PU R P O S E . The purpose of this DSA chapter is to provide information necessary
to support the safety basis requirements of 10 CFR 830.
This chapter provides descriptions of the facility and processes to support assumptions
used in the hazard and accident analyses. These descriptions focus on all major facility
features necessary to understand the hazard analysis and accident analysis, not just safety
SSCs. Expected products of this chapter, as applicable based on the graded approach,
Overview of the facility, its inputs and its outputs, including mission and history.
Description of the facility structure and design basis.
Description of the facility process systems and constituent components,
instrumentation, controls, operating parameters, and relationships of SSCs.
Description of confinement systems.
Description of the facility safety support systems.
Description of the facility utilities.
Description of facility auxiliary systems and support systems.
Existing supporting documentation is to be referenced. Include brief abstracts of
referenced documentation with enough of the salient facts to provide an understanding of
the referenced documentation and its relation to this chapter.
APPLICATION OF THE GRADED APPROACH. The development of this
chapter for Hazard Category 2 and 3 facilities is an iterative process dependent on the
development of the hazard and accident analyses. The facility description should provide a
model of the facility that would allow an independent reader to develop an understanding
of facility operations and an appreciation of facility structure and operations without
extensive consultation of controlled references. The level of detail required in the facility
description is based on the significance of preventive and mitigative features ident ified and
the degree of facility context necessary to understand the analyses. For a Hazard Category
3 facility, provide a brief description of the facility, processes, and major SSCs. Grading
will be based predominantly on complexity.
This chapter does not include information at the level of functional requirements and
performance criteria. That information is provided for safety SSCs only in Chapter 4. In
the basic description of safety SSCs, their categorization as safety-class SSC or safety
significant SSC should simply be noted.