Advanced thermal reactor

FIG. 20.1. Schematic drawing of the Japanese Advanced Thermal Reactor (ATR). 

Finally, we reflect the truism that reactors are not built from theory and reports alone, but are built of material things. We can give an additional welcome to the review of ceramic fuels for advanced thermal reactors by Naito and Kamegashira in that it comes from Japan and extends the international scope of the series. 

There is no unique yardstick to measure competitiveness on a worldwide scale, and nfuel supply conditicxis from country to country. On the basis Aat, in the next century, nuclear energy should provide an important contribution to electric power gen ation it is neccessaey for fast reactOTS to compete with advanced thermal reactors, notably the pressurised water-cooled reactors (PWRs). 

The Plutonium Fuel Fabrication Facility (PFFF), which started operation in 1972, has two fuel fabrication lines for Advanced Thermal Reactor (ATR) (10 ton MOX/year) and FBR (1 ton MOX/year). It has supplied the fuel necessary for the operation of ATR Fugen and FBR Joyo. 

The advanced thermal reactor ATR now under development in Japan is highly heterogeneous in core structure a cluster-type fuel is contained in a pressure tube with coolant, which is separated from 0,0 moderator by a calandria tube, hi such a system, neutron behavior is complicated and then very sensitive to the slight change of structure or material of the core. Therefore, a large amount of experimental data on both microscopic and macroscopic point of view must be accumulated especially for the lattices close to that of the ATR. Then, accuracies of calculatlonal codes which are used for the core design should be confirmed by using those data in reference to the lattices of the ATR. 

Figure VIII-1 shows a simplified schematic diagram of the nuclear steam supply system with the Package-Reactor. The concept resembles a calandria-type pressurized heavy water reactor (e.g., the FUGEN advanced thermal reactor (ATR) or CANDU reactors) since all these employ pressure tubes. But the Package-Reactor is somewhat different from the ATR or the CANDU. The Package-Reactor employs natural circulation with two-phase flow for core cooling and has no recirculation pumps. The height of the pressure tubes of the cassettes is required to be as low as possible to attain a compact unit. Two-phase flow with high void fractions similar to BWRs is adopted to attain natural circulation with a cassette height of 6 m and a fuel rod length of 3.65 m.

SINHA, R.K., AND KAKODKAR, A., Challenges of advanced thermal reactor technology for the 21st Seminar on nuclear power in twenty first century, Challenges and Opportunities (Mumbai, 1999), p 80-90. 

The origins of the SGHWR system can be traced back to the middle of 1957 when the Initial design study of the advanced gas cooled reactor (AGR) was reviewed within the UKAEA. It was decided that, while all promised well, It would only be prudent to have some alternative advanced thermal reactor system under study. Accordingly, the features of a power reactor were broken down Into five main headings - fuel, cladding, coolant, moderator and form of construction. The solutions selected for the AGR were considered and possible alternatives put down which could be evaluated for this, so far, unidentified new system. 

The National Archives (TNA) Public Record Office (PRO) AB 65/422. Advanced Thermal Reactors National Policy etc. BE Eltham. British Nuclear Power Development. ... 

This reaction offers the advantage of a superior neutron yield of in a thermal reactor system. The abiHty to breed fissile from naturally occurring Th allows the world s thorium reserves to be added to its uranium reserves as a potential source of fission power. However, the Th/ U cycle is unlikely to be developed in the 1990s owing both to the more advanced state of the / Pu cycle and to the avadabiHty of uranium. Thorium is also used in the production of the cx-emitting radiotherapeutic agent, Bi, via the production of Th and subsequent decay through Ac (20). 

ACR [Advanced Cracking Reactor] A thermal petroleum cracking process, the heat being provided by partial combustion of the feed at 2,000°C. Developed by Chiyoda Chemical Engineering Construction Company, Kureha Chemical Industry Company, and Union Carbide Corp. in the 1970s. A demonstration plant was operated in Seadrift, TX, from 1979 to 1981. 

MeV H, and 0.8 MeV He3 formed by the D-D reactions in advanced fuel reactors. The energy spectrum of the central plasma can be expected to be Maxwellian at the Tokamak operating temperature ( 10 keV). There is little or no information on the interaction between blistering and externally induced stress. Thermal and mechanically induced stress will influence diffusion and this will have a direct effect on blistering. 

Advances in reactor design, such as the introduction of fluidised bed reactors in which a catalyst is on-stream for only a few seconds before it is stripped of hydrocarbons, removed, regenerated in air at 700 °C and recirculated, have long been of major importance in this reaction." These chemical engineering requirements place strenuous requirements on the thermal stabihty of catalysts used in this process, and rule out the use of materials such as mesoporous MCM-41-type materials or large-pore aluminophosphates such as VPI-5. 

Advanced Gas Cooled Reactor Thermal Reactor-Graphite Moderated... 

R.D. Lonsdale, "An algorithm for solving thermal-hydraulic equations in complex geometries The ASTEC code", in Proceedings of International Topical Meeting on Advances in Reactor Physics, Mathematics and Computation, pp. 1653-1664, Paris, France, 27-30 April, 1987. 

In 1993, calculations with FLOW3D were also started to be included in the validation procedure. Recent work performed for a benchmark exercise, organised by the lAHR Working Group on Advanced Nuclear Reactors Thermal Hydraulics, concerns the numerical simulation of vertical buoyant jets. 

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