Authors & Affiliations

Tsikunov A.G., Alekseev V.V., Zabrodskaya S.V., Tykleeva K.V.
A.I. Leypunsky Institute for Physics and Power, Obninsk, Russia

Abstract

In the course of operation of NPP with any reactor types a continuous production of radioactive hy-drogen isotope – tritium occurs. The sources of tritium are fuel material nuclear fission reactions and the reactions of interaction between neutrons and atomic nuclei of some elements contained in the fuel, structural materials and coolant. Tritium that features high penetrability migrates over the process media. In doing so it partially escapes into the environment. The nature of its behavior essentially depends on the reactor type. Tritium that appears in PWR reactor coolant almost completely enters the environment (discharge into the atmosphere and hydrosphere). The operating experience of national NB-type reactors, as well as the foreign experience testify, that only a minor part of tritium contained in the sodium coolant escapes into the environment. The paper presents an assessment of tritium production rates in the reactor materials for a NB-type reactor, as well as the velocities of tritium ingress into primary sodium coolant. Tentative assessments were made for a MOX-fuel reactor installation, as well as that with mixed nitride fuel under normal operating conditions. The sources of tritium production in a BN-type reactor were identified in the course of this research.

Key words
tritium, reactor material, production rate, ingress rate, nuclear fission reaction, tritium yield factor, ternary fission, denatured isotopic composition

Article Text (PDF, in Russian)

References

UDC 621.039.5

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, issue 1:9, 2015