Integral reactor experiments, design

Unlike the known designs of integral reactors being under development in many countries where either steam or steam-gas pressurizer is applied, the integral reactors developed by RDIPE use a gas pressurizer. Selection of such solution was motivated by several reasons, firstly, the intention to simplify and, consequently, enhance safety of the primary circuit pressure compensation system by elimination of heaters and sprinkler system. Secondly, this approach is based on our 40-year experience in designing and operation of ship-mounted NSSS with gas pressurizers in the primary circuit. It should be pointed out, however, that in the previous cases the pressurizes wee placed outside the reactor vessel. 

The scope of this subject is here limited to a comparison of the values of the ckling B and the excess infinite multiplication factor kx,- , which are variously derived from critical and subcritical experiments. These two Integral parameters can be measured more or less directly. They are about equally Important to the reactor physics design of low-enrichment graphite reactors, since the real question is the size of the assembly which gives a sufficient margin of excess effective k to allow the reactor to reach the planned operating conditions. 

The safety design concept of a power unit with the VBER-150 was selected via the application of a system approach integrating the experience and recent achievements in safety of nuclear power plants and shipboard reactors it meets the requirements for plant location near populated areas and incorporates an enhanced resistance to possible acts of sabotage. 

The reactor plant with RIT reactor of 150 MW thermal is being developed by OKBM on the basis of the design experience of such integral reactors as ABV, AST-500, ATETS-80, ATETS-200, VPBER-600 [15-17, 20-23]. 

The 2" phase (2006-2009) R D activities undertake a SI process optimization and the performance tests of various chemical reactors selected for the SI cycle. The 2" phase research covers a dynamic code development for the SI process, a construction of a lab. scale( l 000 NL/h) SI process, and integrated operations of the process at prototypical pressures. On the other hand, conceptual and basic designs of a pilot scale( 100 Nm /li) SI process and its equipment will also be carried out according to the optimized process established from the theoretical evaluation using a commercial-base computer code and the experiences of the lab. scale construction and operations. Preliminary performance tests of the equipment, mechanical devices, and accessories for the pilot scale SI process should be carried out to obtain the design basis. Not only the several catalysts based on non-noble metals required for section II in the SI cycle but also a membrane for the separation of the hydrogen required for section III will be developed during the 2" phase research period. 

An effective and powerful gas purification system could be designed by integrating additional components for hydrogen and tritium gettering from the coolant gas. Hydride formers such as Ti, Zr, and Ce or a cerium mixed metal were deemed appropriate. A respective experiment was planned at the AVR reactor to test a Cer mixed metal gas purification system with a throughput of 8 Nm /h [8]. 

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