Safety Analysis - std60030071

DOE-STD-6003-96

5. SAFETY ANALYSIS

This chapter of the Standard describes the safety analysis requirements applicable to

fusion facilities and provides guidance for the implementation of these requirements and criteria

for determining that the requirements have been met.

Safety analyses are performed to show that the risks associated with operation of a facil-

ity have been identified, quantified, and managed. Management of risk can be accomplished

(1) by demonstrating that the risk is within the bounds of an approved safety envelope, (2) by

showing that the risk consequences are mitigated to meet the established evaluation guidelines,

and (3) by having the risks themselves eliminated or reduced by demonstrable controls.

The completion of a safety analysis requires information on the facility, the site character-

istics important for evaluating facility safety, and the principal equipment and processes required

to fulfill the facility mission. From this baseline descriptive information, hazards can be identified.

Facility risk descriptions are then developed from the hazard inventories, system functional pro-

cess descriptions, and a listing of off-normal conditions postulated to result from both internal

and external causes. The entire analysis process is documented in a Safety Analysis Report

(SAR) and in Technical Safety Requirements (TSRs); the guidance for these is addressed in

later subsections.

The safety analysis has many purposes. In addition to establishing the safety of the facil-

ity, the safety analysis is used to develop TSRs and to determine readiness for construction and

operational authorization. The graphical illustration of the functional relationship of the major

items included in the safety analysis process is shown in Fig. 5.1.

As discussed in Section 1.3, a risk-based prioritization approach is to be taken in the

implementation of safety analysis requirements as well as in the implementation of the other ele-

ments of this Standard. Actions taken to ensure compliance with requirements are a function of

the several factors cited in the definition of risk-based prioritization. The factors most relevant to

fusion safety analysis considerations are risk and magnitude of hazard. The other factors

included in the risk-based approach are mission and facility life cycle. As such, the importance

of these factors is discussed where appropriate in the applicable sections of this chapter.

The project has the responsibility for the development of specific criteria for the applica-

tion of a risk-based prioritization approach to the system specific criteria. Concurrence with the

specifics of the risk-based approach taken by a facility should be obtained from the regulator

prior to its implementation. The identification of relevant criteria will flow from the nature and

purpose of the system itself.