Lithium Breeder Research Articles

Safety Evaluation of the Blanket Comparison and Selection Study

The results of the safety evaluation of the Blanket Comparison and Selection Study (BCSS) are presented. The safety evaluation measured the relative safety and environmental attractiveness of the final group of BCSS blanket concepts for application with either a tokamak or tandem mirror fusion reactor. Two types of blankets were found to be the most attractive in the safety evaluation. One top-blanket-type is a helium-cooled HT-9 structure with a Li/sub 2/O breeder, which is preferred if tritium effluent control is good; a lithium breeder would be the backup. The other top blanket concept is liquid-metal-cooled V-15 Cr-5 Ti structure with lithium coolant/breeder, preferred if air and water chemical reactions are adequately controlled; 17Li-83Pb would be the backup coolant/breeder material.

An ICF Tritium Production Reactor

The conceptual design of an ICF tritium production reactor is described. The chamber design uses a beryllium multiplier and a liquid lithium breeder to achieve a tritium breeding ratio of 2.08. The annual net tritium production of this 532 MW /sub t/ plant is 16.9 kg, and the estimated cost of tritium is $8100/g.

Tritium control in helium-cooled blankets

As a part of the Blanket Comparison and Selection Study (BCSS), GA Technologies was responsible for the design of helium-cooled, solid- and liquid-metal breeder blankets. Conceptual blanket designs were developed, including the consideration of the generation, transport, and extraction of tritium. Evaluations were made of the inventory and leakage of tritium for helium-cooled Li/sub 2/O and LiAlO/sub 2/ and liquid lithium breeder blankets for tokamak and tandem mirror reactors. To facilitate the evaluation, a solid breeder tritium code TRIT4 was developed. The results from this study indicate that tritium inventories and leakages are acceptable for the proposed helium-cooled blankets. An assumption made in the tritium leakage calculations was that tritium is released to the helium purge and coolant streams as T/sub 2/ and remains in that form. If oxidation to T/sub 2/O is possible, significant reduction in the tritium leakage will be possible. We conclude that more experimental data on breeder material properties and tritium permeation behavior are needed. However, we are certain that an adequate number of different techniques are available to control the breeder tritium inventory and leakage to an acceptable level in helium-cooled solid- and lithium-breeder blankets.

A performance comparison of lithium, helium, and flibe cooled tube/header fusion blankets

The objective of this study is to provide a comparison of thermal-hydraulic and structural performance of lithium, helium, and flibe cooled fusion blankets based on a tube/header geometry in a liquid lithium breeder. Type 316 stainless steel and TZM are considered as representative near-term and long-term, high temperature blanket structural materials, respectively, to show the potentials of each coolant. The flibe-TZM system has the best characteristics, while lithium-316SS, helium-316SS, and helium-TZM are comparable but definitely more limited in operating conditions. These results suggest that molten salt-refractory metal systems deserve more attention.