EPRI Reports on Probabilistic Risk Assessment Models

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What is the main focus of EPRI Report 1013492?

Treatment of parameter and model uncertainty

Guidance on risk-informed decision making

Practical guidance on the use of risk assessment

Probabilistic risk assessment models (correct)

Which EPRI report provides practical guidance on the use of probabilistic risk assessment?

EPRI Report 1013492

EPRI Report 1016737

EPRI Report 1026511 (correct)

None of the above

Where can you find NUREG-1855 for guidance on uncertainties in risk-informed decision making?

EPRI website

NRC website (correct)

External websites

None of the above

What is the primary objective of the course mentioned in Slide 2A?

To give a high-level understanding of NUREG-1855 and EPRI reports Signup and view all the answers

Which report focuses on the treatment of parameter and model uncertainty in probabilistic risk assessments?

EPRI Report 1013492 Signup and view all the answers

What distinguishes NUREG-1855 from the EPRI reports?

It offers treatment of uncertainties in risk-informed decision making Signup and view all the answers

What type of risk-informed activities are outside the scope of the report?

Non-risk-informed activities Signup and view all the answers

In what scenario does the detailed approach in NUREG-1855 NOT apply?

Evaluation of risk at the time of an event Signup and view all the answers

Which regulatory guidance indicates a possibility for a NOED under certain circumstances?

10 CFR 50.69 Signup and view all the answers

When is the detailed approach in NUREG-1855 generically applicable?

For all risk-informed activities Signup and view all the answers

Which activity would result in a 'no' answer for the criterion under discussion?

Component risk ranking Signup and view all the answers

What triggers the exclusion of non-risk-informed activities from the report's scope?

'Type of risk-informed activity evaluation' Signup and view all the answers

What is the main reason for assigning an uncertainty distribution to the frequency estimate of very large earthquakes?

To account for the lack of data due to the rare occurrence of very large earthquakes Signup and view all the answers

What is an example of a model uncertainty, according to EPRI 1026511?

The different models used to predict core melt progression Signup and view all the answers

Which of the following is NOT a reason for model uncertainties?

Differences in data collection methods Signup and view all the answers

What is the main cause of model uncertainties, according to the text?

Limited understanding of the phenomenon being modeled Signup and view all the answers

What is a fundamental difference between the MELCOR and MAAP models?

All of the above Signup and view all the answers

What is the main reason for limited understanding of the physics involved in some phenomena?

Limited understanding of the phenomenon being modeled Signup and view all the answers

What should be considered when combining the results from different hazards and plant operational states?

The exact level of detail used in each analysis Signup and view all the answers

Which hazards may have a significantly higher level of conservative bias in their PRA models?

All of the above Signup and view all the answers

How does the level of modeling vary within a hazard such as an internal event, at-power PRA?

It varies based on the level of detail used in different evaluations Signup and view all the answers

What can lead to a conservative time estimate for providing a means for alternate room cooling?

Evaluating room cooling and equipment failure thresholds conservatively Signup and view all the answers

What can be modeled to a level of detail sufficient to prove they are not important to the results in the analysis of other hazards?

Low-risk sequences Signup and view all the answers

What is considered a more conservative evaluation in defining the onset of core damage for a boiling water reactor?

Defining the onset of core damage for a boiling water reactor occurring at core uncovery Signup and view all the answers

What is the main focus of the staff's assessment in Regime 2?

Ensuring the application PRA risk metric results do not challenge the acceptance guidelines Signup and view all the answers

How does the staff approach peer review findings in Regime 2?

With a higher degree of scrutiny than Regime 1 Signup and view all the answers

What does the staff look for in an assessment in Regime 2?

An assessment that shows the state-of-knowledge correlation does not affect the risk metric results of the PRA Signup and view all the answers

What is the staff's approach to evaluating the application in Regime 2?

Ensuring the proposed performance monitoring is appropriate and adequate for the application Signup and view all the answers

What is the staff's approach to detecting degraded performance in Regime 2?

Ensuring degraded performance can be detected in a timely fashion Signup and view all the answers

What is the staff's approach to monitoring the validity of the assumptions made in the application PRA in Regime 2?

Ensuring the validity of the assumptions made in the application PRA will be appropriately monitored via the implementation of specific measures and criteria Signup and view all the answers