SU333606A1 - Calorimetric method of determination - Google Patents

Description

This invention relates to the field of calorimetric dosimetry in atomic reactors.

Nowadays, dosimetry methods of ionizing radiation from a reactor are widely developed. This is due to the fact that the magnitude of the dose of absorbed energy is used as a measure of the radiation effect of radiation on a substance, as well as to ensure the desired temperature of irradiation of materials in the reactor, it is necessary to know the energy release dose in the samples. In connection with the difficulties of obtaining accurate calculated values of the absorbed dose of energy, various experimental dosimetry methods, in particular calorimetric methods, are being developed, which allow measuring the absolute value of absorbed energy directly in the material under study and at a given location in the reactor core. .

The known stationary calorimetric method is based on the use of electrical heat compensation in the sample under study in an isothermal calorimeter. Under isothermal conditions, the ionizing radiation energy absorbed by the test sample per unit time is equal, in the absence of a sample in the calorimeter

electric power compensating heater.

The disadvantages of this method are that in the measurement process, it is necessary to introduce and remove a sample from the core, when measuring the energy release in the channels of the highly stressed reactors, a large electrical power is required to the electric heater, and it is difficult

take into account the fraction of axial heat leakage from the electric simulator, which leads to an error in the measured dose value.

The purpose of the invention is to improve the accuracy of measurements and to ensure the possibility of carrying out measurements in highly dated atomic reactors. For this, according to the proposed method, it is not necessary to extract the prototype, and not all the energy release in compensation is compensated.

a prototype, but only a small part of it using an electric heater calorimeter connected directly to the entire side surface of the sample. The method of measuring the energy release includes the following steps.

Then a measurement of the turn e. all thermocouples installed in it. The reactor power is increased by some small amount and maintained at this level until a new stationary temperature level is reached throughout the calorimeter. Then the measurement of thermo emf is made. all microthermopairs, after which the reactor returns to the initial stationary power level.

An electric heater is connected, connected to the entire lateral surface of the sample, to which electrical power is supplied, which ensures in a steady state of the calorimetric system a temperature level equal to the temperature observed at an increased reactor power. This power is measured and by comparing this power with the increase in reactor power, the energy release in the sample under study is calculated.

In order to eliminate the influence of changes in the reactor power level on the temperature of the working (main) sample, a sample witness is used, which is set symmetrically relative to the center (maximum) of the energy release and temperature, from both samples is connected to a single device using a differential circuit.

Subject invention

1. Calorimetric method for determining the stationary level of energy release in materials from mixed reactor radiation using electrical compensation

energy release, consisting in the exposure of a calorimetric device with a test sample in the channel of an atomic reactor until reaching a stationary temperature state

a system corresponding to a certain reactor power, temperature control of the outer surface of the device and measurement of the equilibrium temperature of the test sample, characterized in that, in order to increase the accuracy

measurements and the possibility of carrying out measurements on highly stressed atomic reactors, after the step of measuring the equilibrium temperature of the sample, increase the power of the reactor by a certain amount and

after the stationary temperatures are established, they are measured, then the reactor is returned to the initial stationary level, and the electric heater power necessary to achieve the stationary temperature conditions in the calorimetric device, which were observed at the increased reactor power level, is measured.

S. The method according to claim 1, characterized in that the electric compensation of the energy release

produced by heating the entire side surface of the test specimen using an electric heater placed on this surface. 3. The method according to paragraphs. 1 and 2, characterized in that

that simultaneously with the measurement of the temperature increments on the working sample, the constancy of the temperature of the sample-witness, similar to the working sample, is monitored.

Priority calculated from April 26, 1968