Risk-informed and performance-based

U.S. Nuclear Regulatory Commission (1998), Risk-Informed and Performance-Based Regulation, Washington, D.C. 

In the context of the efficient implementation of 10 Cm Part 52, NTDG calls for a new regulatory framework that is fully risk-informed and performance-based and go[es] beyond the ongoing efforts to risk-inform 10 CFR Part 50 for current plants to improve the protection of public health and safety, ehminate regulatory burdens that do not contribute to safety, and increase the confidence of prospective applicants in the regulatory environment for new plants and encourage business decisions to proceed with new nuclear projects (DOE, 2001). 

Duty-holder responsibility Participation and commitment Information availability Nonprescriptive and performance-based Risk management system Management systems Living document Auditor/assessor responsibility. 

Step f considers all of the background information discussed in Section 2.f. If the information requirement is based on a regulatory concern or a special purpose need, then Steps 2 through 5 are bypassed and a QRA should be performed. If the information is needed for decision making, you must determine whether the significance of the decision warrants the expense of a QRA. If not, you may be able to use less resource-intensive qualitative approaches to satisfy your information requirements. Table 8 contains examples of typical conclusions reached from qualitative risk analysis results. 

The objective of this chapter is to provide an understanding of how and why a fire risk assessment is performed. Completing a fire risk assessment provides management the information needed to make risk-based decisions. 

To explain dendritic encapsulation, one needs to know something about dendrimer conformations and dynamics. These can be complex and difficult to map out. This problem leads to a chicken and egg conundrum (to crack a bad encapsulating joke). Ideally, one has information about structure that can be used to rationalize encapsulation behavior. However, as it is difficult to get structural (particularly conformational) information about dendrimers, structures are often proposed based on observed encapsulation behaviors. Thus, a central theme of this chapter will be that the redox unit, as it is perturbed by the structure of the dendrimer, acts as both embedded reporter and performer. This approach runs the risk of generating a circuitous argument. However, in combination with other methods of assessing structure, it hopefully can iterate to a self-consistent model. 

Uncertainty analysis provides an evaluation of the key parameters that contribute to the uncertainty (e.g., variability and imprecision) involved in performing a risk assessment. Also known as probabilistic risk assessment, it provides information that enables decision makers to better understand the strengths, weaknesses, and assumptions inherent in the assessment and to evaluate the conclusions of the risk assessment accordingly. The result of the uncertainty analysis is a distribution of risks that a population may be potentially exposed to and thus, may be used by the risk manager to better understand the implication of the conclusions derived from the risk assessment and to support scientifically based and economically feasible hazardous waste management decisions. 

A risk event is a discrete random occurrence that (if occurring) affects the project. Risk events are identified based on the difficulty to achieve the required project outcome (the characteristics of the product or service), constraints on schedules and budgets, and the availability of resources. The environment in which the project is performed is also a potential source of risk. Historical information... 

In the performance-based design and operation of modem engineered systems, the accurate assessment of reliability is of paramount importance, particularly for civd, nuclear, aerospace and chemical systems and plants which are safety-critical and must be designed and operated within a risk-informed approach (Pata-lano et ah, 2008). 

Moreover, the Advisory Committee on Reactor Safeguards (ACRS, 1999, pg. 2 see also ACRS, 2000) has noted that risk-informed regulation requires a strong research program. In particular, the ACRS (1999, pg. 3) was concerned about the adequacy of current risk assessment methods for dealing with fires software-based digital systems aging of structures, systems and components... human performance safety culture, and low-power and shutdown operations. ... 

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