Process Analysis - doe-std-3007-20070011

DOE-STD-3007-2007

that were used should be identified (i.e., cross-section sets and release versions) along with any cross-

section processing codes that were used. References may be provided to allow a reviewer the opportunity

to further research the methods used in the evaluation. When computer codes are used as part of the

methodology, the type of computing platform along with relevant code configuration control information

should be documented here. This information may be provided by reference.

ANSI/ANS-8.1-1998, Section 4.3 contains requirements for validation of methods and determination of

bias. In addition, validation requirements from other ANSI/ANS-8 Standards should also be followed as

appropriate. Compliance with these requirements shall5 be demonstrated in this subsection of the

evaluation. Reference may be made to more detailed validation reports; however, the results of these

validation reports should be summarized.

If no benchmark experiments exist that match the system being evaluated, it may be possible to

interpolate or extrapolate from existing benchmark data to that system. Sensitivity and uncertainty

analysis tools may be used to assess the applicability of benchmark problems to the system being

analyzed. One example of such a tool is TSUNAMI (Tools for Sensitivity and Uncertainty Analysis

Methodology Implementation). Proper application of TSUNAMI requires covariance data. The analyst

should understand the quality of the underlying nuclear physics data utilized in the application, including

the covariance data.

E. PROCESS ANALYSIS

This section and its contents shall1 be included in the CSE. All normal conditions and credible abnormal

conditions (credible contingencies) shall1 be analyzed and documented. This section shall1 document that

operations are subcritical under all normal conditions and that no credible abnormal condition can lead to

an accidental criticality. This section shall6 identify those controls that have been developed. As part of

this effort, the CSE shall7 document that at least two unlikely, independent, and concurrent changes in

process conditions (i.e., changes in process parameters) must occur before a criticality accident is

possible.

The intent of ANSI/ANS-8.1-1998 regarding application of the Double-Contingency Principle is that two

independent process parameters should be controlled. It is not always possible to control two independent

parameters for every process, thus ANSI/ANS-8.1-1998 does not make the Double-Contingency Principle

a requirement. DOE Order 420.1B also allows DOE to approve cases where the Double-Contingency