Document: NUREG-0800
Document ID: 51b93b24-7bff-4144-949f-36812854b7aa
Document Type: srp
Title: HUMAN FACTORS ENGINEERING
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1612/ML16125A114.pdf
Revision Date: 2023-06
Chapter: 18
Section ID: 18.0
CFR Part: 
CFR Title: 

Content:
s primary tasks, thus may increase operator or overall staff workload. Even when independent tasks do not significantly add to workload, they can still create distractions that may impede primary task performance. An activity that shifts attention away from the primary tasks, even momentarily, can interfere with performance even if little workload is added. An example of such an independent task is provided in NRC Information Notice (IN) 91-77 (NRC, 1991). The IN documented two instances of plants’ difficulty in staffing the fire brigade during a plant fire. In another more recent example, The licensee event report (LER) 50-259/22013-005-01, (TVA, 2014), describes a 18.0-39 Revision 3 – December 2016 situation where the plant’s minimum staffing analysis did not fully consider the impact on staffing of the fire brigade, an Appendix R safe shutdown, and the emergency response organization. In another recent example a senior reactor operator (SRO) who was the fire brigade leader in case of fire was called for drug testing. After he left a fire occurred. The fire brigade responded with no leader for about 30 minutes. The SRO did not leave drug testing because previous communications had reinforced that anyone who did not complete drug testing within prescribed time frame was considered “unfit for duty.” Another example of a common independent task is communicating with plant staff on matters unrelated to the primary task. Generally it is assumed that independent actions will be stopped when any plant transient occurs. However, operating experience shows there have been cases where confusion arises. Such conflicts should be addressed in plant administrative procedures to guide operators in how to manage independent tasks when they may impact operational primary tasks. Without such specific guidance, operators will make decisions on an ad hoc basis. Like dependent tasks, we can divide independent tasks into generic and plant- specific tasks. Further, the