Appendix A: Dimensional Equivalents and Physical Constants

In this appendix we have provided some basic dimension and physical unit constants.

Dimensional Equivalents

Length 1 ft ¼ 12 in. ¼ 30.48 cm ¼ 0.3048 1m¼ 100 cm ¼ 39.37 in. ¼ 3.28 ft Mass 1 lbm ¼ 0.03108 slug ¼ 453.59 g ¼ 0.45359 kg 1kg¼ 100 g ¼ 0.06852 slug ¼ 2.205 lbm Time 1 h ¼ 3600 s 1s¼ 2.778 Â 10À4 h Force 1 lbf ¼ 4.448 Â 105 dyne ¼ 4.448 N 1N¼ 105 dyne ¼ 0.2249 lbf Angle 1 degree ¼ 1.745 Â 10À2 rad 1 rad ¼ 57.30 degree Temperature 1 deg F ¼ 1 deg R ¼ 0.5556 deg C ¼ 0.5556 deg K 1 deg K ¼ deg C ¼ 1.8 deg R ¼ 1.8 deg F deg F ¼ 1.8 deg C + 32 deg C ¼ 0.5556 (deg F À 32) deg R ¼ deg F + 459.69 deg K ¼ deg C + 273.16 deg R ¼ 1.8 deg K deg K ¼ 0.5556 deg R Energy 1 Btu ¼ 777.66 ft-lbf ¼ 252 cal ¼ 1.054 Â 1010 erg ¼ 1054 J 1J¼ 107 erg ¼ 0.239 cal ¼ 0.7375 ft-lbf ¼ 9.485 Â 10À4 Btu Power 1 Btu/h ¼ 2.778 Â 10À4 Btu/s ¼ 2.929 Â 106 erg/s ¼ 0.2929 W 1W¼ 107 erg/s ¼ 9.481 Â 10À4 Btu/s ¼ 3.414 Btu/h (continued)

© Springer Nature Switzerland AG 2019 345 B. Zohuri, Heat Pipe Applications in Fission Driven Nuclear Power Plants, https://doi.org/10.1007/978-3-030-05882-1 346 Appendix A: Dimensional Equivalents and Physical Constants

Pressure 1 lbf/ft2 ¼ 6.944 Â 10À3 lbf/in.2 ¼ 4.78.8 dyne/cm2 ¼ 47.88 N/m2 1 lbf/in.2 ¼ 144 lbf/ft2 ¼ 68,948 dyne/cm2 ¼ 6894.8 N/m2 1 N/m2 ¼ 10 dyne/cm2 ¼ 1.450 Â 10À4 lbf/in.2 ¼ 2.089 Â 10À2 lbf/ft2 Area 1 ft2 ¼ 1.44 in.2 ¼ 929 cm2 ¼ 0.0929 m2 1m2 ¼ 104 cm2 ¼ 1550 in2 ¼ 10.76 ft2 Volume 1 ft3 ¼ 1728 in.3 ¼ 2.832 Â 104 cm3 ¼ 0.02832 m3 1m3 ¼ 106 cm3 ¼ 6.102 Â 104 in.3 ¼ 35.31 ft3 1 gal (US liquid) ¼ 0.13368 ft3 ¼ 0.003785 m3 Density 1 gal (US liquid) ¼ 0.13368 ft3 ¼ 0.003785 m3 1 lbm/ft3 ¼ 0.03108 slug/ft3 ¼ 1.602 Â 10À2 g/cm3 ¼ 16.02 kg/m3 1 kg/m3 ¼ 10À3 g/cm3 ¼ 0.00194 slug/ft3 ¼ 0.06242 lbm/ft3 Viscosity (dynamic) 1 lbm/ft-h ¼ 8.634 Â 10À6 slug/ft-s ¼ 4.134 Â 10À3 g/cm- s ¼ 4.134 Â 10À4 kg/m-s 1 kg/m-s ¼ 10 g/cm-s ¼ 2.089 Â 10À2 slug/ft-s ¼ 2.419 Â 103 lbm/ft-h Thermal conductivity 1 Btu/ft-h-F ¼ 2.778 Â 10À4 Btu/ft-s-F ¼ 1.730 Â 105 erg/cm-s-K ¼ 1.730 W/m-K 1 W/m-K ¼ 105 erg/cm-s-K ¼ 1.606 Â 10À4 Btu/ft-s-F ¼ 0.578 Btu/ft-h-F Surface tension 1 lbf/ft ¼ 1.459 Â 104 dyne/cm ¼ 14.59 N/m 1 N/m ¼ 103 dyne/cm ¼ 0.06854 lbf/ft Latent heat of 1 Btu/lbm ¼ 32.174 Btu/slug ¼ 2.32 Â 107 erg/g ¼ 2.324 Â 103 J/kg vaporization 1 J/kg ¼ 104 erg/g ¼ 1.384 Â 10À2 Btu/slug ¼ 4.303 Â 10À4 Btu/lbm Heat transfer 1 Btu/ft2-h-F ¼ 5.674 Â 103 erg/cm2-s-K ¼ 5.674 W/m2-K coefficient 1 W/m2-K ¼ 103 erg/cm2-s-K ¼ 0.1762 Btu/ft2-h-F

Physical Constants

Gravitational acceleration (standard), g ¼ 32.174 ft/s2 ¼ 980.7 cm/s2 ¼ 9.807 m/s2 Universal gas constant, R ¼ 1545.2 ft-lb/mol-R ¼ 1.987 Btu/lbm-mol- R ¼ 8.314 Â 107 erg/g-mol-K ¼ 8.314 Â 103 J/kg-mol-K Mechanical equivalent of heat, J ¼ 777.66 ft-lbf/Btu ¼ 4.184 Â 107 erg/cal 1 N-m/J Stefan-Boltzmann constant, σ ¼ 0.1713 Â 10À8 Btu/ft2-h-R4 ¼ 5.670 Â 10À5 À erg/cm2-s-K4 ¼ 5.657 Â 10 8 W/m2-K4 Appendix B: Electromagnetic Pump

An electromagnetic pump is a pump that moves liquid metal (or any electrically conductive liquid) using . A magnetic field is set at right angles to the direction the liquid moves in, and a current is passed through it. This causes an electromagnetic force that moves the liquid. Applications include pumping liquid metal through a cooling system.

Introduction

Electromagnetic pumps have been used for pumping liquid sodium in auxiliary circuits such as fill and drain and purification circuits of sodium-cooled fast breeder reactors. Despite their low efficiency, these pumps are used in fast reactors because of their high reliability and low maintenance due to absence of moving parts. Besides, EM pumps can be used for pumping impure sodium. For example, Indira Gandhi Centre for Atomic Research (IGCAR) has developed electromagnetic pumps of various capacities and successfully used them in experimental facilities. Sodium is used as a coolant in fast breeder reactors because of its excellent neutronic and heat transfer characteristics. Sodium is a fairly good conductor of also, and this has led to development of many electromagnetic sensors and devices for use in liquid sodium. One such device is the electromagnetic pump which is used to pump liquid sodium in auxiliary circuits of a fast reactor and in various test facilities. Though centrifugal pumps are used for pumping sodium in the primary and the secondary circuits of the reactor, electromagnetic pumps have been preferred in the auxiliary circuits. Low efficiency of these electromagnetic pumps prohibits their use in the main sodium circuits of a fast reactor. But their ability to operate even with impurities in sodium and their high reliability and almost maintenance-free operation makes them an ideal choice. These electromagnetic pumps work on the principle that

© Springer Nature Switzerland AG 2019 347 B. Zohuri, Heat Pipe Applications in Fission Driven Nuclear Power Plants, https://doi.org/10.1007/978-3-030-05882-1 348 Appendix B: Electromagnetic Pump whenever a current-carrying conductor is placed in a perpendicular magnetic field, a force acts upon it. There are various types of electromagnetic pumps which can be mainly classified as conduction electromagnetic pumps and induction electromagnetic pumps [1]. In conduction electromagnetic pumps [1, 2] the in sodium flows via conduction from an external circuit which requires physical connection of the external circuit to the duct where as in induction pumps, the current is induced in sodium without connecting an external circuit to the stainless steel (SS) duct. Since no physical contact is there with SS duct in case of induction pumps, they are considered to be more reliable compared to conduction pumps. Both the conduction and induction types of pumps have been developed and are in operation in Indira Gandhi Centre for Atomic Research (IGCAR). Induction pumps are mainly of two types—the Flat Linear Induction Pump (FLIP) and the Annular Linear Induction Pump (ALIP). FLIP has a flat duct with stator normally on upper and lower part of the duct. It also has rectangular copper bars welded on its sides for providing a low resistance short circuit path and thereby increasing its efficiency. Besides, the flat duct is less suitable for high-pressure applications; therefore it was decided to use ALIP for Secondary Sodium Fill and Drain Circuit (SSFDC) of Prototype Fast Breeder Reactor (PFBR) presently under construction at Kalpakkam [3]. This pump has a flow rate of 170 m3/h and can deliver a head of 4 kg/cm2. This paper describes the design data of the pump and details of the testing of pump carried out at the Steam Generator Test Facility (SGTF) in IGCAR.

Electromagnetic Pump Working Principle

Liquid metal loops are used for heat removal and for the study of certain magneto- fluidic phenomenon like MHD (magnetohydrodynamic) effects. These loops operate at high temperatures and carry fluids that are invariably toxic in nature. Ensuring the purity of fluid in a closed loop application needs nonintrusive pumps and electro- magnetic pumps. We have designed and analyzed a prototype electromagnetic pump to be used in mercury loop for carrying out various studies. This electromagnetic pump is designed using permanent magnets which are mounted on periphery of rotor, which is rotated using DC motor. The liquid metal flows in a semicircular duct surrounding the rotor. See Fig. B.1, where surface plot of magnetic field density superimposed with contours of magnetic potential of an electromagnetic pump simulated using multiphysics software COMSOL®. ! ! A magnetic field ( b ) always exists around the current ( I )-carrying conductor. rc ! When this currents-carrying conductor is subjected to an external magnetic field (B), rap ! ! the conductor experiences a force perpendicular to the direction of I and B . This is rap because the magnetic field produced by the conductor and the applied magnetic field Appendix B: Electromagnetic Pump 349

Fig. B.1 Schematic of heat removal liquid metal loops

attempt to align with each other. A similar effect can be seen between two ordinary magnets. This principle is used in an electromagnetic pump. The current is fed through a conducting liquid. Two permanent magnets are arranged to produce a magnetic field ! ! B as shown in the Fig. B.2. The supplied current has a (J ) and the rap magnetic field associated with this current can be called as “reaction magnetic field ! ! ! (b).” The two magnetic fields B and b attempt to align with each other; thus this rc rap rc causes mechanical motion of the fluid as illustrated in Fig. B.2. As we stated at the introduction of this appendix, a special type of liquid metal thermomagnetic device is the Annular Linear Induction Pump (ALIP). It is known that electromagnetic pumps have a number of advantages over mechanical pumps: absence of moving parts, low noise and vibration level, simplicity of flow rate regulation, easy maintenance, and so on. However, while developing induction pumps, in particular ALIPs, we are faced with a significant problem of magnetohy- drodynamics (MHD) instability arising in the device. The manifestation of the instability does not allow linear induction pump development in a certain range of flow rate or the development of high efficiencies under certain flow rates and dropping pressure conditions. Linear induction pumps use a traveling magnetic field wave created by three- phase currents and the induced currents and their associated magnetic fields that generate a (see Fig. B.3). The three-phase winding arrangement for the solenoids usually follows the sequence AA ZZ BB XX CC YY where A, B, and C denote the balanced three-phase winding and X, Y, and Z the opposite phase; for 350 Appendix B: Electromagnetic Pump

Fig. B.2 Schematic of electromagnetic pump

Fig. B.3 Cross section of an ALIP in a conceptual representation

 !    a direct balanced system, if A ¼ 0 , B¼ 120 , and C ¼ 240 , then X ¼ 180 ,   Y ¼ 300 , and Z ¼ 60 . The correct winding sequence for the solenoids is obtained by arranging the sequence by the rising phase: AA ZZ BB XX CC YY. The complex flow behavior in this type of device includes a time-varying Lorentz force and pressure pulsation due to the time-varying electromagnetic fields and the induced convective currents that originate from the liquid metal flow, leading to instability problems along the device geometry. The determination of the geometry and of the electrical configuration of a thermomagnetic device gives rise to an inverse Appendix B: Electromagnetic Pump 351

Fig. B.4 Illustration of basic principles of electromagnetic pump

magnetohydrodynamic field problem. When the requirements of the design are defined, this problem can be solved by an optimization technique. Figure B.3a shows ALIP, Annular Linear Induction Pump; Fig. B.3b shows the cross section of the ALIP, and it is an adaptation of a diagram originally drawn by Dong Won Lee, KAERI, Korea Atomic Energy Research Institute. This is adapted with permission [4]. The objective function which must be maximized in the optimization problem is derived from the main design requirement. Usually for an MHD device, this is the efficiency. Other design requirements can be taken into account as constraints. For a nonlinear system, such as for linear induction pumps, the main objective functions are low weight and high efficiency, and so more than one maximum can exist. In this case a technique for global optimization must be used. In a typical electromagnetic pump, the following basic principles do work as follows and is illustrated in Fig. B.4 as: • Liquid metal are conductors. • Based on the Fleming’s left-hand rule. ! • Current flowing vertically through the liquid metal experiences a force (F¼ I ! ! L Â B). As it is illustrated in Fig. B.5, more details and types of EM pump are revealed including different components involved with infrastructure of these types of pumps that is used as part of cooling system in liquid metal breeder fissionable nuclear reactors. Types of electromagnetic pumps include: • Conduction pump: In this case current is directly conducted into fluid through electrodes. It has two variants, alternative current (AC) and (DC). • Induction pump: Current in the conducting fluid is induced by a traveling magnetic field. • Thermoelectric pump: Current flowing through the liquid metal is derived directly from the thermal power contained in the hot liquid metal flow, such as the one that we can encounter in liquid metal fast breeder reactor (LMFBR) of Generation III like French-built Phoenix-II or liquid metal breeder of Generation IV, such as Molten Salt Reactor (MSR) sodium-cooled fast reactor (SFR). See Chap. 2 of this book. 352 Appendix B: Electromagnetic Pump

Fig. B.5 Detailed components of electromagnetic pump

Fig. B.6 Simple applications of EM pump illustration. (a) Image of EM Pump Used in Nuclear Reactor (Courtesy Handbook of Nuclear Engineering by Daniel Gabriel). (b) Assembled EM Pump for Foundry (Courtesy CMI Novacast Inc.)

As far as holistic observation of EM pump application is concerned, Fig. B.6 presents such general application of device as two main driven scenario and they are: • Cooling of nuclear reactor • Pouring and transportation of high-temperature metals in foundry If we take a look at the electromagnetic pump form inside point of view as it is depicted in Fig. B.7, we notice that the electrical current is induced by transformer action. The transformer’s primary coil T in Fig. B.7 is connected to an AC single-phase power source. The transformer pole pieces are arranged in the shape of a picture frame and server as the carrier of magnetic flux. The transformer secondary winding S around the bottom leg of the picture frame as it is shown in Fig. B.7 is molten metal Appendix B: Electromagnetic Pump 353

Fig. B.7 Schematic of electromagnetic pump from inside and is formed by channels in ceramic parts. The turns ratio amplifies the electrical input current to produce very high amperage I in the molten metal. Figure B.8 is a demonstration of a sectional view of electromagnet construction that is added, which consists of a C-shaped pole piece and two excitation coils. The opening in the C straddles the necked-down section of the molten secondary turn, so the magnetic field H crossing the pole gap is perpendicular to the secondary current I, resulting in force Q to move metal through the pump. In Fig. B.9, we see the complete electromagnetic pump from inside perspective of infrastructure. It is surrounded by or encapsulated in ceramic parts to protect it from molten metal contact to prevent any corrosions or any other side effects from liquid metal of internal nuclear core. Pump output Q is varied by controlling input power and can be regulated from almost dropwise flow up to full bore delivery. 354 Appendix B: Electromagnetic Pump

Fig. B.8 Further schematic of electromagnetic pump from inside

Fig. B.9 Complete schematic of electromagnetic pump from inside Appendix B: Electromagnetic Pump 355

Working Principle of Annular Linear Induction Pump (ALIP)

Like all other electromagnetic pumps, Annular Linear Induction Pump (ALIP) works on the principle that whenever a current-carrying conductor is placed in a perpendicular magnetic field, a force acts on the conductor. The magnitude of this force is given by F ¼ BIL, where “I” is the current through the conductor, L is the length of the conductor, and B is the magnetic flux density in which the conductor is placed. In the case of ALIP, there is an annular region in which sodium flows, outside this annular region there are copper windings which are excited by three- phase AC supply and produces a linearly moving magnetic field. This linearly moving magnetic field, according to Faraday’s law of induction, induces a current in the liquid metal (Fig. B.10). The interaction of this current and moving magnetic field produces a force on the sodium resulting in the pumping action as illustrated in Fig. B.10, where it shows the working principle of Annular Linear Induction Pump [5]. Since the working principle of ALIP is similar to an induction motor, the equivalent circuit of ALIP (Fig. B.11) is also similar. At the same time, there are some differences as compared to an inductor motor. Typical slip in induction motors

Fig. B.10 Working principle of Annular Linear Induction Pump [5]

Fig. B.11 Equivalent Circuit of ALIP [5] 356 Appendix B: Electromagnetic Pump is 0.05 or less whereas for ALIP typical slip is in the range of 0.4–0.9 which leads to higher slip losses. The presence of ducts for containing sodium not only introduces additional resistive elements in the equivalent circuit but also leads to higher air gap compared to that in an induction motor. These features lead to reduction in power factor and in efficiency when compared to that of an induction motor. Besides, end effects and hydraulic losses also lead to reduction in efficiency [5]. In Fig. B.11, the following parameters do apply as:

R1—Resistance of stator winding X1—Leakage reactance of stator winding Xm—Magnetic reactance Rf—Fluid resistance Rj—Resistance of inner duct Rw—Resistance of outer duct E—Air gap electromagnetic force (EMF) s—Slip Note that: The winding in the ALIP is circular pancake type and is different from conventional winding used in rotating induction motors.

Advantages and Limitations of Electromagnetic Pumps

There exist some advantages to utilization of this pump in any application, where these EM pumps are installed, while along with such pros, there exist some limita- tion for these pumps and they are all listed below. 1. Advantages • No moving parts, no vibrations, or wear and tear • No seals, no splits • Less maintenance and more reliable • Safe to be used 2. Limitations • Power losses due to back EMF and Ohmic heating • Limited uses since very few liquids are good conductors of electricity References

1. Publishing Co. Inc, New York. 1987. 2. Nashine, B. K., et al. (2007). Performance testing of indigenously developed DC conduction pump for sodium cooled fast reactor. Indian Journal of Engineering and Material Sciences, 14, 209–214. 3. Chetal, S. C., et al. (2006). The design of the prototype fast breeder reactor. Nuclear Engineering and Design, 236, 852–860. 4. Maidana, C. O., & Nieminen, J. E. (2017). First studies for the development of computational tools for the design of liquid metal electromagnetic pumps. Nuclear Engineering and Technol- ogy, 49(1), 82–91. 5. Sharma, P, Sivakumar, L. S., Rajendra Prasad, R., Saxena, D. K., Suresh Kumar, V. A., Nashine, B. K., et al. (2011). Design, development and testing of a large capacity annular linear induction pump. Asian Nuclear Prospects 2010, Energy Procedia, 7, 622–629, Elsevier.

© Springer Nature Switzerland AG 2019 357 B. Zohuri, Heat Pipe Applications in Fission Driven Nuclear Power Plants, https://doi.org/10.1007/978-3-030-05882-1 Index

A Closed Brayton Cycle (CBC), 210 Accelerator-driven systems (ADS), 45 Code of Federal Regulations (CFR), 31 Advanced boiling water reactors (ABWR), 24 Combined cycle (CC), 153 Advanced gas-cooled reactors (AGRs), 99 Combined Cycle Gas Turbine (CCGT), 99 Advanced High-Temperature Reactor Commercial Resupply Services (CRS), 261 (AHTR), 203 Committee on Radioactive Waste Management Advanced Modular Reactor (AdvSMR), 98 (CoRWM), 65 Advanced Small Modular Reactors Computational Fluid Dynamics (CFD), 225 (AdvSMRs), 41, 77, 88, 109 Constant conductance heat pipe (CCHP), Advanced Small Modular Reactors 172, 174 (ASMRs), 21 Construction and Operating License (COL), 70 Air-conditioning (AC), 94, 109 Construction Permit (CP), 70 Alkali-Metal Thermal-to-Electric Conversion Core damage frequencies (CDFs), 109 (AMTEC), 210 American Society of Mechanical Engineering (AMSE), 279 D Annular Linear Induction Pump (ALIP), 348, Decay heat removal (DHR), 205 349, 355 Deliberately Small Reactor (DSR), 40 Arbeitsgemeinschaft Versuchsreaktor (AVR), 74 Department of Energy (DOE), 47, 67, 77, 88 Argentina, 43 Direct Reactor Auxiliary Cooling System Argentina National Atomic Energy (DRACS), 203, 205 Commission (CNEA), 92 Direct Removal Auxiliary Cooling System Atomic Energy Commission (AEC), 231 (DRACS), 208 DRACS Heat Exchanger (DHX), 203 Dual-Purpose metal Cask (DPC), 224 B Brayton cycle, 123, 127, 217, 242 Brazil, 43 E By design, 108 Electric Power Research Institute (EPRI), 15 Electromagnetic pumps (electromagnetic pumps), 250 C Electron beam welding (EBW), 323 Capillary pumped loop (CPL), 170 Energy Policy Act (EPAct), 46 Clinch River Breeder Reactor Project Entropy, 124, 134, 135, 140 (CRBRP), 205 Euratom, 43

© Springer Nature Switzerland AG 2019 359 B. Zohuri, Heat Pipe Applications in Fission Driven Nuclear Power Plants, https://doi.org/10.1007/978-3-030-05882-1 360 Index

European Nuclear Energy Forum (ENEF), 73 High-temperature gas-cooled reactors European Pressurized Water Reactor (EPR), 70 (HTGRs), 74, 88, 98, 99 European Sustainable Nuclear Industrial High-temperature reactor-pebble bed module Initiative, 72 (HTR-PM), 74 Evaluation Methodology Group, 66 High-temperature reactor pebble module Extremely High-Temperature Gas-Cooled (HTR-PM), 99 Reactor (EHTGR), 233 High-temperature reactors (HTRs), 46, 99 High-temperature steam (HTSE), 50 F Human Exploration and Operations Mission First-of-a-Kind (FOAK), 44 Directorate (HEOMD), 257 Fixed conductance heat pipes (FCHPs), Hydrogen Energy and Fuel Cells, 73 172, 174 Flat Linear Induction Pump (FLIP), 348 Fluoride-salt-cooled high-temperature reactors I (FHRs), 52, 204, 209 Idaho National Laboratory (INL), 47 Fort St. Vrain (FSV), 74 Indira Gandhi Centre for Atomic Research France, 43 (IGCAR), 348 Fuel Cycle Crosscut Group (FCCG), 67 Industries Metalurgicas Pescarmona SA (IMPSA), 92 Innovative Nuclear Reactors and Fuel Cycles G (INPRO), 43 Gas-cooled fast reactor (GFR), 74 Integral Molten Salt Reactor (IMSR), 84 Gas-cooled reactor (GFR), 58 Intermediate heat exchanger (IHX), 50, 205 Gas fast reactors (GFRs), 18 International Atomic Energy Agency (IAEA), Gas turbine combined cycle (GTCC), 153 34, 39 Gas turbine-modular helium reactor International Atomic Energy Association (GT-MHR), 100 (IAEA), 106 General Electric (GE), 215 International Commission on Radiological Generation II, 41 Protection (ICRP), 252 Generation III, 41 International Space Station (ISS), 261 Generation IV, 42, 43, 46, 66 Generation IV International Forum (GIF), 43, 48, 77 J Generation Nuclear Plant (NGNP), 46 Japan, 43 Japan Atomic Energy Agency (JAEA), 75 Japan Atomic Energy Research Institute H (JAERI), 95 Heat exchanger (HX), 205 Japan sodium-cooled fast reactor Heat pipe (HP), 214, 239 (JSFR), 205 Heat pipe reactor, 95 Heat recovery steam generator (HSRG), 6, 40 Heating, ventilating and air conditioning K (HVAC), 162 Korea Atomic Energy Research Institute Heavy water, 4 (KAERI), 94 Heavy Water Reactors (HWRs), 18 High-enriched uranium (HEU), 33 High-level waste (HLW), 17 L The High Temperature Engineering Test, 75 Large water-cooled reactors (LWCRs), 109 High-temperature and very high-temperature Lead-bismuth eutectic (LBE), 59 gas-cooled reactors (HTGRs), 18 Lead-cooled fast reactor (LFR), 59 High-temperature gas-cooled reactor pebble- Levelized cost of electricity (LCOE), 112 bed module (HTGR-PM), 88 Light water, 5 Index 361

Light Water Reactor (LWR), 18, 47, 87, 103, P 153, 160 Pebble-bed modular reactor (PBMR), 100 Liquid-controlled heat pipe (LCHP), 173 People’s Republic of China, 43 Liquid metal fast breeder reactors (LMFBRs), Phenomena Identification and Ranking 18, 167, 205 Table (PIRT), 69 Liquid-oxygen (LOX), 260 Plant-Life Management technologies and Plant Loop heat pipe (LHP), 170, 194 License Extension practices Los Alamos National Laboratory (LANL), 230 (PLIM/PLEX), 44 Low-Earth Orbit (LEO), 252 Policy Group (PG), 43 Low-enriched uranium (LEU), 109, 114 Power purchase agreements (PPAs), 83 Power Reactor Inherently Safe Module (PRISM), 208 M Pressure, 118 (MHD), 349 Pressurized water reactor (PWR), 23, 225 Mars Science Laboratory (MSL), 252 Primary Reactor Cooling System Maximum expected operating pressures (PRACS), 205 (MEOP), 191 Production tax credit (PTC), 83 Million tons of carbon (MtC), 64 Protected Air-Cooled Condenser (PACC), 205 Million tons of uranium (MtU), 45 Prototype Fast Breeder Reactor (PFBR), 348 Mixed oxide (MOX), 17 Molten Salt Reactor (MSR), 18, 51, 74 Multi-application small light water reactor R (MASLWR), 88, 103, 114 Radioisotope Heat Units (RHUs), 252 Multi-mission radioisotope thermoelectric Radioisotope-powered TEG (RTG), 243 generator (MMRTG), 252 Radioisotope thermoelectric generator (RTG), 247, 252 Rankine cycle, 133, 134, 138 N Reactor In-Flight-Test (RIFT), 232 National Aeronautics and Space Administration Reactor Vessel Auxiliary Cooling System (NASA), 231, 259 (RVACS), 208 Natural Draft Heat Exchanger (NDHX), 203 Research and development (R&D), 42 Near-Earth object (NEO), 261 Return on investment (ROI), 2, 78 Near-Earth orbit (NEO), 252 Roadmap Integration Team (RIT), 66 New Generation Nuclear Power (NGNP), 47 Russian Federation, 43 Next Generation Nuclear Plant (NGNP), 74, 99 Non-condensable gas (NCG), 183, 328 Nuclear Air-Brayton Combined Cycle S (NACC), 153, 157, 160 Safe Affordable Fission Engine (SAFE), 239 Nuclear Engine for Rocket Vehicle Application Sandia National Laboratories (SNL), 15 (NERVA), 231, 239 Science Mission Directorate (SMD), 257 Nuclear Nonproliferation Treaty (NPT), 34 Secondary Sodium Fill and Drain Circuit Nuclear power plants (NPPs), 15, 42, 46, (SSFDC), 348 70, 114 Small Modular Reactors (SMRs), 2, 14, 34, 67, Nuclear Power System (NPS), 246, 252, 256 87, 100, 106, 114 Nuclear Regulatory Commission Sodium Advanced Fast Reactor (SAFR), 208 (NRC), 47, 83 Sodium-cooled fast reactor (SFR), 53, 74 Nuclear thermal propulsion (NTP), 237, 259 Sodium Fast Reactor (SFR), 71 Nuclear thermal reactor (NTR), 233 South Africa, 43 Nuclear thermal rocket (NTR), 233, 260 Space Nuclear Propulsion Office (SNPO), 231 Spent Nuclear Fuel (SNF), 225 Stainless steel (SS), 348 O State variable, 144 Outer diameter (OD), 164 Steam Cycle High-Temperature Gas Reactor Oxide dispersion strengthened (ODS), 58 (SC-HTGR), 100 362 Index

Steam generator (SG), 205 U Steam Generator Test Facility Ultimate tensile stress (UTS), 280 (SGTF), 348 United Kingdom (UK), 43, 99 Stirling engine, 225 United Nations (UN), 252 Supercritical Water (SCW), 55 United States (US), 43, 99 Supercritical Water-Cooled Reactors University of California at Berkeley (SCWRs), 54 (UCB), 204 Supercritical water reactors Uranium oxide/uranium carbide (UCO), 77 (SCWRs), 18 Switzerland, 43 System Research Plan (SRP), 59 V System Steering Committee (SSC), 43 Vapor Chamber Radiator Study (VCRS), 215 Vapor dome, 135, 140 Variable conductance heat pipe (VCHP), T 172–174 Technical Working Group Variable cryogenic heat pipe (VCHP), 304 (TWG), 66 Variable heat pipe (VHP), 304 Thermionic fuel elements (TFEs), 255 Very-high-temperature gas-cooled reactor Thermoelectric (TE), 210 (VHTR), 47 Thermoelectric General (TEG), 247 Very high-temperature reactor (VHTR), 46, 49, Thorium high-temperature reactor-300 50, 74 (THTR-300), 75 Volume, 118 Total cost of ownership (TCO), 2, 78 Transuranic (TRU) waste, 29 Tristructural-isotropic (TRISO), 50 W Tungsten inert gas welding (TIC), 323 Waste Isolation Pilot Plant (WIPP), 31 Turbopump assembly (TPA), 233 Work, 118