[en] PNP-2 is a computer programme designed to interpret experimental data obtained from a pulsed neutron source on multiplier media in critical or subcritical states populated by thermal neutrons. The programme is in FORTRAN IV. Variation with time of the population of thermal neutrons from the multiplier medium, following its excitation at the time t = KT with neutron bursts appears, in the simplified theory, of the pulsed source method. In PNP-2 reactivity is calculated in relative units (dollars) and the generation time is calculated from the obvious equations from theoretical methods of Gavelis-Russel and Gozani. (author)

[en] The scientific background of radiation protection and hence ''ionizing radiation'' is undergoing substantial regress since a century. Radiations as we are concerned with are from the beginning defined based upon their effects rather than upon the physical origin and their properties. This might be one of the reasons why the definition of the term ''ionizing radiation'' in radiation protection is still weak from an up to date point of view in texts as well as in international and national standards. The general meaning is unambiguous, but a numerical value depends on a number of conditions and the purpose. Hence, a clear statement on a numerical value of the energy threshold beyond a radiation has to be considered as ''ionizing'' is still missing. The existing definitions are, therefore, either correct but very general or theoretical and hence not applicable. This paper reviews existing definitions and suggests some issues to be taken into account for possible improvement of the definition of ''ionizing radiation''. (author)

[en] Operational critical assemblies are subject to the same standards of materials control and accountability (MC and A) as other fissile materials. Typically these assemblies are not easily dismantled and the fuel components cannot be inventoried by traditional methods of destructive or non-destructive materials assay. Because of the large mass or unusual geometry of the fuel components these parts are often categorized as difficult-to-measure (DTM) items. The use of criticality to infer fissile inventory, in conjunction with physical security and two-person control procedures, provides accurate and cost-effective MC and A for these large critical assembly components. This method is being implemented at the Los Alamos Critical Experiments Facility (LACEF) and at several national nuclear research centers in Russia

[en] This paper summarizes the overall pan for inspection and maintenance of reactor structure and Reactivity Control Units (RCU) of HANARO during lifetime. The long-term plan for in-service inspection is introduced in viewpoint of structural integrity of reactor and RCU, and operability of RCU mechanism. This plan includes the list of components to be inspected, the schedule of inspection and maintenance, and the development plan of special tools that are required for the remote inspection and maintenance of reactor and RCU components. Preliminary results of the evaluation on the lifetime of RCU components are summarized based on the operation history since the installation of reactor. A test rig will be designed and constructed for the purposes of verifying the extended lifetime of RCU components being used, the performance of special tools, and the rehearsal of maintenance work as well. (author)

[en] The IBR-2 reactor pulse transfer factor is calculated by varying the basic parameters (prompt neutron life-time, delayed neutron fraction, the top parabolic coefficient and swing of the reactivity of the main moving reflector) because of inevitable errors in the estimates. The calculations confirmed that it is desirable to measure the pulse reactivity in units different from steady-state reactors. The linear approximations of the pulse transfer factor and its logarithm are estimated. (author). 4 refs., 4 figs., 1 tab

[en] The Solution High-Energy Burst Assembly (SHEBA), located at the Los Alamos Critical Experiments Facility, is a homogeneous liquid-fueled reactor that is being prepared for prompt burst operation. As part of the preparations, a reactor safety study was performed in support of the new SHEBA experiment plan. This study looked at the maximum power, total energy yield, and maximum transient pressures that may occur in the reactor during prompt burst operation. The goal of this study is to analyze the neutronic and hydrodynamic behavior of the reactor during burst operation, and to ensure that prompt burst operation does not damage the reactor or exceed the safety envelope of the facility's Safety Analysis Report (SAR)

[en] Point reactor dynamics equations with six groups of delayed neutrons have been computed via weighted-residual method in which the delta function was taken as a weighting function, and the parabolic with or without exponential factor as a trial function respectively for an insertion of large or smaller reactivity. The reactivity inserted into core can be varied with time, including insertion in forms of step function, polynomials up to second power and sine function. A thermal feedback of single flow channel model was added in. The thermal equations concerned were treated by use of a backward difference technique. A WRK code has been worked out, including implementation of an automatic selection of time span based on an input of error requirement and of an automatic change between computation with large reactivity and that with smaller one. On the condition of power varied slowly and without feedback, the results are not sensitive to the selection of values of time span. At last, the comparison of relevant results has shown that the agreement is quite well

[en] The dictionary of nuclear power covers specific terms from A to Z. The appendix includes physical measuring units and translation formulas, dose and activity units and physical constants.

No abstract available

[en] The updated dictionary on nuclear power contains definitions and explanations on nuclear physics, nuclear engineering, nuclear power, radiation effects and radiation protection in alphabetic order. Attachments on units, their conversion and physical constants are included.