[KSCI] Korea Science Citation Index Service

http://dx.doi.org/10.14773/cst.2018.17.6.265

Analysis of CRUD Flake Applied to Abnormal High Beam Current by Shielded-EPMA

Jung, Y.H. (Korea Atomic Energy Research Institute)
Baik, S.J. (Korea Atomic Energy Research Institute)
Ahn, S.B. (Korea Atomic Energy Research Institute)

Publication Information

Corrosion Science and Technology / v.17, no.6, 2018 , pp. 265-271 More about this Journal

Abstract

CRUD specimens, scraped from twice-burned fuel cladding in the Korean Nuclear Power Plant, were analyzed using Shielded-EPMA. The principal elements of the CRUD were identified as Ni and Fe, at an approximate ratio of 1.3 Ni/Fe. To investigate the morphology and composition of the pure metallic materials in the CRUD, coolant impurities must be removed. This can be accomplished by increasing the EPMA current to an abnormally high intensity until the impurities are melted. Normally, EPMA applications are performed at conditions of 20 kV voltage and 20 nA current. But in our study, the applied current was increased up to 1200 nA, over time increments ranging from 5 to 30 seconds. This technique was performed by opening an adjustable aperture for the gun alignment. Results showed impurities contained in the CRUD material disappeared and pure metal materials, e.g., Ni and Fe, remained. This method presents an innovative way to analyze CRUD.

Keywords

CRUD; Shielded-EPMA; Abnormal beam current; Boling chimney hole; $NiFe_2O_4$ ;

Citations & Related Records

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