Nuclear Power Technical and Institutional Options for the Future (1992) / Chapter Skim
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3 Assessment of Advanced Nuclear Reactor Technologies
3 Assessment of Advanced Nuclear Reactor Technologies
Pages 91-160
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From page 91... ...
The major hea~ling.c in l~able~1 (Image Evolutionary Light Water Reactors, etc.) align with the titles of the major sections below in whim tile advanced reactors are discussed.
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From page 92... ...
ce o - ao ~ ~n C~ C)
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From page 93... ...
Atom. The following sections treat ten advanced reactor types -- three large evolutionary LWRs, two m~-s~zed Lows with passive safety features, and five other reactor concepts.
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From page 94... ...
1,200 MWc commercial operation in 1998; 600 MWc is 2000 SOURCE: Electric Power Research Institute. Advanced light Water Reactor Utility Requirements Document, Volume 1, ALWR Policy and Summary of Toastier Requirements.
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From page 95... ...
GE was selected to supply the nuclear steam supply systems, fuel, and turbine generators. Figure ~1 is a diagram of this advanced reactor's pressure vessel and core.
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From page 96... ...
SOURCE: GE Nuclear Energy
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From page 97... ...
or a reactor isolation transients The residual heat removal system Is a triply redundant water delivery/decay heat removal combination Additionally, the elimination of large nozzles on the reactor vessel below the core helps ensure that the core Is not uncovered dunug any LOCA At the came time, a 50 percent reduction Of the total required emergency core cooling system pumping capacity is realized, compared to an equ~valent-s~ze external loop BWR plant. Control and Instn~nentation.
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From page 98... ...
Safety and control factions have been integrated, reducing piping requirements and enhancing safety-related fluid system design. For the ECCS, four l~igh-pressllre pumps take suction from an is-containment refueling water storage tank and inject borated water into the reactor vessel to improve core protection for small pipe breaks.
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From page 99... ...
ADVANCED NUCLEAR REACTOR TECHNOLOGIES 99 FIGURE 3-2 Advanced pressurized water reactor antedated safety systems (1 - Accumulator; 2 = High head safety injection pump; 3 = Residual heat removal heat exchanger; 4 = Residue heat removal/coolant systems pump)
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From page 100... ...
Steam Generators. Desks enhancements in the steam generators include better steam dryers, an increased overall heat transfer area, and slightly reduced full power step - pressure resulting from lower coolant temperatures, compared to the System 80 design.
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From page 101... ...
~ = C 3 C' ~ ~ C To ~ 1 1 cn en 3 fir c E go HE ~ o SO -: _~4 14, .` ~: .
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From page 102... ...
Mid-S~d Light Water Reactors With Passive Safety Features lithe pnnapal U.S. effort to develop mid-s~zed LWRs tenth passive safety features is sponsored by EPRI and the U.S.
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From page 103... ...
The Chairman of We Utility Steenug Committee for EPRl's Advanced LWR Program provided the following thoughts on the choice of the 600 MWe size: This choice was more or less arbitrary. It was arrived at from two directions.
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From page 104... ...
The AP 600 has the proven uranium oxide fueled core, with reductions ~ coolant temperature, flow rates, and core power density to increase design thermal margins. Steam Generators.
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From page 105... ...
Natural air circulation between the reactor containment structure and surrounding shield building provides dependable containment cooling.
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From page 106... ...
This simplified desk with shorter construction times and estimated lower capital costs could compensate for the loss of economy of scale credited to larger plants. Simplified Boiling Water Reactor The SBWR Is a passive design being developed by GE with filial support Mom DOE and EPRI.lDuncan and McCandless, 1988]
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From page 107... ...
It seines as a passive cooling system Mat reduces the temperate aIld pressure In the containment building In the event of a severe accident. During normal operation, an isolation condenser submerged In a pool of water, located above We core and outside the contingent, controls reactor pressure passives (automaticaBy3 without reducing We Guam volume In the reactor vessel.
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From page 110... ...
1acl~] ques AND be applied lo re5~brdig bar assenibE~ ~~ucnu~]
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From page 111... ...
~ _ / ~ ~ FUEL FUEL ~ ~~ CHANNEL MODERATOR _ ~ PUMP ~ I _ 3~) MODERATOR HEAT EXCHANGER FIGURE 3~ Steam supply system of CANDU-3.
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From page 112... ...
The ECCS operation includes provisions for both shortterm injection from pressurized accumulator tanks and long-term recreation of ~ mixture of ordinary and heavy water from the reactor building floor. Control and Ir~s~rnentatiom The reactivity control units are the reactor sensor and actuator portions of the reactor regulating and reactor shutdown systems.
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From page 113... ...
The shield tank, shield tack extension, and deck for the reactivity me~isms are also amenable to offsite construction Safe Integral Reactor CE: has undertaken the design of He SIR jointly with Rolls Royce and Associates Limited, Stone and Webster Engi~eenug Corporation, and the United Kingdom Atomic Energy Authoriq.[Bradbury et al., 1989] She is a PWR ~ which the reactor core, pressurizer, reactor coolant pumps, and steam generators are contained in a single reactor pressure vessel.
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From page 114... ...
Reactor Vessel Steam Generator Lower Support (12) Core Vessel __ Support Key (6)
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From page 115... ...
~ ~ steam Iniector r Emergency Coolant Injection System 1~ Main Feed Startup feed Pump Power Generation System 115 Condenser 1~ Condensate Storage Tank FIGURE 3-7b The safe integral reactor heat removal systems.
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From page 116... ...
the reactor vessel compartment, which houses the reactor pressure vessel and support structure; (2) eight cylindrical steel pressure suppression tanks with external fins, each containing a Pool of water; and (3)
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From page 117... ...
Considerations such as the termination of fuel supply, tile inability to assure spent fuel storage, the possibility of additional requirements being imposed prior to obtaining a long-term license, and larger estimated decommissioning costs led the consortium that owns the plant to seek increased government participation or, absent that increase, to shut the reactor down. The THOR was shut down In late 1989.3[Gas-Cooled Reactor Associates, 1989; HilL 19893 The advanced ~GR concept of GA Tethnolo~es is a helinn~-cooled unit.
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From page 119... ...
The reactor core is a low power density desks that connects of an annular array of hexagonal blocks of graphite fuel elements surrounded by a reflector of unfueled graphite blocs. The design is intended to provide efficient heat transfer to the exterior in order to limit the temperature rise of the fuel in the event of a LOCA.
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From page 120... ...
The once-through shed and tube desk uses helically wound tubes to carry water in at the bosom and steam out at the top. After passing through superheater sections at the top, the steam Is discharged through a nozzle assembly in the upper side wall of the steam generator.[Gas-Cooled Reactor Associates, 1987]
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From page 121... ...
Young, 1989] DOE also stated, The development of the commercial MHTGR is prepared to be stretched out if there are technology development delays associated with validating die plant design without a low leakage containment structure.
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From page 122... ...
~ the main coolant pump stops, the water circulates by natural connation through the density locks, boning the cool borated water into the core and rehung down the reactor. The fuel assemblies are standard pressurized reactor fuel elements with low-ennthed uranium oxide pellets in fuel rods.
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From page 123... ...
Steam generator (4)
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From page 124... ...
Containment. The cont~ent structure is a large, prestressed-concrete reactor vessel In which the cold borated water, the reactor core/nser assembly, and all key safety systems are located.
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From page 125... ...
, ~ generic reactor technology defined by the use of liquid sodium as coolant and metallic uranium and plutonium as fueL The reasons for the safe responses illustrated ~ the EBR-II tests are inherent to the Am. Specifically, the properties of the metallic fuel and the large thermal inertia of the sodi~ pool are key to achieving reactor shutdown passively (i.e., without relying on operator intervention, active components such as control rods, pumps, valves, or the use of balance of plant for heat removal)
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From page 126... ...
Although this arrangement wood require a fieldfabncated vessel, the elimination of the undesirable positive void coefficient characteristic may be deemed wormy of the loss of a sho~fabncated, railshippable reactor vessel The more recent fast flux test facility ttt-r~) constructed at the Hanford site Is a loop-type EMR.
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From page 127... ...
cr z A ~ o o C c: ~ Q o o i: Q)
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From page 129... ...
As discussed earlier In connection with the safety tests at EBR-II, the properties of metallic fuel are a major contn~utor to the passive safety features of the PRISM design. Argonne National Laboratoryis also developing apyrometallurgical reprocess~ system, in connection with the 1fK concept, which could Bad to fuel reprocessing and recycling.
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From page 130... ...
The plant control system, which is not safety grade, provides a high level of automation for normal plant operation and utilizes redundant digital equipment and power supplies to operate nine nuclear steam supplies, three turbine generators, and associated plant equipment from a single control center. Startup, operation, and shutdown of each module are automated.
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From page 131... ...
the technical and the economic feasibility of recycling In LMRs actinides recovered Tom LWR spent fuel.~[Pigford, 1990] The Committee notes that ~ study of separations technology and transmutation systems was initiated In 1991 by the DOE through the National Research Council's Board on Radioactive Waste Management.
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From page 132... ...
~ Hi cow S ID o)
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From page 133... ...
most able to be influenced by a choice of technology, and (b) significant to a fixture determination of whether or not one or more of the advanced reactor technologies Is deployed in the United States.
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From page 135... ...
. In the design of future advanced LWRs, vendors are gmded by the safety design policy presented in the Requirements Document prepared for EPRL The safety design policy states that There will be excellence in safety both to protect the general public and to assure personnel safety and plant investment protecdon.]
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From page 136... ...
The different advanced reactor designs employ different mixes of active and passive safety features to achieve the safety objectives, and there is, of course, more e~enence with certain designs than others. The Committee believes that there currently is no side optimal approach to improved safety.
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From page 137... ...
Dependence on passive safety features does not, of itself, ensure greater safety, the historical defense depth approach must be retainer In particular, for the MHIGR, the Committee was not convinced that a containment structure is unnecessary. Economy Discussion Vendor-estimated overly t capital costs and levelized generating costs are shown in Table 3-3 for the reactor technologies that the Committee examined.
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From page 138... ...
The large evolutionary LWRs have higher estimated total construction costs and longer construction times then the mid-s~zed LWRs with passive safety features but. as shown In Tables ~3 and 3 4.
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From page 139... ...
may be able to compete economically with water reactors if fuel reprocessing (bed developed as part of the integral fast reactor program) tom out to be technically and economically feasible, and if the overnight capital costs of these pits are as low as the vendor mbicates.
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From page 140... ...
utilities tenth several nuclear power plants are likely to be the first customers for such plants if they need large base load electrical generators and if financial risks are acceptable.34 Compared to the large evolutionary reactors, the mid-sized advanced pressurized and simplified boiling water reactors with passive safety features have lower total overnight capital costs (but not lower costs per ldlowatt electric) , hence less total capital at risk.
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From page 141... ...
utilities tenth heavy water technology. On the other hand, the earlier CANDU reactors have a good performance record and could be attractive to certain power producers, particularly if Atomic Energy of Cow, Liter were an investor.[AECL, Undated]
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From page 142... ...
Again, only enhanced and novel features of advanced reactor rlecion~ are discussed All LWRs, including SIR and PIUS, have essentially the same fuel cycle and corresponding environmental implications. Reprocess of spent fuel to '5 Reprocessing ~ not now conmdered economical in the United States for any reactor te~olo~.
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From page 143... ...
gem ~~ =^ ~ Bow ~ got ~~ plied. N~o these ~~ prides a -~ Tier ~ ~= ~e fibers.
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From page 144... ...
Safeguards Ed Physical Security Discussion Safeguards regarding nuclear material in reactors and other facilities must oe considered against diversion of fissionable matenal to nuclear weapons purposes, against sabotage of the power and reprocessing plants leading to a serious accident and release of radioactivity, and against terrorist theft and use of highly radioactive material as a terror weapon. She problem of diversion is usually considered most serious when the facilities are located In countries that have a motivation for developing nuclear weapons.
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From page 145... ...
Fuel cycles should be designed to me ze diversion opportunities and maximize safeguardability, regardless of the country in which they are implemented. The once-through fuel cycle where low enrichment fuels are used and the whole fuel rods, together tenth radioactive fusion products, are boned, has the lowest potential for diversion of sensitive nuclear materials.
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From page 146... ...
As compared to LWRs, the CANDU reactor poses some additional risks of diversion because of two features: (1) replacing fuel while the reactor is Ring increases access to fissionable material, especially plutonium, and (23 production and transportation of heavy water provides access to material that is useful m pro~dumng weapons-grade material.
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From page 147... ...
However, regardless of government Reactance, some research and much development arid design are still required for these reactors. The research and design to demonstrate the passive safety features must be completed before certification.
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From page 148... ...
While a prototype in the traditional sense probably will not be required, federal funding wig likely be required for the first mid-s~zed LWR plant with passive safety features. The level of government resistance required to build such a first plant is uncertain but could be significant.
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From page 149... ...
Although there Is worse e~enence with gas-cooled reactors, most of these reactors are sufficiently different from the MHTGR that much of this e~enence Is not relevant to the technics uncertainties relating to the advanced reactor type.2, Experience tenth the U.S.
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From page 150... ...
. "censmg Discussion The large evolutionary LWRs are furthest along ~ the design certification process They dearly should be most amenable to efficient and predictable licensing and win very likely be the first to be certified For the ~d-s~zed LWRs with passive safety features, EPIC is working closely with the industry to help move the licensing process forward These reactors are likely to be the new type certified.
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From page 151... ...
and recyclir g will raise significant - - = _ · · e e ~ ~ ~ · ~ licensing issues From the viewpoint of commercial licensing, it is tar oenma the evolutionary and mid-s~zed LWRs with passive safety features in hang a commercial desk available for review. Summary It would appear that the large evolutionary LWRs could obtain a ARC design certification as soon as the early to mid-19gOs, and the mid-~d LWRs tenth passive safety features perhaps a little later, followed by CANDU.
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From page 152... ...
The Committee's evaluations and overall assessment are s~nanzed in Figure ~12. The Committee's major conclusions regarding the advanced reactor technologies flow from the above assessment.
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From page 153... ...
as ~D c ~s t1~ ~o D ~ CtS est°~ = (P _ e_ ID ~ ~e U)
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From page 154... ...
If nuclear power plants are to be available to a broader range of potential U.S. generators, the development of the d-id plants with passive safety features is important.
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From page 155... ...
R&D programs ~ Chapter 4. 24 The Gas Cooled Reactor Associates estimates that, if the M~GR is selected as the new trite production reactor, development costs for a commercial MHTGR could be reduced from about $1 billion to $03 - $0.6 billion.p)
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From page 156... ...
1989a. System 80+ TM Advanced Light Water Reactor TethnologyAssessment, A Report to the Committee on Fut are U.S.
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From page 157... ...
1990. Advanced light Water Reactor Utility Requirements Document.
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From page 158... ...
1989. Advanced Pressurized Water Reactor Plant.
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From page 159... ...
Advanced liquid Metal Reactor Program. Paper given at the Nuclear Power Assembly in W~on, D.C.
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From page 160... ...
19~. Improvements in Boiling Water Reactor Designs and SafeW.
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