Project: Operator practices and human-system interfaces in computer-based control stations (O’PRACTICE)
Jari Laarni, Leena Norros, Iina Aaltonen, Hannu Karvonen, Hanna Koskinen, Marja Liinasuo, Leena Salo, Paula Savioja Human activity and systems usability team
SAFIR2010 - Final Seminar 2011, March 10-11, 2011, Hanasaari, Espoo, Finland
Contents
Overview of research activities
Study aim
Method description
Results: operator performance
Results: operator work practices
Systems usability of hybrid CRs
Design implications
OVERVIEW OF RESEARCH ACTIVITIES
INNOVATIVE HSI SOLUTIONS
Halden EID studies LSDs in process control LSD concept development Loviisa IRD-pilot evaluation
INTELLIGENT PROCEDURE USAGE
EOP design workshops Procedure usage in NPPs
EOP usage evaluation
SYSTEMS USABILITY DEVELOPMENT
ConOps development CR modernization experiences Further development of CASU method
ISV method comparison UC method development
Prevalidation method development
EMPIRICAL CR STUDIES
Loviisa reference tests Olkiluoto reference tests
Design
VII Human-System Interface Design
VIII Procedure Development IX Training Program
Development
Planning and Analysis
I HFE Program Management II Operating Experience
Review III Functional Requirements Analysis
and Function Allocation IV Task Analysis V Staffing & Qualifications
VI Human Reliability Analysis
Verification and Validation
X Human Factors Verification and Validation
Operation and in- service
monitoring
XI Design Implementation XII Human Performance
Monitoring
Overall Design Process
Concept of operations
O’PRACTICE O’PRACTICE
O’PRACTICE
(NUREG-0711)
STUDY AIM
History and future of HSIs in nuclear field
CONVENTIONAL ANALOGUE
DESKTOP-BASED
SMART HYBRID
Challenges of hybrid configurations?
METHOD DESCRIPTION
Simulator studies conducted
Two large empirical studies have been conducted at the Loviisa and Olkiluoto training simulators
AIMS
Evaluate the systems usability of hybrid CRs at different usage situations
Study, e.g., factors that
1) Promote and inhibit the development of a general operational picture of the state of the power production process and
2) Support situation awareness and communication processes among CR operators
Loviisa Olkiluoto
Method: scenarios & participants
SCENARIOS
Plant A:
2 accident situations: loss of coolant accident and primary- secondary leakage)
1 complicated failure (electric bus system failure)
Plant B:
3 complicated failures (decay heat removal system (321) failure, ejector failure and an automation failure in a preheater line)
PARTICIPANTS
Plant A:
12 CR crews (42 CR operators in total)
Plant B:
6 crews (21 CR operators)
Data collection methods and measures
Data
Operator performance/behaviour (interviews) Process performance, simulator performance Operator performance/behaviour (video recordings)
Operator performance (expert judgement)
Mental workload (subjective evaluation) CR systems usability (questionnaire)
Results
Performance and workload
Ways of acting
User experience
Evaluation Very good,
resilient and promising
Acceptable, improvements encouraged
Defective, significant changes required
Fulfilmentof standards
RESULTS: OPERATOR PERFORMANCE
general remarks
In both NPPs, the crews’ overall performance was good/excellent
Performance differences were small in accident scenarios
There were somewhat larger differences between crews in incident scenarios
There were no big differences between experts’ and operators’
views
0:00:00 0:05:00 0:10:00 0:15:00 0:20:00 0:25:00 0:30:00 0:35:00 0:40:00
0 1 2 3 4 5 6 7 8 9 10 11
Ilmastointijärjestelmä- tai vuotohälytys I0 kriteeri voimassa Automaattinen hidas alasajo
Reaktorin pikasulku Turpiinien pikasulku A0 kriteeri voimassa
A0: Välitt. toim. TK20-automatiikka pois A1: Prim. piirin jäähdytys 60C/220C A1: Prim. piirin jäähdytys RC:llä A1: Hätäboorauksen estoavaimen kääntö A1: YZ36 manuaalinen laukaisu A1: Jäähdytysgradientin asetus Vuoro 2 Vuoro 4 Vuoro 5 Vuoro 6 Vuoro 7 Vuoro 8 Vuoro 9 Vuoro 10 Vuoro 11 Vuoro 12
on log-file data
Alarm (air conditioning or leakage) Reactor scram
Accident procedure 1 Accident procedure 2
Incident procedure to be used Turbine scram
Accident procedure 3 Accident procedure 4
Automatic slow shutdown Accident procedure to be used Accident procedure 5 Accident procedure 6
Crew 2 Crew 4 Crew 5 Crew 6 Crew 7 Crew 8 Crew 9 Crew 10 Crew 11 Crew 12
• Overall, there were no large differences between crews in problem detection/
response times
evaluation
Crew Performance
0,0 1,0 2,0 3,0 4,0 5,0
Information seeking
Diagnosing Procedure usage Co-operation
Performance dimension
Performance level
Crew 1 Crew 2 Crew 3 Crew 4 Crew 5 Crew 6
• Overall, there were no large differences between crews in performance (according to expert evaluation)
Subjective workload
Overall subjective workload
0 10 20 30 40 50 60 70
SCO RO SS
Operator Role
Workload (%)
Overall subjective workload
0 10 20 30 40 50 60
SCO RO SS
Operator Role
Workload (%)
Scenario 1 (accident) Scenario 2 (incident) Scenario 3 (accident)
Scenario 1 (incident) Scenario 2 (incident)
• SCO’s workload was higher in incidents
• SCO’s workload was higher than that of RO/SS in incidents
PLANT A PLANT B
Differences in performance as a function of scenario difficulty
Causes of performance differences?
RESULTS: OPERATOR WORK PRACTICES
SITUATION AWARENESS LEADERSHIP &
MANAGERIAL SKILLS
COOPERATION
DECISION MAKING
Team building Supporting others
Conflict solving
Problem definition Option generation Risk assesment
Planning Coordination Workload management Process awareness
Team transparency Anticipation
SECONDARY TASK PERFORMANCE Walking around
Navigation
Examples of behavioural
markers
SITUATION AWARENESS LEADERSHIP &
MANAGERIAL SKILLS
COOPERATION
DECISION MAKING
SECONDARY TASK PERFORMANCE
Some behavioural differences
between crews
Team transparency Automation awareness
Communication of alarms/actions Provision of support to others
Amount of absence from work desk Amount of display navigation
Initiative taking Coordination of activities Stating alternative causes of
action
Procedure usage in incident situations
Mechanisms responsible for the outcome
CONTROL ROOM FEATURES Informativeness
Interaction modes
OUTCOME
Process performance Way of acting
User experience
SCENARIO Severity Complexity
Temporal features Familiarity
WORK PRACTICES Way of using information Way of using tools
Communication Collaboration EXPERIENCE
Participation in design Training
CAPABILITIES Knowledge and skills Orientation to work
Expertise in ICT and automation
Example of work practices: operator movement
Average duration of absence from control desk for each operator role
01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00
RO SCO SS Mean
Operator Role Average Duration (min:sec)
Average duration of absence from control desk for each operator role
01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00
RO SCO SS Mean
Operator Role Average Duration (min:sec)
• Effect of CR features
• Operators were away from their workstations longer, e.g., if they had to walk to the panels/
desks to carry out the required control operations
PLANT A PLANT B
Scenario 1 (accident) Scenario 2 (incident)
Scenario 1 (incident) Scenario 2 (incident) Scenario 3 (incident)
Example of work practices: amount of communication
Amount of internal communications for each operator role during different test runs
0 10 20 30 40 50 60 70
RO SCO SS Mean
Operator Role Number of Communications
Amount of internal communications for each operator role during different test runs
0 10 20 30 40 50 60 70 80 90 100
RO SCO SS AO Mean
Operator Role Number of Communications
• Scenario type had an impact on the amount of communication
Scenario 1 (incident) Scenario 2 (incident)
Scenario 3 (more difficult incident) Scenario 1 (accident)
Scenario 2 (incident)
PLANT A PLANT B
Operators acted strictly according to procedures in accident situations
BUT: Procedures are not applied in identical fashion
Differences between the crews in the exact point in time the EOP was taken into use
In incident situations there are large differences in the use of computerized procedures
Skills are required to connect the situation with the procedure
Operators had some problems to know
Whether there is a procedure available for a specific incident or not
What it is and where it is located
Procedures provide support for collaboration between operators
BUT: Collaboration may deteriorate if operators focus too tightly on the accomplishment of a procedure
SYSTEMS USABILITY OF HYBRID CRS
experience
Operators at both plants were quite satisfied with the present CR HSIs, and surprisingly, the overall distribution of the responses was very similar at the two plants
PLANT A PLANT B
Control room is usable and functional (Plant A) -
percentage distribution of all responses (46 respondents)
31
56
12
1 0
10 20 30 40 50 60
fully agree somewhat agree somewhat disagree completely disagree response categories
percentualshare of all responses
Control room is usable and functional (Plant B) -
percentage distribution of all responses (24 respondents)
35
52
12
1 0
10 20 30 40 50 60
fully agree somewhat agree somewhat disagree completely disagree response categories
percentuialshare of all responses
CRs: summary
Hybrid CRs of Finnish NPPs are quite usable complexies
Digitalisation is considered rather as an opportunity than as a threat
New HSIs (e.g., large screen displays, flow chart type EOPs) have been quite well received
BUT:
Secondary tasks are time-consuming
Operator movement
-> Information is distributed; presentation of process information and operations are physically separated
Navigation
-> Critical information is difficult to find
Difficult to get an overview of the power process
Number of LSDs is too small/presented information is not adequate
Team transparency is deteriorated due to digitalization
Observer does not know what the other operators are doing
It takes time to learn the new functionalities
Sufficient amount of training is needed
