An Assessment of Uncertainty in Remaining Life Estimation for Nuclear Structural Materials

Conference · Sat Dec 01 04:00:00 EST 2012

OSTI ID:1111245

Ramuhalli, Pradeep; Griffin, Jeffrey W.; Fricke, Jacob M.; Bond, Leonard J.

In recent years, several operating US light-water nuclear power reactors (LWRs) have moved to extended-life operations (from 40 years to 60 years), and there is interest in the feasibility of extending plant life to 80 years. Operating experience suggests that material degradation of structural components in LWRs (such as the reactor pressure vessel) is expected to be the limiting factor for safe operation during extended life. Therefore, a need exists for assessing the condition of LWR structural components and determining its remaining useful life (RUL). The ability to estimate RUL of degraded structural components provides a basis for determining safety margins (i.e., whether safe operation over some pre-determined time horizon is possible), and scheduling degradation management activities (such as potentially modifying operating conditions to limit further degradation growth). A key issue in RUL estimation is calculation of uncertainty bounds, which are dependent on current material state, as well as past and future stressor levels (such as time-at-temperature, pressure, and irradiation). This paper presents a preliminary empirical investigation into the uncertainty of RUL estimates for nuclear structural materials.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1111245
• Report Number(s): PNNL-SA-86960; 830403000
• Country of Publication: United States
• Language: English

Related Subjects

Bayesian Prognostics
Early Degradation Monitoring
Mechanical Fatigue Management
PHM
Reliability
Remaining Life Calculation
Uncertainity Quantication