Safety Software and System Relationship

DOE-STD-1172-2003

abilities. This NUREG was prepared for the Nuclear Regulatory Commission to aid the

NRC in developing regulatory guidance for the commercial nuclear industry. It is used in

this standard because it provides important insights on the software life cycle that are

not available in industry standards. However, NUREG/CR-6263 is not a DOE Standard

and should not be used as such. Copies of this NUREG are available at no charge to

government agencies (but not government contractors). Send requests for copies from

a government e-mail address to .

Note: When regulations or U.S. Department of Energy directives or other industry standards

are referenced in the Qualification Standard, the most current version should be used.

Safety Software and System Relationship

Safety Software Quality Assurance personnel shall demonstrate a working level

knowledge of the types of safety system software and safety design and analysis

software, including custom software and commercial off-the-shelf software

(COTS). This includes instrumentation and control software and firmware (e.g.,

human-machine interface software, and programmable logic controller software),

and computer calculation and database program software used in the design and

accident analyses of nuclear facilities.

Supporting Knowledge, Skills, and Abilities

Explain the characteristics, application, and limitations of instrumentation and

control software and firmware (e.g., human-machine interface software, and

programmable logic controller software), safety analysis and design software,

and database program software used in the design, accident analyses,

operation, and maintenance of nuclear facilities. This should include both

custom and COTS safety software.

Given examples of safety and non-safety software, determine the controls that

were applied to the safety software to distinguish it from non-safety software.

Describe the process for identifying safety software at a facility, based on the

safety function as described in the facility Documented Safety Analysis.

Safety Software Quality Assurance personnel shall demonstrate a working level

knowledge of the functional interfaces between safety system software

components and the system-level design.

Supporting Knowledge, Skills, and Abilities

Identify how system-level requirements are established and then assigned to

hardware, software, and human components of a digital instrumentation and

control system.

Identify the typical requirements that define functional interfaces between safety

system software components and the system-level design, as described in

standards such as ANSI/IEEE 830, IEEE Guide to Software Requirements

Specifications and IEEE 7-4.3.2, Standard Criteria for Digital Computers in

Safety Systems of Nuclear Power Generating Stations.