TECHNOLOGY PROGRAMME – Radiation safety research and development

Project leader: Peter Dendooven    Personnel

The RADAR project ‚ÄúRADiation sAfety Research & development‚ÄĚ (RADAR) contains several activities related to nuclear safety, security and safeguards. It follows the NINS3 project which ran from 2015 to 2019.

Photo: A spent fuel assembly being lowered into the PGET + PNAR device. The device sits 15 meter underwater at the bottom of the spent fuel pool. (Photo: TVO)

GOSSER II (Geological Safeguards and Security R&D Project)

Finland is scheduled, around the mid-2020’s, to be the first to start the disposal of spent nuclear fuel in a geological repository. The GOSSER II project, running from 2019-2022 and coordinated by the Finnish Radiation Safety Authority STUK, will create a national safeguards approach for this disposal project. The contribution of the Helsinki Institute of Physics to GOSSER II focuses on the continued development and deployment of two methods for non-destructive analysis (NDA) of spent nuclear fuel: passive gamma emission tomography (PGET) and passive neutron albedo reactivity (PNAR). PGET aims at detecting missing fuel pins, whereas PNAR confirms the presence of fissile material and verifies the fuel usage history. Image reconstruction methods for PGET are developed in collaboration with mathematicians from the University of Helsinki and the Lappeenranta-Lahti University of Technology. Collaboration partners are the European Commission, the US Department of Energy, the International Atomic Energy Agency and Provedos Oy.

DEFACTO (Detector for fallout and air concentration monitoring)

In the STUK-HIP joint project DEFACTO, new early warning detectors for improved emergency management are being developed. The detectors aim to improve upon the present ones by distinguishing airborne radioactivity, fallout components and radioactive contamination of the detector box. The detectors are based on scintillation crystals read out by photomultiplier tubes. Their spectroscopic capability enables to distinguish different isotopes.

Gamma ray imaging

Energy-selective gamma ray imaging is a powerful tool in nuclear safety and security to detect radioactive contamination and the illicit transportation of nuclear materials. We collaborate with NeutronGate to develop prompt gamma neutron activation analysis (PGNAA) for various applications. Experiments are performed with a GeGI germanium gamma ray imaging spectrometer in collaboration with the HIP Detector Laboratory.

Personnel based at HIP
  • Peter Dendooven (project leader)
  • Sakari Ihantola (DEFACTO)#
  • Riina Virta (GOSSER II)#

#employed by STUK

Publications RADAR and NINS3

Tupasela T, Dendooven P, Tobin SJ, Litichevskyi V, Koponen P, Turunen A, Moring M, and Honkamaa T 2021 Passive neutron albedo reactivity measurements of spent nuclear fuel Nucl. Instrum. Meth. Phys. Res. 986 164707 (

Litichevskyi V, Peura P, Dendooven P, Tupasela T, Honkamaa T, Moring M, and Tobin SJ 2020 Effect of Water Gap and Fuel Assembly Positioning in Passive Neutron Albedo Reactivity Measurements for Spent Fuel Encapsulation Safeguards Journal of Nuclear Materials Management 48 22-31 (

Backholm R, Bubba TA, Bélanger-Champagne C, Helin T, Dendooven P, and Siltanen S 2020 Simultaneous reconstruction of emission and attenuation in passive gamma emission tomography of spent nuclear fuel Inverse Problems & Imaging 14 317-337 (

B√©langer-Champagne C, Peura P, Eerola P, Honkamaa T, White T, Mayorov M, and Dendooven P 2019 Effect of Gamma-Ray Energy on Image Quality in Passive Gamma Emission Tomography of Spent Nuclear Fuel IEEE Trans. Nucl. Sci. 66 487–496 (

Peura P, Bélanger-Champagne C, Eerola P, Dendooven P, and Huhtalo E 2018 Thin NaI(Tl) crystals to enhance the detection sensitivity for molten 241Am sources Appl. Radiat. Isot. 139 121-126 (

Tobin SJ, Peura P, Bélanger-Champagne C, Moring M, Dendooven P, and Honkamaa T 2018 Utility of Including Passive Neutron Albedo Reactivity in an Integrated NDA System for Encapsulation Safeguards ESARDA Bulletin 56 12-18 (

Tobin SJ, Peura P, Bélanger-Champagne C, Moring M, Dendooven P, and Honkamaa T 2018 Measuring spent fuel assembly multiplication in borated water with a passive neutron albedo reactivity instrument Nucl. Instrum. Meth. Phys. Res. A 897 32-37 (

Bélanger-Champagne C, Vainionpää H, Peura P, Toivonen H, Eerola P, and Dendooven P 2017 Design of a novel instrument for active neutron interrogation of artillery shells PLOS ONE 12 e0188959 (