Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials
In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5419196
- Report Number(s):
- SAND-91-0822; ON: DE91016060
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
ELECTRIC CABLES
AGING
ELECTRICAL INSULATION
NUCLEAR POWER PLANTS
ETHYLENE
EXPERIMENTAL DATA
PROPYLENE
RADIATION DOSES
RADIATION EFFECTS
STANDARDS
THERMAL DEGRADATION
ALKENES
CABLES
CONDUCTOR DEVICES
DATA
DOSES
ELECTRICAL EQUIPMENT
EQUIPMENT
HYDROCARBONS
INFORMATION
NUCLEAR FACILITIES
NUMERICAL DATA
ORGANIC COMPOUNDS
POWER PLANTS
THERMAL POWER PLANTS
220200* - Nuclear Reactor Technology- Components & Accessories
220900 - Nuclear Reactor Technology- Reactor Safety
360106 - Metals & Alloys- Radiation Effects