Development of high-performance block fuel elements for high temperature reactors. Annual report 1972

Automatic translation: Summary: In the development of manufacturing and testing procedures of the pressed ingot elements were in the reporting period achieved the following results: - Graphite matrix The thermogravimetric investigation of the phenolic resins used as binders with regard to their coking behavior showed clear Differences between nominally equal novolak resin shipments and delayed pyrolysis and increased coke yield Addition of hexamethylenetetramine as a hardener. A systematic one Investigation of die-pressed and quasi-isostatically pressed matrix graphites of the A3 type revealed the influence of pressing pressure, binder content and proportion of natural graphite/electrographite in the filler Coking behavior, matrix density and other properties. To avoid cracks in the structure of the pressed block fuel elements due to different coking shrinkage between the fueled and fuel-free zones was a thermal pre-treatment of the fuel-free Zone used isogranules introduced.