TRICO II Core Inventory Calculation and its Radiological Consequence Analyses

Abstract

Two severe accident scenarios are investigated in this paper as they have never been considered previously in the safety analysis report (SAR) of the Congo TRIGA Mark II research reactor (TRICO II) in Kinshasa, the Democratic Republic of Congo. The source term is derived from the reactor core after two postulated accidents: (1) a large plane crash with total destruction of the reactor building and (2) full damage of one fuel element while the reactor building remains intact. Total effective dose (TED), after core inventory, and dose profiles to human organs are derived to assess the operational safety of the reactor. Results from the study will be used to upgrade the current SAR of the reactor as the reactor safety and licensing concepts are changing over the years; the knowledge and lessons learned from the past experience are being updated accordingly with the available data. TEDs to workers of the facility show that higher values are obtained at areas near the source term at the time of the plane crash accident, which dies out as quickly as the plume is carried away following predominant meteorological conditions at the site. The situation with one fuel element totally damaged poses no threat as far as radiation protection is concerned and reveals a maximum TED of 1.30×10−7 mSv at 100 m from the reactor core. This shows that the operation of this type of research reactor is reliable and safe.

Comparative Radiation Dose Study of a Hypothetical Accident in a Research Reactor

“…The human body dose was obtained by ingestion or inha- lation process, which takes into account the metabolism of radioisotopes in the body, type and level of energy of the emitted radiations, and radio-sensitivity of the organs. 29 It was observed that the calculated CEDE are lower, and the highest value primarily affects the thyroid followed by the skin, and thirdly the lungs. 12 The maximum value for this organ is about 7.0 • 10 −1 mSv occurring at a distance of 0.5 km from the source with arrival time of six minute, and it is about 4.1 • 10 −2 mSv at 5 km from the source with arrival time of 01 h : 05 min.…”