Development of a new solid tritium breeder blanket

未来的发电站将采用氘和氚的聚变，因为它需要最低的温度来实现点火。氘是丰富的；然而，氚在自然界中仅以每年0.41千克的速度产生，其半衰期为12.6年，因此极为罕见。一个1吉瓦的聚变反应堆预计每年需要约100公斤的氚，因此我们必须找到一个可持续的供应来源。幸运的是，通过吸收D-T反应产生的中子，可以从锂的嬗变中孕育出氚。证明可持续的氚循环是核聚变面临的主要突出的工程挑战之一。目前的包层概念是在ITER的设计过程中构思出来的，使用锂陶瓷鹅卵石或液态锂铅共晶。固体氚繁殖概念利用锂正硅酸盐或锂偏钛酸盐鹅卵石。然而，这两种材料都有问题；硅酸盐具有较低的抗压强度，这可能导致鹅卵石破碎，并且人们担心钛酸盐是否提供足够高的氚繁殖比。此外，目前的固体增殖概念使用铍作为中子倍增器，这是不可取的，因为它相对罕见，处理起来很危险，而且通常含有难以去除的微量铀。因此，这个项目将着眼于设计一种新型增殖毯，用于使用固体增殖材料的紧凑型聚变反应堆。

A future power station will employ the fusion of deuterium and tritium, as it requires the lowest temperature to achieve ignition. Deuterium is abundant; however, tritium is only generated in nature at a rate of 0.41 kg per year and has a 12.6 year half-life making it extremely rare. With a 1 GW fusion reactor expected to require ~100 kg of tritium annually, it is essential that we identify a sustainable supply. Fortunately, tritium can be bred from the transmutation of lithium driven by absorption of the neutron ejected by the D-T reaction. Demonstration of a sustainable tritium cycle is one of the major outstanding engineering challenges facing fusion. Current blanket concepts were conceived during the design of ITER and use either Li ceramic pebbles or a liquid lithium lead eutectic. The solid tritium-breeding concepts utilise either lithium orthosilicate or lithium metatitanate pebbles. Both materials have issues, however; the silicate has a low crush strength, which could result in pebble fragmentation, and there is concern about whether the titanate offers a sufficiently high tritium breeding ratio. Further, current solid breeder concepts employ beryllium as a neutron multiplier, which is undesirable as it is relatively rare, hazardous to handle, and typically contains trace quantities of uranium that are hard to remove. Therefore, this project will look to design a new breeder blanket for a compact fusion reactor, that uses a solid breeder material.