Format and Content of DOE-STD-3024-98

DOE-STD-3024-98

It is important that an SDD clearly distinguish between the items that are true requirements that the

system must meet and those additional characteristics that are optional. In an SDD, it is intended that

Section 3 would contain only the requirements on the system (and their bases), but not the extra, non-

mandatory performance capabilities that might exist in the actual system design configuration. Section

4 of the SDD, on the other hand, presents a description of the actual system that, not only describes

how the system meets its requirements, but also describes the full capacity and capabilities of the

system. The principle of stating requirements only in Section 3 and describing the full capability in

Section 4 is illustrated in the example below:

Requirement

The output power from the UPS system shall be provided (1) when incoming normal building

electrical power is available, (2) through incoming electrical transients and momentary

disturbances, and (3) for 2 hours following the loss of incoming building power.

Description

The UPS battery is rated at a nominal 125 Vdc and has been sized at 1800 Ampere-hours (Ah).

This sizing has been shown to be capable of driving the full-rated inverter output for 3 hours. This

ensures that the UPS will be able to provide clean electrical power not only when normal building

power is available and through incoming switching transients, but also for a period significantly

greater than the 2 hours required after the loss of building power. The capacity beyond the 2-hour

requirement is an additional and optional design feature, not margin.

Performance capabilities that might exist in the actual installed system that exceed the "requirements"

are not considered to be "requirements" but rather would be extra capabilities. Changes to

characteristics presented in the Description (Section 4) that do not have a corresponding requirement

(Section 3) or exceed the requirements can normally be approved by the contractor facility operating

organization. Changes to a requirement stated in Section 3 would necessitate the review and approval

by the design engineering authority. In considering a particular change request, the design engineering

authority would be expected to review the design basis and in some cases might need to request

approval from the authority that issued the design inputs (for example, a regulatory agency), before

such a change could be approved. For codes and standards identified in an SDD that have been applied

voluntarily at the option of the DOE contractor, the authority to modify that application remains at the

discretion of the contractor. It should be noted that the DOE program for Unreviewed Safety Questions

is aimed at determining if contractor final approval of a change is sufficient or DOE approval is

required.

A major purpose of the SDD is to collect information so that the reader does not have to wade through

numerous complex documents in an effort to locate the pertinent information. The information to be

provided in the SDD is to be a combination of comprehensive (or narrative) and index (or road map)

approaches. This middle-ground approach is based on including that information that the system

engineer, facility operator, or other user may need but not including excessive details such as

specifications of reinforcement bars for the structural members of the building or specific steps in an

alarm response procedure. Engineering judgement must be applied to determine when information

might be more detailed than is worthwhile for the intended audience of the SDDs and hence that

information should only be referenced. The status of the source document for information (that is,

current document or archived historical record) should not be a deciding factor in determining if the

information may be needed by the SDD user. The best approach may often be to provide a brief

summary and a reference to the details. To omit information from an SDD on the basis that the

information might need to be revised sometime in the future if a change were to be made is not a valid

basis. If the information is important to the overall purposes of an SDD and to the intended audience,

it should be included in the SDD.

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