Scope - std102395

DOE-STD-1023-95

1. SCOPE

It is the policy of the Department of Energy (DOE) to design, construct, and operate DOE facilities

so that workers, the general public, and the environment are protected from the impacts of natural

phenomena hazards (NPHs) on DOE facilities. As discussed in 10 CFR Part 830, Nuclear Safety

Management, natural external events need to be evaluated as part of Documented Safety Analysis

(830.204). NPH safety policy requirements for natural phenomena hazard (NPH) mitigation are

established by DOE O 420.1 which is referenced in 10 CFR Part 830, Nuclear Safety Management

Rule.

DOE 0 420.1 and associated NPH Guide, DOE G-420.1-2 requires that structures, systems, and

components (SSCs) at DOE facilities are designed and constructed to withstand the effects of natural

phenomena hazards using a graded approach. The graded approach is implemented by the five (5)

performance categories established for SSCs based on criteria provided by DOE-STD-1021-93.

Performance Category (PC) 0 is for SSCs which require no NPH protection. The performance

categories requiring NPH protection range from PC 1, which represents protection for life-safety at

the level provided by model building codes, to PC 4, which represents protection from release of

hazardous material similar to that provided by commercial nuclear power plants. For each

performance category, NPH design, evaluation, and construction requirements of varying

conservatism and rigor are provided in DOE-STD-1020-2002.

In applying the design/evaluation criteria of DOE-STD-1020-2002 for DOE facilities subjected to

one of the natural phenomena hazards, the establishment of design basis load levels consistent with

the corresponding performance category is required. Design basis load levels are established by

conducting natural phenomena hazard assessments.

For sites containing facilities with structures, systems, and components (SSCs) in only Performance

Category 1 or 2 and having no site-specific probabilistic NPH assessment, it is sufficient to utilize

natural phenomena hazard maps from model building codes or national consensus standards if they

have input values at the specified hazard probabilities. For sites which have site-specific probabilistic

NPH assessments, the SSCs in Performance Category 1 or 2 shall be evaluated or designed for the

greater of the site-specific values or the model code values, unless lower site specific values can be

justified and approved by DOE. Limitations on use of site specific probabilistic NPH assessments

contained in Model Building Codes shall be complied with.

For sites containing facilities with SSCs in Performance Category 3 or 4, a site-specific probabilistic

natural phenomena hazard assessment review shall be conducted if none has been conducted within

the last 10 years. This NPH assessment review shall consider site-specific information as discussed

in DOE-STD-1022-94.

The purpose of this standard, DOE-STD-1023-95, is to provide criteria for natural phenomena

hazard assessments to construct hazard curves. The mean hazard curve shall be used to determine

the design basis NPH event for design and/or evaluation of DOE facilities. This Standard provides

specific criteria applicable to various natural phenomena hazards including seismic, wind and

tornado, and flood.