Investigating Low Temperature Properties of Rubber Seals - 13020
- BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12203 Berlin (Germany)
To achieve the required tightness levels of containers for low and intermediate level radioactive wastes rubbers are widely applied as main sealing materials. The save encapsulation of the radioactive container contents has to be guaranteed according to legislation and appropriate guidelines for long storage periods as well as down to temperatures of -40 deg. C during transportation. Therefore the understanding of failure mechanisms that lead to leakage at low temperatures is of high importance. It is known that the material properties of rubbers are strongly influenced by temperature. At low temperatures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cooling the material changes from rubber-like entropy-elastic to stiff energy-elastic behaviour, that allows nearly no strain or retraction. Therefore, rubbers are normally used above their glass transition but the minimum working temperature limit is not defined precisely, what can cause problems during application. The temperature range where full functionality is possible is strongly dependent on the application conditions and the material. For this investigation mainly ethylene propylene diene (EPDM) and fluorocarbon rubbers (FKM) were selected as they are often used for radioactive waste containers. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) are typically used for the determination of the temperature range of the glass transition process. The standardized compression set measurement according to ISO 815 is common for investigation of rubber sealing materials as the test simulates the seal behaviour after release. To reduce the test time of the standard tests a faster technique giving the same information was developed. Additionally, the breakdown temperature of the sealing function of complete O-ring seals is measured in a component test setup to compare it with the results of the other tests. The experimental setup is capable of measuring the leakage rate at low temperatures by the pressure rise method. A model was developed that allows calculating the minimum working temperature limit of a seal by combining the results of the applied methods. (authors)
- Research Organization:
- WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
- OSTI ID:
- 22224829
- Report Number(s):
- INIS-US-13-WM-13020; TRN: US14V0262045784
- Resource Relation:
- Conference: WM2013: Waste Management Conference: International collaboration and continuous improvement, Phoenix, AZ (United States), 24-28 Feb 2013; Other Information: Country of input: France; 17 refs.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Aging of elastomeric seals for storage casks - 15080
Miscibility Evaluation Of The Next Generation Solvent With Polymers Currently Used At DWPF, MCU, And Saltstone
Related Subjects
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
CALORIMETRY
COMPARATIVE EVALUATIONS
COMPRESSION
COOLING
ELASTICITY
ENCAPSULATION
ENTROPY
ETHYLENE PROPYLENE DIENE POLYMERS
FAILURES
GASKETS
GLASS
INTERMEDIATE-LEVEL RADIOACTIVE WASTES
LEGISLATION
MATERIALS TESTING
RECOMMENDATIONS
RUBBERS
SEALING MATERIALS
TEMPERATURE RANGE 0065-0273 K