357:-water heat transfer ensures the fuel cannot melt through accident alone. In uranium-zirconium alloy hydride variants, the fuel itself is also chemically corrosion resistant ensuring a sustainable safety performance of the fuel molecules throughout their lifetime. A large expanse of water and the concrete surround provided by the pool for high energy neutrons to penetrate ensures the process has a high degree of intrinsic safety. The core is visible through the pool and verification measurements can be made directly on the core fuel elements facilitating total surveillance and providing nuclear non-proliferation safety. Both the fuel molecules themselves and the open expanse of the pool are passive safety components. Quality implementations of these designs are arguably the safest nuclear reactors.
374:
sump pumps automatically pumped the contaminated water outside the containment building. Both a working PORV with quench tank and separately the containment building with sump provided two layers of passive safety. An unreliable PORV negated its designed passive safety. The plant design featured only a single open/close indicator based on the status of its solenoid actuator, instead of a separate indicator of the PORV's actual position. This rendered the mechanical reliability of the PORV indeterminate directly, and therefore its passive safety status indeterminate. The automatic sump pumps and/or insufficient containment sump capacity negated the containment building designed passive safety.
401:. It was designed with an Emergency Core Cooling System (ECCS) that depended on either grid power or the backup Diesel generator to be operating. The ECCS safety component was decidedly not passive. The design featured a partial containment consisting of a concrete slab above and below the reactor – with pipes and rods penetrating, an inert gas filled metal vessel to keep oxygen away from the water-cooled hot graphite, a fire-proof roof, and the pipes below the vessel sealed in secondary water filled boxes. The roof, metal vessel, concrete slabs and water boxes are examples of passive safety components. The roof in the
503:
heat input, the net result was that the reactor would cool. Extending from the bottom of the reactor core was a pipe that lead to passively cooled drain tanks. The pipe had a "freeze valve" along its length, in which the molten salt was actively cooled to a solid plug by a fan blowing air over the pipe. If the reactor vessel developed excessive heat or lost electric power to the air cooling, the plug would melt; the FLiBe would be pulled out of the reactor core by gravity into dump tanks, and criticality would cease as the salt lost contact with the graphite moderator.
95:
rod may not fulfil its mission: It may get stuck due to earthquake conditions or due to deformed core structures. This shows that though it is a passively safe system and has been properly actuated, it may not fulfil its mission. Nuclear engineers have taken this into consideration: Typically only a part of the rods dropped are necessary to shut down the reactor. Samples of safety systems with passive safety components can be found in almost all nuclear power stations: the containment, hydro-accumulators in PWRs or pressure suppression systems in
1981:
1971:
1951:
113:... passivity is not synonymous with reliability or availability, even less with assured adequacy of the safety feature, though several factors potentially adverse to performance can be more easily counteracted through passive design (public perception). On the other hand active designs employing variable controls permit much more precise accomplishment of safety functions; this may be particularly desirable under accident management conditions.
1961:
1083:
265:. If the reactor overheats, thermal expansion of the metallic fuel and cladding causes more neutrons to escape the core, and the nuclear chain reaction can no longer be sustained. The large mass of liquid metal also acts as a heatsink capable of absorbing the decay heat from the core, even if the normal cooling systems would fail.
229:, can not remove residual production and decay heat without either process heat transfer or the active cooling system. In other words, whilst the inherently safe heat transfer process provides a passive safety component preventing excessive heat while the reactor is operating, the same inherently safe heat transfer process
324:
fluoride coolant without fuel provides a flotation layer passive safety component in which lower density graphite that breaks off control rods or an immersion matrix during mechanical failure does not induce criticality. Gravity driven drainage of reactor liquids provides a passive safety component.
59:
An example of a safety system with passive safety components is the containment vessel of a nuclear reactor. The concrete walls and the steel liner of the vessel exhibit passive safety, but require active systems (valves, feedback loops, external instrumentation, control circuits, etc.) which require
51:
Despite the increased safety associated with greater coverage by passive systems, all current large-scale nuclear reactors require both external (active) and internal (passive) systems. There are no 'passively safe' reactors, only systems and components. Safety systems are used to maintain control of
502:
fuel dissolved in it. The MSRE had a negative temperature coefficient of reactivity: as the FLiBe temperature increased, it expanded, along with the uranium ions it carried; this decreased density resulted in a reduction of fissile material in the core, which decreased the rate of fission. With less
84:
In category A (1+2+3+4) is the fuel cladding, the protective and nonreactive outer layer of the fuel pellet, which uses none of the above features: It is always closed and keeps the fuel and the fission products inside and is not open before arriving at the reprocessing plant. In category B (2+3+4)
89:
and uses a moving working fluid when fulfilling its mission. In category C (3+4) is the accumulator, which does not need signal input of 'intelligence' or external power. Once the pressure in the primary circuit drops below the set point of the spring-loaded accumulator valves, the valves open and
373:
at TMI-2 was designed to shut automatically after relieving excessive pressure inside the reactor into a quench tank. However the valve mechanically failed causing the PORV quench tank to fill, and the relief diaphragm to eventually rupture into the containment building. The containment building
158:
in the sense that they involve electrical or mechanical operation on command systems (e.g., high-pressure water pumps). But some engineered reactor systems operate entirely passively, e.g., using pressure relief valves to manage overpressure. Parallel redundant systems are still required. Combined
94:
which utilizes moving working fluids, moving mechanical parts and signal inputs of 'intelligence' but not external power or forces: the control rods drop driven by gravity once they have been released from their magnetic clamp. But nuclear safety engineering is never that simple: Once released the
39:
systems such as diesel-powered motors. Some newer reactor designs feature more passive systems; the motivation being that they are highly reliable and reduce the cost associated with the installation and maintenance of systems that would otherwise require multiple trains of equipment and redundant
34:
or loss of coolant flow). Such design features tend to rely on the engineering of components such that their predicted behaviour would slow down, rather than accelerate the deterioration of the reactor state; they typically take advantage of natural forces or phenomena such as gravity, buoyancy,
352:
or spectrum hardening dissipates heat from the fuel more rapidly throughout the pool the higher the fuel temperature increases ensuring rapid cooling of fuel whilst maintaining a much lower water temperature than the fuel. Prompt, self-dispersing, high efficiency hydrogen-neutron heat transfer
141:
component that could – if so designed – render in a reactor a negative void coefficient of reactivity, regardless of the operational property of the reactor in which it is fitted. The feature would only work if it responded faster than an emerging (steam) void and the reactor components could
396:
inherent safety. The reactor was unsafe at low power levels because erroneous control rod movement would have a counter-intuitively magnified effect. Chernobyl
Reactor 4 was built instead with manual crane driven boron control rods that were tipped with the moderator substance, graphite, a
52:
the plant if it goes outside normal conditions in case of anticipated operational occurrences or accidents, while the control systems are used to operate the plant under normal conditions. Sometimes a system combines both features. Passive safety refers to safety system components, whereas
136:
Reactors could be fitted with a hydraulic safety system component that increases the inflow pressure of coolant (esp. water) in response to increased outflow pressure of the moderator and coolant without control system intervention. Such reactors would be described as fitted with such a
40:
safety class power supplies in order to achieve the same level of reliability. However, weak driving forces that power many passive safety features can pose significant challenges to effectiveness of a passive system, particularly in the short term following an accident.
315:
coolant. The molecular bonds provide a passive safety feature in that a loss-of-coolant event corresponds with a loss-of-fuel event. The molten fluoride fuel can not itself reach criticality but only reaches criticality by the addition of a neutron reflector such as
518:) which provide a flow path for air driven natural circulation from chimneys positioned above grade. Derivatives of this RCCS concept (with either air or water as the working fluid) has also been featured in other gas-cooled reactor designs, including the Japanese
30:, that does not require any active intervention on the part of the operator or electrical/electronic feedback in order to bring the reactor to a safe shutdown state, in the event of a particular type of emergency (usually overheating resulting from a
48:'Passive safety' describes any safety mechanism whose engagement requires little or no outside power or human control. Modern reactor designs have focused on increasing the number of passive systems to mitigate risk of compounding human error.
35:
pressure differences, conduction or natural heat convection to accomplish safety functions without requiring an active power source. Many older common reactor designs use passive safety systems to a limited extent, rather, relying on
288:
atoms and initiate fission, thus reducing the reactor's power output and placing an inherent upper limit on the temperature of the fuel. The geometry and design of the fuel pebbles provides an important passive safety component.
368:
was unable to contain about 480 PBq of radioactive noble gases from release into the environment and around 120 kL of radioactive contaminated cooling water from release beyond the containment into a neighbouring building. The
253:
active controls or (human) operational intervention to avoid accidents in the event of malfunction, and may rely on pressure differentials, gravity, natural convection, or the natural response of materials to high temperatures.
513:
design features a fully passive and inherently safe decay heat removal system, termed the
Reactor Cavity Cooling System (RCCS). In this design, an array of steel ducts line the concrete containment (and hence surround the
750:
Klimenkov, A. A.; N. N. Kurbatov; S. P. Raspopin & Yu. F. Chervinskii (December 1, 1986), "Density and surface tension of mixtures of molten fluorides of lithium, beryllium, thorium, and uranium",
413:
hydrogen explosion. The water boxes could not sustain high pressure failure of the pipes. The passive safety components as designed were inadequate to fulfill the safety requirements of the system.
102:
In most texts on 'passively safe' components in next generation reactors, the key issue is that no pumps are needed to fulfil the mission of a safety system and that all active components (generally
388:
were designed with a positive void coefficient with boron control rods on electromagnetic grapples for reaction speed control. To the degree that the control systems were reliable, this
272:
is an example of a reactor exhibiting an inherently safe process that is also capable of providing a passive safety component for all operational modes. As the temperature of the
441:("AP" standing for "Advanced Passive") uses passive safety components. In the event of an accident, no operator action is required for 72 hours. Recent versions of the Russian
1474:
348:(19.75% U-235) uranium alloy hydride fuel rises, the molecular bound hydrogen in the fuel cause the heat to be transferred to the fission neutrons as they are ejected. This
468:. This was demonstrated throughout a series of safety tests in which the reactor successfully shut down without operator intervention. The project was canceled due to
1668:
365:
171:
response of materials to high temperatures to slow or shut down the reaction, not on the functioning of engineered components such as high-pressure water pumps.
1984:
445:
have added a passive heat removal system to the existing active systems, utilising a cooling system and water tanks built on top of the containment dome.
1115:
129:
respectively. Reactors whose heat transfer process has the operational property of a negative void coefficient of reactivity are said to possess an
1779:
142:
sustain the increased coolant pressure. A reactor fitted with both safety features – if designed to constructively interact – is an example of a
1924:
690:
Directory of
National Competent Authorities' Approval Certificates for Package Design, Special Form Material and Shipment of Radioactive Material
610:
182:
are systems that have been designed with one kind of passive safety feature. In the event of an excessive-power condition, as the water in the
146:. Rarer operational failure modes could render both such safety features useless and detract from the overall relative safety of the reactor.
534:. While none of these designs have been commercialized for power generation research in these areas is active, specifically in support of the
237:
exposed this design deficiency: the reactor and steam generator were shut down but with loss of coolant it still suffered a partial meltdown.
911:
241:
118:
67:(IAEA) classifies the degree of "passive safety" of components from category A to D depending on what the system does not make use of:
1174:
1024:
519:
1413:
938:
1624:
1464:
1403:
1544:
810:
1369:
1108:
589:
85:
is the surge line, which connects the hot leg with the pressurizer and helps to control the pressure in the primary loop of a
2010:
1420:
1042:
1337:
1619:
531:
64:
2015:
1101:
604:
1954:
1929:
1794:
133:
process feature. An operational failure mode could potentially alter the process to render such a reactor unsafe.
1872:
1706:
1308:
1186:
1862:
1711:
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476:
122:
784:
1636:
1469:
724:
539:
484:
435:
1716:
1425:
1179:
848:
510:
546:(home to the Natural convection Shutdown heat removal Test Facility, a 1/2 scale air-cooled RCCS) and the
1974:
1936:
1774:
1601:
1539:
1364:
1268:
1154:
1066:
584:
543:
457:
370:
2005:
1822:
1501:
1073:
569:
527:
406:
234:
56:
refers to control system process regardless of the presence or absence of safety-specific subsystems.
1799:
1408:
1191:
1087:
175:
167:
safety depends only on physical phenomena such as pressure differentials, convection, gravity or the
86:
822:
249:
designs improve on early designs by incorporating passive or inherent safety features which require
125:
usually refer to the thermodynamic and phase-change response of the neutron moderator heat transfer
1964:
1889:
1789:
1701:
417:
31:
1025:"NEUP final report 09-781: Experimental Studies of NGNP Reactor Cavity Cooling Systems with Water"
90:
water is injected into the primary circuit by compressed nitrogen. In category D (4 only) is the
1919:
1894:
1508:
1285:
1043:"NEUP awarded abstract: Modeling and Test Validation of a Reactor Cavity Cooling System with Air"
1003:"The NSTF at Argonne: Passive Safety and Decay Heat Removal for Advanced Nuclear Reactor Designs"
547:
515:
1877:
1784:
889:
682:
559:
246:
969:
749:
1814:
1769:
1231:
1159:
623:
535:
469:
449:
424:
402:
382:
329:
179:
96:
225:
to that failure condition. However most current water-cooled and -moderated reactors, when
1764:
1749:
915:
453:
258:
183:
460:. It was a sodium cooled reactor capable of withstanding a loss of (coolant) flow without
8:
1899:
1684:
1278:
1146:
1125:
946:
574:
480:
296:
1804:
1641:
1568:
1379:
767:
594:
385:
317:
277:
269:
1136:
842:
826:
697:
659:
398:
199:
191:
771:
655:
1093:
984:
759:
651:
488:
405:
complex was made of bitumen – against design – rendering it ignitable. Unlike the
345:
304:
18:
Nuclear power safety method that does not require electrical power nor intervention
1882:
1842:
1296:
616:
579:
507:
428:
103:
53:
27:
1374:
1062:
1002:
1837:
1832:
1827:
1577:
1484:
1453:
1435:
349:
233:
provide a passive safety component if the reactor is shut down (SCRAMed). The
1857:
1999:
1313:
701:
663:
564:
36:
1588:
410:
354:
427:) is a design reported to use passive safety components. In the event of
1646:
1236:
496:
285:
281:
106:
and valves) of the systems work with the electric power from batteries.
1352:
988:
763:
890:"GE'S advanced ESBWR nuclear reactor chosen for two proposed projects"
320:. The higher density of the fuel along with additional lower density
1357:
1347:
814:
599:
360:
344:
operation in research environments because as the temperature of the
222:
143:
1852:
1726:
1721:
1661:
1330:
1258:
1241:
1226:
1201:
818:
788:
642:
Schulz, T.L. (2006). "Westinghouse AP1000 advanced passive plant".
499:
333:
312:
308:
293:
195:
728:
409:, neither the concrete slabs nor the metal vessel could contain a
1867:
1847:
1246:
1221:
300:
284:
atoms. This reduces the chance that the neutrons are captured by
1656:
1651:
1631:
1611:
1596:
1479:
1216:
1196:
1164:
523:
438:
1693:
1549:
1342:
1206:
1063:
Natural convection
Shutdown heat removal Test Facility (NSTF)
492:
465:
461:
420:
337:
321:
262:
226:
187:
91:
198:, causing the power level inside the reactor to lower. The
1554:
1443:
1253:
1211:
693:
442:
378:
203:
26:
is a design approach for safety features, implemented in a
967:
149:
1527:
1391:
550:(home to separate 1/4 scale air and water-cooled RCCS).
280:
increases the probability that neutrons are captured by
217:
safety component during a specific failure condition in
221:
operational modes is typically described as relatively
1071:
1123:
970:"Experience with the Molten-Salt Reactor Experiment"
945:. Nuclear Engineering International. Archived from
683:"Safety related terms for advanced nuclear plants"
361:Examples of reactors using passive safety features
431:, no operator action is required for three days.
1997:
624:Taylor Wilson's intrinsically safe small reactor
60:external power and human operation to function.
611:Failure mode, effects, and criticality analysis
811:"Nuclear Safety Parameters of a TRIGA reactor"
423:(Economic Simplified Boiling Water Reactor, a
1780:Small sealed transportable autonomous (SSTAR)
1109:
381:graphite moderated, water-cooled reactors of
936:
117:Nuclear reactor response properties such as
677:
675:
673:
109:IAEA explicitly uses the following caveat:
1960:
1116:
1102:
968:P.N. Haubenreich & J.R. Engel (1970).
542:programs, with experimental facilities at
311:radioisotopes in molecular bonds with the
242:Nuclear fuel response to reactor accidents
635:
520:High-temperature engineering test reactor
206:meltdown accident proved this principle.
1692:
670:
491:moderated and the coolant salt used was
154:Traditional reactor safety systems are
150:Examples of passive safety in operation
1998:
1707:Liquid-fluoride thorium reactor (LFTR)
641:
590:Russian floating nuclear power station
1712:Molten-Salt Reactor Experiment (MSRE)
1097:
472:before it could be copied elsewhere.
119:Temperature coefficient of reactivity
1717:Integral Molten Salt Reactor (IMSR)
977:Nuclear Applications and Technology
392:did have a corresponding degree of
13:
1526:
694:International Atomic Energy Agency
77:no signal inputs of 'intelligence'
65:International Atomic Energy Agency
14:
2027:
1056:
870:Kemeny, p. 96; Rogovin, pp. 17–18
821:: Reactor Infrastructure Centre,
787:. General Atomics. Archived from
605:Failure mode and effects analysis
411:steam, graphite and oxygen driven
213:safe process directly provides a
80:no external power input or forces
1980:
1979:
1970:
1969:
1959:
1950:
1949:
1800:Fast Breeder Test Reactor (FBTR)
1081:
937:V.G. Asmolov (August 26, 2011).
1035:
1017:
995:
961:
930:
904:
882:
873:
656:10.1016/j.nucengdes.2006.03.049
1790:Energy Multiplier Module (EM2)
914:. Westinghouse. Archived from
864:
855:
803:
777:
758:(6), Springer New York: 1041,
743:
717:
708:
644:Nuclear Engineering and Design
477:Molten-Salt Reactor Experiment
257:In some designs the core of a
190:are formed. These steam voids
123:Void coefficient of reactivity
43:
1:
1005:. Argonne National Laboratory
785:"TRIGA – 45 Years of Success"
629:
485:Oak Ridge National Laboratory
464:and loss of heatsink without
1590:Uranium Naturel Graphite Gaz
7:
2011:Nuclear safety and security
1937:Aircraft Reactor Experiment
1067:Argonne National Laboratory
585:Nuclear safety and security
553:
544:Argonne National Laboratory
458:Argonne National Laboratory
371:pilot-operated relief valve
10:
2032:
1775:Liquid-metal-cooled (LMFR)
570:Nuclear Power 2010 Program
407:Three Mile Island accident
239:
235:Three Mile Island accident
176:pressurized water reactors
1945:
1912:
1900:Stable Salt Reactor (SSR)
1813:
1795:Reduced-moderation (RMWR)
1760:
1743:
1683:
1610:
1602:Advanced gas-cooled (AGR)
1576:
1567:
1519:
1499:
1452:
1434:
1390:
1295:
1277:
1145:
1132:
939:"Passive safety in VVERs"
495:, which also carried the
74:no moving mechanical part
2016:Power station technology
1965:List of nuclear reactors
1805:Dual fluid reactor (DFR)
1421:Steam-generating (SGHWR)
847:: CS1 maint: location (
696:: 1–20. September 1991.
418:General Electric Company
366:Three Mile Island Unit 2
353:rather than inefficient
1955:Nuclear fusion reactors
1920:Organic nuclear reactor
1126:nuclear fission reactor
548:University of Wisconsin
516:reactor pressure vessel
340:have been licensed for
209:A reactor design whose
71:no moving working fluid
823:JoĹľef Stefan Institute
560:Generation III reactor
470:proliferation concerns
330:swimming pool reactors
180:boiling water reactors
115:
24:Passive nuclear safety
912:"Westinghouse AP1000"
791:on September 29, 2009
450:integral fast reactor
403:Chernobyl Power Plant
383:Chernobyl Power Plant
111:
1785:Traveling-wave (TWR)
1269:Supercritical (SCWR)
650:(14–16): 1547–1557.
526:, the South African
454:fast breeder reactor
297:molten salt reactors
263:pool of liquid metal
259:fast breeder reactor
184:nuclear reactor core
1155:Aqueous homogeneous
731:on October 19, 2007
725:"Advanced Reactors"
692:. Vienna, Austria:
575:Nuclear power plant
481:molten salt reactor
261:is immersed into a
1975:Nuclear technology
1088:Nuclear technology
989:10.13182/NT8-2-118
879:Rogovin, pp. 14–15
764:10.1007/bf01127271
704:. IAEA-TECDOC-626.
595:Safety engineering
530:, and the Russian
318:pyrolytic graphite
278:Doppler broadening
270:pebble bed reactor
186:boils, pockets of
2006:Energy conversion
1993:
1992:
1985:Nuclear accidents
1908:
1907:
1739:
1738:
1735:
1734:
1679:
1678:
1563:
1562:
1495:
1494:
1047:inlportal.inl.gov
1029:inlportal.inl.gov
949:on March 19, 2012
943:JSC Rosenergoatom
861:Walker, pp. 73–74
714:Walker, pp. 72–73
399:neutron reflector
200:BORAX experiments
2023:
1983:
1982:
1973:
1972:
1963:
1962:
1953:
1952:
1895:Helium gas (GFR)
1758:
1757:
1753:
1690:
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1524:
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1512:
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1021:
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999:
993:
992:
974:
965:
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934:
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925:
923:
918:on April 5, 2010
908:
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899:
897:
886:
880:
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871:
868:
862:
859:
853:
852:
846:
838:
836:
834:
829:on July 16, 2011
825:. Archived from
807:
801:
800:
798:
796:
781:
775:
774:
747:
741:
740:
738:
736:
727:. Archived from
721:
715:
712:
706:
705:
687:
679:
668:
667:
639:
489:nuclear graphite
350:Doppler shifting
247:Third generation
144:safety interlock
2031:
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2022:
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2020:
1996:
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1491:
1457:
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1300:
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1281:
1273:
1187:Natural fission
1141:
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1128:
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1092:
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1080:
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1054:
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734:
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723:
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713:
709:
685:
681:
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671:
640:
636:
632:
617:Inherent safety
580:Nuclear reactor
556:
538:initiative and
508:General Atomics
363:
244:
152:
131:inherent safety
54:inherent safety
46:
32:loss of coolant
28:nuclear reactor
19:
12:
11:
5:
2029:
2019:
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1991:
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1770:Integral (IFR)
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1058:
1057:External links
1055:
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1034:
1016:
994:
983:(2): 118–136.
973:(PDF, reprint)
960:
929:
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522:, the Chinese
377:The notorious
362:
359:
151:
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139:passive safety
82:
81:
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75:
72:
45:
42:
17:
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1815:Generation IV
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1765:Breeder (FBR)
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907:
891:
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876:
867:
858:
850:
844:
828:
824:
820:
816:
813:. Brinje 40,
812:
806:
790:
786:
780:
773:
769:
765:
761:
757:
753:
752:Atomic Energy
746:
730:
726:
720:
711:
703:
699:
695:
691:
684:
678:
676:
674:
665:
661:
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586:
583:
581:
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576:
573:
571:
568:
566:
565:Nuclear power
563:
561:
558:
557:
551:
549:
545:
541:
537:
536:Generation IV
533:
529:
525:
521:
517:
512:
509:
504:
501:
498:
494:
490:
486:
482:
479:(MSRE) was a
478:
473:
471:
467:
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459:
455:
451:
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432:
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347:
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339:
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306:
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298:
295:
292:Single fluid
290:
287:
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279:
275:
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266:
264:
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248:
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238:
236:
232:
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147:
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107:
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93:
88:
79:
76:
73:
70:
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68:
66:
61:
57:
55:
49:
41:
38:
37:active safety
33:
29:
25:
21:
16:
1823:Sodium (SFR)
1750:fast-neutron
1589:
1135:
1046:
1037:
1028:
1019:
1007:. Retrieved
997:
980:
976:
963:
953:September 6,
951:. Retrieved
947:the original
942:
932:
920:. Retrieved
916:the original
906:
894:. Retrieved
884:
875:
866:
857:
831:. Retrieved
827:the original
805:
793:. Retrieved
789:the original
779:
755:
751:
745:
733:. Retrieved
729:the original
719:
710:
689:
647:
643:
637:
505:
474:
447:
436:Westinghouse
433:
429:coolant loss
415:
393:
389:
376:
364:
355:radionuclide
346:low-enriched
341:
332:such as the
327:
291:
273:
267:
256:
250:
245:
230:
218:
214:
210:
208:
173:
168:
164:
160:
155:
153:
138:
135:
130:
126:
116:
112:
108:
101:
83:
62:
58:
50:
47:
23:
22:
20:
15:
1858:Superphénix
1685:Molten-salt
1637:VHTR (HTGR)
1414:HW BLWR 250
1380:R4 Marviken
1309:Pressurized
1279:Heavy water
1263:many others
1192:Pressurized
1147:Light water
1009:January 20,
892:. GE Energy
735:October 19,
497:uranium-233
483:run by the
456:run by the
44:Terminology
2000:Categories
1642:PBR (PBMR)
922:January 7,
896:January 7,
833:January 7,
795:January 7,
630:References
342:unattended
328:Low power
240:See also:
211:inherently
1694:Fluorides
1358:IPHWR-700
1353:IPHWR-540
1348:IPHWR-220
1137:Moderator
1124:Types of
815:Ljubljana
702:1011-4289
664:0029-5493
600:Fail-safe
487:. It was
223:fail-safe
1727:TMSR-LF1
1722:TMSR-500
1702:Fuji MSR
1662:THTR-300
1502:Graphite
1365:PHWR KWU
1331:ACR-1000
1259:IPWR-900
1242:ACPR1000
1237:HPR-1000
1227:CPR-1000
1202:APR-1400
843:cite web
819:Slovenia
772:93590814
554:See also
500:fluoride
386:disaster
334:SLOWPOKE
313:fluoride
309:actinide
299:feature
294:fluoride
231:does not
227:scrammed
202:and the
196:neutrons
192:moderate
174:Current
161:inherent
1868:FBR-600
1848:CFR-600
1843:BN-1200
1509:coolant
1436:Organic
1321:CANDU 9
1318:CANDU 6
1286:coolant
1247:ACP1000
1222:CAP1400
1160:Boiling
613:(FMECA)
305:fertile
301:fissile
276:rises,
215:passive
169:natural
165:passive
127:process
104:I&C
1913:Others
1853:Phénix
1838:BN-800
1833:BN-600
1828:BN-350
1657:HTR-PM
1652:HTR-10
1632:UHTREX
1597:Magnox
1592:(UNGG)
1485:Lucens
1480:KS 150
1217:ATMEA1
1197:AP1000
1180:Kerena
1074:Portal
770:
700:
662:
607:(FMEA)
532:GT-MHR
524:HTR-10
452:was a
439:AP1000
394:active
390:design
194:fewer
156:active
1930:Piqua
1925:Arbus
1883:PRISM
1625:MHR-T
1620:GTMHR
1550:EGP-6
1545:AMB-X
1520:Water
1465:HWGCR
1404:HWLWR
1343:IPHWR
1314:CANDU
1175:ESBWR
768:S2CID
686:(PDF)
493:FLiBe
466:SCRAM
462:SCRAM
421:ESBWR
338:TRIGA
322:FLiBe
286:U-235
282:U-238
188:steam
92:SCRAM
1890:Lead
1873:CEFR
1863:PFBR
1745:None
1555:RBMK
1540:AM-1
1470:EL-4
1444:WR-1
1426:AHWR
1370:MZFR
1338:CVTR
1327:AFCR
1254:VVER
1212:APWR
1207:APR+
1170:ABWR
1011:2014
955:2011
924:2010
898:2010
849:link
835:2010
797:2010
737:2007
698:ISSN
660:ISSN
540:NGNP
528:PBMR
511:HTGR
506:The
475:The
448:The
443:VVER
434:The
416:The
379:RBMK
336:and
307:and
274:fuel
268:The
204:SL-1
178:and
163:and
121:and
97:BWRs
63:The
1878:PFR
1669:PMR
1647:AVR
1569:Gas
1507:by
1475:KKN
1409:ATR
1324:EC6
1284:by
1232:EPR
1165:BWR
1065:at
985:doi
760:doi
652:doi
648:236
425:BWR
219:all
87:PWR
2002::
1612:He
1578:CO
1454:CO
1375:R3
1045:.
1027:.
979:.
975:.
941:.
845:}}
841:{{
817:,
766:,
756:61
754:,
688:.
672:^
658:.
646:.
303:,
251:no
99:.
1752:)
1748:(
1580:2
1532:O
1530:2
1528:H
1456:2
1396:O
1394:2
1392:H
1301:O
1299:2
1297:D
1117:e
1110:t
1103:v
1076::
1049:.
1031:.
1013:.
991:.
987::
981:8
957:.
926:.
900:.
851:)
837:.
799:.
762::
739:.
666:.
654::
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