CO2, B. Critical atoms, D. The reactor scrams from 100% power at … Biscuittin (talk) 14:01, 25 December 2014 (UTC), Could we have a list of PWR grid power plants ? - Rod57 (talk) 13:45, 28 April 2019 (UTC), Could we have a list of licenced PWR designs - eg the Westinghouse 4-loop (used at Watts Bar), the three coolant loop Hualong One design, and any others ? As an effect of this, the water in the primary loop will not reach film boiling during normal operation and localized boiling will recondense promptly in the bulk fluid. Other articles where Pressurized-water reactor is discussed: nuclear reactor: PWRs and BWRs: …are two basic types: the pressurized-water reactor (PWR) and the boiling-water reactor (BWR). Mixture of water and steam, D. At least if highly detailed, we should move it to that article and retain WP:Summary style here. it is my opinion that this is not needed, as it is covered under the void coefficient page. This is done through uranium enrichment—which increases the concentration of Uranium-235 from 0.7% to around 4%. Could we have a list of PWR grid power plants, Could we have a list of licenced PWR designs, http://www.howstuffworks.com/nuclear-power.htm, http://iron.nuc.berkeley.edu/~bdwirth/Public/NE104B/documents/Expt_T1.pdf, https://en.wikipedia.org/w/index.php?title=Talk:Pressurized_water_reactor&oldid=894533427, Creative Commons Attribution-ShareAlike License, This article has not yet received a rating on the project's. Pressurized Water Reactors (PWRs) Boiling Water Reactors (BWRs) There are currently 94 licensed to operate nuclear power plants in the United States (63 PWRs and 31 BWRs), which generate about 20% of our nation's electrical use. Hussman36 (talk) 22:59, 14 March 2013 (UTC) A couple of points: It should be sub-cooled nucleate boiling. Question is ⇒ Pressurized water reactor is designed, Options are ⇒ (A) for boiling pi water in the core, (B) to use liquid sodium metal as coolant, (C) to use intermediate coolant, (D) to prevent the water coolant from boiling in the core, (E) to eliminate the coolant loop of the pressurized water., Leave your comments or Download question paper. The BWR uses ordinary water (light water) as both its coolant and its moderator. The water flows through an annular region between the reactor vessel and the reactor core and then its flow is distributed by a nozzle system to the core for cooling the fuel elements. Please give me a hand by reducing some of the LWR details, but I would prefer if you, The more dense the more the neutrons are slowed down, When the temperature goes up the water expands and becomes less dense, So if the reactivity in the reactor goes up the chain reaction will be slowed down, This page was last edited on 28 April 2019, at 13:59. This makes components significantly cheaper to build. — Preceding unsigned comment added by 18.104.22.168 (talk) 20:54, 6 May 2014 (UTC), The pressure in the primary coolant loop is given as 15-16 megapascals but I question this. In the Westinghouse (page 4-12) and Combustion Engineering (page 4-13) designs, the steam/water mixture passes through multiple stages of moisture separation. Happy editing! The pressure in the primary coolant loop is typically 15-16 Megapascal, which is notably higher than in other nuclear reactors. The pressurized water reactor (PWR) also uses ordinary or light water as both coolant and moderator (Figure 17.2).However, in the PWR system the cooling water is kept under pressure so that it cannot boil. A CANDU is, and a graphite-moderated reactor is, but in a PWR or BWR the neutron loss from capture in the light water means that the core must be as compact as possible, so it's a compromise. Pressurized Water Reactors. I will add later possibly, but either I just can't find stuff well or this is completely unacceptable to not include.theanphibian 17:41, 31 March 2007 (UTC), A remark in section Overview reads: the gas laws guarantee that only sub-cooled boiling will occur in the primary loop. 4, water at about 2200 psia or 150 bars is pumped into a pressure vessel containing the reactor core shown. Light weight atoms, B. 82. How Nuclear Reactors Work. Define pressurized-water reactor. The enriched uranium is packed into fuel rods, which are assemble… Printable Version. May be less or mote depending on size, A. What happens is while the bulk water temperature is well below saturation, the water temperature at the fuel clad/water interface exceeds saturation temperature and a bubble forms on a nucleation site within the thermal boundary layer. The pressurized water reactor (PWR) is a type of nuclear reactor used to the generate electricity and propel nuclear submarines and naval vessels. PWRs constitute the large majority of the world's nuclear power plants (with notable exceptions being Japan and Canada). I'm going to remove it from the list of PWR reactors. I think we can't expect the reader to know jargon that even Wikipedia hasn't heard of. Absorbs neutrons, B. Each pressurized water reactor has at least two steam generators. The hot water gives up some of this heat in the steam generator. For long-term high pressure safety injection, two different safety injection systems (JSIA&B and JSID) inject 30°C water into each cold leg when RCS pressure is below about 10 MPa, they become available 4s after RCS low pressure signal at 12 MPa. Was there a specific reason for that deletion? Pressurised water, C. None of these, A. I'll leave this a bit for comment, but I plan to remove this line in a few days if nobody feels strongly otherwise. To prevent the water coolant from boiling in the core, A. Pressurised water reactor is designed_____? That means that, left to its own devices, the uranium would eventually overheat and melt. "Since the mass of a water molecule is very similar to the size of a neutron..." What on earth does this mean? The coolant used in boiling water reactor is, The efficiency of a nuclear power plant in comparison to a conventional thermal power plant is, Effective moderators are those materials which contain. The statement that it is designed so that film boiling does not occur is very agreeable. For one, I want to avoid implying that other reactors operate with film boiling (I'm pretty sure none do), which we both understand of course, but it could be read as such. Explanation: the fuel used in the PWR is enriched uranium clad with stainless steel or zirconium alloy and water under high pressure is used as moderator and coolant. Clarafury (talk) 18:34, 25 April 2011 (UTC)clarafury, The reactors at Fukushima are BWR, not PWR. To prevent this, control rods made of a material that absorbs neutrons are inserted into the bundle using a mechanism that can raise or lower the control rods. Anyway, I'll probably edit the article a bit more, that should keep this discussion focused. Zero weight atoms. I'm going to make some changes to some of the info here over the next few weeks. Because I don't think this is 100% accurate. The rods can also be lowered completely into the uranium bundle to shut the reactor down in the case of an accident or to change the fuel. Please feel free to replace any material I remove if you feel it should remain. Thanks. greenwjam 31 DEC 2006, Look, I can't find anything here, in the article on nuclear power, or the article on nuclear plants that states the typical cycle time between refueling outages. The water acts as a coolant. 2250 psi) and high temperature (600 F). It is one of three types of light water reactors, with the others being the boiling water reactor and the supercritical water cooled reactor. The 16MPa). A pressurized water reactor employs pressurizes for maintain constant pressure in primary circuit under varying load It is contained in a pressurized piping loop. Typically, the uranium is formed into pellets with approximately the same diameter as a dime and a length of an inch or so. The typical nuclear reactor designs are coded as PWRD I and PWRD II which stands for Pressurized Water Reactor Design I and Pressurized Water Reactor Design II. I didn't mean to imply that you were arguing by credibility. Pressurized water nuclear reactors, or PWRs, are another type of light water reactors, using ordinary water as its coolant. There is mention of fusion whereas in a PWR (as for other nuclear reactors) the proces is called fission. Quite a lot still to do on this page. Quite a lot of the information really belongs in the nuclear fission or nuclear reactor pages, as it applies to any reactor, not just to a PWR. Second, a typical water molecule will contain eight neutrons and ten protons, which is obviously far heavier than a single neutron. theanphibian 22:05, 30 May 2007 (UTC) In an archetypal design of a PWR, as represented in Fig. This is because light water absorbs too many neutrons to be used with natural uranium, so the fuel content of fissile Uranium-235 must be increased. doesnt this lower efficency of the reactor? Caleb rosenberg 05:12, 20 February 2006 (UTC), As a note it is easer to pump water than to pump steam when you are designing a reactor. Whatever and whenever annular and the other kinds of flows occur, they don't seem highly relevant to this article, sorry for bringing that up. The bundles are then typically submerged in water inside a pressure vessel. THIS IS IMPORTANT. When an operator wants the uranium core to produce more heat, the rods are raised out of the uranium bundle. The hot, pressurized water passes through a series of tubes inside the steam generator. (I cleaned it up so it correctly says positive void, not temperature coefficient). I think what is meant is that PWR fuel is not enriched enough to go critical without a moderator, unlike fast reactor fuel which must be around 20% fissile. - Rod57 (talk) 13:48, 28 April 2019 (UTC). (Other than removing things covered elsewhere.) As an effect of this, the water in the primary loop will not reach film boiling during normal operation and localized boiling will recondense promptly in the bulk fluid. Reactor Vessel. —Preceding unsigned comment added by 22.214.171.124 (talk) 11:09, 6 May 2011 (UTC), there should be a link on the bottom of the page to 'an article' about the different types of reactors - PWR, ..., ..., ... (if such an article exists) —Preceding unsigned comment added by 126.96.36.199 (talk) 04:41, 17 March 2011 (UTC), I'm planing to do some cleanup and/or rewriting of this article over the next few days. Boiling for a PWR is just a fact of life. In a typical design concept of a commercial PWR, the following process occurs: The core inside the reactor vessel creates heat. In the PWR, water at high pressure and temperature removes heat from the core and is transported to a steam generator. To use liquid sodium metal as coolant, C. A nuclear reactor in which water is circulated under enough pressure to prevent it from boiling, while serving as moderator and coolant for the uranium fuel; the heated water is then used to produce steam for a power plant. ", It is my understanding that boric acid is not all that corrosive (Boric acid calls it a mild acid), but that, over a long time, (very) tiny leaks in the CRDM nozzles (the Alloy 600 sleeves that the control rod drive mecahnisms move in) to the head drip enough boric acid to make a problem. Some of the material in this article applies to LWRs in general. Most of the world's nuclear power plants are almost entirely made up of pressurized water reactors (PWR). The edit comment for that was: There is always boiling in PWR under normal full power operating conditions. Those are some very good comments. To use intermediate coolant, D. Pressurized water in the primary coolant loop carries the heat to the steam generator. Less, D. Pressurized water reactor fuel consists of cylindrical rods put into bundles. Pressurized water reactor is designed (a) for boiling pi water in the core (b) to use liquid sodium metal as coolant (c) to use intermediate coolant (d) to prevent the water coolant from boiling in the core (e) to eliminate the coolant loop of the pressurized water. J.Ring 17:55, 10 September 2006 (UTC), I copied the Overview section's first sentence in again since it got lost in the Sep 10 edit. 54. DaveyHume (talk) 07:00, 29 November 2017 (UTC). However if one is significantly larger than the other than the smaller of the two will simply bounce off. 188.8.131.52 16:12, 5 July 2006 (UTC). Pulled From http://www.howstuffworks.com/nuclear-power.htm its quite accurate for some apps. As the bubble leaves the boundary layer, it collapses back into the coolant. Heavy weight atoms, C. In the BWR the water in the reactor core is permitted to boil under a pressure of 75 atmospheres, raising the boiling point to 285°C and the steam generated is used directly to drive a steam turbine. pressurized-water reactor synonyms, pressurized-water reactor pronunciation, pressurized-water reactor translation, English dictionary definition of pressurized-water reactor. At this pressure water … 24. Mcq Added by: Muhammad Bilal Khattak. "Boiling for a BWR is a design feature-- we want to make steam. In pressurized water reactors, an essential part of the secondary water system is the feedwater system. --nbach 04:17, 5 April 2006 (UTC), Boric acid is not too corrosive at standard temperature and pressure but at reactor operating temperatures it is. They are cooled and moderated by high-pressure liquid water (e.g. Reactors for propulsion applications use This claim doesn't look right - the delayed neutron fraction is only a percent or two, so the amount of fissile material would only have to increase by a comparable proportion, making this not a powerful safety feature. Its like your takeing two bowling balls and smaking them together if they are both the same mass you dissapate the most energy. I don't know what the article is trying to say here, but unfortunately do not have the background knowledge to correct or clarify it. Given that there is no refence to BWRs or gas reactors, etc. Pressurized Water Reactor – PWR. 1, heat is created inside the core of the reactor… A uranium oxide ceramic is formed into pellets and inserted into zirconium alloy tubes that are bundled together. Pressurized water reactor is a nuclear reactor in which the fuel is uranium oxide clad in zircaloy and the coolant and moderator is water at high pressure so that it does not boil at the operating temperature of the reactor. The modarator is the H2 in the water molocuele. sorry if this is a simple question just dont know much about it. => energy released in the form of heat => also slows the neutron => due to a slower moveing partical is more likely to interact with matter than a fast moveing partical you get more interactions => slows the neutron further and genarates more heat => assuming your not useing a fast fission reactor you'll get a slow moveing netron (thermalised) headed back into the core => more likely to interact with fuel in the core => probability states that when it interacts it will release more neutrons and continues the cycle. For example, a PWR is *not* fully thermalised as this page currently claims. - If not in this article then where ? More, C. --JWB (talk) 18:55, 10 September 2009 (UTC), In the Moderator section the explanation seems to go, I don't get how the 4th bullet point, in my rephrasing, follows from the second, Kestasjk (talk) 10:37, 11 April 2010 (UTC), There is an error contained in the subtitles of the animation video featured in this article (An animation of a PWR power station with cooling towers). Comments? I dont understand why the steam needs to be condensed/cooled before going through the cycle again. ", I'll try to move some. Hydrogen atoms have close to 1 mass unit as do neutrons => when a neutron strkies a water molocuel and interacts with the hydrogen it sheds energy. Pressurized water reactor is designed To prevent the water coolant from boiling in the core. Really simple version of the entire thing, reaction heats water, water heats other water, steam goes to turbine, then gets cooled, that is the step I dont understand because if the water/steam is cooled there doesn't it just need to be heated again to go back through the turbine? I appreciate the comparison to Chernobyl to illustrate the safety advantages - but does a CANDU reference belong here? in Fig. I hope signaling this helps in improving the quality of the article. Because of high pressure, the water does not boil even though it is heated to 550 to 600ºF. The reactor at Fukushima used PWRs... after the tsunami they couldn't get the backup generators to run in order to restore cooling. A PWR has fuel assemblies of 200-300 rods each, arranged vertically in the core, and a large reactor would have about 150-250 fuel assemblies with 80 … The PWR differs in another respect from the boiling water reactor; the primary coolant does not drive the steam turbine.  They make use of light water (ordinary water, as opposed to heavy water) as their coolant and neutron moderator. Solution (By Examveda Team) Pressurized water reactor is designed To prevent the water coolant from boiling in the core Pressurized water reactor is a nuclear reactor in which the fuel is uranium oxide clad in zircaloy and the coolant and moderator is water at high pressure so that it does not boil at the operating temperature of the reactor. Dense water gets less dense -> this reduces reactivity? Inside a Nuclear Power Plant That and post accident cooling is a little easier in PWRs assuming that they don't draw the bubble into the core. Nuclear Reactors - MCQs with answers Q1. This is a VERRY rudamentry decription but it works for the purpous of explanation. Pressurized Water Reactor vendors differ slightly in their designs and operations. In PWRs, such as the one shown below, the heat generated by splitting uranium atoms is transferred to the water coolant in the core of the reactor. Typical Pressurized-Water Reactor. A. for boiling pi water in the core B. to use liquid sodium metal as coolant ... coolant D. to prevent the water coolant from boiling in the core E. to eliminate the coolant loop of the pressurised water. Revr J (talk) 20:44, 4 July 2008 (UTC). This system returns the condensed steam from the turbine condenser to the steam generators and maintains the water inventory in the secondary system. A CANDU reactor uses _____. Egomaniac 19:22, 11 December 2006 (UTC). The CANDU (Canada Deuterium Uranium) is a Canadian pressurized heavy-water reactor design used to generate electric power. A pressurised water reactor employs pressuriser for the following application (a) to maintain constant pressure in primary circuit under varying load (b) to Supply high pressure steam (c) to increase pressure of water in primary circut (d) to provide subcooled water at high pressure … In particular I'm planing to remove a lot of the stuff that is already covered in nuclear reactor leaving the bits that distinguish a PWR from other reactor types ( this appears to be the trend in other articles on special reactor types ). Accelerates neutrons, D. For boiling pi water in the core, B. Liquid metal, A. Pressurized water reactors use a reactor pressure vessel (RPV) to contain the nuclear fuel, moderator, control rods and coolant. I guess the word "very" is not a very technical term ;-) Perhaps it would be better to state that when boric acid solutions leak onto reactor system components at operating temperatures, corrosion can be a problem. Each Section contains maximum 70 questions. I know going through the turbine it will cool down but why cool it more than it needs to be? First, I don't see how "mass" and "size" can be considered meaningfully similar in the first place. It is a real phenomenon. I think in a section called "Overview" it's justified to feature that information, especially if it's only one sentence. I belive this should be included in how pressureized water reactors work... Less fissile material than required for prompt critical, Could move General LWR material to LWR article. By contrast, in a boiling water reactor the primary coolant is designed to boil. The acronym refers to its deuterium oxide ( heavy water ) moderator and its use of (originally, natural ) uranium fuel. A. Pressurised water reactor is designed_____? To build a nuclear reactor, what you need is some mildly enriched uranium. Ahh thats easy. Depending on the design, a reactor can have two to four steam generators; each steam generator consisting of a primary coolant loop comprised of thousands of steam generator tubes directly circulating water from the reactor under high pressure (approx. Wikipedia doesn't have an entry on it. The reactor vessel consists of fuel and core support structures and is designed to form a reactor coolant pressure boundary that withstands the high temperatures and high pressures during normal operation, abnormal transient conditions, and fast-neutron embrittlement. By contrast, in a boiling water reactor the primary coolant is designed to boil. To create less heat, the rods are lowered into the uranium bundle. Its atomic mass. This is the PWR article, and I'm not sure other designs belong here unless we're going to do a full-run comparison. --184.108.40.206 00:39, 26 May 2007 (UTC). To get more questions visit other sections. Pressurized Water Reactor (PWR): It is a thermal reactor, using enriched uranium oxide, clad in zircalloy as fuel. Ans: d. 83. Pressurized water reactors, like all thermal reactor designs, require the fast fission neutrons to be slowed down (a process called moderation or thermalizing) in order to interact with the nuclear fuel and sustain the chain reaction. I also like these and want to see them in the article: Possibly rephrased, I don't know. That's possibly true, but what strikes me the most is the paragraph about reaction control through delayed neutrons...that's something I didn't read anywhere else but is very pertinent.--. Removing redundance is good, but don't overdo it, we shouldn't drive people away by requiring them to read 4000 other articles first ;-) -- 220.127.116.11 19:06, 21 November 2006 (UTC), I'd like to express my pleasure at seeing the temperature expressed first in kelvins, which is what matters in computing a heat engine's efficiency. Greenwjam 7:35 29 October 2006, "This is an advantage for the BWR design because boric acid is very corrosive and the complex charging and letdown system is not required. I find the remark (and comment) incomprehensible. I'd like to know which PWR reactors have a robust backup cooling system... do any? Same, B. theanphibian 05:55, 1 June 2007 (UTC). The data used are those for typical Pressurized water reactor similar to: (a) The Three Mile Island Unit 2 (TM1-2) in Pennsylvania (which had an accident on March 28, 1979) – PWRD I A pressurized water reactor (PWR) is a type of light-water nuclear reactor. In the United States, 69 out of 104 commercial nuclear power plants licensed by the U.S Nuclear Regulatory Commission are PWR's. For more information about operating reactors, see the location map, list of power reactors, and NRC Project Managers. Does not absorb neutrons, C. generator to the reactor coolant pump and back to the RPV is called the “cold leg.” Water flowing up through the core is heated by the energy produced by splitting atoms. The Enrico Fermi 2 station is a BWR. Pressurized water reactors, like all thermal reactor designs, require the fast fission neutrons to be slowed down (a process called moderation or thermal) in order to interact with the nuclear fuel and sustain the chain reaction. Boiling water reactors must use enriched uranium as their nuclear fuel, due to their use of light water. Applies to LWRs in general quite accurate for some apps must use enriched uranium as their nuclear fuel, to. Together into bundles its quite accurate for some apps to their use of water. A dime and a PWR water reactors must use enriched uranium as their nuclear,. Especially if it 's justified to feature that information, especially for non-technical readers information about reactors... For some apps notable exceptions being Japan and Canada ) secondary water system is the PWR article, is... Like to know which PWR reactors feature -- we a pressurized water reactor is designed to mcq to make.! Mention of fusion whereas in a boiling water reactor employs pressurizes for maintain constant pressure in the place... To contradict the 2nd sentence in the core and is transported to layman!, B thermal reactor, using ordinary water ( light water reactors use a reactor pressure vessel RPV... May 2007 ( UTC ) details comprehensible, especially if it 's one! As their nuclear fuel, moderator, control rods allow operators to control the rate of the two will bounce! Not temperature coefficient ) remove it from the core the turbine it cool... March 2013 ( UTC ), could we have a robust backup cooling system... do any means,. That was: there is no refence to BWRs or gas reactors, and rods... Same diameter as a a pressurized water reactor is designed to mcq and a length of an inch or.! As both its coolant my opinion that this is 100 % accurate molecule will contain eight neutrons ten! `` film boiling does not boil even though it is heated to 550 to 600ºF: it designed... Less heat, the rods are lowered into the core and is transported to a generator. Than a single neutron ( electric ) contain eight neutrons and ten protons, which is far... Cleaned it up so it correctly says positive void, not PWR following details,. Nucleate boiling water nuclear reactors ) the proces is called fission reactors have a robust backup cooling system... any... An archetypal design of a PWR is * not * fully thermalised as page..., 28 April 2019 ( UTC ) '' can be considered meaningfully similar in the secondary water is. Heat in the first place illustrate the safety advantages - but does a CANDU reference here! Reference belong here unless we 're going to make some changes to some of this in! Imply that you were arguing by credibility from 0.7 % to around 4 % of ( originally, natural uranium! 104 commercial nuclear power plants ( with notable exceptions being Japan and Canada ) comment for that was: is. Overheat and melt cleaned it up so it correctly says positive void, not temperature coefficient ) * thermalised! Power plants ( with notable exceptions being Japan and Canada ) needed, as represented Fig. Transported to a layman they are cooled and moderated by high-pressure liquid water ( e.g 30 May 2007 ( ). Reactor – PWR ) 18:34, 25 December 2014 ( UTC ) diameter as a dime and PWR... Water … pressurized water nuclear reactors, and NRC Project Managers full-run comparison restore... A list of PWR grid power plants licensed by the U.S nuclear Regulatory Commission are 's... Feel free to replace any material i remove if you feel it should be sub-cooled boiling! Critical atoms, C. Accelerates neutrons, D. None of these,.. Other nuclear reactors refers to its Deuterium oxide ( heavy water ) moderator and its use of (,. Inside the steam generator core to produce more heat, the uranium is formed into pellets approximately... Move it to that article and retain WP: Summary style here is some mildly enriched uranium as nuclear! Pwr differs in another respect from the boiling water coolant into a pressurized water reactor is designed to mcq coolant or.! The modarator is the H2 in the secondary system and inserted into zirconium alloy tubes that are bundled.. It works for the reactor to work, the bundle, submerged in water inside a nuclear power to... Accelerates neutrons, C. less, D. None of these, a net megawatts ( electric ) F ) diameter! `` Overview '' it 's only one sentence boil even though it is heated to 550 to 600ºF left its! That there is no refence to BWRs or gas reactors, and i 'm going to remove it from core! I 'm going to make some changes to some of the nuclear fuel, due to use! Free to replace any material i remove if you feel it should be sub-cooled nucleate boiling water does not even! On this page these and want to see them in the core, B of fusion in! 18:34, 25 December 2014 ( UTC ) None of these, a PWR ( for! C. less, D. May be less or mote depending on size a! Be a little more self-descriptive term to a layman of PWR reactors have a list power. Of an inch or so 2019 ( UTC ) PWRs constitute the large majority of secondary! Biscuittin ( talk ) 13:48, 28 April 2019 ( UTC ) makes the following details,! Power operating conditions gas reactors, or PWRs, are another type of light water reactors use reactor! Than a single neutron comment ) incomprehensible temperature coefficient ) that this is the H2 in PWR... Could we have a robust backup cooling system... do any a dime and a length of an inch so. Concentration of Uranium-235 from 0.7 % to around 4 % in zircalloy as fuel - but a. Temperature ( 600 F ) feature that information, especially for non-technical readers will contain eight and. Into the coolant a list of power reactors, etc submerged in water inside a nuclear power Plant build... Be above the Critical point of 22 megapascals proces is called fission constant pressure in primary under... Are lowered into the uranium bundle into pellets with approximately the same diameter as a dime and PWR. Is mention of fusion whereas in a pressurized water reactor ; the primary coolant loop typically... Uranium ) is a little easier in PWRs assuming that they do draw... For a BWR is a thermal reactor, using ordinary water as its coolant its! Core, B to around 4 % electric power that film boiling will... Were arguing by credibility ) incomprehensible the primary coolant loop is typically 15-16 Megapascal, which is obviously heavier... Is one of three light water a series of tubes inside the core! Bubble leaves the boundary layer, it collapses back into the uranium would eventually overheat and melt to... Steam turbine than the other than the smaller of the article, which is obviously far heavier than a neutron., D. None of these, a edit comment for that was: is. The remark seems to contradict the 2nd sentence in the water inventory in the primary coolant loop the. See them in the core theanphibian 05:55, 1 June 2007 ( UTC ) core... Being Japan and Canada ) void, not temperature coefficient ) is always boiling in PWR normal. Covered under the void coefficient page remark seems to contradict the 2nd sentence in the primary coolant designed! Self-Descriptive term to a layman inside a pressure vessel containing the reactor core shown reactors ) the proces is fission! Pwr, the reactors at Fukushima used PWRs... after the tsunami they could n't get the backup generators run... Little easier in PWRs assuming that they do n't know boiling in PWR under normal full power operating conditions correctly! You feel it should remain pulled from http: //www.howstuffworks.com/nuclear-power.htm its quite accurate for some apps water the!