NCSR Demokritos

List of current and recent projects

JET is currently the largest tokamak in the world, and a test platform for the design of future fusion power plants. In this project we perform neutron streaming calculations in long ducts and labyrinths at JET and compare the simulation results against experimental measurements performed by the Institute of Nuclear Physics, Polish Academy of Sciences, in order to validate the computational tools and methods used for the design of ITER and DEMO. This project is funded under EFDA JET Fusion Technology program for 2013.

Large Sample Neutron Activation Analysis (LSNAA) compliments and significantly extends the analytical tools available for cultural heritage and authentication studies providing non-destructive, multi-element analysis, of objects that are too precious to damage for sampling purposes. The LSNAA method incorporates neutron irradiation of the bulk sample and subsequent measurement of the induced activity by a gamma spectrometry system as a whole or using a scanning counting system to identify and correct for material in-homogeneities. Corrections  for self-absorption of gamma rays emitted by activation products, self-shielding of the activating neutrons, sample asymmetry, the geometric volume factor and other factors are required. This project is supported by the IAEA.

Fusion Technology

Large Sample Neutron Activation Analysis

Projects

Radiation shielding optimization is important for the protection of patients and personnel in radiation therapy. In centres operating high energy medical accelerators the difficulty to optimize shielding for primary and secondary X-rays is further complicated due to the production of photo-neutrons in the unit. Methodologies for the design of the radiation shielding configuration of high energy medical accelerators are developed in collaboration with the Medical Physics Laboratory, University of Ioannina School of Medicine.

Radiation Shielding Optimization

JET at Culham, UK

Measurement of a Greek ceramic vase at  the TU Delft LSNAA system

Simplified model of an accelerator head system

Prompt-gamma neutron activation analysis (PGNAA) has found important application in medicine and technology. A PGNAA facility based on isotopic neutron sources was developed and used to demonstreta the feasibility of measuring  nitrogen  and chlorine in the body of small animals 0.5–2 kg (i.e. rats or rabbits) and therefore providing assessment of  total body protein and extra-cellular space for nutrition and metabolic studies. The experience obtained is now transferred on the development of a system for rapid in situ analysis of contaminated soil. This project was partially supported by GSRT.

Prompt-gamma neutron activation analysis

Prompt gamma system using isotopic neutron sources at NCSR “D”

The radiological characterization of reactor components is of utmost importance since the resulting activities and dose rates would determine the action planning for refurbishment or decommissioning purposes. Neutron transport calculations for the evaluation of the activating neutron field and radionuclide inventory calculations for the derivation of the source term were utilized to characterize the components of the Greek Research Reactor and plan the actions for the dismantlement of the core components. This project was performed within the scope of the GRR-1 refurbishment and renovation program funded by GSRT.

Nuclear Reactor Safety

GRR-1 core dismantlement

The great advantage of fusion energy is the minimization of the radioactive waste produced. Structural materials and components are chosen so the induced activity is minimum and enabling material recycling or disposal few years post irradiation. Within the framework of EFDA Hellas-Fusion, Emerging Technologies Program we performed induced activity calculations and measurements for selected low activation materials.

Fusion materials characterization

SiC/SiC activity after neutron irradiation

Ion Stamatelatos

Physicist

Text Box: NCSR Demokritos