Event Scenario Identification and Classification

DOE-STD-6003-96

e. the design of human-machine interface to build on strengths and protect against the

susceptibility of human error in operating crews.

Safety in design includes

a. identifying the potential off-normal conditions and incorporating systems performing

safety functions in the facility design to reduce the overall risk from those conditions;

b. designing reliable safety features using appropriate codes and standards that will

ensure the availability of the safety when required;

c. categorizing the facilities to their appropriate risk potential because the level of safety

features that are required for a given facility will be a direct function of the significant

risks present in a facility;

d. using defense-in-depth concepts in the design to ensure the safety of the public,

worker, and the environment;

e. incorporating the as-low-as-reasonably-achievable (ALARA) principles in the facility

design to reduce the risk potential to the workers during normal and off-normal

conditions.

The specific features associated with the design of a facility are discussed in detail in

Chapter 6.

5.4.1 Event Scenario Identification and Classification

Figure 5.2 is a flow chart that can be used to understand the steps required in the analy-

sis process. First, a list of postulated initiating events should be developed. Based on the

generic hazard and accident scenario identification (presented in Appendix B), these initiating

events could include the following:

a. loss of coolant (e.g., water and cryogen);

b. loss of flow;

c. magnet transients (arcing, quench, coil displacement, and magnet missile);

d. transient overpower;

e. plasma disruptions [including vertical displacement events (VDEs) and runaway

electrons];

f. loss of vacuum;

g. initiating events in the tritium plant;