Experimental fast reactors

Mixed oxide (MOX) fuel, 21.0-wt% Pu in 18.0-wt% enriched uranium, was irradiated from the 16 to 35 cycle at the 3" row in the experimental fast reactor JOYO. Tire effective full power days were 1019.33, and the peak bumup was 143.8 GWd/t. Atotal of 1560 days have passed from the reactor shut down to analysis. 

In Japan, fast reactor development program symbolises national nuclear fuel recycling program, as it is stated in the national long-term plan [2.3]. The experimental fast reactor Joyo has shown excellent performance for more than 20 years. The prototype reactor Monju (280 MW(e)) was stopped temporarily due to the leak in the non-radioactive secondary circuit in 1995. The design of demonstration fast reactor (DFBR-600 MW(e)) is in progress [2.4, 2.5]. 

It should be noted that in other South and East Asia countries with few indigenous fossil fuel and little uranium ore reserves there is the same situation concerning effective nuclear fuel breeding by LMFR. Republic of Korea s LMFR program consists of development, design and construction of a prototype reactor of 150-350 MW(e) power. The first fully-proven reactor is planned to be in operation by 2025. In China, experimental fast reactor CEFR-25 is planned to become critical in 2005. 

OPERATIONAL EXPERIENCE AND UPGRADING PROGRAM OF THE EXPERIMENTAL FAST REACTOR JOYO... 

Twenty years of sueeessful operations at the experimental fast reactor JOYO provide a wealth of experience eovering eore management, chemical analysis of sodium and cover gas for impurity control, natural convection tests, upgrade of fuel failure detection system, corrosion product measurement, development of operation and maintenance support system, and replacement of major components in the cooUng systems. Some of the data obtained is stored in a database to preserve the related knowledge. This experience and accumulated data will be useful for the design of future fast reactors. 

The experimental fast reactor JOYO at the Japan Nuclear Cycle Development Institute s Oarai Engineering Center attained initial criticality in April 1977 and was the first liquid metal cooled fast reactor in Japan. From 1983 to 2000, JOYO operated with the MK-II core as an irradiation test bed to develop the fuels and materials for future Japanese fast reactors. Thirty-five duty cycle operations and thirteen special tests with the MK-II core were completed by June 2000 without any fuel pin failures or serious plant trouble. The reactor is currently being upgraded to the MK-III core. This paper provides a review of the operational experiences obtained through the JOYO s operation. 

SAWADA, M., et al.. Experiment and Analysis on Natural Convection Characteristics in the Experimental Fast Reactor JOYO, Nuclear Engineering and Design, 120 (1990) pp. 341-347. 

AOYAMA, T., et al., The Operational Experience of the Experimental Fast Reactor JOYO, Proc. 3" Asian Symposium on Research Reactor, Ibaraki, Japan, 11-14 November 1991, JAERI (1991) pp. 75-82. 

MAEDA, Y, et al.. Current Status and Upgrading Program of the Experimental Fast Reactor JOYO, Proc. World Nuclear Congress and Expo (ENC 98) Trans., Nice, France, 25-28 October 1998, Vol. IV, Workshops, (1998) pp. 21-30. 

YOSHIDA, A., et al.. Upgrading Program of the Experimental Fast Reactor Joyo, Book of Abstracts Int. Conf on Nuclear Engineering (ICONE-9), Nice, France, 8-12 April 2001, Vol. 2, ASME (2001) p. 492. 

Brazil. Fast reactor activities in Brazil are mostly research-oriented and have the objective of establishing a consistent knowledge base which can serve as a support for a future transition to the activities more directly related to design, construction and operation of an experimental fast reactor. Due to the present economic difficulties and uncertainties, the programme is modest, with a potential... 

Japan. During the period from April 1996 to March 1997, the 30th duty cycle operation has been started on the experimental fast reactor Joyo. The cause investigation on sodium leak incident has been completed and safety examination is being performed on the prototype fast reactor Monju. 

L. Guimaraes et. alii, Conceptual Design of an Intermediate Heat Exchanger for a 60 MWt Experimental Fast Reactor , Proceedings of the 9th Power Plant Dynamics, Control Testing Symposium, May 24-26, Knoxville, Tennessee, USA (1995). 

Finally the R and D in support of the operation of PHENIX and SUPERPHENIX, in support of the "knowledge-acquisition" programme, and CAPRA and EFR programmes is presented, as well as the present status of the stage 2 dismantling of the RAPSODIE experimental fast reactor. 

STAGE 2 DISMANTLING OF THE RAPSODIE EXPERIMENTAL FAST REACTOR... 

This report describes the development and activities on fast reactor in Japan for the period of April 1996 - March 1997. During this period, the 30th duty cycle operation has been started in the Experimental Fast Reactor "Joyo". The cause investigation on the sodium leak incident has completed and the safety examination are being performed in the Prototype Fast Breeder Reactor "Monju". The three years design study since FY1994 on the plant optimization of the Demonstration FBR has been completed by the Japan Atomic Power Company (JAPC). 

Figure 2.1 Operating History of Experimental Fast Reactor JOYO...

Koch, L. J., Experimental Breeder Reactor-II (EBR-II) An Integrated Experimental Fast Reactor Power Station, Argonne National Laboratory, Argonne, Illinois. 

China The completion of the construction and initial criticality of the 65 MWth (25 MWe) Chinese Experimental Fast reactor (CEFR-25) in the year 2000 have been approved by the Chinese Government, as one of the targets of advanced reactor development in China. Based... 

Delayed almost 20 months, it is still waiting to win the approval of the State Planning Commission for the Chinese Experimental Fast Reactor (CEFR) project. Some meetings to demonstrate the necessity to execute now the program of the CEFR design and construction have been conducted in China. Fortunately the possitive conclusion has been obtained, which would be an important promotion to win the approval. 

Recently some meetings for proving the necessity to design and construct now the experimental fast reactor have been held in China. The conclusion drawn from those meetings is positive and conducive to the approval for the CEFR by the State Planning Commission. 

Since 1992 we have been working in what we call Feasibility Phase, which has, among others, the objective of submitting to the Brazilian authorities, a report composed of six volumes 1) Global View 2) Reference Design (primary circuit) for an Experimental Fast Reactor, 3) Survey of Brazilian Research Institutions, 4) Survey of Brazilian Industrial Park, 5) Survey of Brazilian Universities and, 6) Preliminaiy Planning for Next Phases These volumes are planned to be ready by the end of 1995 and will be useful for identifying possible partnerships... 

A Reference Design for the primary circuit of a 60 MWt experimental fast reactor is completed. Some parameters and characteristics have been selected mostly based on the Integral Fast Reactor (IFR) concept. Fuel pin dimensions and other data were used for calculations which lead to a general core configuration. Some calculations were also independently performed at lEN, and the differences in methodologies are being evaluated. Table 1 shows the main primary circuit parameters. 

In Japan, the self-actuated shutdown system (SASS) has been developed as a passive safety feature (Takamatsu et al. 2007 Nakanishi et al. 2008) using the phenomena that electromagnetic force of the control rod latch will be lost when alloy temperature exceeds the Curie point. Several kinds of in-sodium transient testing have been carried out together with in-pile experiments in the experimental fast reactor Joyo. This mechanism is effective to the robust restraint core, which is designed for seisnuc requirements. 

In Japan, the experimental fast reactor "Joyo started operation in 1975 following the criticality test equipment called fast critical assembly (FCA). Joyo has run irradiation tests for domestic fuel material and increased the core thermal output as well. At the beginning of operation, the thermal output of the core was 100 MW. Currently, it employs a third-generation core, called the MK-in, with 140 MW thermal output. 

As early as 1951, first nuclear electricity was produced at the experimental fast reactor EBR-I, but both this reactor and the E. Fermi Plant suffered accidents in the 1960s, and in the 1980s the USA stopped the construction of fast reactors and the work on a closed fuel cycle for nonproliferation reasons. 

It should be emphasized, that although designs and parameters of the early experimental fast reactors showed a wide variability, those of the commercial-sized plants are rather similar. Even with the initiation of a wholly new line of development, such as Pb and Pb-Bi cooled reactor designs, it is interesting to observe that their parameters are close to those of traditional reactors being advocated elsewhere. It is a further proof that the laws of physics and the principles of good engineering inevitably lead to similar optimal solution. 

CEFR (China) China Experimental Fast Reactor... 

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