Development of Cladding Material Creep Rupture Detection System Using Laser Resonance Ionization Mass Spectrometry for the Fast Reactor

Ito, Chikara   ; Nose, Shoichi; Harano, Hideki; Arima, Toshihiro*

In the experimental fast reactor JOYO, an on-line instrumented material irradiation rig developed to acquire various irradiation data. The Material Testing Rig Temperature Control (MARICO) is capable of collecting creep rupture strength data for fast reactor fuel cladding materials. The irradiation using MARICO rig began in 1994 with JOYO's 29th operational cycle and ended in 1998 with the 32nd cycle. A ruptured sample might not be able to be specified with a device of MARICO in the irradiation examination. To improve irradiation technology, the trace rare gas detection technique using laser resonance ionization mass spectrometry (RIMS) is applied to creep rupture experiment. The irradiation capsules are labeled with tagging gases. The identification uses isotope analysis of the tagging gas leaked out of the breached steel capsule, diffused in the argon cover gas. The RIMS device analyzed the isotopic composition of the cover gas of which it took a sample. As that result, the isotopic composition that it was measured with a RIMS device corresponded with the tag gas identified by the MARICO device.