Figure 2-1. Basic Guidelines for Preliminary NPH Performance Categorization

DOE-STD-1021-93

SSC is a "safety-class" item as defined in Section 2.3 (a), and

its failure due to an NPH event would result in off-site

release consequences greater than or equal to the

PC-4

unmitigated release associated with a large (200 MW)

Category A reactor severe accident

SSC failure has adverse release consequences greater than

PC-3

safety-class SSC Evaluation Guidelines, but not severe enough

to place it in PC-4.*

a. SSC performs emergency functions to preserve health and

safety of workers as defined in Section 2.4(d),

PC-2

b. SSC is part of a building used for assembly of more than

300 persons in one room,

c. It has been classified "safety-significant."

a. SSC is a building/structure with potential human

occupancy, or

b. SSC failure may cause fatality or serious injuries to in-

PC-1

facility workers, or

c. SSC failure can be prevented cost-effectively by NPH

design.

PC-0

Figure 2-1

Basic Guidelines for Preliminary NPH Performance Categorization of

Structures, Systems, and Components

Notes:

SSC = Structure, System, or Component

Use this Figure only in the context of Section 2 of this document; also see Subsection 2.5 for System

Interaction Effects

* Also Refer to DOE-G-420.1-2 for additional applications.

2-3