[en] An inverse kinetics algorithm applicable to the plutonium-fuelled zero-energy fast reactor PURNIMA has been developed for the interpretation of kinetic experiments. By introducing reactivity perturbation of various kinds and analysing the resultant neutronic behaviour, the worths of various reactivity manipulation mechanisms of PURNIMA reactor have been determined. The technique has proven to be a reliable method for determining the inherent neutron source strenght in the reactor. (orig.)

[en] The precise estimation of Pearson correlations, also called 'representativity' coefficients, between core configurations is a fundamental quantity for properly assessing the nuclear data (ND) uncertainties propagation on integral parameters such as k-eff, power distributions, or reactivity coefficients. In this paper, a traditional adjoint method is used to propagate ND uncertainty on reactivity and reactivity coefficients and estimate correlations between different states of the core. We show that neglecting those correlations induces a loss of information in the final uncertainty. We also show that using approximate values of Pearson does not lead to an important error of the model. This calculation is made for reactivity at the beginning of life and can be extended to other parameters during depletion calculations. (authors)

No abstract available

[en] Three methods for measuring the reactivity of a system in sub-critical state in the presence of a neutron source are described, namely the method of ''shooting source'', the method of dumping of unknown absorber, and the method of introducing the calibrated absorber. The described methods do not require additional equipment, except for an analogue reactometer with a possibility of adjusting the source component in the computing block. The methods are universal since they cover not only the critical assemblies but also any high-intensity reactors in sub-critical stage and permit the temperature effect, the poisoning effects, etc. to be measured. Besides that, the methods may be applied both in the absence and in the presence of a strong neutron background in the reactor

[en] The subject is covered under the following headings: (1) introduction, (2) design of WWER type reactors, (3) reactor physics calculations, (4) theoretical fundamentals for determining reactivity effects by reactivity measurements, (5) reactivity measurements and evaluation methods, (6) operating parameters, and (7) transferability of the methods and outlook. 56 references are included

[en] The accuracy of reactivity meters is usually checked with a reactor kinetic simulator operating to an accuracy exceeding the expected accuracy of the measuring device. The present report describes a method to evaluate accuracy by comparing the response R(t) of the reactivity meter to a given function n(t) with the value of the reactivity function r(t) calculated from the same input function instead of using the input reference signal r(t) to the simulator with the output signal R(t) from the reactivity meter. This method has been successfully used by applying sawtooth and exponential input signals for the determination of the accuracy of reactivity meters developed in the Central Research Institute for Physics. (author)

[en] The results of calculations of various models of the BN-600 reactor using the method developed earlier to calculate the contribution of neutron-capture reactions to the effective energy release in the nuclear reactor core are presented in the paper. Three models of the BN-600 reactor have been calculated: a cell model, a blanket cell and a homogeneous core (with uranium, MOX, and hybrid fuels)

[en] Nowadays, various digital methods making use of microcomputers for neutron detector signals and determining the reactivity by numerical calculations are used in reactor control systems in place of classical reactivity meters. In this work, a calculation based on the ''The Time Dependent Transport Equation'' has been developed for determining the reactivity numerically. The reactivity values have been obtained utilizing a computer-based data acquisition and control system and compared with the analog reactivity meter values as well as the values calculated from the ''Inhour Equation''

No abstract available

[en] A method for at-power reactivity measurements is presented. The method is based on a trapezoidal perturbation of the reactor state, which can be generated easily by means of ordinary control rods. Both theoretical and experimental work are discussed, and a simple algorithm for the correction of space-time effects is suggested