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Author

Kristian Otto Aleksi Kurhela

Other affiliations: University of Helsinki
Bio: Kristian Otto Aleksi Kurhela is an academic researcher from Helsinki Metropolia University of Applied Sciences. The author has an hindex of 1, co-authored 1 publications receiving 1 citations. Previous affiliations of Kristian Otto Aleksi Kurhela include University of Helsinki.

Papers
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TL;DR: In this article, the results obtained in a Nordic Nuclear Safety Research project during the second intercomparison exercise for the determination of difficult to measure radionuclides in decommissioning waste are reported.
Abstract: This paper reports the results obtained in a Nordic Nuclear Safety Research project during the second intercomparison exercise for the determination of difficult to measure radionuclides in decommissioning waste. Eight laboratories participated by carrying out radiochemical analysis of 3H, 14C, 36Cl, 41Ca, 55Fe and 63Ni in an activated concrete. In addition, gamma emitters, namely 152Eu and 60Co, were analysed. The assigned values were derived from the submitted results according to ISO 13,528 standard and the performance assessments were determined using z scores. The measured results were compared with activation calculation result showing varying degree of comparability.

5 citations


Cited by
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TL;DR: In this article , the authors describe the calculations and gamma activity measurements performed for the activated concrete samples to determine the boundary between radioactive parts and concrete that can plausibly be free-released from regulatory control.
Abstract: Abstract FiR 1 is a TRIGA Mark II-type research reactor in Finland. It was in operation between 1962 to 2015 and will be dismantled in 2022 to 2023. Preliminary calculations of the activities in the reactor main structures were performed in an earlier stage of the decommissioning project. Samples of the activated parts of the reactor biological shield concrete were drilled in December 2018 to validate these estimates. This paper describes the calculations and gamma activity measurements performed for the activated concrete samples to determine the boundary between radioactive parts and concrete that can plausibly be free-released from regulatory control. The activities have been estimated with a two-step calculation process using the MCNP and ORIGEN-S calculation codes and measurements using an ISOCS gamma spectrometer with a high-purity germanium detector.

1 citations

Journal ArticleDOI
TL;DR: Significant gravel mines, representative of four regions of Hungary (northeast, central, northwest, and southwest) were systematically sampled to characterize their sand and pebbles as potential constituents of nuclear-grade concrete as discussed by the authors .
Abstract: Significant gravel mines, representative of four regions of Hungary (northeast, central, northwest, and southwest) were systematically sampled to characterize their sand and pebbles as potential constituents of nuclear-grade concrete. The samples were analysed for their elemental compositions as a function of the mining locality and grain size, using two complementary neutron-based analytical techniques, prompt gamma activation analysis (PGAA) and neutron activation analysis (NAA). The combined analysis resulted in reliable mass fractions for over thirty elements that could be used to assess the radiation shielding and activation properties of the resulting concrete, essential in nuclear applications, by means of computer simulations. The studied aggregates are proven to be appropriate constituents for biological shielding at radiological centres, NPPs, and at nuclear research installations, even in mixed neutron/gamma radiation fields. The elemental compositions also revealed geochemical differences between the sedimentologically different regions.
Journal ArticleDOI
TL;DR: In this article , a three-year project within the Nordic Nuclear Safety Research (NKS) community was initiated in order to carry out intercomparison exercises on difficult to measure (DTM) radionuclides in real decommissioning waste.
Abstract: Abstract A need for method validation in radiochemical analyses of decommissioning waste is a challenging task due to lack of commercial reference materials. Participation in an intercomparison exercise is one way for a laboratory to assess their performance and validate their analysis results. A three-year project within the Nordic Nuclear Safety Research (NKS) community was initiated in order to carry out intercomparison exercises on difficult to measure (DTM) radionuclides in real decommissioning waste. Both Nordic and Non-Nordic laboratories participated. This paper reports the results from the final year of the project focusing on beta- and gamma emitter (i.e., easy to measure, ETM) analysis in spent ion exchange resin. The assigned values were derived from the participants’ results according to ISO 13528 standard and the performances were assessed using z scores. The results showed generally good performances for both DTMs and ETMs.
Journal ArticleDOI
01 May 2022-Talanta
TL;DR: In this article , the authors propose a methodology for the organization and analysis of coordinated interlaboratory comparisons (ILC) for the performance assessment and the uncertainty evaluation of available measurement techniques (methods and tools) of radioactive materials.