Reducing measurement uncertainty in 63Ni measurements in reactor coolant water with high 60Co activities

Gautier

et al. 2020

This paper reports the results obtained during an intercomparison exercise for the determination of difficult to measure radionuclides in activated reactor pressure vessel (RPV) steel samples. In total, eight laboratories participated analysing 14C, 55Fe and 63Ni activity concentrations in RPV steel. In addition, some laboratories also analysed 60Co activity concentrations. Corresponding activity concentrations were also determined using activation calculations. Robust statistical techniques were utilised for the analysis of the results according to ISO 13528 standard. The results showed good agreement for 55Fe and 63Ni results whereas 14C results had significant differences. 60Co results were in quite good agreement.

Section: Discussionmentioning

confidence: 99%

Intercomparison exercise on difficult to measure radionuclides in activated steel: statistical analysis of radioanalytical results and activation calculations

Gautier

et al. 2020

“…The preliminary plan was to dissolve the steel samples in concentrated acids and, after hydroxide precipitation of investigated metals, separate Fe and Ni from each other and disturbing matrix with anion exchange. Then Ni fractions from anion exchange would be further purified from Co either by co-precipitating Ni with DMG (traditional method) [8,11] or by extraction chromatographic column separation with Ni resin (a newer method) [12][13][14]. Actually, the both methods are based on the complexation of Ni by DMG but the procedures are different in practice, direct mixing of sample and DMG solutions in a beaker vs. column separation.…”

Section: Testing Of Methods 2 In Determination Of 55 Fe and 63 Nimentioning

confidence: 99%

“…In order to verify the effectiveness of the Ni purification from 60 Co, the eluate was measured using gamma spectrometry. The results showed significant presence of 60 Co and thus, the Ni-resin purification was repeated according to Eriksson et al [13].…”

Section: Determination Of 14 C 55 Fe and 63 Ni Using Methods 11mentioning

confidence: 99%

Determination of 14C, 55Fe, 63Ni and gamma emitters in activated RPV steel samples: a comparison between calculations and experimental analysis

Räty

et al. 2019

Determination of 14 C, 55 Fe, 63 Ni and gamma emitters in two different types of activated reactor pressure vessel (RPV) steel samples were carried out. The gamma emitters were analysed using HPGe detectors with ISOCS and standard geometry calibrations. Two radioanalytical procedures for the 14 C, 55 Fe, 63 Ni analysis were developed using inactive samples and activated samples were analysed using modified procedures. A Monte Carlo code was used for the modelling of the activation results. The obtained measured and calculated results were comparable.

“…However, the change of two subsequent 10 g AG resins to one 30 g AG resin was not successful to increase the Fe yield in the purified fractions as the yields lowered from 48 to 80% to 13-19%. As discussed in previous publications [12,14,22,27], purification of Ni from Co can be challenging. The yield results for Ni in inactive concrete subsamples show that about 90% of the Ni was carried over to the final purified Ni fraction.…”

Section: Testing Of Methods 1 In Inactive Concrete and The Radiochemical Analysis Of 41 Ca 55 Fe And 63 Ni In Activated Concretementioning

confidence: 99%

“…CoreF correction is a mathematical corrective function for deviations of TDCR at higher quench levels. [2,[22][23][24]28]. Three parallel subsamples of 0.5 g inactive concrete were used for experimenting the initial Method 2.…”

Section: Testing Of Methods 1 In Inactive Concrete and The Radiochemical Analysis Of 41 Ca 55 Fe And 63 Ni In Activated Concretementioning

confidence: 99%

Development of 3H, 14C, 41Ca, 55Fe, 63Ni radiochemical analysis methods in activated concrete samples

2021

Development of 3H, 14C, 41Ca, 55Fe and 63Ni radiochemical analysis methods were carried out independently by two laboratories using both inactivate and activated concrete samples. Two preliminary radioanalytical procedures for the non-volatile radionuclides (41Ca, 55Fe, 63Ni) and one Thermal oxidation method for the volatile radionuclides (3H, 14C) were developed. The difficulties in the method development and analysis of results are discussed.