Event/accident Simulation Model of the Reactor Pressure Vessel Internal Segmentation Activity

2019 ⦽ǎႊᔍᖒ⠱ʑྜྷ⦺⫭ ⇹ĥ⦺ᚁݡ⫭ םྙ᫵᧞Ḳ

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Event/accident Simulation Model of the Reactor Pressure Vessel Internal Segmentation Activity

Dankook University, 119, Dandae-ro, Dongnam-gu, Cheonan-si, Chungcheongnam-do, Republic of Korea *

[email protected]

1. Introduction

Though the occurrence of accidents caused by technical problems has been reduced due to the development of various technologies, accidents caused by human error still relatively high. Therefore, task analysis and related performance shaping factors were derived in the previous study [1], in order to reduce the human error for the decommissioning activity, such as the reactor pressure vessel internal segmentation. In this paper, the event/accident simulation model on the reactor pressure vessel internal segmentation is described how to make it step by step.

2. Event / Accident Simulation Model

The event/accident simulation model refers to a model of variables for event/ accidents that may occur in the reactor pressure vessel internal segmentation. It is possible to understand the influence relationship between events and accidents that may occur based on the performance shaping factor derived from the eight task analysis of the reactor pressure vessel internal segmentation [1].In this paper, an event/accident simulation model for ³Human´KDVEHHQGHYHORSHG, which is one of level 1 performance shaping factor for the reactor pressure vessel internal segmentation. The performance shaping factors of Level 2 and Level 3 for ³+XPDQ´ are shown in Table 1. A total of three (3) event/accident simulation models such as stress, fatigue, and safety awareness were been developed by integrating the contents of nine (9) Level 3 performance shaping factors.

Table 1. Level 2 and Level 3 performance shaping factors for ³+uman´ Level 2 Level 3 Psychologi cal State Stress Emotional State Safety Awareness Physical State Fatigue Physical Capability Discomfort Performanc e Capability

Task Knowledge and Memory Experience

Personal capability

2.1 Event / Accident Simulation Model for Stress

There are various influencing factors in stresss [2]. But in this paper, these factors are limited to the activity of the reactor pressure vessel internal segmentation as follow;

- Stress due to occupation or responsibility during work

- Stress due to possible safety accidents during work

- Stress due to work shift

- Stress due to environmental factors

Fig. 1 shows the relationship between stress and influencing factors.

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Fatigue also has various influencing factors [3]. But fatigue factors for reactor pressure vessel internal segmentation are selected as follows;

- Fatigue due to Repetitive work - Fatigue due to work intensity - Fatigue due to tension during work - Fatigue due to job accumulation

Fig. 2 shows the relationship between selected fatigue factors.

Fig. 2. Relationship between fatigue and influencing factors.

2.3 Event / Accident Simulation Model for Safety Awareness

Safety awareness refers to the cognitive function of the severity of consequences associated with human diagnosis or decision [1]. Therefore, five (5) factors were derived for reduction and increase of safety awareness. Fig. 3 shows the relationship between the five factors.

ˍ Reduced safety awareness

- About the duration of repetitive tasks - Whether the work experience ˍ Increased safety awareness

- Safety training for related tasks

- Compliance with safety regulations and procedures

- Tension for work

Fig. 3. Relationship between safety awareness and influencing factors.

3. Conclusion

Human error can be caused by various factors.In this paper, the major influencing factors of stress, fatigue, and safety awareness are identified for ³+XPDQ´, which are the causes of human error. Then an event / accident simulation model is developed EDVHG RQ ³+XPDQ´ IDFWRU. Identification of these influencing factors of importance can be used to ascertain which factors are more important to manage due to stress, fatigue, and safety awareness using by VENSIM program [4]. Through further study, an event / accident simulation model will be generated for the entire influencing factors on the reactor pressure vessel internal segmentation.

REFERENCES

[1] Hyun-Jae Yoo, Chang-su Nam, Byung-Sik Lee, ³Task Analysis for Decommissioning Activities LQ 1XFOHDU 3RZHU 3ODQWV´ .RUHDQ 5DGLRDFWLYH Waste Society Fall Meeting (2018).

[2] Chang-Il Ahn, Gwi-Yeo-Roo Ahn, Seon-AhYoon, ³A Study of Development of Stress Inventory for the NXFOHDU3RZHU3ODQW¶V2SHUDWRU´ (2008). [3] Sei-Jin Chang, Sang-Baek Koh, ³&RUUHODWHV RI

6HOI UDWHG )DWLJXH LQ .RUHDQ (PSOR\HHV´ J Prev Med Public Health (2005).

[4] Korea Atomic Energy Research Institute, Development of Human Error Countermeasures for Nuclear Safety (2016).