KR20140004184A - Tunable fusion blanket for load following and tritium production - Google Patents

Abstract

A fusion chamber for an inertial enclosed fusion power plant is disclosed. The chamber includes regions for the flow of coolant around the exterior of the chamber, with compartments of high temperature resistant metal alloys such as tungsten and vanadium containing tin or other materials with desired neutron interaction properties. Tin can be inserted or removed to increase or decrease the thermal energy output and to increase or decrease the corresponding neutron growth rate.

Description

Tunable Fusion Blanket for Load Following and Tritium Production

The inventions created by research or development under the auspices of the Federal Government of the United States of America;

Claim of right to Korea

The United States Government has signed an agreement between the United States Department of Energy and Lawrence Livermore National Security, LLC regarding the operation of the Lawrence Livermore National Laboratory. In accordance with AC52-07NA27344.

Cross Reference of Related Application

This application is a provisional United States patent application filed on Feb. 8, 2011 entitled "Tunable Fusion Blanket Offering the Ability to Produce Extra Tritium and Load Follow". Claims priority of these applications in connection with Application 61 / 437,508 and the International Patent Treaty (PCT) Application US2011 / 059814, filed Jan. 1, 2011 under the name "Inertial Confinement Fusion Chamber." On the basis of. Each of these applications is incorporated herein by reference.

The present invention relates to power generation using a fusion reaction. In particular, the present invention relates to an inertial enclosed fusion power plant capable of continuously real-time control of fusion power and tritium production rates.

The National Ignition Facility (NIF), the world's largest and most active laser system, is in operation at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. One of NIF's operational goals is to demonstrate the first fusion ignition at the laboratory. Early experiments ignited It proceeded to produce about 20 MJ of power from a self propagating fusion burn wave. The facility eventually has the capacity to achieve outputs of 150-200 MJ. The NIF is designed as research equipment, where "shots" are made on targets containing deuterium-tritium for the study. Techniques for NIF can be found in Fusion Science and Technology, Volume 60, pp 11-16 (2011), by Moses et al., Incorporated herein by reference.

The demand for energy, especially clean energy, is growing rapidly. LLNL will introduce a fusion-based power plant in the United States by 2030, but prior to that, it will be introduced in the form of a power plant before commercialization. A project known as the LIFE technology offers a way to expand carbon-free energy around the world. The technology will provide clean energy that does not emit carbon in a safe and sustainable manner without the risk of nuclear proliferation.

As with any technology that produces electrical energy that is spread to many consumers, one challenge for LIFE is to vary the amount of energy that must be provided at different times, for example, at different times of the day, at different months, and at different years. will be. Consumers expect to get very reliable electrical energy and require a power plant to produce more energy for heating than at other times, for example, on warmer months or days of the year. The result is that suppliers of electrical energy should be able to increase and decrease the amount of electrical energy produced by their facilities. Thus, the fusion chamber, in which the fusion reaction takes place, has reliability and long life, as well as providing a mechanism that allows the fusion chamber to provide more or less amount of heat to generate electrical energy at different times. That is one of the challenges associated with fusion energy.

In the technology disclosed herein, a fusion power plant is provided having a fusion chamber in which capsules containing deuterium and tritium fuel are injected multiple times per second. While the individual fuel capsules contained in the hohlraum (“target”) reach the center of the chamber, a number of lasers are fired onto the target to heat and compress the fuel so that a fusion reaction occurs. Heat from the fusion reaction is captured by the coolant circulating around the chamber. This heat is used to generate electricity. The preferred mode of operation of the plant is to produce tritium to replace the tritium burned in the previous targets.

Our approach to the structure of the fusion chamber is a segmented tubular design for the first wall, as described in more detail in the patent application entitled "Inertial Confinement Fusion Chamber" referenced above. Use This design provides a fusion chamber with efficient thermal coupling, low mechanical stress, and high strength to weignt ratio. The modular approach of the fusion chamber also separates the fusion chamber from the optics, allowing rapid removal and replacement of the blanket and the first wall simply by connecting or releasing piping connections, rather than reconstructing the correct optical path. The fusion chamber is cooled with liquid lithium coolant circulating through the individual segments.

The present invention increases the flexibility in controlling tritium breeding ratios and thermal energy by filling or emptying areas within the fusion blanket for operators of fusion power plants. This regulation allows the fusion plant to follow the load, allowing the fusion blanket to be adjusted to deliver different amounts of heat energy and corresponding electrical energy to the grid in real time and to control tritium production.

1 shows a fusion chamber and its segmented design.
2 is a perspective view of half of one segment of the fusion chamber.
3 is a cross-sectional view of one segment of the fusion chamber shown in FIG. 2.
FIG. 4 is another cross-sectional view of the segment of the fusion chamber shown in FIG. 2, showing additional compartments used to provide control over output energy and tritium propagation.

1 shows an overall design of a fusion chamber 20 that can be used for the implementation of the present invention. The chamber 20, PCT / US2011 / 059820, was named 2011 "Inertial Confinement Fusion Power Plant Which Decouples Life-Limited Components From Plant Availability". It will be placed in a fusion power plant, such as disclosed in Applicant's US patent application filed on November 8, 2010, which is incorporated herein by reference.

As shown in FIG. 1, the chamber consists of a number of identical sections 100. Each section 100 can be made in a factory and transported to a power plant using conventional transfer equipment. In a field maintenance facility, the modular chamber sections are mounted in a common support frame, as described in the application referenced immediately above. The fully assembled chamber and frame are transported for installation in a vacuum vessel surrounding the chamber. Installation of the chamber requires only connecting the cooling inlet pipe and the outlet pipe to each quarter section of the chamber with independent piping.

2 is a perspective view of a half segment 100 of the fusion chamber 10. As shown, the segment includes a first wall consisting of tubes 110 arranged in parallel covering an underlying structure, through which lithium coolant is circulated. Beam port openings 120 of the segment are also shown. Lithium is first sent to a plenum that supplies coolant to one quarter of the total chamber. Coolant is first sent to the first wall tube where it experiences the highest heat flux. Upon exiting the first wall tube, the lithium is circulated to the blanket entry port 130. The coolant present in the blanket is circulated through port 140. Four quarter sections of the entire chamber have independent tubing.

48 openings 120 with a total of about 5% solid-angle are provided so that the laser beams can reach the chamber center. At the beam port, the first wall pipes have a radially outward path and bend at the back of the blanket. The top and bottom of the chamber are provided with additional openings for individual connection with the target injection system and the debris removal / vacuum pumping / target capture system.

3 is a cross sectional view through the midpoint of a normal segment 100, which is a segment that does not include the characteristic configurations of the present invention. Depending on the extent to which the regulation of energy production and tritium proliferation is required, only a few segments of the fusion chamber may comprise the features of the present invention. On the other hand, greater flexibility can be obtained by including the inventive features in all segments of the chamber, one of which is shown in FIG. 4.

3, a first wall tube 110 is shown along with the base structure 150. The liquid lithium coolant enters tube 110 through plenum 160 which connects to all the tubes of segment 100. The similar plenum (not shown) on the other side of the segment collects liquid lithium after passing through tube 110. Once lithium exits the first wall tube 110, it can be recycled to the base structure 150 for further heating of the coolant. In another embodiment, all of the lithium is recycled, thereby requiring only one cooling loop for segment 100. If desired, the first wall tube 110 and the base structure 150 may have independent piping to meet different cooling requirements or to use alternative coolant.

The cooling of the base structure 150 is designed such that the coolest coolant is delivered to the structural material. This is achieved through "skin cooling" by the coolant entering the blanket at the top and flowing down at high speed through smaller cooling channels. The coolant reverses direction as it reaches the bottom of the blanket and rises through bulk region 170 at a lower speed. Low temperatures and high speeds in the skin area provide the most efficient cooling. The blanket coolant is introduced through port 130 and drawn out through similar port 140.

As described in more detail in the patent applications referenced herein, the coolant entering the first wall tube at 470 ° C. leaves the first wall and enters the base structure (blanket) at about 510 ° C. The coolant reaches approximately 550 ° C. at the bottom of the blanket. When pure steel, the coolant is heated to an outlet temperature of 575 ° C. at the top of the blanket. Higher temperatures can be obtained through the use of nonstructural insulating panels. For example, tungsten is compatible with liquid lithium up to 1300 ° C or higher. Our design uses pure steel and supplies lithium at an outlet temperature of 575 ° C. However, depending on the proper choice of materials, future fusion chamber designs may allow even higher temperatures.

The fusion chamber is designed according to the ASME pipe cord. Specifically, the chamber comprises one third of the basic tensile strength of a given material, two thirds of yield strength, two thirds of creep rupture strength, and 0.01% creep per 1000 hours. is designed at a rate. In this evaluation, temperature dependent properties are used.

The present invention provides a fusion chamber that provides the operator of a power plant with the flexibility to control tritium growth rate and thermal energy by filling or emptying areas within the fusion blanket. Such real-time control may be required when additional tritium needs to be produced, for example, to overcome shortcomings of less than expected production or exceeded expectations, or to fuel new fusion facilities. This regulation allows the fusion power plant to follow the load, allowing the fusion power plant to be adjusted to deliver different amounts of heat energy and corresponding electrical energy to the grid in real time.

Real-time adjustment of tritium growth rate and heat output energy is achieved by filling compartments, such as compartments 170, within the fusion blanket with tin or other material having desired neutron interaction properties. This material can be inserted or removed to a desired level to increase or decrease the thermal energy output and to increase or decrease the corresponding tritium growth rate. The materials used may be stagnant, flowing liquids or movable solids. If necessary, additional neutron generating materials, such as beryllium or beyllium titanium (Be ₁₂ Ti), can further improve performance. By allowing the fusion blanket to capture neutrons and energy released from the fusion reaction, the collected energy can be converted into thermal energy in the form of tritium and flowing hot coolant for the production of new fusion fuel.

4 illustrates one embodiment of compartments 200. Compartments 200 may be made of a metal alloy that maintains strength even at high temperatures to maintain high strength in structural components while maximizing thermal energy production. Such alloys include materials such as tungsten, vanadium and the like. The compartments may be optionally filled or emptied with high temperature resistant materials such as tin or gadolinium.

In previous inertial fusion energy engines, thermal energy was reduced by reducing the fusion target output, reducing the repetition rate of the fusion source, or by discarding excess thermal energy using a cooling tower. Each of these approaches has a negative impact on the economics of the power plant. In contrast, our approach enables the coordination of thermal energy and tritium production without negatively impacting the economics of the power plant.

In the embodiment shown in FIG. 4, tin is used in the tungsten chamber 200. The tin is stationary, but can be pumped out (or inserted and removed) to any position to switch the fusion engine from "power mode" where tin is present to de-tinted "tritium growth mode". . Our analysis of tritium growth rate and the benefits of bulk materials is shown in the table below. When the blanket is completely cooled with liquid lithium, ie when all segments of the fusion chamber are as shown in FIG. 3, tritium growth rate and gain are indicated in the first line. Tritium growth rates and gains when there are tin containing (and tin free) tungsten compartments are shown in the second and third lines of the table. Finally, the results for the tungsten compartment loading and withdrawing Be ₁₂ Ti / Sn blankets are shown in the last two rows of the table.

design Tritium growth rate benefit Full lithium blanket 1.48 1.12 Tinned blanket 1.15 1.21 Tinned blanket 1.33 1.14 Blanket with Be ₁₂ Ti / Sn 1.02 1.32 Blanket with Be ₁₂ Ti / Sn removed 1.18 1.27

Unlike conventional approaches, the present invention enables real time adjustment. The resulting fusion thermal energy and tritium production rates are continuously tracked and other actions as needed to further produce tritium for new plant startups or to reduce the plant's energy production during periods of low demand. The conditions are balanced.

The preferred embodiment of the present invention has been described above. It will be appreciated that modifications can be made in such a manner as to add or remove the materials from the fusion blanket to enable control of thermal energy output and tritium growth rate. Accordingly, the scope of the invention is defined by the appended claims.

Claims (16)

In a fusion chamber,
A plurality of segments forming the fusion chamber when fitted together, each segment comprising:
A first wall positioned to face a central region of the fusion chamber within which a fusion reaction occurs; And
A blanket region disposed behind the first wall and including a passageway for receiving a fluid coolant therein;
At least one of the segments includes an additional region, wherein a high temperature resistant material may be provided within the additional region to capture additional neutrons from the fusion reaction in the fusion chamber.
Fusion chamber.
The method of claim 1,
The additional area includes a compartment for containing the high temperature resistant material,
Fusion chamber.
3. The method of claim 2,
And the high temperature resistant material comprises tin.
3. The method of claim 2,
And the high temperature resistant material comprises beryllium.
3. The method of claim 2,
Wherein the high temperature resistant material comprises beyllium titanium (Be ₁₂ Ti).
3. The method of claim 2,
Wherein the high temperature resistant material comprises gadolinium.
3. The method of claim 2,
Wherein the compartment comprises at least one of tungsten and vanadium.
The method of claim 1,
The first wall of each segment includes a set of tubes arranged in parallel across the front wall of the segment, each tube behind the front wall from a first plenum disposed behind the front wall. A fusion chamber extending to a second plenum disposed, wherein the first and second plenums are connected to a fluid coolant supplied to cool the set of tubes.
The method of claim 1,
Wherein each of the segments includes the additional region, and a high temperature resistant material may be provided within the additional region to capture additional neutrons from the fusion reaction in the fusion chamber.
Fusion chamber.
The method of claim 1,
Each segment further comprises two or more openings for allowing a laser beam to pass through the segment to a central region of the fusion chamber and a support structure for supporting the segment in place to form the fusion chamber,
Fusion chamber.
The method of claim 1,
Wherein the fluid coolant comprises liquid lithium.
In the method of adjusting the output energy of the fusion chamber,
Wherein the fusion chamber in which the fusion reaction takes place comprises a blanket region comprising a first wall positioned to face its central region and comprising a passageway disposed behind the first wall and containing a fluid coolant,
The output energy adjustment method of the fusion chamber,
Controllably inserting and removing material from the blanket to capture additional neutrons from the fusion reaction,
Method of adjusting the output energy of a fusion chamber.
The method of claim 12,
Controllably inserting and removing material from the blanket to capture additional neutrons from the fusion reaction further controls the proliferation of tritium in the blanket region,
Method of adjusting the output energy of a fusion chamber.
The method of claim 12,
And the blanket region further comprises a compartment for the material to capture additional neutrons.
15. The method of claim 14,
And the material comprises tin or gadolinium.
16. The method of claim 15,
And the fluid coolant comprises lithium.

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