The Laboratory of Radiometry

Pavilion C-6, premises 004

 

An essential element for implementation of nuclear energy (EJ) in Poland is to develop educated academic staff, now there is lack of people who might constitute such staff. The reproduction may be made only on the basis of wide scale research program in the field of EJ and related to this.

 

Proposed research areas by the Department of Nuclear Energy related to the operation and use of LR will cover the following topics: 

  • Application of subcritical accelerator controlled systems or thermonuclear reactor for the transmutation spent of nuclear fuel
  • The work using equipment LR will concern the radioactivity measurements induced in the sample materials.

It is about:

  • Materials used in the construction of equipment components constituting an external source of neutrons to control subcritical power system, based on fission reaction. These elements are flammable shield (for the controlled accelerator - ADS) and structure of hydro-nuclear reactor (for the synthesis of hybrid system - fission).
  • Materials originating in the process of spent nuclear fuel in reactors.
  • In the case of structural materials research includes two types.
  • Suitable ADS systems for the project will rely on the following specific tasks
  • A measurement is taken with gamma spectrometers in LR, absolute residual activity nuclides formed in flammable shields of different materials (W, Hg, Th) by proton beam irradiation with a high energy (200 ÷ 1000 MeV). Such opportunities exist in Russian laboratories and cooperation is established.
  • The calculation of simulated formation of radioactivity in flammable shields.
  • Comparison of radionuclide activity to the measured and calculated.
  • On the other hand, research project will estimate the performance of neutron activation of appropriate spectrum materials in a hydro-nuclear reactor zones treated with the highest neutron flux densities. On this basis, it can be further specified the volume of produced radionuclides and their Disposal. For a reliable size assessment, it is necessary to verify numerical computational experiments (enforceable provision in LR) with the application of a neutron source Spectra Energy and radiation spectrometer in decays arising from radionuclides, mainly of gamma radiation.

 

Materials from the spent fuel containing actinides will be available within the framework of international cooperation. The contents of the test samples can be determined using the alpha particle spectrometry and gamma (available in LR), and confronted with the results of theoretical calculations using a code MCB. Such comparison will test the reliability of calculations.

  

Research of physics on high-temperature gas reactor core (Generation IV) for burning plutonium and rare actinides produced in nuclear fuel cycle.

  

Reactors of Generation IV, with improved safety performance and energy efficiency, arecurrently the most drop-down in the field of nuclear energy. High-temperature reactors are particularly interesting for Poland due to the possibility of their use within the framework of so-called carbon-nuclear synergy. An interesting issue is to investigate whether they can be also useful for nuclear firing transformation products occurring in fuel reactor of II and III generation (i.e. generated actinides).As well as, verification efficiency calculations of MCB firing code should be confronted by the relevant experiments. In case of sub-critical systems, they will be possible to confront with the measurement results. The relevant samples obtained through international cooperation, will be measured using alpha and gamma spectrometers (LR) irradiated in a thermal reactor under high fluence.


Development and application of MCB code for simulation calculations of transmutationreactor materials. 

The MCB Code initiated and developed theoretically in the Department of Nuclear Energy (WEiP AGH) by Dr. Jerzy Cetnara and developed in collaboration with the Royal University of Technology (KTH) in Stockholm and it was already recognized by the international community's nuclear power industry. However, it requires further development, as by checking an accuracy of the calculations using nuclear transmutation. For example, this code is calculating the efficiency of burning actinides mentioned in the previous paragraph. The importance is to have an opportunity to check the performance of simple experimental reaction (short chain transformations 1 ÷ 2 responses) possible to carry out LR using existing sources of neutron and spectrometers. Longer chain reactions and decay can be initialized only by using neutron sources with high performance (available in the Netherlands,/Petten/or/Grenoble/in Northern France streaming high-reactors) and irradiated samples shall be sent to the LR to make alpha-and gamma-spectrometric measurements.

 Nuclear data validation to design the transmutation, fission and hydro-nuclear reactors.

 

 

The experience gathered in the course of projects conducted of among others by KEJ team.Coordinated Research Project (CRP) “Analytical and Experimental Benchmark Analyses of Accelerator Driven Systems (ADS)”, Project title: Benchmark on the ADS target activation experiment, Contract No 13395/R0,17.XI.2005 – 4.II.2011. show that the reliability of nuclear data in many areas is still clearly insufficient. In particular, this applies to slightly less energy ranges operated neutrons, characteristic of subcritical accelerator-controlled systems for the transmutation of isotopes, or hydro-nuclear reactors. To improve the quality of active libraries sections may result of performed experimental verification and adequate measurements.  

 

Capabilities of these facilities provide Radiometry Laboratory including:

  • HPGE coaxial detector with capacity of 100% of the complete track spectrometric INSPECTOR and Canberra Genie 2000 software and detector Si (Li) for measuring the X-ray and low-energy gamma rays with the same measuring path.
  • Pulsed neutron generator tube GENIE 16 GT-SODERN – for the measurements of hydro-nuclear reactor.

 

Thus, the program of research project provides:

  • Irradiation of samples of different materials using neutron sources / both isotope 241Am-Be and 252Cf and tube neutron generator.
  • Measurement of excited activity using w/Dim. gamma detectors y.
  • Confrontation results of calculations made by using validated nuclear data with relevant measurements. Conclusions.

 

The study on properties of fuel cycle track

Fuel cycle, in which the role of reproductive material instead of producing 238U fully 232Th, it’s producing value 233U has long been the subject of research and often the preferred option (eg. For a Nobel Prize winner C.Rubbii).  It has a fundamental advantage, which is practical absence of trans-plutonium in the cycle and negligible quantities of produced plutonium. Problems connected with fuel containing transplutonium unambiguously suggest that the closed fuel cycle Th-U will be easier to implement than the same - the U-Pu. Another advantage is the great global thorium resources in the fields of high concentrations. Also variant of nonproliferative cycle is reachable through:  

  • accompanying the produced 233U isotopes /t.j. 232U indirectly hard source (2.6 MeV) gamma radiation of 208Tl/;
  • dilution of 233U to 238U, or "rotting" nuclear material.

 

However, the introduction to the cycle of the heavier isotope of 6 neutrons from 232Th, mustresult in appearance of transplutonium, which several times lower than in the U-Pu cycle. It is therefore obvious that this cycle can not be free from defects. The results need more accurate diagnosis, including experimental properties of the cycle. In addition, it inspires to available KEJ remaining at the disposal of significant amount of thorium oxide (> 200 kg), with a unique on an international scale.

Thus - with its use – it can be attributed to the following experimental study:

 

  • Irradiation of samples of different actinides (eg 238U, 235U, 237Np) in included track kit using neutron sources / both isotope 241Am-Be and 252Cf and tube neutron generator /. (It is assumed variants of a set of different spectra neutrons:  hard and a lesser degree downturn)
  • Flow measurements using neutron detectors.
  • Measurement of excited activity using gamma detectors y.
  • Confrontation of the results of measurements and calculations. Conclusions.