[1F03-04.1F06-07] Subcritical Experiment and Analysis

[1F03] Detection of gamma ray radiated from capture reaction of ²³⁸U in sub-critical system

*Yasushi Nauchi¹, Tadafumi Sano², Shunsuke Sato¹, Motomu Suzuki¹, Hirokazu Ohta¹, Hironobu Unesaki² (1. CRIEPI, 2. KURRI)

Keywords:238U, capture gamma ray, sub-critical system, KUCA, low enriched

A polyethylene moderated subcritical system are mocked up. The average ²³⁵U enrichment of the system is reduced to 5.4% by combined use of 93%-EU fuel and natural uranium fuel plates. By driving the system with a ²⁵²Cf, gamma ray spectrum is measured outside the system with a HP-Ge detector. As the results, 4060keV photons radiated from capcure reactions of ²³⁸U are measured, although they are overwrapped with prompt fission gamma rays and decay gamma rays from short-lived fission products.