Identifying and Documenting Design Requirements

DOE-STD-1073-2003

Configuration Management

location of piping class breaks

location of isolation valves

location of seismic class breaks

location of test features

Some supporting features may be outside the system boundary, such as electrical power,

instrument air, lubricating oil, and ventilation. In addition, some complete systems may

cross multiple facility and activity boundaries, such as ventilation systems.

3.3

Identifying and Documenting Design Requirements

Once the set of CM SSCs is identified, the contractor must identify and document the

design requirements for this set of SSCs. The contractor must assess the effects of

changes to the design requirements of CM SSCs through the configuration management

process. Furthermore, the contractor must maintain the design requirements for CM

SSCs throughout the life of the nuclear activity.

The documentation should identify which of the design requirements are required for

safety and which are necessary for cost, environmental, or other considerations, so the

impacts of changes can be better assessed.

The design requirements to be documented include those that affect:

function,

installation,

performance,

operation, and

maintenance.

3.3.1 Design Process

Figure 3-4 illustrates the process of identifying design requirements for CM SSCs. The

design process has three elements:

Design Inputs consist of those specific criteria, limits, bases, or other initial

requirements (such as specific functional requirements, specific codes and

standards, and specific regulatory commitments) upon which the detailed final

design is based. In comparison to design constraints, design inputs are specific in

nature; i.e., they are specific to one design activity. For example, a design input

for a given air-operated valve might be that it needs to open in ten seconds against

a differential pressure of 100 psig. Design inputs should consider the effects of

the operating environment (e.g., radiation, temperature, pressure, humidity,

chemical spray), material condition, and aging (e.g., erosion, corrosion, fatigue,

chloride stress or intergranular stress corrosion cracking, and embrittlement).

For example, the design requirements should consider the effects of radiation

3-6