Verification of tritium production evaluation procedure using Monte Carlo code MCNP for in-pile test of fusion blanket with JMTR

To evaluate exactly the total amount of tritium production in tritium breed ing materials during in-pile test with JMTR, the 'tritium monitor' has been produced and evaluation of total tritium generation was done by using 'tri tium monitor' in preliminary in-pile mock-up, and verification of procedure concerning tritium production evaluation was conducted by using Monte Carl o code MCNP and nuclear cross section library of FSXLIBJ3R2. Li-Al alloy (L i 3.4 wt.%, 95.5% enrichment of Li-6) was selected as tritium monitor mater ial for the evaluation on the total amount of tritium production in high Li -6 enriched materials. From the results of preliminary experiment, calculat ed amounts of total tritium production at each 'tritium monitor', which was installed in the preliminary in-pile mock-up, were about 50-290% higher th an the measured values. Concerning tritium measurement, increase of measure ment error in tritium leak form measuring system to measure small amount of tritium (0.2-0.7 mCi in tritium monitor) was found in the results of prese nt experiment. The tendency for overestimation of calculated thermal neutro n flux in the range of 1-6 x 10(13) n cm(-2) per s was found in JMTR and th e reason may be due to the beryllium cross section data base in JENDL3.2. ( C) 2000 Elsevier Science B.V. All rights reserved.