CHAPTER 08: GENERATION IV ADVANCED NUCLEAR POWER REACTORS | A Book: Nuclear Energy

According to the World Nuclear Association, as of May 2020:

An international task force is sharing R&D to develop six nuclear reactor technologies for deployment between 2020 and 2030. Four are fast neutron reactors;
All of these operate at higher temperatures than today’s reactors. In particular, four are designated for hydrogen production;
All six systems represent advances in sustainability, economics, safety, reliability and proliferation-resistance;
Europe is pushing ahead with three of the fast reactor designs; and
A separate programme set up by regulators aims to develop multinational regulatory standards for Generation IV reactors.

The Generation IV International Forum (GIF) was initiated by the US Department of Energy in 2000 and formally chartered in mid-2001. It is an international collective representing governments of 13 countries where nuclear energy is significant now and also seen as vital for the future. Most are committed to joint development of the next generation of nuclear technology. The original charter members of GIF are Argentina, Brazil, Canada, France, Japan, South Korea, South Africa, the UK and the USA. They have been joined by Switzerland, China, Russia, Australia and, through the Euratom research and training programme, the European Union. The purpose of GIF is to share R&D rather than build reactors.

Most of these are party to the 2005 Framework Agreement, which formally commits them to participate in the development of one or more Generation IV systems selected by GIF for further R&D. Argentina, Australia and Brazil did not sign the Framework Agreement, and the UK withdrew from it. Russia formalized its accession to the Framework Agreement in August 2009 as its tenth member, with Rosatom as implementing agent. In 2011 the 13 members decided to modify and extend the GIF charter indefinitely. (Australia joined as the 13th GIF member country in June 2016.) In February 2015 the Framework Agreement was extended for ten years, with Rosatom signing for the extension in June, and Euratom in November 2016. In November 2018, the UK became the 12th member to ratify the Framework Agreement. Argentina and Brazil remain non-active members.
In May 2019 Terrestrial Energy, the Canadian developer of a molten salt reactor, became the first private sector company to join GIF.

The GIF is a cooperative international initiative organized to carry out the research and development needed to establish the feasibility and performance capabilities of the next generation nuclear energy systems.

1. GENERATION IV NUCLEAR POWER REACTORS:

The focus of this initiative was to identify and select six nuclear energy systems for further development. The six selected systems employ a variety of reactor, energy conversion and fuel cycle technologies. Their designs feature thermal and fast neutron spectra, closed and open fuel cycles and a wide range of reactor sizes from very small to very large. Depending on their respective degrees of technical maturity, the Generation IV systems are, expected to become available for commercial introduction in the period between 2015 and 2030 or beyond.

The selected Generation IV nuclear reactors defined by the GIF:

1. Gas-Cooled Fast Reactors (GFR): Represent a fast-neutron-spectrum, helium-cooled reactor and closed fuel cycle;

2. Lead-Cooled Fast Reactors (LFR): Represent a fast-spectrum lead of lead/bismuth eutectic liquid-metal-cooled reactor and a closed fuel cycle for efficient conversion of fertile uranium and management of actinides;

3. Sodium-Cooled Fast Reactors (SFR): Represent a fast-spectrum, sodium-cooled reactor and closed fuel cycle for efficient management of actinides and conversion of fertile uranium;

4. Supercritical Water-Cooled Reactors (SCWR): Represent a high-temperature, high-pressure water-cooled reactor that operates above the thermodynamic critical point of water;

5. Very High-Temperature Gas Reactors (VHTR): Represent a graphite-moderated, helium-cooled reactor with a once-through uranium fuel cycle; and

6. Molten Salt Reactors (MSR): Produce fission power in a circulating molten salt fuel mixture with an epithermal-spectrum reactor and a full actinide recycle fuel cycle.

2. FOCUS OF GENERATION IV NUCLEAR POWER REACTORS:

The six selected designs of generation IV nuclear power reactors reflect advances in sustainability, economics, safety and reliability, and proliferation resistance, ensuring that these reactors are:

2.1 Sustainable:

Ensuring that the GIF Generation IV nuclear energy systems provide sustainable energy generation that meets clean air objective long-term availability of systems and effective fuel utilization for worldwide energy generation; and minimize and manage their nuclear waste in order to reduce the long-term stewardship in the interest of improved protection for the public health and environment. These objectives will be, achieved by:

Extending the nuclear fuel supply into future centuries by recycling used fuel to recover its energy content, and by converting 238 U to new fuel;
Having a positive impact on the environment through the displacement of polluting energy and transportation sources by nuclear electricity generation and nuclear-produced hydrogen;
Allowing geologic waste repositories to accept the waste of many more plant-years of nuclear plant operation through substantial reduction in the amount of wastes and their decay heat; and
Greatly simplifying the scientific analysis and demonstration of safe repository performance for very long time-periods (beyond 1000 years), by a large reduction in the lifetime and toxicity of the residual radioactive wastes sent to repositories for final geologic disposal.

2.2 Economical:

Ensuring that the GIF Generation IV nuclear energy systems will have a clear life-cycle cost advantage over other energy resources, and these reactors will have a level of financial risk comparable to other energy resources. These objectives will be, accomplished by:

Achieving economic life-cycle and energy production costs through a number of innovative advances in plant and fuel cycle efficiency, design simplifications, and plant sizes;
Reducing economic risk to nuclear projects through the development of plants built using innovative fabrication and construction techniques, and possibly modular designs; and
Allowing the distributed production of hydrogen, fresh water, district heating, and other energy products to be, produced where they are, needed.

2.3 Safe and Reliable:

Ensuring the GIF Generation IV nuclear energy systems will excel in safety and reliability, and will have a very low likelihood and degree of reactor core damage. These objectives will be, achieved by:

Increasing the use of inherent safety features, robust designs, and transparent safety features that can be understood by non-experts; and
Enhancing public confidence in the safety of nuclear energy.

2.4 Proliferation Resistant and Physically Secured:

Ensuring that the GIF Generation IV nuclear energy systems will increase the assurance that they are very unattractive and the least desirable route for diversion or theft of weapons-usable materials, and these reactors will provide increased physical protection against acts of terrorism. These objectives are, achieved by:

Providing continued effective proliferation resistance of nuclear energy systems through improved design features and other measures; and
Increasing physical protection against terrorism by increasing the robustness of new facilities.

Most Generation IV systems are, aimed at R&D advances that enable high operating temperatures. This will allow greenhouse-gas-free nuclear energy to be more broadly, substituted for fossil fuels in the production of hydrogen and process heat.

3. TECHNICAL ATTRIBUTES OG GENERATION IV NUCLEAR POWER REACTORS:

The selection of the GIF Generation IV reactor technologies was, based on the fundamental conviction that these reactors will shape the future of nuclear energy around the world, ensuring that the increasing demand for energy is, met with clean, safe, and affordable nuclear energy. Here are the findings of a quick analysis of the attributes:

All the selected six reactors operate at a higher temperature than present reactors;
Three out of the six selected reactors are fast reactors. Fast reactors are, defined as a type of nuclear reactors, which make little or no use of a moderator to slow down the high-energy neutrons. They represent a category of nuclear reactors in which the fission chain reaction is sustained by fast neutrons which need no neutron moderator but which requires the use of relatively rich fuel in fissile material;
One out of the remaining three-selected reactor is epithermal reactor. Epithermal reactors are, defined as nuclear reactors in which the nuclear fission is induced predominantly by epithermal neutrons;
Out of the remaining two reactors, one is thermal reactor whereas the other can be either a fast reactor or thermal reactor. Thermal reactors are, defined as nuclear reactors in which fission is, induced primarily by neutrons of such low energy that they are in substantial thermal equilibrium with the material of the core;
Two out of the six selected reactors, use helium as coolant and one of them is a fast reactor and the other is a thermal reactor. Fast reactor which used helium as coolant operate at the temperature of 850 °C whereas thermal reactor operates at the temperature of 1000 °C;
The remaining four reactors use various coolants including – water, sodium, fluoride salts, pb-Bi. These four reactors operate at the varied temperatures in the range from 550 °C to 800 °C;
The sizes of these 6 selected reactors vary from 50-150 MWe to 1500 MWe; and
Four out of the six selected reactors generate electricity and hydrogen whereas the remaining two reactors generate only electricity. These reactors use a combination of open and closed fuel recycles.

4. FUEL CYCLE AND FUEL:

A Technology Roadmap for Generation IV Nuclear Energy System reported a study, which established an understanding of the ability of various reactors to be, combined in so-called symbiotic fuel cycles. Here is a graph (Figure 8-2) which illustrates the process:

Fast reactors can operate in three distinct fuel cycle roles. A conversion ratio less than 1 (“transmuter”) converts transuranics into shorter-lived isotopes to reduce long-term waste management burdens. A conversion ratio near one (“converter”) provides a balance of transuranic production and consumption. This mode results in low reactivity loss rates with associated control benefits. A conversion ratio greater than 1 (“breeder”) affords a net creation of fissile materials, but requires the recycle of more uranium in the reactor and fuel cycle. An appropriately designed fast reactor has flexibility to shift between these operating modes; the desired actinide management strategy will depend on a balance of waste management and resource extension considerations.

In conjunction with the actinide management goal, research plans will consider means to reduce the waste generation by features such as improved thermal efficiency, the greater utilization of fuel resources, and the development of superior waste forms for the SFR closed fuel cycle. Efforts will also be, made for achieving reductions for waste generated from the operations and maintenance and the decommissioning of system facilities, and the amount of waste migrating to the environment.

Generation IV nuclear energy systems comprise the nuclear reactor and its energy conversion systems, as well as the necessary facilities for the entire fuel cycle from ore extraction to final waste disposal. Generation IV systems can be broadly divided into fast and thermal reactors that address the above challenges with differing emphasis and technology.

For example, combinations of thermal reactors and fast reactors are, found to work well together. As shown in the graph, they feature the recycle of actinides from the thermal systems into the fast systems, and exhibit the ability to reduce actinide inventories worldwide. Improvements in the burnup capability of gas- or water-cooled thermal reactors may also contribute to actinide management in a symbiotic system. Thermal systems also have the flexibility to develop features, such as hydrogen production in high-temperature gas reactors or highly economical light water reactors, which are part of an overall system offering a more sustainable future. This is a motivating factor in the roadmap for having a portfolio of Generation IV systems rather than a single system – Realizing that various combinations of a few systems in the portfolio will be able to provide a desirable symbiotic system worldwide.

5. DESCRIPTION OF GENERATION IV NUCLEAR POWER REACTORS:

Here is a brief description of each GIF Generation IV reactor:

5.1 Gas-Cooled Fast Reactors (GFR):

The GFR system features a fast-spectrum helium-cooled reactor [shown below] and closed fuel cycle. Like thermal-spectrum helium-cooled reactors such as the GT-MHR and the PBMR, the high outlet temperature of the helium coolant makes it possible to deliver electricity, hydrogen, or process heat with high conversion efficiency.

The GFR uses a direct-cycle helium turbine for electricity and can use process heat for thermochemical production of hydrogen. Through the combination of a fast-neutron spectrum and full recycle of actinides, GFR minimize the production of long-lived radioactive waste isotopes. The GFR’s fast spectrum also makes it possible to utilize available fissile and fertile materials (including depleted uranium from enrichment plants) two orders of magnitude more efficiently than thermal spectrum gas reactors with once-through fuel cycles. The GFR reference assumes an integrated, on-site spent fuel treatment and refabrication plant.

5.2 Lead-Cooled Fast Reactors (LFR):

LFR systems are Pb or Pb-Bi alloy-cooled reactors with a fast-neutron spectrum and closed fuel cycle. One LFR system is, shown below. Options include a range of plant ratings, including a long refueling interval battery ranging from 50–150 MWe, a modular system from 300–400 MWe, and a large monolithic plant at 1200 MWe. These options also provide a range of energy products.

The LFR battery option is a small factory-built turnkey plant operating on a closed fuel cycle with very long refueling interval (15 to 20 years) cassette core or replaceable reactor module. Its features are, designed to meet market opportunities for electricity production on small grids, and for developing countries that may not wish to deploy an indigenous fuel cycle infrastructure to support their nuclear energy systems. Its small size reduced cost, and full support fuel cycle services can be attractive for these markets. It had the highest evaluations to the Generation IV goals among the LFR options, but also the largest R&D needs and longest development time.

The options in the LFR class may provide a time-phased development path: The nearer-term options focus on electricity production and rely on more easily developed fuel, clad, and coolant combinations and their associated fuel recycle and refabrication technologies. The longer-term option seeks to further exploit the inherently safe properties of Pb and raise the coolant outlet temperature sufficiently high to enter markets for hydrogen and process heat, possibly as merchant plants. LFR holds the potential for advances compared to state-of-the-art liquid metal fast reactors in the following:

Innovations in heat transport and energy conversion are a central feature of the LFR options. Innovations in heat transport are, afforded by natural circulation, lift pumps, in-vessel steam generators, and other features. Innovations in energy conversion are afforded by rising to higher temperatures than liquid sodium allows, and by reaching beyond the traditional superheated Rankine steam cycle to supercritical Brayton or Rankine cycles or process heat applications such as hydrogen production and desalination;

The favourable neutronics of Pb and Pb-Bi coolants in the battery option enable low power density, natural circulation-cooled reactors with fissile self-sufficient core designs that hold their reactivity over their very long 15- to 20-year refueling interval. For modular and large units more conventional higher power density, forced circulation, and shorter refueling intervals are used, but these units benefit from the improved heat transport and energy conversion technology;
Plants with increased inherent safety and a closed fuel cycle can be achieved in the near- to mid-term. The longer-term option is, intended for hydrogen production while retaining the inherent safety features and controllability advantages of a heat transport circuit with large thermal inertia and a coolant that remains at ambient pressure. The favourable sustainability features of fast spectrum reactors with closed fuel cycles are also retained in all options; and
The favourable properties of Pb coolant and nitride fuel, combined with high temperature structural materials, can extend the reactor coolant outlet temperature into the 750–800ºC range in the long term, which is potentially suitable for hydrogen manufacture and other process heat applications. In this option, the Bi alloying agent is, eliminated, and the less corrosive properties of Pb help to enable the use of new high-temperature materials. The required R&D is more extensive than that required for the 550ºC options because the higher reactor outlet temperature requires new structural materials and nitride fuel development.

5.3 Sodium-Cooled Fast Reactors (SFR):

The Sodium-Cooled Fast Reactor (SFR) system features a fast-spectrum reactor [shown below] and closed fuel recycles system. The primary mission for the SFR is management of high-level wastes and, in particular, management of plutonium and other actinides. With innovations to reduce capital cost, the mission can extend to electricity production; given the proven capability of sodium, reactors to utilize almost all of the energy in the natural uranium versus the 1 percent utilized in thermal spectrum systems.

A range of plant size options are available for the SFR, ranging from modular systems of a few hundred MWe to large monolithic reactors of 1500–1700 MWe. Sodiumcore outlet temperatures are typically 530–550ºC. The primary coolant system can either be arranged in a pool layout (a common approach, where all primary system components are housed in a single vessel), or in a compact loop layout, favoured in Japan. For both options, there is a relatively large thermal inertia of the primary coolant. A large margin to coolant boiling is, achieved by design, and is an important safety feature of these systems. Another major safety feature is that the primary system operates at essentially atmospheric pressure, pressurized only to the extent needed to move fluid. Sodium reacts chemically with air, and with water, and thus the design must limit the potential for such reactions and their consequences. To improve safety, a secondary sodium system acts as a buffer between the radioactive sodium in the primary system and the steam or water that is contained in the conventional Rankine-cycle power plant. If a sodium-water reaction occurs, it does not involve a radioactive release.

Two fuel options exist for the SFR: (1) MOX and (2) mixed uranium-plutonium-zirconium metal alloy (metal). The experience with MOX fuel is considerably more extensive than with metal.

SFR require a closed fuel cycle to enable their advantageous actinide management and fuel utilization features. There are two primary fuel cycle technology options:

An advanced aqueous process; and
The pyroprocess, which derives from the term, pyrometallurgical process.

Both processes have similar objectives:

Recovery and recycle of 99.9 percent of the actinides;
Inherently low decontamination factor of the product, making it highly radioactive; and
Never separating plutonium at any stage.

These fuel cycle technologies must be adaptable to thermal spectrum fuels in addition to serving the needs of the SFR. This is, needed for two reasons:

First, the startup fuel for the fast reactors must come ultimately from spent thermal reactor fuel; and
Second, for the waste management advantages of the advanced fuel cycles to be realized (namely, a reduction in the number of future repositories required and a reduction in their technical performance requirements), fuel from thermal spectrum plants will need to be processed with the same recovery factors.

Thus, the reactor technology and the fuel cycle technology are, strongly linked. Consequently, much of the research recommended for the SFR is relevant to crosscutting fuel cycle issues.

5.4 Super-Critical Water-Cooled Reactors (SCWR):

SCWR are high-temperature, high-pressure water-cooled reactors that operate above the thermodynamic critical point of water (374°C, 22.1 MPa or 705°F, 3208 psia). One SCWR system is, shown below. These systems may have a thermal or fast-neutron spectrum, depending on the core design. SCWR have unique features that may offer advantages compared to state-of the- art LWR in the following:

SCWR offer increases in thermal efficiency relative to current-generation LWR. The efficiency of a SCWR can approach 44 percent, compared to 33–35 percent for LWR;
A lower-coolant mass flow rate per unit core, thermal power results from the higher enthalpy content of the coolant. This offers a reduction in the size of the reactor coolant pumps, piping, and associated equipment, and a reduction in the pumping power;
A low-coolant mass inventory results from the once-through coolant path in the reactor vessel and the lower-coolant density. This opens the possibility of smaller containment buildings;
No boiling crisis (i.e., departure from nucleate boiling or dry out) exists due to the lack of a second phase in the reactor, thereby avoiding discontinuous heat transfer regimes within the core during normal operation; and
Steam dryers, steam separators, recirculation pumps, and steam generators are, eliminated. Therefore, the SCWR can be a simpler plant with fewer major components.

The Japanese supercritical light water reactor (SCLWR) with a thermal spectrum has been the subject of the most development work in the last 10 to 15 years and is the basis for much of the reference design. The SCLWR reactor vessel is similar in design to a PWR vessel (although the primary coolant system is a direct-cycle, BWR-type system). High-pressure (25.0 MPa) coolant enters the vessel at 280°C. The inlet flow splits, partly to a downcomer and partly to a plenum at the top of the core to flow down through the core in special water rods.

This strategy provides moderation in the core. The coolant is heated to about 510°C and delivered to a power conversion cycle, which blends LWR and supercritical fossil plant technology; high-, intermediate and low-pressure turbines are employed with two reheat cycles. The overnight capital cost for a 1700-MWe SCLWR plant may be as low as $900/kWe (about half that of current ALWR capital costs), considering the effects of simplification, compactness, and economy of scale. The operating costs may be 35 percent less than current LWR.

The SCWR can also be, designed to operate as a fast reactor. The difference between thermal and fast versions is primarily the amount of moderator material in the SCWR core. The fast spectrum reactors use no additional moderator material, while the thermal spectrum reactors need additional moderator material in the core.

5.5 Very High-Temperature Reactors (VHTR):

The VHTR is a next step in the evolutionary development of high-temperature gas-cooled reactors. The VHTR can produce hydrogen from only heat and water by using thermochemical iodine-sulfur (I-S) process or from heat, water, and natural gas by applying the steam reformer technology to core outlet temperatures greater than about 1000°C. A reference the VHTR system that produces hydrogen is, shown below.

A 600 MWth VHTR dedicated to hydrogen production can yield over 2 million normal cubic meters per day. The VHTR can also generate electricity with high efficiency, over 50 percent at 1000°C, compared with 47 percent at 850°C in the GTMHR or PBMR. Co-generation of heat and power makes the VHTR an attractive heat source for large industrial complexes. The VHTR can be, deployed in refineries and petrochemical industries to substitute large amounts of process heat at different temperatures, including hydrogen generation for upgrading heavy and sour crude oil. Core outlet temperatures higher than 1000°C would enable nuclear heat application to such processes as steel, aluminum oxide, and aluminum production.

The VHTR is a graphite-moderated, helium-cooled reactor with thermal neutron spectrum. It can supply nuclear heat with core-outlet temperatures of 1000°C. The reactor core type of the VHTR can be a prismatic block core such as the operating Japanese HTTR, or a pebble-bed core such as the Chinese HTR-10. For electricity generation, the helium gas turbine system can be directly set in the primary coolant loop, which is called a direct cycle. For nuclear heat applications such as process heat for refineries, petrochemistry, metallurgy, and hydrogen production, the heat application process is generally coupled with the reactor through an intermediate heat exchanger (IHX), which is called an indirect cycle.

5.6 Molten Salt Reactors (MSR):

Molten Salt Reactors (MSR) are liquid-fuelled reactors that can be used for production of electricity, actinide burning, production of hydrogen, and production of fissile fuels.

Electricity production and waste turndown are, envisioned as the primary missions for the MSR. Fissile, fertile, and fission isotopes are, dissolved in a high-temperature molten fluoride salt with a very high boiling point (1,400 C) that is both the reactor fuel and the coolant. The near-atmospheric-pressure molten fuel salt flows through the reactor core. The traditional MSR designs have a graphite core that results in a thermal to epithermal neutron spectrum.

In the core, fission occurs within the flowing fuel salt that is heated to ~700ÂºC, which then flows into a primary heat exchanger where the heat is, transferred to a secondary molten salt coolant. The fuel salt then flows back to the reactor core. The clean salt in the secondary heat transport system transfers the heat from the primary heat exchanger to a high-temperature Brayton cycle that converts the heat to electricity. The Brayton cycle (with or without a steam bottoming cycle) may use either nitrogen or helium as a working gas).

6. OUTLOOK FOR GENERATION IV NUCLEAR POWER REACTORS:

A Technology Roadmap for Generation IV Nuclear Energy Systems by the US Department of Energy Nuclear Energy Research Advisory Committee and the Generation IV Forum in December 2002. A report, GIF R&D Outlook for Generation IV Nuclear Energy Systems, produce on August 21, 2009, stated that while much is being undertaken and advanced every year within the committees and working groups, it is important to revisit the expectation of what will be accomplished by the Generation IV International Forum in the next years, through 2013.

6.1 System Technologies:

As always, each Forum member is free to choose the systems that it will advance, as well as to pursue any options or alternatives to the systems outside the System Research Plan. With respect to the six Generation IV systems, presented in order of their level of cooperative activity today, the Forum expects the following progress in five years:

Gas-Cooled Fast Reactors (GFR):

For the GFR, a set of essential technology projects will also have been, created. Feasibility issues regarding fuel forms and actinide recycling, system safety and analysis, and cost will be much better understood and on their way to resolution. The GFR will be nearing a point at which it may assess its progress toward the goals. Key viability tests will be in operation;

Lead-Cooled Fast Reactors (LFR):

For the LFR, formal collaborations will have begun, and a set of exploratory projects will have been, created. Feasibility issues regarding coolant and materials, energy conversion and components, actinide recycling, and system safety will be much better understood and preparations for viability testing will be underway;

Sodium-Cooled Fast Reactors (SFR):

For the SFR, the full complement of technology projects will also have been, created. Feasibility issues regarding actinide recycling, competitive capital cost, in-service inspection and repair, and alternate energy conversion with gas or supercritical CO2 cycle will be resolved, or nearly so. An assessment of progress toward the goals will have been, completed for the major options. Key performance issue, tests will be in planning, with some in operation, and decisions will have been, made about advancing one or more prototypes. Fresh operating experience will be, gathered from new SFR in various countries or from the restart of Monju;

Super-Critical Water-Cooled Reactors (SCWR):

For the SCWR, a set of essential technology projects will have been, created. Feasibility issues regarding core layout and spectrum, fuel forms and possible recycling, and system thermal hydraulics and safety will be much better understood and on their way to resolution. The SCWR will be nearing a point at which it may assess its progress toward the goals. Key viability tests will be in operation;

Very High Temperature Reactors (VHTR):

For the VHTR, the full complement of technology projects will have been, created. Feasibility issues regarding hydrogen production, fuel performance, and high-temperature design including both the core and intermediate heat exchanger will be resolved, or nearly so. An assessment of progress toward the goals will have been, completed for the major options. Key performance issue tests, will be in planning, with some in operation, and decisions will have been made about advancing one or more prototypes; and

Molten Salt Reactors (MSR):

For the MSR, formal collaborations will also have begun, and a set of exploratory projects will have been, created. Feasibility issues regarding its fuel cycle, salt chemistry with dissolved fuel isotopes (including transuranics), and materials compatibility will be much better understood and preparations for viability testing will be underway. Issues on the operation and safety of the coupled MSR reactor and fuel-processing unit will be, clarified.

R&D synergies will be, developed between system steering committees, in domains such as requirements, design rules and codes, equipment, instrumentation, components and subsystems.

6.2 Missions and Resources:

The world is changing, and the Forum is monitoring the needs and pacing of the research and development. It is, anticipated that some changes in emphasis or scope in the systems during the next five years, which are presented next.

While there is much debate about when or even if a large-scale deployment of a hydrogen economy may happen, it is now well understood how vital a role, hydrogen currently plays in the production of premium transportation fossil fuels and chemical feed-stocks. At the same time, there is a growing interest in the utilization of nuclear systems to produce high-grade process heat for a range of industrial applications. The Forum has encouraged its high-temperature systems to broaden their mission to include process heat applications more generally. This is an important way to make nuclear energy more relevant as a non-greenhouse-gas-emitting source of primary energy beyond electricity;
A growing awareness of water shortages exists in many regions of the world. While the missions of Generation IV have included electricity, hydrogen production, and actinide management in the original Roadmap, we may be nearing a time when desalination should be, highlighted in the missions if current generation reactors cannot successfully address it. The forum will continue to monitor this, as the development of such new energy products that can expand nuclear energy’s benefits beyond electrical generation contribute to the sustainability goals of the Forum;
There is a growing interest in addressing the needs of countries and regions that are better served by, smaller systems. While a few options with small module size are being, pursued within the six Generation IV systems, these are, intended to complement the evolutionary designs of industry for near-term deployment, and thereby provide for the long- term future need. Of course, the specific technologies developed in Generation IV (such as new materials, fuels, or energy conversion technologies) may be adopted in these evolutionary designs in advance of their application in Generation IV systems; and
From the perspective of uranium resource conservation, many of the Generation IV systems investigated are fast neutron reactors that use plutonium and uranium recovered from spent fuel by reprocessing, and depleted uranium. Thorium was, examined carefully by the Fuels Crosscutting Group during the original Roadmap and it was, not considered a first priority for Generation IV. However, it was noted that an interest in the use of thorium resources and are already seeing exploration of thorium-based fuels in some Generation IV systems to understand their potential benefits. It is encouraged that the systems to examine this alternative and take advantage of related insights gained in other collaborative activities.

6.3 Technical Cooperation and Membership:

Technical cooperation and engagement of the research community worldwide plays a key role in the successful development of Generation IV systems. In the next five years, the Forum will expand the number of topical sessions that we sponsor in international conferences and events:

These will inform the global research community of the technical interests, research problems, and breakthroughs with the hope of stimulating more participation by academia, industry, and laboratories;
The Forum will monitor the level of funded collaborations by industry, with the aim of significantly increasing this in the future; and
The Forum will continue to facilitate cooperation amongst its members in the next stage of development of Generation IV systems, that of major technology demonstrations.

Finally, it is, noted that the membership has changed over the years. While among the original signatories to the Generation IV Charter, Argentina and Brazil have made the decision to become inactive in the Forum largely because of changes in national research priorities. The United Kingdom decided to allow its technical community to continue to participate in Generation IV, though uniquely through the membership of EURATOM. More recently, in 2006, China and Russia are the newest signatories to the Charter. In regards to the Framework Agreement, China acceded in 2007, the Republic of South Africa acceded in 2008, and Russia plans to accede in 2009. The original intent of the Forum remains the same—to bring the collaborative efforts of the major developers of next-generation nuclear energy systems to bear in a concerted effort. It is therefore important to be able to revisit the Forum’s present membership and organizational structure from the viewpoint of each member’s true input to its R&D activities. Likewise, the Forum welcomes the prospect of additional members that can bring significant resources and capabilities, and hope to report the successful entry of new members to the Forum over the next five years.

Resources:

This chapter was published on “Inuitech – Intuitech Technologies for Sustainability” on June 21, 2011; and
This chapter was updated on 10 June 2020

Chapter 09 …