Control room operating crews are a crucial component in maintaining the safety of nuclear power plants. The primary support to operators during disturbances or emergencies are numerous emergency operating procedures. Further support is provided by reoccurring crew training in which the crews practice on handling anticipated disturbances in full-scale simulators. Due to the complexity of nuclear power plants and the small number of previous accidents to learn from, every possible accident scenario cannot be covered by the procedures and hence not trained on in the simulator. This raises the question of how operators can be prepared and able to cope with unexpected events by other means.   This thesis investigates the possibilities of operating crews to act flexibly in situations where stable responses in the form of prescribed actions sequences from procedures cannot be applied. The study is based on the safety research paradigm of resilience engineering and the four cornerstones of resilience; learning, monitoring, anticipating, and responding (Hollnagel, 2011). The meaning and applicability of the resilience cornerstones were examined by interviewing a domain expert at the time employed by the OECD Halden Reactor Project. Subsequently, eight semi-structured interviews with operator training personnel at a Swedish nuclear power plant provided the main data of this study.   This study shows that the resilience cornerstones were applicable to the work of nuclear power plant crews during emergency operations. In addition, the study provides findings regarding which artefacts (e.g. procedures) or crew characteristics (e.g. ways of communicating) support the cornerstone functions. The base thesis is that procedures always shall be used, but in situations where an operator perceives that no procedure is applicable, the crew have an opportunity to discuss the problem to come up with some other solution, i.e. act flexibly. Some trainers argued that the room for flexibility is there when needed, but it is not as certain how much flexibility and what kind of flexibility the operators are given. However, it does not seem like the flexibility, or lack of flexibility, given to operators is in itself the most problematic issue in the preparation of crews for unexpected events. Instead, this study identified several other problems of training and everyday work that could negatively affect crews’ capability to handle unexpected events. On the other hand, the trainers highlighted communication and teamwork to be important when the unexpected strikes and that much focus have been shifted towards such issues in training. Hence this can be claimed to be an important contribution given by the training today in successfully handling unforeseen events.

BillerudKorsnäs AB (BK) i Gävle är ett av de världsledande företagen inom tillverkning av vätskekartong. För att fortsatt vara ett ledande företag arbetar de dagligen med förbättringsförslag för att utveckla och öka fabrikens säkerhet och tillgänglighet. Detta examensarbete innehåller ett av många förbättringsförslag på avdelningen, Lut och Kraft. BillerudKorsnäs AB har en tydlig önskan om att åtgärda ett känt problem som kan leda till förödande ekonomiska konsekvenser.  Examensarbetet har bestått av att införa en automatisk nedkylningssekvens av mesaugnen, med fokusområde på säkerhet och programmering. Säkerhet är ett brett område och arbetsuppgifterna har avgränsats till automationsnära uppgifter för att hålla sig inom tidsramen på tio veckor. För att hålla samma kontinuitet och standard hos BK har programmeringen utgått från att använda nuvarande programmeringsspråk funktionsblocks diagram i styrsystemet AC450 från ABB.  Metoden som har använts i arbetet är aktionsforskning som innehöll planering, riskanalys och dokumentation för att minimera och eliminera tänkbara risker, relaterade till personsäkerhet och maskinutrustning.  Målsättningen med examensarbetet var att ha en fungerade, säker och pålitlig nedkylningssekvens. För att optimera processen, avlasta processoperatören och förbättra arbetsmiljön i kontrollrummet genom att automatisera ett arbetsmoment. Simuleringen har påvisat att nedkylningssekvensens funktion uppfyller BK önskan. På grund av fabriksstopp under examensarbetets tidsram har idrifttagning blivit försenat och provkörningen har flyttats fram. / BillerudKorsnäs AB (BK) in Gävle is one of the world-leading companies in the manufacture of liquid board. To continue to be a leading company, they work daily with improvement proposals to develop and increase the factory's safety and availability. This thesis contains one of many improvement proposals in the department, Lut och Kraft. BillerudKorsnäs AB has a clear desire to remedy a known problem that can lead to devastating financial consequences.  The degree project has consisted of introducing an automatic cooling sequence of the lime kiln, with a focus area on safety and programming. Security is a broad area and the tasks have been limited to automation-related tasks to stay within the time frame of ten weeks. To maintain the same continuity and standard at BK, the programming has been based on using the current programming script function block diagram in the control system AC450 from ABB.  The method that has been used in the work is action research that included planning, risk analysis and documentation to minimize and eliminate possible risks, related to personal safety and machine equipment.  The goal of the degree project was to have a functional, safe, and reliable cooling sequence. To optimize the process, relieve the process operator and improve the working environment in the control room by automating a work step. The simulation has shown that the function of the cooling sequence fulfills the BK desire. Due to a factory shutdown during the degree project's time frame, commissioning has been delayed and the test drive has been moved forward.