Introduction - std1021

DOE-STD-1021-93

1.0

INTRODUCTION

1.1

Purpose

The purpose of this standard is as follows:

(a)

To provide, for the purpose of Natural Phenomena Hazard (NPH) design and evaluation,

criteria for selecting performance categories (PCs) of structures, systems, and components

(SSCs) in accordance with the requirements specified in DOE Order 420.1 (Reference 10)

and the NPH Guide to DOE O 420.1 (DOE G 420.1-2) (Reference 11).

(b)

To recommend general procedures for consistent application of the above performance

categorization criteria so that the Department of Energy (DOE) review and approval process

is simplified.

1.2

Scope

The criteria and recommendations presented in this standard shall apply to performance categorization of

SSCs for the purpose of mitigating natural phenomena hazards in all DOE facilities covered by DOE Order

420.1.

1.3

Background

For several years, design and evaluation of DOE facilities subjected to natural phenomena hazards were

performed in accordance with the guidelines provided in UCRL-15910 (Reference 6) and DOE 5481.1B

(Reference 3). The use of UCRL-15910 was referenced in DOE 6430. IA, General Design Criteria

Manual. When DOE 5480.28 (Reference 1) was issued, UCRL15910 was superseded and issued as DOE-

STD-1020-94 and now revised as DOE-STD-1020-2002 (Reference 9). Subsequently, DOE 5480.28 and

DOE 6430.1A were superseded by DOE Order 420.1 and the associated guides, DOE G 420.1-1, 420.1-2.

To ensure that the level of conservatism introduced in the NPH design/evaluation process is appropriate for

facility occupancy and other characteristics such as importance, cost, and hazards to people on and offsite

and to the environment, UCRL-15910 used the "performance goal" as a "target" design/evaluation

parameter. The performance goal for an SSC was defined as its annual frequency of probable failure to

perform or annual probability of exceedance of acceptable behavior limits. Depending on the severity of

consequences of SSC failure, the 1990 version of UCRL-15910 grouped the facilities into four usage

categories, and assigned a target performance goal for each usage category. The four usage categories

were: (i) General Use, (ii) Important or Low Hazard, (iii) Moderate Hazard, and (iv) High Hazard. No

detailed guidance was provided in UCRL-15910 to perform this categorization.

In applying the UCRL-15910 methodology, facility usage categories were often correlated with facility

hazard classes that were determined in accordance with DOE 5481.1B (Reference 3, for all facilities except

nuclear facilities), DOE 5480.5 (Reference 7, for non-reactor nuclear facilities), and DOE 5480.6

(Reference 8, for nuclear reactor facilities). The three hazard classes that were used in these three orders

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