Tru transmutations study in a thorium-based PWR fuel cycle

Full text: Thorium fuel is well known as a high proliferation resistance fuel cycle option by producing less Transuranic(TRU) than uranium fuel. Kyung Hee Thorium Fuel (KTF), one of the design concepts of the thorium fuel utilization, has been studied as an alternative fuel cycle concept to a conventional PWR. KTF design concept has two advantages for TRU transmutation. One is a high moderator to fuel volume ratio in a seed fuel assembly which will result in a high consumption rate of fissile plutonium isotopes and minor actinides(MAs) by either fission or capture reaction. The other is high discharge burnup of the seed and the blanket fuel in the KTF design. The high burnup of a fuel can decrease the inventory of heavy nuclides including the plutonium and MAs due to their long residence time in a reactor. Parametric studies were performed for the optimization of Transmuranic (TRU), Plutonium, and Minor Actinides (MA) transmutation in the KTF design. It is shown that high transmutation ratio can be achieved by using spent fuel decayed shortly. The transmutation ratio is not dependent upon the loading mass, however, the maximum transmutation mass of TRU in KTF is 514 kg/GWe-yr which is 2.5 times than that of TRU production mass from a conventional PWR. Heterogeneous loading method of TRU is better than homogeneous, however, homogeneous loading method is better than heterogeneous for the transmutation of MA only. In order to evaluate proliferation resistance potential of the KTF design, BCM, SNS, and TG indices are calculated. Adding TRU or Plutonium to the KTF design can increase the proliferation resistance potential of the spent fuel