Thermal hydraulic design of irradiation facility based on O-16 (n,p) N-16 activation in TRIGA reactor

Amano, Bernadeth Luzares (author), Končar, Boštjan (mentor), Suikkanen, Heikki (co-mentor)

Water, typically used as the primary coolant in facilities such as fusion and fission reactors, could be exposed to a large amount of neutrons causing water activation. This phenomenon could cause radiation damage to electrical components and increase the dose to personnel. As there are only few sources of gamma rays with energies in the range of 6 MeV and 7 MeV, an irradiation system using activated cooling water as a source of energetic gamma rays is proposed at the Jozef Stefan Institute (JSI) TRIGA Mark II research reactor. A water activation irradiation loop design is proposed, inserted into a radial piercing port of a research reactor. In this thesis, a numerical model of the irradiation loop was developed and a CFD analysis was performed using ANSYS CFX. Pressure and velocity profiles were established and will serve as design limits and criteria reference for assembling the actual facility. Moreover, the N-16 concentration inside the loop was studied. Its formation and decay inside the loop were predicted. This shall serve as reference for future experimental designs and further studies to be conducted using the proposed facility.

• Language: English
• Keywords: CFD analysis, water activation, irradiation facility, TRIGA
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FMF - Faculty of Mathematics and Physics
• Year: 2022
• PID: 20.500.12556/RUL-142337
• COBISS.SI-ID: 127910659
• Publication date in RUL: 30.10.2022

Secondary language

• Language: Slovenian
• Title: Termo-hidravlična zasnova obsevalne zanke z aktivacijo O-16 (n,p) N-16 v TRIGA reaktorju

Abstract

Voda s katero običajno hladimo fuzijske in fisijske reaktorje je lahko izpostavljena večji količini nevtronov in se pri tem aktivira. Sevanje zaradi aktivacije vode lahko povzroči poškodbe električnih komponent in poveča prejeto dozo za osebje. Ker obstaja le malo virov gama žarkov z energijami v območju med 6 MeV in 7 MeV, za preučevanje pojava na raziskovalnem reaktorju TRIGA Mark II na Institutu »Jožef Stefan« predlagajo obsevalni sistem z uporabo aktivirane vode kot vira gama žarkov. Predlagana je zasnova obsevalne zanke, ki je vstavljena v radialno odprtino raziskovalnega reaktorja. V tem magistrskem delu smo razvili numerični model obsevalne zanke in izvedli analizo s pomočjo programa za računalniško dinamiko tekočin (RDT) ANSYS CFX. Izračunali smo porazdelitve tlaka in hitrosti, ki bodo služile kot projektna osnova za dejansko izdelavo obsevalne zanke. Poleg tega smo proučevali obnašanje koncentracije izotopa dušika 16N v zanki. Pri tem smo upoštevali njegov nastanek in razpad znotraj zanke. Izračunane koncentracije dušika 16N bodo služile kot referenca za prihodnje zasnove eksperimentov in nadaljnje študije v predlagani obsevalni napravi.

• Keywords: RDT analiza, aktivacija vode, obsevalna zanka, TRIGA