Measurement of TPR distribution in natural LiTiO/Be assembly with DT neutrons

Kondo, Keitaro; Tatebe, Yosuke; Ochiai, Kentaro; Sato, Satoshi; Takakura, Kosuke; Onishi, Seiki; Konno, Chikara  

In the previous blanket neutronics experiments conducted at the FNS facility of Japan Atomic Energy Agency, the following disagreements between experiments and analyses have been pointed out: (1) In the experiment with a Li-enriched LiTiO layer and a beryllium layer, approximately 10% overestimation was found for the tritium production rate (TPR) when a neutron reflector composed of SS316 was attached. (2) In the experiment with natural LiO pebbles sandwiched by beryllium layers, TPR was overestimated near the rear beryllium layer by up to 10%. In order to confirm the above problems clearly, a new blanket neutronics experiment using a natural LiTiO layer and beryllium layers with DT neutrons was conducted at FNS. TPR distributions inside the LiTiO layer were measured with LiCO pellets with and without the source reflector. The measured TPR well agreed with the calculation within an estimated experimental error of 6% in the both experiments. The influence of the reflector was not remarkable in the present experiment. Contrary to our expectation, no remarkable difference was observed in the TPR distribution around the rear beryllium layer.