Thought Leadership

Advanced Component Failure Simulation Software Holds Promise for Nuclear Industry

Category: News & Events
James Carter • June 10, 2019

At the Canadian Nuclear Society’s May 2019 conference on “Materials, Chemistry and Fitness for Service for Nuclear Systems,” I introduced the audience to advanced simulation software that assesses how, why, where, and when components or systems fail. I described how the Virtual Life Management® (VLM) process enabled by this software, VPS-MICRO®, has successfully supported diagnostics; prognostics; forensic failure analysis; design, operation, and maintenance optimization; life-extension decisions; and other applications.

I’m optimistic that the VLM technology may be useful in certain situations that arise on Modus engagements or otherwise for our clients – for example, informing life extension and retirement decisions and evaluating chronic equipment failure. I’ve presented a summary-level discussion of VLM below.

Current predictive failure analyses rely on real-time trend monitoring of parameters such as temperature or vibration. Historical failure data is also employed, including physical “testing to failure.” For example, consider an auto manufacturer that cycles a door hinge or a spring on a test stand for thousands, maybe millions of times to gain confidence in the part’s reliability.

The VLM simulation accomplishes the same testing in virtual space at significantly lower cost, in shorter time, and with higher confidence. For example, the U.S. Food and Drug Administration (FDA) and Federal Aviation Administration (FAA) have accepted VLM analysis for 90% reliability at 90% confidence (90/90). That level can be raised to 95/95 or even 99/99, as VLM permits many more data points at lower cost and shorter time.

In the component and system design stage, Finite Element Analysis (FEA) is used to identify points of high loading in a component and inform design considerations for failure mitigation. However, not all product failures occur at the highest stress areas, nor do they originate at the global component level where FEA is applied. Failure is a localized process that occurs deep within the material microstructure itself.

Moreover, FEA considers the material being tested to be a homogeneous microstructure. It is not. Cracks initiate and propagate within the granular structure of a component and lead to failure that may not be manifested by FEA alone. VLM employs stochastic methods to address the microstructure variability and fracture mechanics to create a more accurate representation of component behavior under cyclic loading. External factors such as temperature, pressure, friction, and lubrication are incorporated into the model to more accurately create a virtual life simulation.

Specific applications of VLM have included:

  • Condition assessment of components/systems in service
  • Plant life extension factors assessment
  • Operation and maintenance cost and performance optimization
  • Metal/alloy/composite selection for product design
  • Reduction of excessive and costly factors of safety and redundancies
  • New product time-to-market acceleration
  • Warranty claims and associated financial accruals reduction
  • Credible forensic failure analysis

VLM technology has been successfully applied in numerous industries. including airline, medical device, military, oil and gas, manufacturing, transportation, and others. VPS-MICRO and the VLM process can now be used on conventional components and systems at any steam plant, including nuclear. However, the nuclear or steam power generation industries have not yet employed VLM – my presentation at the CNS conference was the first introduction of the technology to the nuclear industry.

Interest was strong, including from regulators. For the technology to be applied to nuclear components, software verification, validation and acceptance by regulators such as CNSC and NRC would be necessary but not likely difficult, considering VPS-MICRO has been accepted by FDA and FAA.