Keywords

1 Introduction

The real impact of global climate change will be more severe than predicted, which means that the energy sector still needs major structural changes. The World Meteorological Organization (WMO) noted that the concentration of greenhouse gases in the atmosphere has neither slowed down nor declined in its 16th WMO Greenhouse Gas Bulletin. Countries must translate climate change commitments into action. The Intergovernmental Panel on Climate Change (IPCC) also holds a similar view. In its “Special Report on Global Warming of 1.5 °C”, it pointed out that the past greenhouse gas reduction targets cannot effectively avoid the worst effects of climate change, which means that addressing climate change requires stronger carbon mitigation constraints and actions [1]. But pinning all hopes of tackling climate change on renewable energy would be a risky path. Some scholars have raised warnings. For example, the large-scale deployment of wind and solar power with intermittent characteristics on multiple time scales will have an incalculable impact on the existing power system architecture, and generate additional investment in power grid flexibility transformation or construction of supporting energy storage facilities [2, 3]. Climate change will also cause changes in climate variables such as wind and water vapor, resulting in increased uncertainty in the power generation potential of renewable energy sources such as wind power and solar energy [4].

In 2021, for the first time in many years, the Chinese government’s work report changed its expression of nuclear power development, referring to the “active and orderly development of nuclear power”. Although there has been a broad consensus on the emission reduction potential of nuclear energy and efforts to promote the deployment of nuclear energy development projects, the development of nuclear energy projects still faces many challenges. For the public, in addition to the safety factors that limit the large-scale deployment of nuclear energy, the economics of nuclear energy projects is also one of the core challenges. In addition to the inherent factors such as huge investment, high project risk cost, and long payback period, we have found an interesting phenomenon, that is, nuclear energy projects around the world have not been compensated for their environmental benefits as effectively as wind power, solar energy or even gas heating projects, but in fact carbon trading, clean fund concessional loans and other methods should also be gradually introduced.

Since nuclear power plants do not produce carbon dioxide emissions, policies that set explicit or shadow prices for carbon dioxide emissions can also affect their economic attractiveness compared with fossil fuel alternatives [5]. The difference between different energy forms puts nuclear energy projects at a disadvantage in energy market competition. Incorporating the carbon emission reduction contribution of nuclear energy projects into the carbon trading system can increase the source of income and improve the economics of nuclear energy projects, which seems to be a simple and feasible way to solve the “dilemma”. However, there is no accurate measurement method for carbon emission reduction during the operation period of nuclear energy projects. In China, the methodology to support its further development into Chinese Certified Emission Reduction (CCER) is also blank. The above situation is the real research gap.

In order to achieve the purpose of filling up the above research gap, this paper constructs a set of calculation and analysis framework for nuclear energy carbon emission reduction by sorting out the registered CCER development methodology in China. This paper also refers to the “Project Additionality Demonstration Tool” in the standard process of the Clean Development Mechanism (CDM) and CCER project development, and conducts a comparative analysis of the carbon emission reduction of nuclear energy heating projects in Shandong, China based on the alternative baseline scheme.

2 Literature Review

This study analyzes the literature in the fields of nuclear carbon emission reduction contribution, carbon emission reduction calculation method, role of additionality and demonstration method.

Nuclear energy is a clean energy source, which is generally considered to not generate CO2 during the operation period and will play a huge role in global carbon reduction efforts. This view has been widely accepted by the whole society.

Under a climate change regulatory regime that limits carbon dioxide emissions, nuclear energy is economically more attractive than fossil fuels, and nuclear energy is being favored by some environmental groups as a carbon-free energy source [5]. The recognition by governments and international organizations of the value of nuclear energy and its contribution to decarbonizing the world’s energy system will encourage policymakers to explicitly include nuclear energy in their long-term energy plans and nationally determined contributions under the Paris Climate Agreement, the International Energy Agency (IEA) noted in its Global Nuclear Energy Development Report. At the same time, the EU’s mid- and long-term energy strategy “Vision 2050 for an integrated energy system” also clearly states that nuclear energy and renewable energy will become the pillars of the EU’s power system [6, 7], and will achieve carbon balance in 2050. However, in discussions on the eligibility of nuclear power generation for sustainable funding, the EU also stressed that the current recognition of nuclear energy’s environmental and climate contribution still needs to be improved. In addition to qualitative analysis, quantitative analysis of some studies points out that nuclear energy has certain comparative advantages among many clean energy sources, which provides strong support for measuring the contribution of nuclear energy to carbon emission reduction. The research on the carbon emission coefficient of different energy forms based on the life cycle method shows that the average carbon emission of nuclear power LCA is 65 g CO2/kWh, which is higher than that of wind power and lower than that of solar power [8]. More data support the nuclear power LCA carbon emission coefficient between 1.8–20.9gCO2/Kwh [8,9,10]. The greenhouse gas emission coefficient of China’s nuclear power chain has been reduced from 13.71g CO2/Kwh in the mid-1990s to 11.9gCO2/Kwh, which is significantly lower than coal and other fossil energy sources, and most of them are concentrated in the nuclear power construction period [11,12,13]. Empirical studies in China, the United States, Japan and France show that the long-term carbon emission coefficient of nuclear energy is lower than that of renewable energy, but current nuclear energy reduction effect in China is relatively limited compared to other countries [14].

Accurate calculation of carbon emissions/emission reductions is the basis for emission reduction policy formulation, mechanism design, and market transactions. It is particularly important to study and master calculation methods. The IPCC guidance manual provides a common method for calculating carbon emissions by multiplying activity level data by emission coefficients. This method is suitable for the compilation of national greenhouse gas inventories [15], but for specific projects, the use of default values usually leads to large deviations in the calculation results. Fine metering also includes the CO2 emission data of power plants obtained by the European Environment Agency (EEA) by monitoring the waste emissions and emission density of thermal power projects. This method requires the power plant to have complete flue gas monitoring equipment, and the cost is relatively high [16]. Chinese scholars have also conducted further research on project-based energy carbon emissions using mature methods. For example, explore modeling based on combustion mechanism analysis and statistical law to predict greenhouse gas emissions from coal-fired power plants [17]. This model is based on the analysis of the influencing factors of CO2 emission factors, and the calculation of comprehensive emission factors considering fuel combustion and process factors [18] However, in order to meet the balance between the actual measurement cost and the calculation accuracy, it is still practical to use the emission factor measurement method [19].

In order to deal with the problem of global warming, IPCC has led the development of calculation methods for emission reductions of CDM projects. The method development must explain basic issues such as project scope, emission sources, and baselines. Among them, the baseline directly determines the carbon reduction and environmental benefits of CDM projects [20]. Before China suspended the methodological review and project approval of the CCER project in 2017, as many as 200 corresponding CDM methodologies had been translated and transformed. In fact, most of China’s current carbon emission reduction calculation standards are also derived from the project development methodology under the CDM mechanism. During the pilot period, the methods and principles in the calculation regulations for carbon emissions/emission reductions in each regional market are basically the same. They are all based on the emission factor method, the material balance method and the actual measurement method. The main difference is the selection of some default values [21].

Scholars at home and abroad have conducted in-depth research on the role of additionality, the method of demonstration and its effectiveness. Additionality determines the supply and quality of offset credits in the carbon market [22], which is essential for the environmental integrity of offset mechanisms and clean development mechanisms [23]. The most common way to demonstrate additionality is through barrier analysis and investment analysis. This means that if the project is not registered as a CDM activity, there are obstacles to its realization and the proposed project is less financially attractive than at least one other credible alternative. Finally, consider whether the proposed project type has been widely deployed in the relevant department or region through practical analysis [24]. Most views hold that the emission reduction mechanism based on additionality is generally effective or at least in the progress of being perfected, and can achieve greenhouse gas emission reduction [25, 26], but attention should be paid to the problems in the development process [27]. The technical and economic evaluation of wind power, hydropower and other projects that do not consider CDM benefits finds that their internal rate of return is high and the possibility of additionality is low. Similar results provide evidence for this view [28]. In addition to the shortcomings of the rules, additionality descriptions and assessment tools also have problems such as overly complex assessment procedures [29]. In the process of project methodology, additionality is also an important issue to be discussed. The methodology development research in China’s energy field has covered wind power, hydropower and other clean energy forms.

Through literature analysis, we found that the current research in the field of nuclear carbon emission reduction focuses on the macro-level such as industry and industry, which also verifies the realistic dilemma mentioned in the introduction of this study. In addition, the results of literature analysis help us determine the calculation method of carbon emission reduction of nuclear energy projects, and clarify the importance and method of additionality demonstration of nuclear energy projects.

3 Methodology

This chapter uses CDM methodology, EU carbon Emission reduction Trading system and carbon emission reduction quantification methods in China’s voluntary emission reduction methodology to calculate carbon emission reduction. According to GB/T33760-2017 “Based on General Requirements for Technical Specifications for Assessment of Greenhouse Gas Emission Reductions of Projects” and GB/T32150-2015 “General Rules for Accounting and Reporting of Greenhouse Gas Emissions of Industrial Enterprises”, this chapter studies the boundary range, emission source identification, baseline, emission factor, and activity level data of the calculation method of carbon emission reduction of nuclear energy projects.

3.1 Nuclear Energy Carbon Emission Reduction Calculation Method

The calculation method of carbon emission reduction of nuclear energy projects adheres to the following basic principles: (1) Select appropriate GHG emission sources, data and methods. (2) Include all greenhouse gas emissions adapted to the project needs. (3) Adopt the same criteria, procedures and calculation period. (4) Minimize uncertainty and deviation. (5) Release fully transparent information in accordance with national policies and trade secrets ensuring that assumptions, values and methods used do not overestimate emission reductions.

Fig. 1.
figure 1

Project based carbon emission reduction assessment procedure

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The evaluation procedure that should be adhered to for project-based carbon emission reduction calculations is shown in the Fig. 1.

3.1.1 Determine the Type of Accounting Gas

The types of GHGs to be assessed should be determined according to project needs. Combined with the current focus of carbon market trading, nuclear energy projects should focus on calculating CO2, but should not ignore CH4, N2O, fluoride, etc. that may exist in the production process of the project.

3.1.2 Determine Project Boundaries

The project boundary refers to the spatial extent covered by project activities and emissions-related matters in the baseline scenario. It includes the considered emissions from all sources of greenhouse gases that are within the control of project participants and that are appreciable and reasonably attributable to the project. Since the scope of production activities of a nuclear energy project is relatively clear, the boundary of a nuclear energy project should include project-related equipment, facilities (systems) or organizations that are affected by the project. The emission source of the project points to the physical unit or process that emits greenhouse gases into the atmosphere. The nuclear energy project should identify the emission source separately according to Table 1, and should not be omitted due to the actual calculation process.

Table 1. Potential carbon emission sources of nuclear energy projects
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3.1.3 Determine Baseline Scheme

Different types of projects should choose different baseline Schemes. For new projects, the baseline Schemes should be based on the mainstream technologies adopted in the industry or in the region or the technologies required by national policies. For reconstruction and expansion projects, the baseline Schemes should be determined according to the needs of target users, which can be compared with the technology before reconstruction or with reference to new projects. The emission source of the baseline shall be identified according to the method of GB/T 32150 or by referring to other related methods. The argument for additionality is relative to the baseline of alternatives. Common central heating methods in northern China include: coal-fired thermal power plants, coal-fired boiler rooms, gas-fired thermal power plants, gas-fired boiler rooms, gas-fired distributed cooling, heating and power supply stations and other heating sources [30].

3.1.4 Carbon Emission Reduction Calculation Method

According to the project, the emissions of each greenhouse gas in each greenhouse gas source under the project and baseline scenarios in a certain period are calculated respectively, and the project emissions and baseline emissions are obtained by summarizing. The emission factor calculation method is adopted, and the general formula is shown in (1)–(2):

$$ ER = BE - PE - LE $$
(1)

where: \(ER\) refers to project emission reduction, \(BE\) refers to baseline emissions, \(PE\) refers to project emissions, and \(LE\) refers to emissions caused by gas leakage during project operation. The units are all tons of carbon dioxide (tCO2).

The baseline emissions, project emissions and leakage emissions can all be calculated by multiplying activity level data and corresponding emission factors. As shown in formula (2):

$$ E = AD \times EF \times GWP $$
(2)

where: \(E\) refers to baseline emissions, project emissions or leakage emissions. Units are tons of carbon dioxide equivalent (tCO2e). \(AD\) refers to activity level data, determined according to the emission source. \(EF\) is the emission factor matching the activity level data. \(GWP\) is the greenhouse gas potential value, which should refer to the data provided by the IPCC.

For nuclear energy heating projects, whether it is a small reactor heating mode or an extraction heating mode relying on large-scale nuclear power, the loss of heat transmission should be considered.

$$ BE = HS_{BL} \times EF_{CO2} /\eta_{L} $$
(3)
$$ HS_{BL} = HS_{PJ} - LOSS_{PJ} + LOSS_{BL} $$
(4)

where: \({HS}_{BL}\) refers to the heat supply of the baseline scheme. \({HS}_{PJ}\) refers to the heat supply of the project. \({LOSS}_{BL}\) refers to the heat loss of the heat transfer link of the baseline scheme. \({LOSS}_{PJ}\) refers to the loss of the heat transfer link of the project Heat. \({EF}_{CO2}\) refers to the heating carbon dioxide emission factor of the baseline scheme. This variable is obtained by converting the carbon dioxide emission factor per unit of standard coal and the conversion coefficient of standard coal per unit of heat. \({\eta }_{L}\) refers to the net thermal efficiency of the coal-fired boiler.

For nuclear energy heating projects in the small reactor heating mode, since electricity is purchased from outside in the operation process, it is necessary to take into account the carbon emissions caused by the additional electricity consumption of the project. At the same time, it also adheres to the principle of conservatively estimating emission reductions. In addition, the project considers carbon emissions from sporadic fossil fuel use during the operating period.

$$ PE = PE_{EC} + PE_{FF} $$
(5)
$$ PE_{EC} = EC \times EF_{PE} $$
(6)

Among them: \({PE}_{EC}\) refers to the carbon emissions caused by the project’s additional electricity consumption. \({PE}_{FF}\) refers to the carbon emissions caused by the project’s direct use of fossil fuels. \(EC\) is the annual extra power consumption of the project, and \({EF}_{PE}\) is the average power emission factor of the power grid where the project is located.

3.2 Key Points of Nuclear Additionality Demonstration

3.2.1 Investment Analysis

After identifying the baseline scheme, the project applicant should screen out at least one suitable alternative and make an investment analysis. The so-called investment analysis is to prove that the proposed project, in the absence of CER income: (1) is not economically or financially optimal; (2) is not economically or financially feasible. If the proposed project, without CER revenue, emits less GHGs, but because the economic benefits are not optimal, the investor will choose an alternative with higher emissions but higher economic benefits.

Common methods include: (1) simple cost analysis, which is used for projects that will not generate any income; (2) comparative investment analysis, which is used for projects that will generate income, usually it is necessary to select a certain economic indicator and the alternative selected in the first step. For nuclear energy projects, optional indicators include internal rate of return, net present value, levelized kWh (heating) cost, etc.; (3) Baseline analysis, which is also used for projects that generate income, but requires Note that this baseline analysis is not related to the baseline in 3.1.3. It refers to selecting a specific indicator to compare with a baseline. Optional indicators include return on capital, long-term loan interest rates, and officially released investment decision indicators. Etc., nuclear energy projects can choose the average yield of the power industry as the baseline. Therefore, when conducting investment analysis of nuclear energy projects, it is not necessary to strictly demonstrate its economic infeasibility, but only to prove that it is not the optimal choice economically.

3.2.2 Barrier Analysis

This step can be skipped if it has been demonstrated in the investment analysis that the proposed project is not “economically or financially optimal” or “economically or financially infeasible”. However, if similar results cannot be obtained, a barrier analysis method must be used to demonstrate that (1) the proposed project cannot be implemented due to some barriers; and (2) the barriers do not affect at least one of the alternatives. In other words, although the proposed project is economically optimal (or feasible), it is not feasible for other reasons, and at least one alternative is not affected by those reasons.

The so-called “barriers” include (1) other investment barriers other than the economic/financial barriers in the second step (e.g. the proposed project does not allow any private capital entry by law); (2) technical barriers (e.g. the ability to operate and maintain Technicians for this project cannot be found in the proposed project implementation area/adjacent areas, thus creating obstacles to the operation and management of the project).

To sum up, if a nuclear energy project is economically feasible, it is difficult to advance the project due to obvious obstacles such as public safety concerns, technical verification of the first reactor, demonstration construction, and scientific research purposes, and even there are laws that strictly restrict the entry of private capital into a nuclear energy project. At the same time, in the case of encouraging investment in other clean energy fields such as wind power and photovoltaics, it is a feasible option to focus on the additionality argument on the analysis of obstacles.

3.2.3 Universal Analysis

Generality analysis is usually used as a supplementary verification after the preceding arguments have been completed. Including: (1) Analysis of whether there are similar projects for the proposed project; (2) Analysis of the difference between similar projects and the proposed project. To be considered similar, two projects need to meet the following conditions: (1) are located in the same country or region and/or rely on similar science and technology; (2) have a similar scale; (3) have a similar legal environment, Investment climate, available technologies, size of capital, etc. For nuclear energy projects, its technical specificity determines that there are no other forms of energy similar to it. Therefore, the universal analysis of nuclear energy projects will not be a hindrance to project applications.

From the analysis of the additionality demonstration methods combined with the characteristics of nuclear energy projects, it shows that the focus and path of additionality demonstration of nuclear energy projects of different types, stages and application scenarios are also different. The actual case finds the argumentation method that suits its own demands.

4 Emprical Results and Analysis

4.1 Case Study Regions and Data Sources

Haiyang Nuclear Energy Pumping and Heating Project is located in Haiyang, Shandong Province, relying on Haiyang Nuclear Power Unit No. 1. The main technical feature is the intermediate stage extraction of conventional island steam turbines of nuclear power units. Public information shows that after the project is put into operation, the heating area of the second phase of the project is 4.5 million m2, and 100,000 t of raw coal can be saved in each heating season, reducing the heat emission to the environment by 1.3 million GJ. The average heating index in this area is 45 W/m2.

The case project data are all taken from the approved project feasibility study report. Through the project feasibility study report, environmental impact assessment report and other documents, it is confirmed that the implementation of this project can contribute to local sustainable development in terms of reducing greenhouse gas emissions and reducing pollutant emissions.

The power system emission factor is taken from the baseline emission factor of China’s regional power grid of the emission reduction project in 2019.

4.2 Carbon Emission Reduction Calculation Results

The type of greenhouse gas calculated by the project is CO2. The project boundary is the nuclear energy extraction heating production boundary and all users connected to the heating pipe network. The project has no fossil energy combustion emission sources, and the electricity required for its production can be supplied by the Haiyang Nuclear Power Station, and there is no externally purchased electricity emission source. The waste treatment process is not considered as a process emission source due to lack of monitoring data. Therefore, the project has no emission sources as a whole.

Baseline options (Table 2) are identified based on the heating services available in the Shandong region where the project is located, capable of providing the same level of heating as the proposed nuclear energy project activity.

For the nuclear extraction heating project, the coal-fired boiler is the most convenient way to realize central heating in combination with the resource endowment and economic development level of the project location and Shandong region. Therefore, the alternative scheme for the nuclear heating project is proposed as follows:

  1. (1)

    Implement the project activities without the benefit of emission reduction;

  2. (2)

    The project activities that provide the same heating capacity by means of centralized heating with coal-fired boilers.

Table 2. Potential baseline alternatives for nuclear extraction heating
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The annual assumed carbon emission reduction calculation results of the nuclear heating project are shown in Table 3. From the calculation results, it can be seen that the estimated value of annual carbon emission reduction is about 274100 tons of CO2. Since many default values are used in the calculation, the accuracy of the results needs to be further improved. In addition, compared with the publicly reported data of 180000 tons of emission reduction, the comparative analysis shows that the potential error factor is the net thermal efficiency of fossil fuel boilers. The value calculated in this study is conservative, and the publicly reported data may not consider the impact of this factor.

Table 3. Annual carbon emission reduction of nuclear energy extraction heating project
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4.3 Carbon Emission Reduction Calculation Results

On the basis of identifying the baseline scheme, the economic attractiveness between the nuclear heating project and the alternative scheme is compared with the investment comparison analysis method given in the CDM project joint tool for baseline identification and additionality demonstration (v05.0.0). The commonly used levelized heating cost is selected as the financial index, which is derived from the “Projected Costs of Generating Electricity, 2020 Edition”published by the International Energy Agency.

The formula for calculating the cost of standardized heating is as follows:

$$ LCOH = \sum\nolimits_{t} {\frac{{I_{t} + M_{t} + F_{t} }}{{\left( {1 + r} \right)^{t} }}/\sum\nolimits_{t} {\frac{{H_{t} }}{{\left( {1 + r} \right)^{t} }}} } $$
(7)

where: \(LCOH\) refers to the levelized heating cost (yuan/GJ). \({I}_{t}\) is the investment amount in the year t. \({M}_{t}\) is the operating cost in the year t. \({\text{M}}_{{\text{t}}}\) \(F_{t} \) is the fuel cost in the year t. \( H_{t}\) is the total amount of heat supply in year t. \(r\) is the discount rate.

Table 4 shows the main calculation parameters and results of levelized heating cost for nuclear extraction heating and coal-fired boiler heating. When the internal rate of return is required to be 8%, the levelized heating cost of the proposed project is 49.20 yuan/gj, which is slightly higher than that of the alternative scheme, which is 47.86 yuan/gj. Only from the cost point of view, the project needs to expand revenue channels to make up for the cost disadvantage. Therefore, since the construction of the project has good demonstration benefits for nuclear heating and emission reduction, carbon emission reduction benefits or subsidies can be obtained. This is consistent with the statement in the project feasibility study report.

In terms of Barrier Analysis, nuclear heating technology is advanced and faces technical and investment risks, and has not been commercialized in China. At the same time, the project complies with the requirements of current laws and regulations, and is not an object of enforcement by existing laws and regulations. Nuclear energy heating projects are not included in any policies and regulations that are conducive to the development of clean energy, such as subsidies, tax reductions, concessions, and quota systems. Therefore, it can be considered that there are certain obstacles in the project.

For Universal Analysis, we refer to the CCER “Guidelines for Universal Analysis (v3.1)” to identify geographic scope, scale, technology, fuel source and project attributes one by one. The project is located within the geographical scope of Shandong Province, with a thermal load scale of 31.5MW. It is a nuclear energy heating project that utilizes gas extraction from the steam turbine of a nuclear power plant. After on-site investigation and online inquiry, there is no heating project with similar scale and the same technology and fuel source within the geographical scope of the project. Therefore, this project is not universally implemented in Shandong Province and is not universal.

Table 4. Investment analysis of nuclear heating projects and alternatives
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5 Conclusions

The calculation framework of carbon emission reduction of nuclear energy projects established by this research reveals that the accurate calculation of carbon emission reduction of nuclear energy projects is feasible from the calculation logic and method, and there is no particularity in the design and parameter selection of calculation methods and verification methods. At the same time, through the comparative analysis of the levelized heating cost in the additionality demonstration, it is preliminarily verified that when the coal price is about 650 yuan/t, the economics of the nuclear energy heating project in Shandong is not significant, and the carbon emission reduction brought by nuclear energy heating The so-called inadequacy of “economics” will be further improved. In fact, the “economics” of nuclear energy heating projects is seriously affected by the “baseline” and the results of parameter selection. In addition, this also provides a method and paradigm reference for nuclear-armed countries around the world to explore the economic improvement path of nuclear energy projects.

Through the analysis of the carbon emission reduction calculation method and the results of the case study, the specific conclusions can be drawn as follows:

  1. (1)

    The carbon emission reduction of the nuclear energy extraction and heating project in the case study is about 274,100 t, which is in the order of magnitude as the emission reduction of large-scale emission reduction projects in the market. From the perspective of the project, the market adaptation of the nuclear energy extraction and heating project higher degree. However, the emission reduction of a single unit of nuclear power projects generally reaches millions of tons of CO2, which is much higher than that of nuclear energy heating projects.

  2. (2)

    The carbon emission reduction of nuclear energy projects is affected by factors such as regional energy consumption structure, application scenarios, and project scale. Among these factors, the regional energy consumption structure determines the value of the grid emission factor, which has a fundamental impact on the emission reduction of the project. For example, the carbon emission factors of power grids in North China and Northeast China are relatively large because of the high proportion of fossil energy in the power grid energy structure in these regions. This makes the potential carbon emission reduction benefits of deploying nuclear energy projects in the above regions even greater. This idea also provides another strong support for the deployment of nuclear energy projects in northern and inland regions.

  3. (3)

    In the case study, the levelized heating cost of the nuclear steam extraction heating project is slightly higher than that of the alternative, which creates an illusion. When we increase the coal price by 100 yuan/t, the \(LCOH\) of the alternative scheme becomes 52.99 yuan/t. At this time, the nuclear energy extraction steam heating project is more economical. Therefore, the carbon emission reduction calculation and additionality demonstration of nuclear energy projects should carefully select the baseline. This suggests that our nuclear energy projects will give full play to their advantages in the energy situation with high coal prices. When there is no obvious disadvantage in the economics of nuclear energy projects compared with other alternatives, the demonstration of the additionality of nuclear energy projects should focus on analyzing the obstacles such as technological advancement and market promotion.

In China, the CCER mechanism is currently in a stagnant state, but during the research process, we found that the expectation of the restart of the CCER market is becoming clearer. In the future, the development of project-based carbon emission reduction calculation methods should show a trend of broader application fields and more accurate parameters. In order to promote the incorporation of nuclear energy projects into the carbon emission reduction market mechanism, it is also necessary to proceed from the perspective of engineering practice. The first task is to fully learn from mature experience and conduct research on project-based carbon emission reduction measurement methods. In fact, as the emission reductions of CCER projects are consumed year by year in a stagnant state, and new energy projects such as wind power and photovoltaics gradually achieve grid parity, nuclear energy heating projects will have the opportunity to provide stable voluntary certified emission reductions for China’s carbon market supply.

Finally, the prospect of further research is proposed:

  1. (1)

    In order to meet the data accuracy requirements of emission reduction project development, nuclear energy projects should establish a perfect data monitoring and statistical system, and optimize the calculation parameters through field research.

  2. (2)

    Promote the transformation of economic benefits of carbon emission reduction of nuclear energy projects, and select projects with appropriate emission reduction scale and high urgency for economic improvement to carry out pilot projects.

  3. (3)

    In the face of a wider range of nuclear energy applications, it is necessary to do reserve research on the calculation method of nuclear energy carbon emission reduction based on the project caliber in more scenarios.