Determinating the stored Wigner energy accumulation rate in the graphite moderator

12/25/2015 2015 - #04 Fuel cycle and nuclear waste management

Mochalov A.M. Najmushin A.G. Nesterov V.N. Pugachyov D.K.

https://doi.org/10.26583/npe.2015.4.11

According to latest publications, new methods to determine the value of the Wigner energy in the graphite are required. Purpose: to develop method for determining the rate of accumulation of the Wigner energy in the graphite moderator. Stored energy is proportional to the number of point defects in the crystal structure, so the decision comes down to the determination of this number. The article contains analysis of four models to form cascades of defects. Analysis of results allowed identifying two models that give physically correct values in the area of low and high energy neutrons. According to models, point defects concentration depends on neutron flux density and temperature in a specific way. The values of the cascade function allows to determine the relations of changes in the number of defects and the energy stored during in irradiated graphite and annealing of defects in graphite after irradiation. It is found that a self-sustaining release of stored energy is possible only in the graphite operated at sufficiently low temperatures to 100°C. The condition of self-sustaining release of stored energy is valid for an adiabatic process. Comparative analysis of calculation results and the experimental data proved that this method satisfactorily describes the process of changing the Wigner energy during and after irradiation of graphite.

References

1. Cyganov A.A., Hvostov V.I., Komarov E.A., Kotlyarevskij S.G., Pavlyuk A.O., Shamanin I.V., Nesterov V.N. Problemy utilizacii reaktornogo grafita ostanovlennyh promyshlennyh uran-grafitovyh reaktorov [Problems of waste graphite reactor shutdown industrial uranium-graphite reactors]. Izvestiya Tomskogo politehnicheskogo universiteta. 2007, v. 310, no. 2. pp. 94–98 (in Russian).
2. GoncharovV.V., Burdakov N.S., Virgil’ev Ju.S., Karpuhin V.I., Platonov P.A. Dejstvie oblucheniya na grafit yadernyh reaktorov [The action of radiation on graphite nuclear reactors]. Moscow. Atomizdat Publ., 1978 (in Russian).
3. Tompson M.W. Defekty i radiacionnye povrezhdeniya v metallah [Defects and radiation damage in metals]. Moscow, Mir Publ., 1971. 368 p.(in Russian).
4. Nesterov V.N., Shamanin I.V., Emets E.G., Cyganov A.A., Kotlyarevskij S.G., Pavljuk A.O. Analiticheskaya shema defektoobrazovaniya v kristallicheskoj reshetke grafita pri reaktornom obluchenii [Analytical Scheme of Defects Evolution in the Crystal Lattice of Graphite at the Reactors Irradiation]. Izvestija vuzov. Yadernaya energetika. 2008, no.1, pp. 120–128 (in Russian).
5. Cyganov A.A., Savinyh P.G., Komarov E.A., Kotljarevskij S.G., Pavlyuk A.O., Shamanin I.V.,Nesterov V.N. Zapasyonnaya energiya v grafite kladok ostanovlennyh promyshlennyh uran-grafitovyh reaktorov [The stored energy in graphite layings shut down industrial uranium-graphite reactors]. Izvestiya Tomskogo politehnicheskogo universiteta. 2008, v. 312, no. 2, pp. 32–38 (in Russian).
6. Grafit kak vysokotemperaturnyj material [Low-cycle deformation and fracture of structural graphites at high temperatures]: translated from the English. Edited by K.P. Vlasova. Moscow, Mir Publ., 1964, 423 p. (in Russian).
7. Virgil’ev Yu.S., Baldin V.D. Vliyanie variacii svojstv na rabotosposobnost’ reaktornogo grafita GR-280 [Influence of variation in the performance properties of the reactor graphite GR-280]. Atomnaya energiya. 2000, v. 88, no. 2, pp. 119–125 (in Russian).

stored energy Wigner energy reactor graphite cascade function defects

Link for citing the article: Mochalov A.M., Najmushin A.G., Nesterov V.N., Pugachyov D.K. Determinating the stored Wigner energy accumulation rate in the graphite moderator. Izvestiya vuzov. Yadernaya Energetika. 2015, no. 4, pp. 101-110; DOI: https://doi.org/10.26583/npe.2015.4.11 (in Russian).