Equipment response spectra for nuclear power plant systems

An analytical method is developed whereby a simple estimate can be obtained of the maximum dynamic response of light equipment attached to a structure subjected to ground motion. The natural frequency of the equipment, modeled as a single-degree-of-freedom system, is considered to be close or equal to one of the natural frequencies of the N-degree-of-freedom structure. This estimate provides a convenient, rational basis for the structural design of the equipment and its installation.The approach is based on the transient analysis of lightly damped tuned or slightly nontuned equipment-structure systems in which the mass of the equipment is much smaller than that of the structure. It is assumed that the information available to the designer is a design spectrum for the ground motion, fixed-base modal properties of the structure, and fixed-base properties of the equipment. The results obtained are simple estimates of the maximum acceleration and displacement of the equipment. The method can also be used to treat closely spaced modes in structural systems, where the square root of the sum of the squares procedure is known to be invalid.This analytical method is also applied to nontuned equipment-structure systems for which the conventional floor spectrum method is mathematically valid. A closed-form solution is obtained which permits an estimate of the maximum response of the equipment to be determined without the necessity to compute time histories as required by the floor spectrum method.     

Geotechnical investigations at nuclear power plant sites

The vibratory ground motion criteria for nuclear plant sites in the United States are based on comprehensive geologic, seismologic and site soils investigations. This paper summarizes the field, laboratory and office studies necessary to evaluate the regional geology and seismology of the region surrounding the site; results from these studies are used to define the most significant earthquakes for the site. In addition, field and laboratory investigations of site soil properties at nuclear plant sites are outlined; these investigations lead to the dynamic soil properties required for site-response analyses, and to the generalized subsurface profile for the site.     

Active seismic response control systems for nuclear power plant equipment facilities

To sustain severe earthquake ground motion, a new type of anti-seismic structure is proposed, called a Dynamic Intelligent Building (DIB) system, which is positioned as an active seismic response controlled the structure. The structural concept starts from a new recognition of earthquake ground motion, and the structural natural frequency is actively adjusted to avoid resonant vibration, and similarly the external counter-force cancels the resonant force which comes from the dynamic structural motion energy. These concepts are verified using an analytical simulator program. The advanced application of the DIB system, is the Active Supporting system and the Active Stabilizer system for nuclear power plant equipment facilities.     

From conventional nuclear power reactors to accelerator-driven systems

Due to many factors, there is again increase in trend to use the nuclear power for energy production. But spent fuel from nuclear power plants has become one of the crucial problems of nuclear energy exploitation. Some problems attributed to the conventional nuclear power reactors along with their solutions and a historical transition from nuclear power reactors to accelerator-driven systems are briefly reviewed in the present work. It is argued that accelerator-driven systems (ADS), for transmutation of nuclear waste and energy production, are good alternatives to the conventional nuclear power plants. Important differences between the conventional nuclear reactors and the ADS along with the ADS physics are discussed. The ADS is considered to be relatively safe as compared to the other nuclear power reactors commonly in use.     

A physical-topological characterization of group response to nuclear power

A physical-topological model of societal response to the introduction of a technology such as nuclear power is proposed. The formulation is based on a conceptual-geometric construct familiar in physics and mathematics. An interesting feature of the model is that it provides for the intrinsic inclusion of such intra-societal conflict manifestations as opinion reversals, opinion polarizations and apparent inconsistencies. The general applicability of this characterization to other societal conflict domains is suggested.     

Variability in dynamic characteristics and seismic response due to the mathematical modeling of nuclear power plant structures

Calculated variations in dynamic characteristics and seismic response of nuclear power plant structures caused by different modeling assumptions are quantified. Four different mathematical models were created to describe the same structure, the Zion nuclear power station auxiliary/fuel-handling/diesel-generator complex. The modeling idealizations are a detailed finite element model, a detailed finite element model with masses lumped at selected nodes, a detailed finite element model with the constraint of rigid floors, and an equivalent beam model. Dynamic characteristics and response quantities are determined for the models and compared. Results indicate that large variations in dynamic characteristics and response can be introduced by modeling assumptions when a need exists to reduce the number of dynamic degrees of freedom.     

Engineering characteristics of earthquake ground motions

This paper describes those engineering characteristics of earthquake ground motions pertinent to the development of vibratory motion criteria at nuclear plant sites. It includes a discussion and evaluation of current techniques used to characterize earthquake events and strong motion records, and the geologic factors that influence the ground shaking at a site. In addition, the paper provides an assessment of the data base on which the engineer must draw when formulating criteria; this data base includes the current library of strong motion measurements, artificial earthquake records, empirical scaling curves derived from strong motion records, and soils and geologic data presently available at accelerograph stations.     

High-temperature heat pipes for power modules of space nuclear power systems

The results of an experimental analysis of the technology for producing high-temperature heat pipes and choosing their structure so as to ensure a long service life and high performance characteristics required for the power modules of space nuclear power systems with an out-of-core energy conversion system are examined. It is estimated that the operation of molybdenum-lithium heat pipes, fabricated using the technology developed, for the power modules of such nuclear power systems will be stable for >10⁵ h. 2 figures, 1 table, 13 references. State Enterprise Krasnaya Zvezda. Translated from Atomnaya énergiya, Vol. 89, No. 1, pp. 82–86, July, 2000.     

Regenerative cesium-vapor-supply systems for thermal-emission nuclear power plants

Scientific-Industrial Organization Red Star. Translated from Atomnaya Énergiya, Vol. 71, No. 6, pp. 573–575, December, 1991.     

Space nuclear power systems with turbomachine energy conversion

The expansion of space exploration requires the development of sufficiently powerful and reliable power facilities which can operate for a long time. Such facilities could be nuclear power systems and nuclear-powered propulsion systems with turbomachine energy conversion. The development of such systems at the present time is based on the results of work performed as part of the nuclear rocket motor program. The data presented in this article attest to the fact that our country plays a leading role in the construction of such of reactors. To maintain our leading position in space nuclear technologies, it is important to use and further develop the existing unique engineering and technological bases. __________ Translated from Atomnaya énergiya,Vol. 103, No. 1, pp. 48–50, July, 2007.     

New-generation space thermionic nuclear power systems with out-of-core electricity generating systems

The basic problems of the development of long service life thermionic nuclear power systems for space applications for supplying power to transport power modules, intended for placing spacecraft in a geostationary orbit using electrorocket motors and for providing prolonged operation of onboard systems for up to 10–15 years, are examined. Concepts for power systems with multi- and single-element thermionic low-temperature energy-conversion systems, which are placed outside the reactor core and in which heat is delivered to the emitters using molybdenum-lithium heat pipes at 1600–1670 K, are discussed as an example. Computational results are presented for the electro- and thermophysical characteristics of electricity generating systems and power systems with different variants of the design-technological solutions, including the possibility of increasing the service life by reserving a part of the thermionic electrical power. The mass/size characteristics of the power systems with basic variants of the systems are obtained and recommendations based on research and development work are made, 8 figures, 8 references. Translated from Atomnaya énergiya, Vol. 89, No. 1, pp. 22–34, July, 2000.     

核电厂事故情况下气载放射性物质所致地面照射剂量的评价

核电厂事故情况下,气载放射性物质沉积导致的地面照射剂量是场外公众辐射剂量的重要组成部分。本文选取~(90)Sr、~(137)Cs和~(239)Pu等核素,结合其物理去除作用以及再悬浮过程,分析了核电厂事故后地面照射中沉积外照射和再悬浮吸入内照射所致的公众辐射剂量随时间的变化规律。     

Economic benefits of advanced materials in nuclear power systems

A key obstacle to the commercial deployment of advanced fast reactors is the capital cost. There is a perception of higher capital cost for fast reactor systems than advanced light water reactors. However, cost estimates come with a large uncertainty since far fewer fast reactors have been built than light water reactor facilities. Furthermore, the large variability of industrial cost estimates complicates accurate comparisons. Reductions in capital cost can result from design simplifications, new technologies that allow reduced capital costs, and simulation techniques that help optimize system design. It is plausible that improved materials will provide opportunities for both simplified design and reduced capital cost. Advanced materials may also allow improved safety and longer component lifetimes. This work examines the potential impact of advanced materials on the capital investment cost of fast nuclear reactors.     

Prospects for the development of propulsion nuclear power systems

Questions concerning the development of propulsion nuclear power systems are examined. The priorities for promising systems for the naval and civilian fleets are determined-reliability and survivability, secretiveness, safety, technical-economic indicators, ecology. Each group of requirements is analyzed in detail. Special attention is focused on the direction of development of reactor cores for nuclear-powered propulsion systems. __________ Translated from Atomnaya énergiya, Vol. 103, No. 4, pp. 211–215, October, 2007.     

Methodology to evaluate the effectiveness of fire protection systems in nuclear power plants

A methodology for the evaluation of a fire protection system in a nuclear power plant is described. A system of Monte Carlo simulation modules has been developed, divided into the four phases of a fire scenario: ignition, detection, suppression and propagation. An interactive graphics computer program, FIRES, has been written to support these models. The system has been applied in a test case analysis of several zones of an operating plant. The models appear capable of providing interpretable and useful results.