Ehsan Boustani; Mostafa Hassanzadeh; Rohollah Ahangari
Abstract
The occurrence of core uncovering following a loss of coolant accident is conceivable and should be taken into account for its significant possible consequences. Source terms are calculated using ORIGEN 2.1 code, and the gamma dose of the uncovered core is calculated for three different normal and anticipated ...
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The occurrence of core uncovering following a loss of coolant accident is conceivable and should be taken into account for its significant possible consequences. Source terms are calculated using ORIGEN 2.1 code, and the gamma dose of the uncovered core is calculated for three different normal and anticipated accidents scenarios. Under containment gamma dose rates have been calculated analytically as well as using MCNPX 2.6.0 code. The uncovered core of the Tehran research reactor is supposed to operate in nominated power of 5 MW for 30 days. The results illustrated that the under-containment dose rate of gamma in some locations would be about 200 Svh-1, far from the annual occupational exposure limit of 50 mSv. For preventing this occurrence, it would be possible to use an emergency make-up tank as an engineered safety feature, with functions of the avoidance of damaging fuel after the loss of coolant accident as well as controlling exposure from the core.
Afshin Hedayat
Abstract
Fast neutron irradiation is one of the most strategic radiation applications of research reactors. Usually, it is performed around the reactor core containing lower neutron flux. In this paper, a hybrid object has been introduced and analyzed to enhance irradiating ...
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Fast neutron irradiation is one of the most strategic radiation applications of research reactors. Usually, it is performed around the reactor core containing lower neutron flux. In this paper, a hybrid object has been introduced and analyzed to enhance irradiating applications of the fast neutrons in the core of a Material Testing Reactor (MTR). The tool includes an old-type low-consumed HEU control fuel element, a dry channel, and a Cd filter. It is supposed to be installed at the internal neutron trap (D4 positions) of TRR core configuration. Calculating results are very promising for using the proposed tool to increase neutron fluxes, reduce thermal and epi-thermal neutron fluxes, and shift the neutron spectrum toward the fast neutron region (hardening effect) at the chosen irradiating location. Primary safety parameters are also checked and passed successfully. Furthermore, there are also some other presented safety items which must be checked carefully and conservatively in order to refabricate and install such a irradiating tool in an in-core location of a MTR.
