Determination of nuclear graphite impurities by prompt gamma activation analysis to support decommissioning operations

Elemental composition of non-irradiated nuclear grade graphite was determined by Prompt Gamma Activation Analysis (PGAA) to quantitively assess some neutron activation precursors. The knowledge of these data is paramount for an accurate radiological characterization of the material before decommissioning of graphite-moderated nuclear reactors. Bulk results of most of the nuclides were consistent with benchmark Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and literature data. In the case of N-14 and Cl-35, depth distribution profiles were observed and quantified for the first time. These outcomes could shine a light on C-14 and Cl-36 depth distribution profiles and fractional release during leaching experiments.