A new method for detecting a malfunction in the reactor - on features of behavior of the moments of the random variable time to achieve a given level of the number of neutrons in the reactor. Under the time to achieve a given level of neutron numbers mean random time until it reaches a stochastic process for the total number of neutrons in the reactor at this level. This value can be considered as a stochastic analog reactor period. At the points of dangerous changes in reactivity, which can lead to a crash, the moments (such as mean and variance) of the random variable time to achieve the level of the number of neutrons in the reactor have singularities. Modeling the behavior of these moments for different processes in the reactor, we can keep track of their characteristics, thereby controlling the safety of the reactor. The considered examples show the relationship between the possible malfunction in the reactor and the specific behavior of the moments of the time to reach a level indicating a real possibility of the proposed method of control of NPP safety. There is no need to conduct any experiments. Not be required and cumbersome calculations. They are as follows the reactivity in time and get the behavior of the moments of time to achieve a given level, corresponding to the change of reactivity. It is possible analytical approaches to this problem.
Keywords: monitoring of the reactor, the time to reach a given level of the number of neutrons.
1. Ryazanov V.V. Distribution of the neutron lifetime in a nuclear reactor // The 3nd International Conference Current Problems in Nuclear Physics and Atomic Energy, June 7 - 12, 2010 Kyiv, Ukraine, Institute for Nuclear Research NAS of Ukraine, 2011, Proceedings of the NPAE-2010, p. 544 - 548.
2. Ryazanov V.V. Neutron number first-passage time distribution and the reactor time constant // Atomic Energy. - October 2011. - Vol. 110. - Iss. 6. - P. 376 - 388.
3. Ryazanov V.V. Stochastic analog reactor period – time achievement a given level of number of neutrons // Proble-my bezpeky atomnyh electrostantsiy i Chornobylya (Problems of nuclear power plants and of Chornobyl). – 2012. - . Iss. 19. - P. 11 - 19. (Rus)
4. Ovdienko Yu. N. Safety assessment of VVER-1000 transient operating conditions and reactivity accidents using a model of the spatial kinetics. Dissertation for the degree of PhD. - Kyiv, 2010. (Rus)
5. Ryazanov V.V. Stochastic analog of reactor period - time to reach a given level of number of neutrons. The 4-nd International conference: Current Problems in Nuclear Physics and Atomic Energy, Sept. 3 - 7, 2012. Book of ab-stracts. Kyiv, р. 128 - 129.
6. Sarkisov A.A., Puchkov V.N. Physical basis of the operation of nuclear steam generating plants. - Moskwa: Energoatomizdat, 1989. - 504 p. (Rus)