HTGR Knowledge Base

Conference Article: Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

Lafitte, R.; Marchand, J.D. (Bonnard et Gardel, Ingenieurs-Conseil, Lausanne (Switzerland))

Abstract

The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed.

view the full text of this article (21 pages, format: PDF, size= 995kB)

key words: closures; direct cycle cooling systems; htgr type reactors; liners; pressure dependence; prestressed concrete; reactor licensing; reactor safety; reactor vessels; specifications; temperature dependence; thermal expansion; containers; cooling systems; expansion; gas cooled reactors; graphite moderated reactors; licensing; reactor components; reactor cooling systems; reactors; safety
Reference:
International Atomic Energy Agency, Vienna (Austria). International Working Group on Gas-Cooled Reactors. Specialists meeting on gas-cooled reactor safety and licensing aspects, Lausanne, Switzerland, 1-3 September 1980. Summary report. Jan 1981
International Atomic Energy Agency, Vienna (Austria). International Working Group on High-Temperature Reactors.
IWGGCR--1, pp:163-183