Guidelines For Selecting Performance Category

DOE-STD-1021-93

2.0

GUIDELINES FOR SELECTING PERFORMANCE CATEGORY

2.1

General

(a)

This section provides guidelines for selecting SSC performance categories that are consistent

with the requirements of the NPH Guide for DOE Order 420.1 (DOE G 420.1-2), DOE-STD-

3009-94 (CHG-1), 10 CFR Part 830, DOE 5480.30, and DOE 5481.1B. The provisions of

this standard are intended to satisfy DOE Order 420.1 and the NPH Guide for DOE Order

420.1 with (DOE G 420.1-2) respect to performance categorization of SSCs.

(b)

Provisions of this standard apply only to NPH evaluation of SSCs.

(c)

The guidelines in this section have been reached through consensus engineering judgments

with the objective of satisfying DOE's NPH safety policy. However, each facility manager

shall consider all facility-specific safety, design, and performance issues while applying these

guidelines.

(d)

Guidelines provided in this section are intended to satisfy the minimum NPH mitigation

requirements of DOE Order 420. 1. However, an SSC may be placed in a performance

category that is higher than the category determined on the basis of these guidelines if it is

considered necessary from cost or mission considerations.

(e)

Personnel performing SSC categorization shall have thorough understanding of operations

and safety bases of the systems and facilities to which these SSCs belong. They also shall

have the necessary experience, technical knowledge, and understanding of safety-class and

safety-significant SSCs as defined in the requirements of DOE-STD-3009. This standard

provides guidelines and recommends procedures for performing the necessary tasks.

(f)

Performance categorization shall be initially performed considering the basic categorization

guidelines (see Subsection 2.4), that will establish the preliminary performance category. The

preliminary performance category shall then be modified by considering applicable system

interaction effects (see Subsection 2.5), which are also known as "two over one protection" in

the nuclear industry.

2.2

Data Sources

(a)

Data and information necessary for applying the guidelines given in this standard

shall be obtained from the design basis system studies, accident analyses, and calculations

performed for the following purposes:

(i)

Hazard classification of all facilities, except nuclear facilities, in accordance with

DOE O 5481.I B (Reference 3) which results in facility hazard classes: High Hazard

(HH), Moderate Hazard (MH), and Low Hazard (LH).

2-1