Power Plutonium Research Articles

Investigation of UO2 fuel efficiency for ABV small modular reactor

ABSTRACT In recent years, small modular reactors have received considerable attention in various countries due to having some capabilities such as small dimensions. The ABV reactor is a small modular reactor with a power of 45 MWth. For this reactor, various applications such as use as a desalination plant, source of electrical and thermal energy, etc. have been considered. In this reactor, an unconventional metal fuel called silumin with 16.5% enrichment and a cycle length of 3000 days has been used. The main purpose of this research is to investigate the performance of conventional UO2 fuel while maintaining the initial cycle length as the main fuel of ABV reactor. To achieve this purpose, the performance of UO2 fuel with enriches of 8%, 10%, 12%, 14%, and 16% with different percentages of Gd2O3 has been investigated. To perform the calculations, the RELAP5 thermohydraulic code and the PARCS neutronic code have been coupled by using a Parallel Virtual Machine, and the reactor core quantities included: effective multiplication factor, relative power distribution, feedback coefficients, plutonium and uranium isotope concentrations, axial and radial temperature distribution of fuel rod, heat flux and DNBR have been calculated and is within an acceptable range for this design.

ZPPR Benchmarks for Large LMFBR Core Physics from JUPITER Cooperative Program Between United States and Japan

Under the International Reactor Physics Experiment Evaluation Project (IRPhEP) framework, in the cooperative JUPITER program between the United States and Japan, benchmarks are established to study large fast breeder reactor (FBR) core physics utilizing nine Zero Power Plutonium Reactor (ZPPR) critical experimental cores. These benchmarks cover a wide variety of core concepts including homogeneous and heterogeneous configurations, clean and engineering mock-up cores of 600- to 1000-MW(electric)–class sizes, and various core parameters such as criticality, reaction rate, and reactivity. Recently, detailed experimental information from original documents from Argonne National Laboratory has been scrutinized very carefully to establish the benchmark model and to evaluate quantitatively the experimental uncertainty. The benchmarks supply users with heterogeneous cell models and three-dimensional (3-D) core configurations, which are simplified to a degree that preserves the important physical features of the ZPPR cores such as plate heterogeneity, different drawer types, and 3-D core arrangement. Further, the benchmark handbook includes as-built information of the ZPPR cores as a complete set of electronic form; therefore, a user can develop his or her own benchmark model if necessary. The analysis of the benchmark with the deterministic or Monte Carlo method demonstrates its usefulness both for improving analytical methods and for validating nuclear data.

PLUTON: A Three-Group Model for the Radial Distribution of Plutonium, Burnup, and Power Profiles in Highly Irradiated LWR Fuel Rods

A three-group model (PLUTON) is described, which predicts the power density distribution, plutonium buildup, and burnup profiles across the fuel pellet radius as a function of in-pile time and parameters characterizing the type of reactor system with respect to fuel temperature and changes of density during the irradiation period. The PLUTON model is a part of two fuel performance codes (ASFAD and FEMAXI-V), which provide all necessary input for this model, mainly local temperatures and fuel matrix density across the radius. Comparisons between measurements and predictions of the PLUTON model are made on fuels with enrichments in the range 2.9 to 8.25% and with burnup between 21 000 and 64 000 MWd/t. It is shown that the PLUTON predictions are in good agreement with measurements as well as with predictions of the well-known TUBRNP model. The proposed model is flexibly applicable for all types of light water reactor (LWR) fuels, including mixed oxide, and for fuel tested in the Organization for Economic Corporation and Development’s Halden heavy water reactor. The PLUTON three-group model is based on analytical (theoretical) consideration of neutron absorption in a resonant region of the fuel in its apparent form. It makes the model more flexible in comparison with the semi-empirical TUBRNP one-group model and allows the physically based model analysis of commercial LWR-type fuels at high burnup as well as analysis of experimental fuel rods tested in the Halden heavy water reactor, which is one of the main test reactors in the world. The differences in fuel behavior in the Halden reactor in terms of burnup distribution and plutonium buildup can be more clearly understood with the PLUTON model.

Systems-Analysis Assessment of the Effectiveness of Measures for Decreasing the Proliferation Risk of Fissioning Materials

Approaches to nonproliferation analysis from the standpoint of the potential dange of fissioning materials are demonstrated for two problems: the proliferation risk in a long-time global strategy for growth of nuclear fuel cycle and the choice of an efficient strategy for the utilization of weapons and power plutonium in Russia.

Use of Plutonium in Reactor Fuel

Investigations performed to substantiate the strategy of safe development of nuclear power in Russia, taking account of the available resources, the state of the economy, and the transition of the country to a market economy, have shown that plutonium used as reactor fuel makes it possible to obtain a comprehensive solution to fundamental problems, many of which cannot be satisfactorily resolved with a uranium-based open fuel cycle. Thus, it has been established with respect to nuclear safet y that on the basis of physical and technical principles liquid-metal-cooled fast reactors have a greater potential for inherent safety; from the standpoint of nuclear disarmament it is of fundamental importance to decrease the amount of accumulated weapons and power plutonium and correspondingly to decrease the risk of proliferation of this nuclear material at the storage stage; fr om the standpoint of solving ecological problems the concept of radiation-safe storage of nuclear wastes, which can be implemented only by extracting plutonium from the spent fuel, is attractive; and so on. Thus, analysis of the assumptions and directions of development of nuclear power under altered conditions confirms the position that the use of plutonium in reactor fuel is one of the most fundamental aspects of the internal logic of the deve lopment of nuclear power. In the opinion of the authors rejection of plutonium will lead, directly or indirectly, if not to the cu rtailment of nuclear power, then to substantial limitation of its role in large-scale power production in the future. Utilization of Plutonium in VVER-1000. Preliminary investigations and the experience gained in the European countries in working with mixed uranium‐plutonium fuel in light-water reactors attest to the real possibility of using plutonium as VVER-1000 fuel. Computational investigations of the possibility of using power plutonium in VVER-1000 type reactors have been per

Current status of scientific activity in Russia on high level radioactive waste transmutation and use of weapon grade and power plutonium in subcritical systems driven by proton accelerator

Features of neutron fuel cycles with the accelerator-driven system (ADS) as well as fission product and actinide transmutation in the ADS are analyzed in this paper: fuel type, fertile materials, neutron consumption, secondary radioactivity, change in radiotoxicity of actinides. The use of weapon-grade and power plutonium in the ADS is also considered. Information on various design versions of the ADS blanket including study of the sectioned blanket with neutron valves, its performance and R&D programme, including a neutron source driven by the 56.MeV “Istra” proton linac, is given.

Physics Studies of a Heterogeneous Liquid-Metal Fast Breeder Reactor

The first physics measurements for a heterogeneous design of a 1000-MW(thermal) liquid-metal fast breeder reactor were made in the Zero Power Plutonium Reactor (ZPPR) during the last half of 1976. ...

Use of Zero Power Plutonium Reactor Measurements as a Support of Criticality Prediction for the SNR-300

Evaluations of criticality measurements performed in various SNEAK and Zero Power Plutonium Reactor (ZPPR) cores are compared. The best available methods of calculations (including transport theory) are used. The ZPPR results support well the trend indicated by the SNEAK evaluations for clean cores and for cores with followers; for cores with absorbers partially inserted, the agreement is only rough. Evaluations of control rod worth measurements are therefore also compared, using the routine method of calculation for SNR-300 (diffusion theory). The control rod worths are largely underestimated in SNEAK (C/E = 0.89), but only slightly underestimated in the ZPPR (C/E = 0.97). The difference in the nature of core fuel (uranium in SNEAK, plutonium in the ZPPR) could be at the origin of this discrepancy.

Analyses and Measurements of Gamma-Ray Heating in the Demonstration Benchmark Plutonium-Fueled Critical Assembly

Absolute gamma-ray heating was investigated in Assembly 2 of the Zero Power Plutonium Reactor (during operation in support of the Demonstration Reactor Benchmark critical program). Three loading co...

Heterogeneity Effects in ZPPR Assembly 2—A Plutonium-Fueled Demonstration Fast Reactor Study

An extensive series of measurements has been made in the Demonstration Reactor benchmark, the Zero Power Plutonium Reactor (ZPPR) Assembly 2, to provide physics data necessary for LMFBR design. An important objective of the program was to test the applicability of data obtained in the plate-fueled critical to a power reactor design with a more homogeneous composition. Sufficient, fuel inventory was obtained in the form of rods which were used, within sodium-filled calandria, to build large zones in which direct comparisons of parameters could be made with those in the plate zones. A variety of quantities worth of Compared in the two environments. In addition to the direct reactivity worth of rod-for-plate substitution, comparisons are given for small sample and rates,reaction Worths’ neutron spectrum, reaction rate ratios, in-cell reaction rates, reaction rate scans, sodium-void coefficient, and 238U Doppler coefficient. The experiments are Compared With calculations using the ARC system and NDFB/Version-I data. It is found that many parameters of interest can be adequately studied in the plate geometry and that the calculation methods, in genidentified a good representation of the heterogeneity effects. Some areas are identified in which further experimental and analytical study is needed.

The Design and Mechanical Performance Characteristics of the Zero Power Plutonium Reactor

The Zero Power Plutonium Reactor (ZPPR) is a fast experimental reactor that operates at very low power levels and is used to simulate proposed fast power plutonium reactors in the 1000-MW range. The reactor is built on two large tables, one stationary and one movable, with numerous roller bearings on the underside for ease of travel. Half of the reactor is built on each table, and then the tables are brought together before the reactor can go critical. The tables are each designed to support at least 120 tons of fuel and structural material. Load tests were conducted to prove the system and to determine deflections in the foundation and runways. Many safety devices are built into the table drive system, such as an electric feed-rail system that disconnects the power supply to the drive motor if a relay fails, three speeds of table closing to control reactivity-addition rates, and two independent table-separation systems. Fuel control rods are used for reactivity changes; fuel and poison safety rods are used for shutdown control. Core material is loaded into 2 × 2 × 23-in. drawers, and the drawers are slid into matrix tubes stacked 10 feet high on the tables. Matrix tubes and drawers and the tables were aligned to obtain a minimum gap at the interface.

Discussion: “The Design and Mechanical Performance Characteristics of the Zero Power Plutonium Reactor” (McCarthy, P. B., and Lawroski, Harry, 1970, ASME J. Eng. Power, 92, pp. 166–172)

Discussion: “The Design and Mechanical Performance Characteristics of the Zero Power Plutonium Reactor” (McCarthy, P. B., and Lawroski, Harry, 1970, ASME J. Eng. Power, 92, pp. 166–172)