INPRO collaborative project: GAINS (Sustainability Assessment)

From INPRO Wiki
Revision as of 14:06, 4 August 2020 by SHIROKIYD (talk | contribs) (Created page with " This page is the "Appendix III" to Environmental Impact from Depletion of Resources During 20...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
This page is the "Appendix III" to Environmental Impact from Depletion of Resources

During 2008–2011, INPRO conducted the collaborative project GAINS [3], with participation by Belgium, Canada, China, Czech Republic, France, India, Italy, Japan, Republic of Korea, Russian Federation, Slovakia, Ukraine, USA and the European Commission, with Argentina as an observer.
This appendix summarizes the findings of GAINS, focusing on the issue of demand for uranium resources by possible NESs until the end of the twenty-first century.

Introduction

The overall objective of the GAINS project was to develop a standard framework — including a methodological platform, assumptions and boundary conditions — for assessing future NESs, taking into account sustainable development, and to validate the results through sample analyses.
It is to be noted that this project did not have a specific goal to evaluate the potential global supply of uranium until the end of the century and beyond, but focused on the introduction of advanced nuclear reactor technologies and associated fuel cycle strategies in a heterogeneous real world model, with the cooperation of different countries in the nuclear fuel cycle to achieve a number of sustainability goals, including a reduction of the global demand for uranium.

FIG. 1. Selected world models for fuel cycle analysis in GAINS [3].
FIG. 2. Heterogeneous model with non-synergistic groups NG1–NG3 [3].
FIG. 3. Heterogeneous model with synergistic groups and specific reactor types and fuel services identified [3]. HTR — high temperature reactor; HWR — heavy water reactor; LWR — light water reactor; MNA — multilateral nuclear approach.

The project used two main models to investigate the possible development of nuclear power during the twenty-first century. One model employed the assumption of a complete homogeneous world, i.e. a world that involves uniform nuclear technology application in each and every country. A second, more realistic, approach was to define a heterogeneous world with three different groups (NG1–NG3) of non-personified countries with different policies regarding the back end of the nuclear fuel cycle. The three groups NG1–NG3 are defined as:

  • NG1: General strategy is to recycle used fuel. This group plans to build, operate and manage FRs and use fuel recycling facilities and geological disposal facilities for highly radioactive waste (from reprocessing).
  • NG2: General strategy is to either directly dispose of used fuel, or reprocess used fuel abroad. This group plans to build, operate and manage thermal reactors and geological disposal facilities for highly radioactive waste (in the form of used fuel and/or reprocessing waste) and/or work synergistically with another group to have its fuel recycled.
  • NG3: General strategy is to use fresh fuel, and send used fuel abroad for either recycling or disposal, or the back end strategy is undecided. This group has no plans to build, operate and manage used fuel recycling facilities or permanent geological disposal facilities for highly radioactive waste. It may obtain fabricated fuel from abroad, and may arrange for export of used fuel.

In addition, in the three group approach, non-synergistic and synergistic behaviours of the world are assumed. The selected models of the world are shown in Fig. 1.
A synergistic world requires communication and material flow between groups of countries, whereas a non-synergistic world would not exchange nuclear materials other than fresh fuel. Figures 2 and 3 illustrate non-synergistic and synergistic models of the world, respectively.
GAINS performed parametric evaluations of a payback time for investments in technology development for FRs and a closed nuclear fuel cycle versus planned national deployment of such technologies. It was concluded that, at least within the twenty-first century, the world is likely to follow the heterogeneous model shown in Fig. 3.
Several analytical tools were used in the GAINS study, but most analytical results were produced using the computer codes MESSAGE, NFCSS and DESAE, available from the IAEA (brief descriptions of these tools can be found in the overview volume of the updated INPRO manual). In many cases, participants in the study also used their national computer codes (Commelini–Sicard (COSI) by France, Dynamic Analysis of Nuclear Energy System Strategies (DANESS) and Verifiable Fuel Cycle Simulation Model (VISION) by the USA, and Tool for Energy Planning Studies (TEPS) by India) to support the project. The GAINS report [3] includes a brief description and the results of cross-verification of all these codes.

Global demand for power supply by nuclear energy

The GAINS project, inter alia, evaluated a series of available studies with nuclear power scenarios and documented a brief summary thereof in the final report [3]. The studies included: International Nuclear Fuel Cycle Evaluation [42], Joint Study: Assessment of Nuclear Energy Systems Based on a Closed Nuclear Fuel Cycle with Fast Reactors [43], and Nuclear Energy Development in the Twenty-first Century [44] by the IAEA; Nuclear Fuel Cycle Transition Scenario Studies [45], Strategic and Policy Issues Raised by Transition from Thermal to Fast Reactors [46], Advanced Nuclear Fuel Cycles and Radioactive Waste Management [47], and Trends in the Nuclear Fuel Cycle [48], by the OECD/NEA; Red Impact Synthesis Report by SCK·CEN [49]; and Partitioning and Transmutation European Roadmap for Sustainable Nuclear Energy by the European Commission [50].

FIG. 4. GAINS scenarios for modelling nuclear power generation in the twenty-first century [3]. IPCC — Intergovernmental Panel on Climate Change.

Based on comprehensive analysis and intensive discussions of the available projections on nuclear demand in the twenty-first century, GAINS selected two nuclear energy demand scenarios (as illustrated in Fig. 4):

  • A high nuclear energy demand scenario, a variant of the medium expectation of the IPCC Special Report on Emission Scenarios. In this scenario, global annual nuclear energy generation reaches approximately 700 GW(e) by 2030, 1500 GW(e) by the middle of the century and 5000 GW(e) by 2100.
  • A moderate nuclear energy demand scenario, assuming approximately 600 GW(e) by 2030, 1000 GW(e) by mid-century and 2500 GW(e) by the end of the century.

Types of reactors considered in GAINS

GAINS has developed an internationally verified database for material flow analysis of NESs with reactors and nuclear fuel cycles of different types. The reactor types used in basic calculations of GAINS correspond to proven thermal and FR technologies, leaving little doubt as to the feasibility of the corresponding nuclear power plants. The following types of reactors are included in the GAINS database:

  • Light water cooled and moderated reactors (LWRs) with low, medium and high burnups (45 × 103–60 × 103 MWˑd/t) and different thermal efficiencies;
  • Heavy water cooled and moderated reactors (heavy water reactors (HWRs)) with different types of fuel (UO2, ThO2, 233U and PuO2);
  • FRs with different conversion factors (1.00–1.16) and different burnups (31–100 MWˑd/t).

In all cases, it was assumed that FRs were started from the U–Pu fuel load obtained from reprocessing of the SNF of LWRs.

Scenarios considered in GAINS

As mentioned previously, GAINS looked at homogeneous and heterogeneous scenarios, and for the latter, at non-synergistic and synergistic behaviours.
For a homogeneous world, the following NES scenarios were considered: BAU+ (business as usual with present day and advanced LWRs, with ‘+’ standing for the latter) and BAU+–FR (business as usual with introduction of FRs). First, the results for the selected homogeneous scenarios will be presented, followed by the heterogeneous non-synergistic and synergistic scenarios.

BAU+ scenario in a homogeneous world

The homogeneous scenario without introduction of FRs is presented here. The global NES in the BAU+ scenario includes standard LWRs (as installed at 2008) and a conventional HWR, and after 2015, gradually adds advanced types of LWRs called advanced light water reactors (ALWRs), with higher burnups and thermal efficiencies, which completely replace the standard LWRs after 2055. The global power generation is shown in Fig. 5 and the uranium consumption is shown in Fig. 6.

The total global uranium consumption reaches 36.1 × 106 t and 20.9 × 106 t by 2100 for the high and moderate BAU+ cases, respectively.

BAU+–FR scenario in a homogeneous world

The BAU+–FR scenario includes, in addition to FRs, standard LWRs (as installed at 2008) and conventional HWRs, and after 2015, ALWRs with higher burnup, which completely replace the standard LWRs by 2055.
In this scenario, FRs (with a conversion rate of 1.0, a so called break even core design) — in addition to standard LWRs and HWRs — are assumed to be initially introduced in 2021 at a low rate of 1 GW·a of power generation per year for the first 10 years; after 2031, the installation rate is increased to 9.5 GW·a and 19.5 GW·a for the moderate and high cases, respectively; after 2051, the installation rate is only limited by the amount of plutonium available for the FRs and the overall growth rate.
Figure 7 shows the total power generation for the different types of reactors, and Fig. 8 shows the global cumulative uranium consumption together with the limits from the Red Book 2009 (known and ultimate resources) [35].
In this homogeneous scenario BAU+–FR, the total uranium consumption reaches, by 2100, values of ~25 × 106 tU and ~15 × 106 tU for the high and moderate cases, respectively.

BAU+–FR scenario in a heterogeneous world

The heterogeneous world model extends the BAU+–FR homogeneous scenario by dividing the world into three non-geographic groups, NG1–NG3, where the countries within a group all adopt the same fuel cycle strategy (see Section III.1 above). The first nuclear power group (NG1) adopts recycling and a transition to FRs, as assumed in the (global) homogeneous BAU+–FR scenario. NG2 continues with the BAU+ strategy of a once through fuel cycle based on standard LWRs and HWRs, plus ALWRs, without recycling. NG3 starts to introduce LWRs and HWRs beginning in 2008 and replacing them by ALWRs after 2015. The 6% share of global HWRs are all modelled as part of NG2.
The heterogeneous cases use the same overall nuclear power demand curves for high growth and moderate growth as the homogeneous cases. The contributions of each group NG1–NG3 to the global nuclear power generation during the twenty-first century are based on extrapolation of data available in 2009 and on expert evaluations carried out within GAINS: by 2100 — NG1:NG2:NG3 = 0.4:0.4:0.2.
As stated previously, in the heterogeneous model, a non-synergistic and a synergistic world were considered in GAINS. The results of the non-synergistic scenarios in a heterogeneous world will be discussed first.

Heterogeneous BAU+–FR scenario in a non-synergistic world

For the non-synergistic world model, no movement of used nuclear fuel occurs between groups NG1 and NG2 in this scenario. This limits the amount of LWR and ALWR spent fuel available in NG1 for reprocessing and starting of FRs. An example of such a heterogeneous non-synergistic global NES was presented in Fig. 2 above.
The total power generation during the century globally and for three non-geographical groups are shown in Fig. 9.
Figure 9 illustrates the assumptions made for this scenario. The groups NG3 and NG2 install standard LWRs, ALWRs and HWRs, and only group NG1 also installs FRs with a conversion rate of 1.0 (a break even FR design). The combined power generation of the three groups is the same as that defined for the homogeneous case.
Figure 10 shows the cumulative uranium consumption of this non-synergistic heterogeneous scenario BAU+–FR.

FIG. 10. Cumulative uranium consumption for the non-synergistic heterogeneous scenario BAU+–FR for the high case [3]. ktHM — kilotonnes of heavy metal.

The value of global uranium consumption by 2100 for the heterogeneous non-synergistic scenario BAU+–FR (Fig. 10) is ~31 × 106 tU for the high case (and ~17 × 106 tU for the moderate case, not shown in Fig. 10). These values are between the values for the homogeneous BAU+ scenario (Fig. 6, ~36.1 × 106 tU for the high case and ~21 × 106 tU for the moderate case) and the values for the homogeneous BAU+–FR scenario (Fig. 8, ~24 × 106 tU for the high case and ~14 × 106 tU for the moderate case). This means that the full potential of FRs to reduce the need for uranium resources cannot be achieved in this scenario BAU+–FR. As stated above, this is caused by the non-availability of sufficient spent fuel to be reprocessed (to produce MOX fuel) in the group NG1 in this non-synergistic heterogeneous model.