Assessment of operator task-handling complexity in nuclear power plant accident scenarios

doi:10.16265/j.cnki.issn1003-3033.2025.06.1386

Abstract

Abstract:

To rigorously assess the complexity of operator task execution under nuclear power plant accident scenarios, this study proposes an operator task-handling complexity (OTHC) evaluation model based on information entropy and image entropy. The model evaluates complexity from three dimensions: interface information complexity (IIC), task complexity (TC), and protocol complexity (PC). It establishes an evaluation system comprising eight complexity indicators, including interface layout, icons, text, and color. The entropy weighting method was employed to objectively assign weights, enabling quantitative evaluation of complexity using the model. To validate the model's effectiveness, a primary circuit small-break loss-of-coolant accident diagnosis task was used as a case study, for which a complexity network diagram is constructed, and the proposed model is applied to assess complexity. Subjective workload data are collected using the national aeronautics and space administration task load index (NASA-TLX) scale. The results show that the OTHC of the primary circuit is higher than that of the secondary circuit. The complexity assessed by the constructed model is highly positively correlated with subjective complexity, effectively reflecting the actual level of task processing complexity.

Key words: nuclear power plants, accident scenarios, operators, task complexity(TC), assessment model, image entropy

CLC Number:

X945

JIANG Qike, WANG Yanxin, LI Pengcheng. Assessment of operator task-handling complexity in nuclear power plant accident scenarios[J]. China Safety Science Journal, 2025, 35(6): 128-133.

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复杂度指标	权重w_j
ILC	0.103 0
GC	0.133 3
TEC	0.128 7
CC	0.124 0
PLC	0.108 7
PSC	0.123 0
MTC	0.137 7
IMTC	0.141 9

节点	相邻节点	类别	节点	相邻节点	类别
S	A、B、C、D、E	1	F、G	A	7
A	F、G	2	I、J	B	8
B	I、J	3	K	C、L、M	9
C	K	4	L、M	K	10
D	N	5	N	D	11
E	O、P	6	O、P	E	12

输入	输出	节点	类别
0	1	a	1
1	0	p、q、r、s、t、v	2
1	1	b	3
2	0	u	4
1	2	c、d、e、g、h、l、o	5
2	2	f,k	6

节点	相邻节点	类别	节点	相邻节点	类别
a	b	1	l	g、o、u	10
b	a、c	2	o	j、t、u	11
c	b、d、p	3	p	c	12
d	c、e、f	4	q	e	13
e	d、f、q	5	r、s	k	14
f	d、e、h、k	6	t	o	15
g	h、k、l	7	u	l、o	16
h	f、g、v	8	v	h	17
k	f、g、r、s	9	—	—	—

复杂度指标	一回路	二回路
ILC	1.275	1.451
GC	2.680	2.922
TEC	2.913	2.913
CC	1.701	1.559
PLC	2.106	1.182
PSC	4.059	3.322
MTC	3.500	2.922
IMTC	3.212	3.212
OTHC	2.870	2.626