A Cause Analysis Model of Nuclear Accidents in Marine Nuclear Power Plants Based on the Perspective of a Socio-Technical System
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper analyzed the cause for nuclear accidents in marine nuclear power plant through a socio-technical system. This system can consider the couplings among the plant system and its operator, the environment and other factors. The technical control and social intervention on accident are analyzed through a case study. The causal factors and accident causal chains are drawn. Generally, this research includes many factors to form a complex system and explored a novel solution scheme for such a problem. Thus, this research is meaningful and interesting. Some clarifications or the description of details are necessary. My particular comments are as follows:
1. Fig. 1 tries to present the characteristic analysis of socio-technical system. The socio-technical system is a big and abstract concept. Its rough content should be described with key considerations or elements firstly in a brief way. This can help readers to understand the particular content of this problem quickly.
2. Probability function and accident definition: The accident should be defined first and the relationship with probability should be described.
3. Some figures are not clear due to image type. Clear figures are expected.
4. English and presentations should be significantly improved for clarity and exact meanings.
Comments on the Quality of English LanguageEnglish and presentations should be improved significantly.
Author Response
Thank you for your letter and for the reviewers′comments concerning our manuscript. Those comments are helpful and very valuable for revising and improving our manuscript, as well as the important guiding significance to our researches. We have studied the comments carefully and have made detailed revisions which we hope meet with your approval. Revised portions are marked in yellow in the revised manuscript. The revisions and the detailed responses to the reviewers' comments are as following:
Comments and Suggestions for Authors
This paper analyzed the cause for nuclear accidents in marine nuclear power plant through a socio-technical system. This system can consider the couplings among the plant system and its operator, the environment and other factors. The technical control and social intervention on accident are analyzed through a case study. The causal factors and accident causal chains are drawn. Generally, this research includes many factors to form a complex system and explored a novel solution scheme for such a problem. Thus, this research is meaningful and interesting. Some clarifications or the description of details are necessary. My particular comments are as follows:
- 1 tries to present the characteristic analysis of socio-technical system. The socio-technical system is a big and abstract concept. Its rough content should be described with key considerations or elements firstly in a brief way. This can help readers to understand the particular content of this problem quickly.
Response:According to the reviewer's suggestion, this paper analyzes the nuclear accident causation model in marine nuclear power plants from four perspectives: holistic, hierarchical, dynamic, and feedback, as shown in Figure 2.(Page 5, lines 191-205)
Figure 2. Analyzing Perspectives of Nuclear Accident Causation Model
- Probability function and accident definition: The accident should be defined first and the relationship with probability should be described.
Response:According to the reviewer's suggestion, the definition of a nuclear accident has been added in Section 2.2.(Page 5, lines 207-228)
2.2 Nuclear accident and Bayesian network theory
(1)Nuclear accident
A nuclear accident is an unforeseen event at a large nuclear facility that may result in radiological damage to people inside the plant. In serious cases, radioactive material leaks outside the plant, contaminating the surrounding environment and causing a hazard to public health. A small break loss of coolant accident (SBLOCA) is caused by a small break in the reactor coolant system pipeline or connected components, resulting in a coolant loss rate that exceeds the normal replenishment capacity of the coolant supply system. After the SBLOCA occurred, the regulator pressure and water level continued to decrease, and the make-up water system was put into the main coolant system as required. If the regulator pressure water and level stop dropping after replenishing water, it means that the break is small, the break flow is lower than the replenishment flow rate, and the existing power operation can be maintained. If the make-up water system input fails, or if the regulator pressure and water level continue to drop after the make-up water system is input due to a large breach, it may lead to severe accidents.
(2)Bayesian network theory
The probability of a nuclear accident is uncertain, and Bayesian theorem is a result of probability theory that is related to conditional probability of its random variable and marginal distribution. Applying Bayesian probability to nuclear accidents is feasible because it allows us to represent posterior probabilities in terms of prior probabilities, conditional probabilities, and evidence.
- Some figures are not clear due to image type. Clear figures are expected
Response: According to the reviewer's comments, the clarity of the image has been modified.
- English and presentations should be significantly improved for clarity and exact meanings.
Response:The paper has been revised and polished. It has been modified in the paper and mark it in highlighting in yellow.
Comments on the Quality of English Language
English and presentations should be improved significantly.
Response:The paper has been revised and polished. It has been modified in the paper and mark it in highlighting in yellow.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper uses Bayesian analysis to locate the main factors that cause accidents in marine nuclear power plants.
The authors should address a few weaknesses before publishing.
· Please explain the acronym SBLOCA in the abstract.
· A critical discussion of the results in light of previous research is missed.
· In the Conclusions, you sum up the methodology approach followed rather than present the main conclusions derived from the analysis.
· What do you recommend for preventing nuclear accidents according to your analysis of the key stakeholders for theoretical and practical implementation?
Author Response
Thank you for your letter and for the reviewers′comments concerning our manuscript. Those comments are helpful and very valuable for revising and improving our manuscript, as well as the important guiding significance to our researches. We have studied the comments carefully and have made detailed revisions which we hope meet with your approval. Revised portions are marked in yellow in the revised manuscript. The revisions and the detailed responses to the reviewers' comments are as following:
Comments and Suggestions for Authors
The paper uses Bayesian analysis to locate the main factors that cause accidents in marine nuclear power plants.
The authors should address a few weaknesses before publishing.
- Please explain the acronym SBLOCA in the abstract.
Response:According to the reviewer's comments, an explanation for SBLOCA has been added in section 2.2. (Page 5, lines 211-213)
A small break loss of coolant accident (SBLOCA) is caused by a small break in the reactor coolant system pipeline or connected components, resulting in a coolant loss rate that exceeds the normal replenishment capacity of the coolant supply system.
- A critical discussion of the results in light of previous research is missed.
Response:According to the reviewer's suggestion, the future research directions were added after the conclusion of the paper. (Page 23 lines 594-597)
- The future work
The data resulting from the expert assessment is subject to more uncertainty even after fuzzification. A learning mechanism for expert preferences is implemented to better inspire experts to form correct preferences.
- In the Conclusions, you sum up the methodology approach followed rather than present the main conclusions derived from the analysis.
Response:According to the reviewer's comments, the author adds the conclusion of the analysis to the conclusion. (Page 23, lines 579-583)
(4) According to the reverse inference of Bayesian networks, when the operator makes a mistake, the low-pressure safety injection system fails to be successfully put into operation, and the probability of pump 2 failure increases from 0.85 to 0.91. In other words, it can be concluded by forward reasoning that the increase of the failure probability of pump 2 will greatly increase the occurrence of severe nuclear accidents.
- What do you recommend for preventing nuclear accidents according to your analysis of the key stakeholders for theoretical and practical implementation?
Response:According to the comments of the reviewers, the author adds recommendations for the prevention of nuclear accidents in the fifth conclusion. (Page 23, lines 586-593)
The two nodes of insufficient response time and inadequate research and design institutions have the greatest variability, which are the important factors causing the development of marine reactors into severe accidents. Therefore, emergency measures to extend the response time and improve and optimize the research institution are developed. However, the secondary factors such as the regulatory agencies, organizational communication and the state of the pump also need to take appropriate emergency measures, which provides a strong basis for preventing nuclear accidents from the source.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper is written professionally with all elements of peer-reviewed papers. The authors have deep knowledge of the topic. The reasoning behind the applied methodology is robust. However, the paper needs some improvements.
Minor comments:
13 – why casualties? Please explain. Nuclear accidents do not cause many causalities. Please provide data on causalities due to nuclear issues in Czarnobyl, Three Mile Island, and Fukushima accidents.
182 – Please compare with the standard INES scale of nuclear incidents and accidents. Please comment on the differences.
296 – Please provide reference.
317—Please provide more information about SBLOCA and compare it with LOCA in a land-based reactor. Please indicate differences.
377 – why 12 experts, and what experts? Please explain.
456 – Please indicate directions for future research.
General comments:
a) The paper lacks a broad introduction to the topic of nuclear accidents and their consequences. Please add.
b) The past and current development of marine nuclear reactors are not indicated. Please add.
c) Please add more supporting references to the paper. Please perform a more complex literature study on the topic.
d) Please indicate briefly the history of the nuclear accidents starting from the earliest ones with references, e.g.: https://doi.org/10.1016/j.nucengdes.2018.08.006 ; https://doi.org/10.1016/j.nucengdes.2019.110467
Author Response
Thank you for your letter and for the reviewers′comments concerning our manuscript. Those comments are helpful and very valuable for revising and improving our manuscript, as well as the important guiding significance to our researches. We have studied the comments carefully and have made detailed revisions which we hope meet with your approval. Revised portions are marked in yellow in the revised manuscript. The revisions and the detailed responses to the reviewers' comments are as following:
Comments and Suggestions for Authors
The paper is written professionally with all elements of peer-reviewed papers. The authors have deep knowledge of the topic. The reasoning behind the applied methodology is robust. However, the paper needs some improvements.
Minor comments:
13 – why casualties? Please explain. Nuclear accidents do not cause many causalities. Please provide data on causalities due to nuclear issues in Czarnobyl, Three Mile Island, and Fukushima accidents.
Response:The formulation of the three major nuclear accidents has been added as suggested by the reviewers. (Page 2, lines 63-70)
The Three Mile Island nuclear leak accident [9] did not cause any casualties, but it caused huge economic losses and public panic. A large amount of radioactive material was released in the Chernobyl nuclear accident [10], resulted in the immediate death of 31 people. Over the next 15 years, an estimated 60-80 people died from radiation exposure and 134 developed severe radiation illness. The Fukushima nuclear accident [11] had long-term effects on the environment and public health, forcing the evacuation of large numbers of residents. As of February 2018, 159 cases of cancer have been diagnosed among residents of Fukushima Prefecture, with 34 suspected cases of cancer.
[9] Sich, A.R. The Chernobyl Nuclear Power Plant Unit-4 Accident[M]. Reference Module in Earth Systems and Environmental Sciences, 2021.
[10] Leslie, M. Amid Uncertainty for US Nuclear Power, Three Mile Island Shuts Down[J]. Engineering, 2020, 6(1): 4-5.
[11] Akahane K, Yonai S, Fukuda S, et al. The Fukushima Nuclear Power Plant Accident and Exposures in the Environment[J]. Environmentalist, 2012, 32(2): 136- 143.
Explanation:The release of large quantities of radioactive pollutants and toxic gases following a severe nuclear accident, accompanied by other accidents such as hydrogen explosions, can cause serious damage to workers.
182 – Please compare with the standard INES scale of nuclear incidents and accidents. Please comment on the differences.
Response:According to the reviewer's suggestion, the explanation of differences in classification of nuclear accidents is added. (Page 5, lines 258-273)
According to the International Nuclear Event Scale (INES), nuclear accidents are categorized into seven levels, ranging from level one to level seven, with a gradual increase in radiological consequences and severity. However, the MNPPs are mostly integrated small pressurized water reactors, and their nuclear accident classification has not been clearly defined.
From the radioactive safety analysis of nuclear accidents, MNPPs nuclear accidents are divided into seven levels according to the specific radiation dose, while nuclear power plant accident levels are not defined by specific values. Nuclear accidents in MNPPs are categorized into four levels from power output, and into three levels from depth defense. Nuclear power plants, on the other hand, do not have a clearly defined accident level in these two areas.
296 – Please provide reference.
Response:References is cited. (Page 12, line 392)
[42] Leveson, N. System safety and computers. Addison Wesley, Boston,America, 1995.
317—Please provide more information about SBLOCA and compare it with LOCA in a land-based reactor. Please indicate differences.
Response:According to the reviewer's suggestion, a description of SBLOCA has been added to the nuclear accident analysis. (Page 5, lines 211-220)
A small break loss of coolant accident (SBLOCA) is caused by a small break in the reactor coolant system pipeline or connected components, resulting in a coolant loss rate that exceeds the normal replenishment capacity of the coolant supply system. After the SBLOCA occurred, the regulator pressure and water level continued to decrease, and the make-up water system was put into the main coolant system as required. If the regulator pressure water and level stop dropping after replenishing water, it means that the break is small, the break flow is lower than the replenishment flow rate, and the existing power operation can be maintained. If the make-up water system input fails, or if the regulator pressure and water level continue to drop after the make-up water system is input due to a large breach, it may lead to severe accidents.
Explanation:The principle of loss of coolant accidents(LOCA)of land-based reactors and marine reactors is the same, but according to the size of the break, the LOCAs are divided into small break, medium break and large break.
377 – why 12 experts, and what experts? Please explain.
Response:According to the reviewer's suggestion, the expert specific description is added. (Page 16, lines 472-476)
The 12 experts include four different levels of relevant staff, namely five designers related to China Shipbuilding Industry Corporation, two members of the relevant subject matter team of the Nuclear Power Institute of China, three staff of nuclear power plant operation and maintenance, and two chief engineers of a naval base.
456 – Please indicate directions for future research.
Response:According to the reviewer's suggestion, the future research directions were added after the conclusion of the paper. (Page 23 lines 594-597)
- The future work
The data resulting from the expert assessment is subject to more uncertainty even after fuzzification. A learning mechanism for expert preferences is implemented to better inspire experts to form correct preferences.
General comments:
- The paper lacks a broad introduction to the topic of nuclear accidents and their consequences. Please add.
Response:According to the reviewer's suggestion, a literature review on nuclear accidents and their consequences has been added. (Page 2 lines 63-94)
The Three Mile Island nuclear leak accident [9] did not cause any casualties, but it caused huge economic losses and public panic. A large amount of radioactive material was released in the Chernobyl nuclear accident [10], resulted in the immediate death of 31 people. Over the next 15 years, an estimated 60-80 people died from radiation exposure and 134 developed severe radiation illness. The Fukushima nuclear accident [11] had long-term effects on the environment and public health, forcing the evacuation of large numbers of residents. As of February 2018, 159 cases of cancer have been diagnosed among residents of Fukushima Prefecture, with 34 suspected cases of cancer. The hazards of nuclear accidents and its consequences are enormous, and the related research of nuclear accidents is of great significance to prevent the occurrence of nuclear accidents and formulate emergency strategies. Kwag et al. applied an improved probabilistic safety assessment (PSA) methodology, which is a PSA framework based on Bayesian networks with fault trees, combined with additional on-site observations and vulnerability assessment under severe accident conditions [12]. Silva et al. used the three-level PSA method to calculate the cost and analyze the consequences of a single severe accident, and carried out sensitivity analysis to determine the cost-sensitive parameters of a severe accident, and showed the cost of a single severe accident as an indicator to evaluate the consequences of a severe accident [13]. Mohsendokht et al. proposed a new severe accident management framework to deal with the risk of radionuclide release into the environment, in order to reduce the impact of severe accidents on the early release of radioactive substances in the VVER-1000 nuclear reactor [14]. Xuefeng et al. studied the hydrogen risk and hydrogen control system of the loss of coolant accident of marine reactor, analyzed the hydrogen production rate and steam release rate, and simulated the two-dimensional flow field and the transport and distribution of hydrogen in the tank [15]. Ouyang et al. conducted the atmospheric radioactive diffusion caused by severe accidents in MNPPs, established a simulation model of atmospheric diffusion of radionuclides over the ocean, and studied the effects of seawater absorption on atmospheric diffusion of radionuclides at different heights [16]. Zhang [17], Wang [18-19] et al. conducted source term analysis on the severe accidents of large break loss of coolant accident in MNPPs combined with ship power failure, steam generator heat transfer tube damage combined with ship power failure, focusing on the release and migration rules of radionuclides. It provides data support for emergency decision-making of nuclear accident consequences.
[9] Sich, A.R. The Chernobyl Nuclear Power Plant Unit-4 Accident[M]. Reference Module in Earth Systems and Environmental Sciences, 2021.
[10] Leslie, M. Amid Uncertainty for US Nuclear Power, Three Mile Island Shuts Down. Engi, 2020, 6(1),4-5.
[11] Akahane, K.; Yonai,S.; Fukuda,S.; Miyahara, N.; Yasuda, H.; Iwaoka, K.; Matsumoto, M.; Fukumura, A.; Akashi, M.; The Fukushima Nuclear Power Plant Accident and Exposures in the Environment. Envi. 2012, 32(2),136-143.
[12] Kwag, S.; Oh, J. Development of Network-based Probabilistic Safety Assessment: a Tool for Risk Analyst for Nuclear Facilities. Pro. Nucl. Ene. 2019, 110(1),178-190.
[13] Silva, K.; Ishiwatari, Y.; Takahara, S. Cost Per Severe Accident as an Index for Severe Accident Consequence Assessment and Its Applications. Reliab. Eng. Syst. Safe. 2014, 123(3),110-122.
[14] Mohsendokht, M.; Jamshidi, M. Re-evaluation of Level 2 PSA Results of a VVER-1000 NPP with Consideration of Innovative Severe Accident Management Strategies. Ann. Nucl. Energy. 2021, 151(2),107966.
[15] Lyu, X.F.; Liu, S.; Ji, K.; Feng, Y.; Wang, S.F.; Huang, Z.C. Research on Hydrogen Risk and Hydrogen Control System in Marine Nuclear Reactor. Ann. Nucl. Energy. 2020, 141,107373.
[16] Ouyang, K.H.; Chen, W.Z.; He, Z.Y. Analysis of the Radioactive Atmospheric Dispersion Induced by Ship Nuclear Power Plant Severe Accident. Ann. Nucl. Energy. 2019, 127,395-399.
[17] Zhang, Y.Z.; Zhang, F.; Zhao, X.W.; Zheng, Y.F. Source Term Analysis in Severe Accident Induced by Large Break Loss of Coolant Accident Coincident With Ship Blackout for Ship Reactor. Ato. Ene. Sci. Tech. 2013, 47(9),1565-1571.
[18] Wang, W.; Chen, L.S.; Zhang, F.; Liu, H.P. Radioactive Analysis on Accident of SG-tube Rupture Coupled with Whole Ship Blackout. Ato. Ene. Sci. Tech. 2015, 49(5),871-876.
[19] Wang, W.; Chen, L.S.; Zhang, F.; Cai, Q. Source Term Analysis on Blackout Accident of Marine Reactor. Ato. Ene. Sci. Tech. 2014, 48(6),1038-1038.
- b) The past and current development of marine nuclear reactors are not indicated. Please add.
Response:As suggested by the reviewer, a description of marine nuclear reactors has been added in the first paragraph of the introduction. (Page 1 lines 33-48)
At present, the application of marine nuclear power equipment in the field of national defense is mainly reflected in nuclear-powered submarines, nuclear-powered aircraft carriers and nuclear-powered cruisers. In terms of the number and development strength of nuclear-powered ships, the United States and Russia lead the world. In 1954, the United States "Nautilus" nuclear-powered submarine service opened the first marine nuclear power application. There are more than 300 nuclear-powered submarines in the world, with more than 160 in service, mostly using small pressurized water reactor technology [1]. There are 12 nuclear-powered aircraft carriers in the world, all using small pressurized water reactor technology. The development of marine nuclear power equipment in the civil field is mainly manifested in three application scenarios: nuclear merchant ship, nuclear icebreaker and floating nuclear power plant at sea. In the 1950s, the United States, the Soviet Union, Japan, and Germany began to study civilian nuclear-powered ships. In 1957, the world's first nuclear-powered icebreaker “Lenin” built by the Soviet Union was launched, and in 1959, the world's first nuclear-powered merchant ship “Savannah” built by the United States was launched, which opened the prelude to the peaceful application of civil marine nuclear power equipment [2].
[1] Cheng, L. The application prospect of small nuclear reactor power supply in the field of ocean engineering. China Offshore Plat‐form, 2018, 33(6), 1-5.
[2] Zheng, J.; Yu, F.; Zhu, J.M.; Liu, C.G.; Wang, X.Y.;Zhu, Y.F. Development Status and Prospect of Marine Nuclear Power Equipment in China and Abroad, Engineering science in China, 2023,25(03), 62-73.
- c) Please add more supporting references to the paper. Please perform a more complex literature study on the topic.
Response: According to the reviewer's suggestion, literature research on the topic has been added to the introduction. (Page 2 lines 73-94 and 121-133)
Kwag et al. applied an improved probabilistic safety assessment (PSA) methodology, which is a PSA framework based on Bayesian networks with fault trees, combined with additional on-site observations and vulnerability assessment under severe accident conditions [12]. Silva et al. used the three-level PSA method to calculate the cost and analyze the consequences of a single severe accident, and carried out sensitivity analysis to determine the cost-sensitive parameters of a severe accident, and showed the cost of a single severe accident as an indicator to evaluate the consequences of a severe accident [13]. Mohsendokht et al. proposed a new severe accident management framework to deal with the risk of radionuclide release into the environment, in order to reduce the impact of severe accidents on the early release of radioactive substances in the VVER-1000 nuclear reactor [14]. Xuefeng et al. studied the hydrogen risk and hydrogen control system of the loss of coolant accident of marine reactor, analyzed the hydrogen production rate and steam release rate, and simulated the two-dimensional flow field and the transport and distribution of hydrogen in the tank [15]. Ouyang et al. conducted the atmospheric radioactive diffusion caused by severe accidents in MNPPs, established a simulation model of atmospheric diffusion of radionuclides over the ocean, and studied the effects of seawater absorption on atmospheric diffusion of radionuclides at different heights [16]. Zhang [17], Wang [18-19] et al. conducted source term analysis on the severe accidents of large break loss of coolant accident in MNPPs combined with ship power failure, steam generator heat transfer tube damage combined with ship power failure, focusing on the release and migration rules of radionuclides. It provides data support for emergency decision-making of nuclear accident consequences.
Mahmudah et al. focused on socio-economic factors and used a combination of Fuzzy Analytic Hierarchy Process (AHP) and Fuzzy VIKOR research methods to prioritize the top ten standard factors and find the most suitable location for nuclear power plants [29]. Based on the accident model and process of the system theory, Ceylan et al. adopted the Bayesian network (BN) modeling method to conduct a comprehensive safety analysis of the water fog system of the oil cargo ship, and obtained the dynamic structure composed of complex elements [30]. Oettingen et al. used the Monte Carlo research method to conduct critical analysis of the Louis Slotin nuclear accident, and established a numerical model and the influence of system components on the critical state. The critical state method was applied to the mass function of tungsten carbide reflector [31-32]. Antonello et al. conducted a qualitative analysis of hazard based on system theory accident models and process principles, and studied the dynamic behavior of accident scenarios through modeling and simulation [33].
[29] Mahmudah, R.SN.; Putri, D.I.; Abdullah, A.G.; Shafii, M.A.; Hakim, D.L.; Setiadipura, T. Developing a Multi-Criteria Decision-Making model for nuclear power plant location selection using Fuzzy Analytic Hierarchy Process and Fuzzy VIKOR methods focused on socio-economic factors. Clea. Eng. Tech. 2024,19,100737.
[30] Ceylan, B.O.; Sezer, S.I.; Akyuz, E. An integrated system theoretic accident model and process
(STAMP)-Bayesian network (BN) for safety analysis of water mist system on tanker ships. Appl. Ocean. Res. 2025, 154,104344.
[31] Oettingen, M. Criticality analysis of the Louis Slotin accident. Nucl. Eng. Des. 2018,338,92-101.
[32] Oettingen, M. A criticality study on the LA-1 accident using Monte Carlo methods. Nucl. Eng. Des. 2020,359,110467.
[33] Antonelloa, F.; Buongiorno, J.; Zio, E. A methodology to perform dynamic risk assessment using system theory and modeling and simulation: Appli. Nucl. Batter. 2022,228,108769.
- d) Please indicate briefly the history of the nuclear accidents starting from the earliest ones with references, e.g.: https://doi.org/10.1016/j.nucengdes.2018.08.006 ; https://doi.org/10.1016/j.nucengdes.2019.110467
Response: According to the reviewer's suggestion, an overview of marine reactor nuclear accidents has been added. And the references listed by the reviewer have been cited in the introduction. (Page 5 lines 208-220)
A nuclear accident is an unforeseen event at a large nuclear facility that may result in radiological damage to people inside the plant. In serious cases, radioactive material leaks outside the plant, contaminating the surrounding environment and causing a hazard to public health. A small break loss of coolant accident (SBLOCA) is caused by a small break in the reactor coolant system pipeline or connected components, resulting in a coolant loss rate that exceeds the normal replenishment capacity of the coolant supply system. After the SBLOCA occurred, the regulator pressure and water level continued to decrease, and the make-up water system was put into the main coolant system as required. If the regulator pressure water and level stop dropping after replenishing water, it means that the break is small, the break flow is lower than the replenishment flow rate, and the existing power operation can be maintained. If the make-up water system input fails, or if the regulator pressure and water level continue to drop after the make-up water system is input due to a large breach, it may lead to severe accidents.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have addressed our comments and improved the manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors improved the manuscript satisfactorily according to the reviewers' comments.
Reviewer 3 Report
Comments and Suggestions for AuthorsAll necessary corrections and improvements were provided. Accepted.