User talk:Moni3/Chernobyl

Comments on bibliography

• Gale, Robert; Hauser, Thomas (1988). Final Warning: The Legacy of Chernobyl, Warner Books. ISBN 0446514098
• Gould, Peter (1990). Fire in the Rain: The Democratic Consequences of Chernobyl, The Johns Hopkins University Press. ISBN 080184052X

• Concise discussion of what led to the accident. Easier for me to understand, but not detailed.

• Marples, David (1988). The Social Impact of the Chernobyl Disaster, St. Martin's Press. ISBN 0312024320

• Introduction dedicated to what led to the accident. Well-written for lay readers.

• Medvedev, Grigori (1991) (tr. Evelyn Rossiter). The Truth About Chernobyl, BasicBooks. ISBN 2226040315

• Medvedev originally wrote this book under the title "Chernobyl Notebook"; he was a nuclear engineer and plant inspector and had previously worked at the Unit-One reactor at Chernobyl. His accounts are both technical and personal. The book seems equally dedicated to discussing the technical aspects of nuclear power and precisely what went wrong, and Medvedev's perceptions about which people specifically were to blame in the management decisions. The more personal issues in the book are written with affectations that in English border on not being a solid reliable source. There seems to be no neutrality involved and at times an excess of exclamation points and other style issues ("Now we shall return to the night of the 26th"). Originally written in Russian, so I don't know if this is how reliable sources are written in that language and culture. However, the author's expertise in the Soviet nuclear program and the fact that many of his opinions regarding blame are supported by quoted testimony still make this a very strong source. Publication date of 1991: source is not reliable for any revelations following the fall of the Soviet Union (core meltdown, any documents unclassified, etc.)

• Medvedev, Grigori (1993) (tr. Evelyn Rossiter). No Breathing Room: The Aftermath of Chernobyl, BasicBooks. ISBN 0465051146

• Foreword by Marples (above) with an excellent discussion of the Soviet culture and management system. Rest of the book is more personal and I so far am not able to use much of it.

• Medvedev, Zhores (1990). The Legacy of Chernobyl, W.W. Norton & Company. ISBN 039302802X

• Very technical discussion about nuclear energy. Excellent source. Somewhat difficult for me to understand. Publication date 1990: some info will have changed.

• Mould, R. F. (2000). Chernobyl Record: The Definitive History of the Chernobyl Catastrophe, Institute of Physics Publishing. ISBN 075030670X

• Very thorough, somewhat technical. Need assistance in places understanding it. Excellent overall discussion.

• Mycio, Mary (2005). Wormwood Forest: A Natural History of Chernobyl, Joseph Henry Press. ISBN 0309094305

• Emphasis on surrounding natural resources. Mentions some statistics that are not cited. Jumps around and uses personal accounts of individual experiences instead of overall trends and statistics.

• Nuclear Energy Agency (1987). Chernobyl and the Safety of Nuclear Reactors, Organisation for Economic Co-operation and Development, Paris. ISBN 9264129758
• Petryna, Adriana (2002). Life Exposed: Biological Citizens after Chernobyl, Princeton University Press. ISBN 0691090181
• Shcherbank, Iurii (1989) (tr. Canadian Institute of Ukranian Studies). Chernobyl: A Documentary Story, Canadian Institute of Ukranian Studies. ISBN 0920862640

• (First name also appears as Yuri in other sources) Provides first-hand accounts of individual experiences with the disaster. No details or technical issues. Good for quotes or examples of one person's experiences.

• United Nations Development Programme, United Nations Children's Fund, (22 January 2002). "The Human Consequences of the Chernobyl Nuclear Accident: A Strategy for Recovery". Retrieved November 2010.

Technical review

I'm not sure how much you want this to turn into a copyedit so I'll drop my first comments here. This is regarding para 2, "Chernobyl Nuclear Power Plant", which I think does a reasonable job of explaining the differences between the reactor types and how moderation works but may benefit from some tweaks. I've made some suggestions below (obviously dependant on your approval and on what can be supported by the sources). EyeSerene^talk 11:23, 24 November 2010 (UTC)

The Chernobyl power station featured four RBMK reactors (in Russian literally "reactor high-power boiling channel type" but translated as "reactor cooled by water and moderated by graphite"), as opposed to the pressurized water reactors (PWRs) more commonly found in the United States and other Western countries. To create the controlled atomic fission conditions found in nuclear reactors, neutrons emitted by the reactor's radioactive fuel must be slowed enough to enable their efficient capture by fissile atoms within the fuel, which themselves then split releasing energy and more neutrons to sustain the reaction. Different reactor designs make use of various methods to "moderate" the nuclear reaction. In many PWRs, water or heavy water (water containing a higher-than-normal proportion of the Deuterium isotope of Hydrogen) is used to slow the neutrons. In the RBMK reactors, solid graphite was used as a moderator material, with nearly 2,500 block columns interspersed between 1,660 fuel channels containing Uranium dioxide-based fuel rods surrounded by a casing (or cladding) made of zirconium alloy. Movable Boron control rods pierced the graphite stack, acting as throttles when withdrawn and brakes when inserted because boron carbide absorbs neutrons and decreases heat and energy. Heated by the fuel rods, the graphite stack in turn heated water pumped in at the bottom of the reactor, turning it to steam. This was piped to two electricity-generating turbines in a nearby building. Additionally, the RBMK design made use of a separate water-cooling system.

I tried to create a mixture between our versions, because on first glance I put myself in the place of where I was before I started reading about nuclear engineering and I thought I would get lost quickly. But I don't know what else I can change. Perhaps we should keep this open and ask some diligent readers if they can follow the technical discussion in the article after it's posted to the mainspace. So for now, I think your rewrite of this paragraph is fine. I'm glad my understanding and expression of it is so far mostly ok.

Otherwise, the article will get several copy edits before and after it gets posted to the mainspace. My primary concern is that my points about nuclear engineering are accurate and easy to understand by lay readers.

I hope to work some on the article late this week and add more material to the reaction section. I'm not sure where you are, but it's Thanksgiving week here and pretty much a bust for being productive, although I'm going to try to sneak a few hours of writing in. I appreciate your time and effort. Thanks. --Moni3 (talk) 15:54, 24 November 2010 (UTC)

Okay, no probs. A tweaked version is posted below (only because we edit-conflicted as you posted the above), but feel free to use or not :) I was only intending to look at the technical sections - perhaps "copyedit" was the wrong word. EyeSerene^talk 16:01, 24 November 2010 (UTC)

The Chernobyl power station featured four RBMK reactors (in Russian literally "reactor high-power boiling-channel type"), as opposed to the pressurized water reactors (PWRs) more commonly found in the United States and other Western countries. To create the controlled atomic fission conditions found in nuclear reactors, neutrons emitted by the reactor's radioactive fuel must be slowed enough to enable their efficient capture by fissile atoms within the fuel, which themselves then split releasing energy and more neutrons to sustain the reaction. Reactor designs differ in how they slow down, or "moderate", the nuclear reaction. In many PWRs, water or heavy water (water containing a higher-than-normal proportion of the deuterium isotope of hydrogen) is used; in the RBMK reactors, solid nuclear graphite is the moderator material. An RBMK reactor vessel consists of nearly 2,500 8-metre (26 ft) high graphite columns arranged in a cylindrical layout, each pierced lengthways by a zirconium alloy-clad pressure channel. 1,660 of these channels house the reactor's uranium dioxide-based fuel rods; the rest contain its control rods and cooling systems. Boron carbide, which absorbs neutrons, enables the control rods to act as throttles on the nuclear reaction when withdrawn from the channels and brakes when inserted. Heated by the fuel rods, the graphite stack boils water which is pumped in at the bottom of the reactor and passes up through the channels. The high-temperature water/steam mixture is piped out at the top to electricity-generating turbines, before being cooled and fed back into the reactor. Although this serves to remove sufficient heat from the reactor under normal operation, the RBMK design also provides for a separate emergency water-cooling system.

I'm afraid I can't help myself when I edit article pages - you either get a full copyedit or nothing (it's probably pathological). That being the case, instead of trying to rewrite your article for you I'll comment on specific things below :) EyeSerene^talk 11:33, 26 November 2010 (UTC)

• Para 3, Chernobyl Nuclear Power Plant:
  • "The graphite in RBMK reactors can reach a temperature of 700 °C (1,292 °F), so must be kept away from air" It's really the oxygen in the air that's the problem - is it worth clarifying that?
  • "either by being under water, or inert gases, helium, and nitrogen" Is there a way to to reflect the fact that, although RMBK reactors contain water, the inert gas blanket seems to be the primary way of ensuring no oxygen is present to allow graphite combustion.
  • "the neutrons speed up too quickly, and nuclear fission ceases" Strictly speaking the neutrons don't speed up, they just aren't slowed down (if that distinction makes sense!)
  • "the graphite would continue to absorb neutrons even if water was not present" This is talking about a slightly different thing to the previous sentence (and should really use "moderate" rather than "absorb"). In PWRs the water itself is the moderator. Without water the neutrons aren't slowed down and can't be captured as efficiently by the fissile atoms in the fuel thereby producing more neutrons, so the chain reaction basically fizzles out. In RMBKs the graphite is the moderator and will continue do this job whether water is present or not; the water is mostly just a cooling mechanism (it will absorb and moderate some neutrons but this isn't it's primary purpose). This is why it's so crucial in the RMBK design that the boiling water isn't allowed to turn completely gaseous (ie into steam) in the pressure channels and therefore why it's pumped in at high pressure (high pressure=high boiling point).
  • "more heat and energy would be created" Again, strictly speaking more heat (heat and energy are the same thing) isn't being created, it's just that the heat that was always being created isn't being removed - either because the water isn't circulating or because it's turned to steam, which being many times less dense than water can't cool as efficiently.
  • "Contemporary design of the pipes leading into and out of the Chernobyl reactor ensured that if any of them underneath the reactor ruptured, water or steam contaminated with radiation was contained in pipes beneath the reactor. However, if any of the pipes leading out of the reactor from above were ruptured, the water or steam would not be contained." For clarification, how about "Contemporary design of the pipes leading into and out of the Chernobyl reactor ensured that if any that ran underneath the reactor ruptured, water or steam contaminated with radiation would be contained in a water-jacket. However, those pipes that ran above the reactor were not similarly jacketed."?

Flow versus temperature question

I see you and others are engaged in the commendable task of drafting revisions to this already quite informative article, but I noticed one thing that didn't seem to make sense in the original non-sandbox version of the article. In the section "Conditions prior to the accident," the next to last paragraph includes the sentences

"As part of the test plan, at 1:05 a.m. on 26 April extra water pumps were activated, increasing the water flow. The increased coolant flow rate through the reactor produced an increase in the inlet coolant temperature of the reactor core."

I am physicist, not an nuclear engineer, but to me this looks puzzling, since ordinarily an increased coolant flow would produce decreased temperature, other things being equal. Perhaps the coolant was warmed by the friction of the increased pumping rate, or perhaps there were cavitation effects that increased the temperature. But in the final version of the description of how events unfolded, this point should be clarified so as not to puzzle people like me. CharlesHBennett (talk) 21:33, 14 February 2011 (UTC)