The Wiki-INPRO (under development)

The International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) was established in 2000 to help ensure that nuclear energy is available to contribute to meeting the energy needs of the 21st century in a sustainable manner.

This Wiki is an initial attempt to formulate in a structured manner the accumulated experience and knowledge on the concepts, ideas, and methodology relevant to the INPRO domain.

The content of the Wiki is an opinion of the expert community and does not represent the official position of the IAEA, unless explicitly mentioned or referenced from a relevant IAEA publication.

Introduction

Figure 1. Four tasks in INPRO for sustainability of nuclear energy systems.

Figure 2. The essence of INPRO task areas.

INPRO derived its concept of a sustainable development of nuclear energy from the United Nations (UN) sustainable development concept issued in the 1987 Report of the World Commission on Environment and Development. The following is the reports definition for sustainable development.

“Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs”.

INPRO is an IAEA forward looking project that integrates all areas important to sustainability of nuclear energy. There are four tasks in INPRO for sustainability of nuclear energy systems, as shown in Figure 1; these are global scenarios analysis, role of innovations in sustainability, sustainability assessments and strategies, and outreach and dialogue. Figure 2 captures the essence of INPRO task areas.

INPRO Methodology

INPRO developed a methodology for performing a sustainability assessment of nuclear energy systems. An INPRO sustainability assessment of nuclear energy addresses the four UN areas with six key assessment areas: economics, safety, environmental impact, waste management, proliferation resistance and infrastructure.

The development of the INPRO methodology was through consultancy and technical meetings with INPRO member states, international experts, and evaluation over time. In 2008 the IAEA published “Guidance for the Application of an Assessment Methodology for Innovative Nuclear Energy Systems, INPRO Manual-Overview of the Methodology”, INPRO also published the lessons learned document after applying the methodology in 2009. Since then, INPRO has been updating the INPRO manuals in six areas with 9 INPRO manuals, as shown in Figure 3. These manuals support the INPRO Methodology for Sustainability Assessment of Nuclear Energy Systems.

Framework of INPRO methodology

INPRO used the goals to develop a fundamental basic principle (BP) for each assessment area. Each assessment area has one fundamental BP, which defines the goal or target that the NES needs to achieve to be sustainable.

In the INPRO methodology each BP has user requirement (UR) and criteria (CR) which enables an assessment of the NES for sustainability. A UR defines what should be done to meet the target/goal of the INPRO methodology basic principle (BP). The UR is for specific institutions (users) involved in nuclear energy development, deployment and operation, i.e., the developers/designers, government agencies, facility operators, and support industries. A CR enables the INPRO assessor to determine whether or how well a UR is being met by a given NES. A logical CR is associated with some important feature of (or measure for) an NES and is usually presented in the form of a question that has to be answered positively. Figure 4 shows the framework of INPRO methodology. Each assessment area/manual has a BP; with 2-7 UR per BP; and 1-6 CR per UR.

Figure 4.Diagram showing framework of INPRO methodology.

Nuclear energy system assessment (NESA) process

In summary an assessment using the INPRO methodology is a process of making a judgement about the long-term sustainability of an evolutionary or innovative NES. The fulfilment of URs is checked by an assessor via CR.

A criterion consists of an indicator (IN) and an acceptance limit (AL).

An indicator (IN) is part of the criterion. The INPRO methodology uses two types of indicators: numerical and logical. A numerical indicator may be based on a measured or calculated value that reflects a property of a nuclear energy system (NES), such as the probability of severe core damage after an accident. A logical indicator is usually associated with some necessary feature of an NES and usually is presented in the form of a question, with either a positive (yes) or negative (no) assessment.

An acceptance limit of an INPRO criterion (CR) is a target, either qualitative or quantitative, against which the value of an indicator (IN) can be compared by the INPRO accessor leading to a judgement of acceptability (pass/fail, good/bad, better/poorer). In correspondence to the two types of indicators there are also two types of acceptance limits, numerical (for quantitative targets) and logical (for qualitative targets). Typically, a logical AL is a positive (yes) or negative (no) answer to a question raised by the indicator.

The sustainability assessment in the CR-level appears in Figure 5. When the CR are met the NES is considered sustainable. When the CR are not met it identifies gaps and thus gives the developer, designer, or State a chance to change the design of or options in an NES, to lead to a sustainable NES. Sustainability covers an NES for its entire lifecycle, from design through construction, operation, and decommissioning.

Figure 5. Diagram of CR-level sustainability assessment.

Figure 6 shows the process of assessing the sustainability of a nuclear energy system. The steps are as follows:

• Select the NES and the associated components.
• Collect design information including the functioning of the NES or a component, and any additional information needed for the assessment.
• Decide on the INPRO areas for the assessment. A full INPRO assessment covers all six area, or a limited scope assessment just covers one or more areas.
• Criteria fulfilled for all the UR?

  - Yes, NES sustainable; 

  - No, modification to the NES. Technology User can Modify NES; Technology Developer can modify / Define R&D needs to close gaps.

• Reassess to confirm sustainability

Figure 6. Flowchart for the NESA, showing outcomes of CR fulfilment.

The ultimate goal of INPRO methodology assessment is to check whether the NES fulfils all the CR and hence UR, and BP, therefore represents a long-term sustainable system for a MS or MS-Group. The NESA can help designers, technology holders, and States by identifying gaps and weaknesses in the NES. These assessments then give States and designers the opportunity to make changes in the design or planning stages of an NES when it is much more cost effective. This process supports the development of more sustainable options. Furthermore, the NESA is helpful for a State when comparing two options for an NES, or looking at synergies in options, to aid in identifying the option(s) that is the most sustainable for their needs.

The areas and basic principles in NESA

Therefore, there are a total of 8 INPRO manuals for the assessment of a nuclear energy system. Each area has one BP, and from 2-7 CR. This section gives a more in depth look into each assessment area.

Economics

For an NES to meet long-term sustainability, the nuclear energy must be available and affordable. Nuclear energy must be competitive with other energy sources, not necessarily the cheapest option. Figure 7 contains the INPRO BP for economics along with user requirements.

Figure 7. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in economics.

Environment

There are two aspects regarding the environment. One aspect concerns the environmental impact from depletion of resources, and the other discusses the environmental impact of stressors.

Environment Impact from Stressors

Fig. 8 shows the BP and UR for an INPRO sustainability assessment in environment impact from stressors.

Figure 8. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in environment impact from stressors.

Environment Impact from Depletion of Resources

Fig. 9 shows the BP and UR for an INPRO sustainability assessment in Environment impact from depletion of resources.

Figure 9. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in Environment impact from depletion of resources.

Waste Management

Fig. 10 shows the BP and UR for an INPRO sustainability assessment in waste management.

Figure 10. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in waste management.

Safety

The safety principles and requirements developed within INPRO are based on extrapolation of current trends and seek to encompass the potential interests of developing countries and countries in transition. For nuclear reactors, the fundamental safety functions are to control reactivity, remove heat from the core, and confine radioactive materials and shield radiation. For fuel cycle installations, they are to control sub-criticality and chemistry, remove decay heat from radionuclides, and confine radioactivity and shield radiation.

Safety of Nuclear Reactors

Fig. 11 shows the BP and UR for an INPRO sustainability assessment in Safety of nuclear reactors.

Figure 11. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in Safety of nuclear reactors.

Proliferation Resistance

Fig. 12 shows the BP and UR for an INPRO sustainability assessment in proliferation resistance.

Figure 12. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in proliferation resistance.

Infrastructure

Fig. 13 shows the BP and UR for an INPRO sustainability assessment in infrastructure.

Figure 13. The basic principle (BP) and user requirements (UR) for an INPRO sustainability assessment in infrastructure.

Performing a NESA

Fig. 14 shows the steps in performing a NESA.

Figure 14. Steps in performing a NESA.

Case study

INPRO methodology has been applied several times to the nuclear energy systems based on evolutionary water cooled reactors, as well as sodium cooled fast reactors. The NESA of Belarus can be seen in INPRO Assessment of the Planned Nuclear Energy System of Belarus, and the NESA of BN-1200 can be seen in Limited Scope Sustainability Assessment of Planned Nuclear Energy Systems Based on BN-1200 Fast Reactors.

Analysis Support for Enhanced Nuclear Energy Sustainability (ASENES)

INPRO has developed a service for Member States “Analysis Support for Enhanced Nuclear Energy Sustainability (ASENES)”. The main purpose of this service is to assist and guide Member States on scenario development and analysis, comparative evaluation of nuclear energy system/scenario options and road mapping to support strategic planning towards enhanced nuclear energy sustainability.

The main service modules:

1. Modelling Nuclear Energy Systems (NES);
2. Economic Evaluation of Alternative Nuclear Energy Systems;
3. Comparative Evaluation of NES/ Scenario Alternatives;
4. Road-mapping for enhanced nuclear energy sustainability.

Nuclear energy system evolution scenario modelling could help better understand the key issues of, and find plausible solutions for, enhanced nuclear energy sustainability.

Economic evaluation of alternative nuclear energy systems is useful to evaluate competitiveness of NES options.

Comparative evaluation of nuclear energy system or scenario options based on problem structuring and the state-of-the art judgement aggregation/uncertainty analysis methods could be used to support the multi-criteria selection of a preferred nuclear energy system through a substantive dialogue with decision makers.
Road mapping activities would help represent the status, prospects, benefits and risks associated with a variety of options for the national nuclear energy system configuration and evolution scenario. Given sufficient detail, it could indicate opportunities for saving time, effort and resources for improving characteristics of a national nuclear energy system through cooperation with other countries.