Commercial Power Reactors Research Articles

Fracture Control in the Nuclear Power Industry

AbstractThe majority of the world's commercial power reactors are similar to U.S.-designed pressurized-water (PWR) or boiling-water (BWR) designs in which the nuclear core resides in a large, heavy-walled ferritic steel pressure vessel. Fracture control of these vessels combines the quantitative approach of linear elastic fracture mechanics (LEFM) with qualitative materials testing: lower-bound fracture toughness data and conservative applied stress intensities are used to estimate maximum permissible flaw sizes, and Charpy properties are related to minimum permitted service temperature in the steel containment. The Canadian designed CANDU–PHW reactors employ hundreds of small-diameter zirconium alloy pressure tubes, rather than a single large vessel, as the primary containment for the pressurized coolant. Fracture control philosophy is based on the demonstrated tolerance of pressure tubes to artificial flaws, proven in a large, continuing experimental program. Pressure tubes have been shown to “fail-safe...

Core Motion Monitoring

Experimental methods for detecting types of motion within and surrounding reactor cores were employed, including the dominating influence of noise analysis techniques and the associated theoretical bases underlying these methods. Out of extensive tabulations of demonstrated applications, particular attention was given to specific methods for measuring core barrel motions, in-core instrument vibrations, steam void velocity, fuel motions, and control rod vibrations.Selected features of types of in-vessel motion monitoring programs found in commercial power reactors were noted along with their motivations. Advantages and disadvantages can be cited for specific techniques.

Intense Particle Beams

Substantial progress has been made recently in generation, focusing, and transport of intense electron and light ion beams. The impetus for this work has been to develop a 1 MJ, 1014W particle beam device for inertial confinement ignition experiments and to create a practical technology base for application to future commercial power reactors.

Performance characteristics of the high power density, flux-conserving Tokamak (FCT) reactor

Most of the fusion Experimental Power Reactor (EPR) and commercial power reactor designs have been limited to low-β (ratio of plasma pressure to magnetic field pressure), low power density Tokamak systems. In an effort to redesign a viable, economically attractive power reactor that could meet the electric utilities needs, the flux-conserving Tokamak concept has emerged as a leading contender. In this paper, we examine the operating characteristics of an FCT reactor and show that such a system would be comparable in size to an EPR but produce more than five times the fusion power. It will be seen that the FCT concept could provide the utility industry with compact reactor systems of moderate electrical output (between 500 and 1000 MWe) without requiring large extrapolations in plasma size and technology beyond that of the Tokamak Fusion Test Reactor (TFTR) currently under construction.

Tokamak Fusion Power Reactors

The major parameters and corresponding economic characteristics of a representative class of commercial tokamak fusion power reactors are examined as a function of four major design parameters: plasma ..beta../sub t/, toroidal magnetic field strength, first-wall lifetime, and power output. It is shown that for ..beta../sub t/ equal to or greater than 0.06, the minimum cost of energy is obtained for toroidal field strengths of approximately 8 to 9 T. Tokamak power plants exhibit an economy of scaling with a lower cost of energy for larger power reactors. Representative design parameters, costs, schedule, and technology advances are presented for a sequence of three reactors that could lead to the demonstration of commercial feasibility of this class of tokamak fusion power reactors near the turn of the century.

Review: BNL Tokamak graphite blanket design concepts

The BNL minimum activity graphite blanket designs are reviewed, and three are discussed in the context of an experimental power reactor (EPR) and commercial power reactor. Basically, the three designs employ a 30 cm or thicker graphite screen. Bremsstrahlung energy is deposited on the graphite surface and re-radiated away as thermal radiation. Fast neutrons are slowed down in the graphite, depositing most of their energy, which is then radiated to a secondary blanket with coolant tubes, as in types A and B, or removed by intermittent direct gas cooling (type C). In types A and B, radiation damage to the coolant tubes in the secondary blanket is reduced by one or two orders of magnitude, while in type C, the blanket is only cooled when the reactor is shut down, so that coolant cannot quench the plasma.

Common mode failure analysis

Standard Reliability analysis techniques have demonstrated the capability to evaluate system vulnerability to random component failures. Recently, in the nuclear power industry, interest has been developing in methods to consider systematic, nonrandom, so-called Common-mode failures which are not tractable in quantitative terms using the usual fault tree or reliability block diagram approaches. This paper summarizes the state of the art as reliability engineers seek to extend the techniques to include multiple failures from a common cause (or in a common mode). Qualitative extensions of both the fault tree and the reliability block diagrams have been used to evaluate the adequacy of reactor protection circuitry for commercial power reactors.

Experimental determination of damping in nuclear power plant structures and equipment

A summary of damping values for structures and equipment obtained in several full-scale dynamic tests performed on a research reactor, three experimental power reactor plants, and a commercial power reactor plant is given. The testing techniques used include steady state shakers, dynamite blasting, and snapback. In an appendix, guidelines are presented for required frequency resolution and record length for damping estimation from blast or snapback records. The influence of system non-linearity upon damping interpretations is also discussed.

Atomic Power Safety: A Common Sense Approach

All sources of fuel are needed to supply the increasing power needs of a growing population. Atomic fuel competes economically with fossil fuels under most conditions and eliminates undesirable environmental pollution by stack effluents. Both fossil- and atomic-fueled plants have waste hot water which necessitates controls to prevent changes in the ecology. The 25-year record of health and safety of atomic energy programs in the United States should be comforting to the public. Radiation exposures from commercial power reactors have been a very small fraction of permissible limits, and the Atomic Energy Commission has recently further restricted releases from such reactors so that the average exposure to the public will be only about 1% of that from the natural background.

Preface: Plutonium Utilization in Commercial Power Reactors

"Preface: Plutonium Utilization in Commercial Power Reactors." Nuclear Technology, 15(2), pp. 107–108

A comparison of pellet and vipac nuclear fuels

Cold-press-sinter pellet fuels, under development since 1954, are widely used in commercial thermal power reactors and are generally accepted as being the standard fuel type. This widespread use has resulted in the development of considerable technology related to this fuel type, and the system is reasonably well understood. If proper attention is devoted to design and fabrication, pellet fuel performs satisfactory and meets the performance requirements imposed by present operating conditions. Vibrationally compacted ceramic fuel is considered to be the most promising alternate fuel form. Although of interest since 1959 [1, 2], the effort devoted to the development of vipac fuel has been considerably less than for pellet fuel. Consequently, vipac fuel is not generally accepted for commercial application at the present time. However, the concept is of continuing interest because it possesses several potential advantages over pellet type fuel.

A Solid State Plant Protection System for a Commercial Power Reactor

A Solid State Plant Protection System for a Commercial Power Reactor

Commercial Power Reactors Can Be Economical Source of Plutonium–238

Commercial Power Reactors Can Be Economical Source of Plutonium–238

Authors and Papers

Authors and Papers