Accessible Requires Authentication Published by De Gruyter August 18, 2021

Thorium-based CANDU qualification as plutonium burner

Qualifikation des Betriebs von Brennstoffen auf Thoriumbasis in CANDU Reaktoren zur Plutoniumverbrennung
R. Neacşa, A. Rizoiu and I. Prisecaru
From the journal Kerntechnik


Converting the weapon grade Plutonium from the U.S.A., Russia, U.K. etc. to Mixed OXide fuel and using it in power reactors was seen as a feasible way to both dispose Plutonium and produce energy. Using Thorium-based fuels in CANDU has been investigated since early 1980’s, they were designed and tested in Canada as mixed ThO2-UO2 (both LEU and HEU) and mixed ThO2-PuO2, (both reactor- and weapons-grade) ([1]). In this respect, Thorium might also be seen as a valuable driver for weapon grade Plutonium annihilation. Our goal was to investigate ThO2-PuO2 MOX in the aim to propose a suitable fuel for the existing and future CANDU units in Romania. Both weapon grade and reactor grade Plutonium were considered as fissile drivers for Thorium. Since this is only an exploratory study, some key design parameters such as fuel pellet density and ThO2/PuO2 ratio were considered to span over a certain range imposed by MOX fuel fabrication technology and limited Plutonium availability. Eighteen fuel compositions were considered and cell calculations were performed for 37 and 43-element bundles using several computer codes.


Die Umwandlung des waffenfähigen Plutoniums der USA, Russlands, Großbritanniens usw. in gemischten Oxid-Brennstoff und dessen Verwendung in Leistungsreaktoren wird als ein gangbarer Weg angesehen, sowohl Plutonium zu entsorgen als auch Energie zu erzeugen. Die Verwendung von Brennstoffen auf Thoriumbasis in CANDU wird seit Anfang der 1980er Jahre untersucht; sie wurden in Kanada als gemischtes ThO2-UO2 (sowohl LEU als auch HEU) und gemischtes ThO2-PuO2 (sowohl reaktor- als auch waffentauglich) ([1]) entworfen und getestet. In dieser Hinsicht könnte Thorium auch als wertvolle Antriebskraft für die waffengradige Plutoniumvernichtung angesehen werden. Unser Ziel war die Untersuchung von ThO2-PuO2-MOX um einen geeigneten Brennstoff für die bestehenden und künftigen CANDU-Einheiten in Rumänien vorzuschlagen. Sowohl waffen- als auch reaktortaugliches Plutonium wurde als spaltbare Antriebskraft für Thorium betrachtet. Da es sich hierbei nur um eine explorative Studie handelt, wurden einige wichtige Entwurfsparameter wie die Brennstoffpelletdichte und das ThO2/PuO2- Verhältnis über einen bestimmten Bereich betrachtet, der durch die MOX-Brennstoffherstellungstechnologie und die begrenzte Verfügbarkeit von Plutonium bedingt ist. Achtzehn Brennstoff-zusammensetzungen wurden in Betracht gezogen, und es wurden Zellberechnungen für 37- und 43-Element-Bündel unter Verwendung mehrerer Computercodes durchgeführt.


We gratefully acknowledge the useful advices of Dr. Iuliana Vişan and Mrs. Andreea Moise concerning the SERPENT results interpretation. Special thanks to Dr. Silviu Florea for the Linux workstation management. We highly appreciate the continuous support of Mr. Gheorghe Olteanu, head of the Fuel Performance Group in ICN, coordinator of the Nuclear Fuel research programme of RATEN (The Technologies for Nuclear Energy State Owned Company).


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Received: 2020-03-04
Published Online: 2021-08-18
Published in Print: 2021-08-31

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