A Comprehensive Study of the ¹⁴C Source Term in the 10 MW High-Temperature Gas-Cooled Reactor

Abstract

While assessing the environmental impact of nuclear power plants, researchers have focused their attention on radiocarbon (14C) owing to its high mobility in the environment and important radiological impact on human beings. The 10 MW high-temperature gas-cooled reactor (HTR-10) is the first pebble-bed gas-cooled test reactor in China that adopted helium as primary coolant and graphite spheres containing tristructural-isotropic (TRISO) coated particles as fuel elements. A series of experiments on the 14C source terms in HTR-10 was conducted: (1) measurement of the specific activity and distribution of typical nuclides in the irradiated graphite spheres from the core, (2) measurement of the activity concentration of 14C in the primary coolant, and (3) measurement of the amount of 14C discharged in the effluent from the stack. All experimental data on 14C available for HTR-10 were summarized and analyzed using theoretical calculations. A sensitivity study on the total porosity, open porosity, and percentage of closed pores that became open after irradiating the matrix graphite was performed to illustrate their effects on the activity concentration of 14C in the primary coolant and activity amount of 14C in various deduction routes.

Calculation and Analysis of the Source Term of the Reactor Core Based on Multivariate Analysis of Variance

“…Lee and Ko [5] developed a method to quantify the source term in each source term category identified in the level II probabilistic safety assessment analysis of nuclear power plants; then, the obtained source term characteristics were compared with other source terms. Liu et al [6] conducted a series of experiments on the primary coolant and in various deduction methods was clarified. Fang et al [7] carried out ab initio calculations of the antineutrino flux of a new isotope reactor and provided accurate numerical calculations of the lepton wave function.…”