A. G. Volkovich

Experience of Application of New Remote Controlled Instruments for Scanning of Distribution of Radioactive Contamination in Rooms With High Dose Rate

When carrying out the decommissioning of nuclear facilities is necessary to measure the distribution of radioactive contamination in the rooms and the equipment at high levels of background radiation. In the decommissioning of the reactor in the MR NRC “Kurchatov Institute” for such problems is developed and applied a few special systems with remote control. For a survey of high-level objects used mounted on the robot radiometric system. To determine the composition of pollutants and use a portable collimated spectrometric system. To obtain a detailed distribution of contamination of used remote-controlled gamma camera.Copyright

Visualization of Radioactive Sources Without Gamma-Radiation With UV Imaging Systems

New UV cameras are suitable for imaging of α-contamination by fluorescence of atmospheric air the near ultraviolet (wavelength — 280 – 390 nm) region. Their parameters are: FOV for detecting in UV spectral region is 8° × 6°. The optical FOV is about 48° × 36°. DayCor SUPERB UV camera has sensitivity 3×10−18 W/cm2 enables detection and displaying corona emission as weak as 1.5 pC at distance 8 m, and capture moving targets without smearing the output image. Instruments sensitivity for alpha contamination registration in terms of minimum measurable activities (MMA) have been estimated as, 40–100 Bq/cm2 (measurement time is 3600–600 sec correspondently).Copyright

A rapid method for analysis of radioactive waste for the presence of fuel matrix components

The presence of large amounts of 137Cs and 90Sr radionuclides in radioactive waste severely complicates its analysis for the presence of fuel matrix components. Labor-consuming procedures for determining uranium and plutonium radionuclides in soils and water are hardly applicable in this case. A rapid method based on these procedures was developed for determining fuel matrix components in both liquid and solid radioactive waste. The procedure was tested in the course of works on dismantling the MR reactor of the National Research Centre Kurchatov Institute. Samples of water, bottom slime, and deposits on the walls of ponds in the central room of the MR reactor and of deposits from the dismantled active drain system were analyzed.

Measurements of photon ionizing radiation fields in the reactor room of the 4th power-generating unit of the chernobyl nuclear power plant

A radiation examination of the reactor room of the damaged fourth unit of the Chernobyl nuclear power plant was performed. The most strongly radiating surfaces were determined. Digital maps of the distribution of the effective surface activity on the inner surfaces of the room were constructed from the measurement results. 4 figures, 1 table, 10 references.

Characterisation of MR Reactor Pond in NRC “Kurchatov Institute” Before Dismantling Work

In this work complex α-, β-, γ-spectrometric research of water, bottom slimes and deposits on walls of the reactor pond and the storage pond of the MR reactor was made. Identify, that the main dose forming radionuclide, during dismantling work on the reactor MR, is Cs-137. It is shown, that specific activity of radionuclides in bottom slimes considerably exceed specific activity of radionuclides in water from ponds, and near to high level radioactive waste. It is detected that decreasing the water level in reactor ponds on 1m, increase the exposure dose rate at a distance 1m from the pond in 2 times. The observed increase in exposure dose rate can be explained by contribution on dose rate the cesium-137 deposed on walls of the storage pond. Effectiveness of cleaning of walls of the pool of storage from deposits by a water jet of high pressure is investigated.Copyright

Experience of Gamma-Locator System Using for Radiation Monitoring During Rehabilitation Works at Temporal Radwaste Storage Area of Kurchatov Institute

Remote monitoring of radiological conditions on large areas is important task during large-scale activity with radioactive contamination/materials. We present results of application of an automatic system for remote measurements of radiological conditions at territory of rehabilitation activity. The system is scanning collimated spectrometric detector, its construction and main performance characteristics are shortly described. System, including two different measurement heads was used during three years for radiological monitoring of area rehabilitation works at temporal radwaste storage area of RRC Kurchatov Institute. The results of its application for exposure dose rate monitoring at particular control points from separate strong sources located in the territory of activity are presented and special cases are studies in details. The method of EDR calculation in 3-D space around territory of activity and analysis of relative input of main gamma-sources into EDR are presented. The results of application of the system during rehabilitation activity at territory of temporal storage of radioactive wastes of RRC Kurchatov Institute have shown high efficiency of this system for such operations.Copyright