. (Rus)
11. Kirilov P.L., Bogoslovskaya G.P. Heat and mass transfer in nuclear power plants – Moskva: Energoatomizdat, 2000. – 456 p. (Rus)
12. Final Safety Analysis Report. T. 4. Chap. 4. Reactor. Part 3. Neutronic calculations. 43-923.203.254.ОБ.04.03. Rev. 1. Ф. Khmelnitsky NPP. Unit # 2. - 2005. (Rus)
13. Branch solution. OTR 1234.03.127-08. NAEC "Energoatom" «On the change of the signal algorithm AZT at AUU». - 2008. (Rus)