Comments on: What Happened at Chernobyl?

By: Antinuclear Spin Machine Exploiting Fossil Fuel Disasters

Antinuclear Spin Machine Exploiting Fossil Fuel Disasters — Thu, 20 May 2010 15:30:55 +0000

[...] the Chernobyl Disaster pales in comparison to the 2010 Fossil Fuel Meltdown. In 2005, the World Health Organization [...]

By: Avoiding Energy Sprawl

Avoiding Energy Sprawl — Thu, 06 May 2010 13:27:30 +0000

[...] compared against the so-called “dangerous” nuclear power, will kill more people than Chernobyl every [...]

By: One Month Until the 26th Anniversary of Chernobyl

One Month Until the 26th Anniversary of Chernobyl — Sat, 27 Mar 2010 01:17:52 +0000

[...] so much find peace in their life. A recent article about how Chernobyl came to be from 3/10/10. what happened at chernobyl/ A series of photographs of the affected children with commentry by the photographer who seen the [...]

By: Greg Molyneux

Greg Molyneux — Wed, 17 Mar 2010 14:31:50 +0000

Best of luck with the paper Nils.

By: Nils

Nils — Wed, 17 Mar 2010 03:26:35 +0000

Just wanted to say I enjoyed this article immensely and it helped me a lot in the writing of an engineering paper for my second-year Mech.Eng. class.

The supplementary links helped the explanations thoroughly, as well.

Thanks!

By: David Lewis

David Lewis — Tue, 09 Mar 2010 15:49:41 +0000

I’ve looked around for the book I read on Chernobyl back when it happened but I’m not sure what the title was. The idea that the director of the facility ignorantly commanded the more knowledgeable reactor operators to blow the facility up, and they, more or less horrified, followed his orders, is in older books. For instance, from a review on Amazon of a book called “Chernobyl: The Forbidden Truth”, by Alla Yaroshinskaya:

“An individual who had the appropriate civil service rank was appointed director of the facility, even though he had no understanding of a nuclear reactor, and had never worked at a nuclear power plant. (The bulk of his experience was in large transformers for long-distance power lines.) He simply marched in and demonstrated his authority by giving orders to the reactor operators until he had created a meltdown. By the time that the district manager arrived – horrified – and took over, the damage was done.”

By: Nuclear Fission for Dummies: Moderation

Nuclear Fission for Dummies: Moderation — Mon, 08 Mar 2010 02:56:30 +0000

[...] Chernobyl, a Russian RBMK reactor, was a graphite-moderated plant. Water acts as a coolant in the RBMK but the graphite acts as the moderator. However, as voids form in an RBMK, power increases because the graphite still moderates the neutrons and now more neutrons reach the moderator because there is no water to absorb them. Thus, as the temperature rises in an RBMK, power rises, causing temperature to rise further, and so on. [...]

By: Jack Gamble

Jack Gamble — Sun, 07 Mar 2010 15:57:03 +0000

I doubt he intended to make the number sound higher than it was, just the fact that it is impossible to count, certainly not the thousands that Greenpeace would have you believe. The best anyone can do is hypothesis as too how many thyroid cancer cases were caused by Chernobyl and not the over 2,000 nuclear weapons detonated in the atmosphere during the cold war, or just simple genetics.

Also a good point about the forest growing back. The environment recovered much faster than expected.

By: Brian Mays

Brian Mays — Sat, 06 Mar 2010 22:38:51 +0000

Rod – As I recall, the number of recorded deaths from thyroid cancer was 10 or less. Fortunately, thyroid cancer is a very treatable condition.

The number of cases of thyroid cancer in the region went up after the accident, and no doubt, much of it was due to the iodine-131 that was released during the accident. However, we’ll probably never know how much of this increase in thyroid cancers was due to the accident and how much was due to the discovery of normally occurring occult cancers that would have never been detected if the increased screening of the population after the accident had not been implemented.

By: Brian Mays

Brian Mays — Sat, 06 Mar 2010 22:27:52 +0000

What is commonly called a graphite “tip” on the RBMK control rods is actually a rod of graphite, which is called a “follower” or a “rider” and is over four meters long. It takes the place of the control rod when it is withdrawn.

The control rod channels in this reactor were filled with water, so when the control rod was withdrawn, water would take its place, if the follower did not exist. Water absorbs neutrons, so the graphite follower was used to displace this water, which improves the neutron economy.

When the control rods were reinserted, after being completely pulled out of the core, there was a brief increase in power, but only at the very bottom of the core, where the water below the follower was replaced with graphite as the rod fell. Both water and graphite are moderators, but water is a more efficient moderator than graphite. Thus, it wasn’t an introduction of extra moderation that caused the problem, but the displacement of the water, which absorbs neutrons, that lead to the increase in reactivity. Unfortunately, this was sufficient to drive the power excursion further, leading to the accident.