Long-Term Investigations of Metal Seals for Storage Casks of Radioactive Materials

Abstract

The Bundesanstalt für Materialforschung und –prüfung (BAM) is a federal institute for materials research and testing in Germany and has been involved in the qualification and safety evaluation procedures of metal seals from the early beginning of the interim storage licensing procedures for radioactive materials, stored in dual purpose casks. Regarding this subject, BAM investigates the long-term behavior of metal seals under the influence of temperature using experimental data and analytical approaches. The development of numerical models is in progress as well. Systematic experimental investigations performed by BAM indicate a continuous decrease of the remaining seal force and the usable resilience considering the leak tightness. Hence, there is a fundamental interest of describing time and temperature dependency to gain predictable values for the long-term behavior and to achieve reliable results with help of short-term tests. The paper gives an overview about the sealing principle, test program and test results of metal seals of the type HELICOFLEX® HN200. The aging effect, respectively the long-term behavior in dependency of time and temperature, are introduced for two different outer liner materials, aluminum and silver.

Experimental research on the friction and leakage of the metal rubber seal for reciprocating motion

“…[5][6][7] Elastic metal seals, such as metal O-ring, C-ring, and W-ring, are developed to replace the elastomer rubber seals in extreme environments. [8][9][10][11] Researchers are using innovative designs to improve the performance of metal seals, [12][13][14][15][16] and advanced materials are used to manufacture seals for extreme environments. 17,18 The combinations of polytetrafluoroethylene (PTFE) with other materials such as glass fibers, stainless steel, graphite, and bronze are used to develop reciprocating seals.…”

“…Researchers are using innovative designs to improve the performance of metal seals, 12–16 and advanced materials are used to manufacture seals for extreme environments. 17,18 The combinations of polytetrafluoroethylene (PTFE) with other materials such as glass fibers, stainless steel, graphite, and bronze are used to develop reciprocating seals.…”