Talk:Containment building

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[edit] Requirements section

Is this very specific section about the detailed american requirements necessary in a general article about containment buildings? Maybe it can be slimmed down or something? 83.255.187.141 (talk) 23:38, 5 May 2008 (UTC)

[edit] Chernobyl accident Containment building

I do believe Chernobyl did have a containment building. It was what I had learned, and confirmed with this source: (Can anyone else confirm it?) "At Chernobyl, this reactor containment building was a very simple, thin-metal-walled building, not like the three-to-six-foot thick steel-reinforced concrete containments we have in the United States and all countries other than Russia and the former Soviet Union countries." http://www.hps.org/publicinformation/ate/q1462.html —Preceding unsigned comment added by Slythfox (talkcontribs) 07:16, 29 March 2008 (UTC)

[edit] Some components not discussed

I found this odd passage "[Note: For security reasons, many of the common features of a containment will not be discussed here.]"

Why is this? If the information is public/not secret, should it not be included? I find this form of self-censorship not compatible with the spirit of wikipedia. Any thoughts? --Jimius 22:49, 25 Jun 2005 (UTC)

A fair comment. All I can say is that in the U.S. at least there is extreme concern about nuclear power plants being struck by aircraft [1] or attacked by a large (say 20 people) group of suicidal terrorists. I elected not to comment on either the weak nor the strong spots. I didn't say how to get in, for example. I didn't say where the Emergency Core Cooling System pumps are. I didn't discuss at all how to defeat containment.
Spent fuel pools are one well-known example of a weak spot, although they usually aren't inside containment. [2]
But your point is well taken. I would rather have written much more. Simesa 7 July 2005 17:36 (UTC)

Then why doesnt the U.S. surrond them with SAMS like the Starstreak missiles and CWIS like the Phalanx? --Xexos 00:27, 17 September 2006 (UTC)

[edit] Aircraft

  • I read pdf and it says there is no threath from civilian aviation aircraft being used by terrorists to strike against Nuclear Plants. So where does the "extreme concern" come from? The report by Edward J. Markey (who appertanly was anti-nuclear from the get-go)? But that one was debunked by the report you posted. --Jimius 17:26, 10 July 2005 (UTC)

Regarding the '88 Sandia test, what does this mean? Is a "2.5-inch deep gouge" enough to compromise the containment?

No. Actually, the impact wouldn't have come close to reaching containment itself - the plane hit the "missle shield", which is designed to protect the containment structure.
The main damage in an airplane strike is from the engine rotors, which act like bolts of steel. The jet fighter used had two powerful engines. Simesa 15:10, 29 November 2005 (UTC)
    • I've read conflicting views about this. If I remember correctly, the plane used in a test was a small plane or in some way different than a large passenger plane, so it did not answer the question definitively. Some say that a large plane, or multiple large planes, could penetrate the containment building, others think that it cannot, but think that a plane that has been modified with a hardened nose may be able to penetrate it. Others think that it is impossible altogether, though a few might be trying to discourage anyone from trying. The containment building aside, some think that the spent fuel pool building, control room and parts of the cooling system outside of the containment building could be taken out with a plane. Even if the spent fuel pool building is unpenetrated, the collision may shift the fuel rods around and bring them closer together or shut down the water circulation system, which could lead to a fire and radiation release. I was wondering if the control room is destroyed, could that even lead to some kind of radiation release or would the emergency systems take over? -- Kjkolb 04:29, 5 January 2006 (UTC)
The plane used was an two-person F-4 Phantom fighter/bomber with two engines. Again, the main penetration damage comes from the engine rotors - because of weight, you couldn't put something like a jet rotor in the nose of a airliner. The test definitely was not definitive, more because the target was not a true containment missle shield.
There are other ways of manually shutting the plant down even if the control room was unable to control the plant, as shown in the Browns Ferry plant's insulation fire.
Each fuel rod is held in place inside the bundle by several spacer grids, and the bundles are placed in a grid in the spent fuel pool, so it is unlikely that they'd be rearranged. They're under 20 feet of water. However, I haven't seen any recent studies on aircraft impact into SFPs - the last I read, SFPs were a concern.
Simesa 16:23, 5 January 2006 (UTC)
Thanks, I've been wondering about such things. Do you really think that it would be impossible to harden the nose of a plane, though? The concorde has a bunch of weight near the nose so it can be lowered when it takes off and lands. Also, I would think that a cone-shaped piece of magnesium or steel would be better than a jet engine for penetration. As for weight problems, the plane could be flown relatively empty and the load could be balanced with weight in the back. Some bunker buster bombs use a hardened nose to penetrate shielding and there used to be a document online that said a containment building might not be able to withstand an impact with a hardened nose projectile, but it appears to have been taken down.
There is an article about spent fuel pools here. -- Kjkolb 06:16, 28 January 2006 (UTC)

[edit] Design Basis Threat

Who says you need as many as 20 atttackers? The design basis attack is 4 people: 3 outsiders + 1 insider using nothing more than hand-held automatic weapons approaching on the ground. See http://www.thebulletin.org/article.php?art_ofn=jf02hirsch. Security by obscurity is a joke -- all of the details you mentioned (and far more) are documented in Plant Data Books, which may be read at your leisure in the NRC's reading room.

  • I find the idea of attacks on a nuclear plant to be pretty pointless at best. When Greenpeace activists tried to enter the plant at Borssele the security system kicked in and they were simply locked out and subsequently apprehanded. They claimed a victory though (but then again, it's Greenpeace, hard to take seriously) even though they did not get past any of the security measures (excluding the fence around the terrain). What good would a strike against a plant do? Force a meltdown? Blow something up? Steal weapon's grade material? I think the threat is being severly overrated under the flag of fearmongering. Something which seems to be happening all to often these days sadly enough. --Jimius 17:26, 10 July 2005 (UTC)
The Design Basis Threat was revised [3] but the details have been kept secret - 9/11 was pulled off by 19 guys with boxcutters, which is why the concern is 20. There are (or at least were) places to find detailed information regarding each US plant, but I won't say where. Aircraft, beyond the pdf, I won't discuss. Simesa 05:34, 13 July 2005 (UTC)

[edit] Removal of 'components not discussed' note

So can we remove the odd-sounding phrase, and just accept that User:216.164.138.57 doesn't want to talk about the design? Ojw 20:39, 1 August 2005 (UTC)

I agree, we should remove the bit about not discussing things because of "security" and complete the article. Simesa, unless you have some special knowledge not avalible to the general public, I don't see why you should bother being tight-lipped about this. Bryce

Unless he knows something that is not public knowledge or otherwise classified/etc, I see no reason for it to be witheld from the article. Simesa is of course free not to add it, but then the article shouldn't state that he left information out. --Jimius 17:26, 5 August 2005 (UTC)

[edit] Drywell

The article seems to say that drywell only refers to a certain kind of boiling water containment building. Is it also used as a generic name? -- Kjkolb 04:29, 5 January 2006 (UTC)

[edit] "meltdown" and NRC Containment Regulations

The design criteria used to judge the adequacy of ECCS design is based on the analytically determined "peak clad temperature" and the amount of "clad oxidation" during the sequence. These criteria are much easier to achieve than the "meltdown" that the article claims to be the design basis of the containment buildings. That is, the "peak clad temperature" and "clad oxidation" limits are such that they occur before a losing a coolable geometry. The term "meltdown" is entertaining, but inaccurate when describing containment design. The industry uses the term "core damage" to capture exceeding of any or all of these criteria. See 10CFR50.54 and Appendix K.

"'Primary reactor containment' means the structure or vessel that encloses the components of the reactor coolant pressure boundary, as defined in § 50.2(v), and serves as an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment." See 10CFR50 Appendix J, II A. (Option A) "Containment system means the principal barrier, after the reactor coolant pressure boundary, to prevent the release of quantities of radioactive material that would have a significant radiological effect on the health of the public." See 10CFR50 Appendix J, II (Option B).

The adequancy of containment is judged by its ability to remain leak-tight as determined by three periodic and prescriptive tests of the building itself.

[edit] Release of Radioactive Gases

Referring to this addition:

Although the containment building is designed to prevent the release of radioactive materials, it has not always prevented this. During the Three Mile Island accident, small amounts of radioactive gases were were released. In addition to accidental release, radioactive gases were deliberately released into the atmosphere by the operators to relieve presure on the primary system and avoid curtailing the flow of coolant to the core.

That release of radioactive gases was NOT due to failure of the containment, but of other devices that were meant to filter out radioactive isotopes and didn't. I want a revision of this section or it to be deleted. theanphibian 05:28, 1 June 2007 (UTC)

He's correct, the containment wasn't even challenged. Contaminated water from the open PORV on top of the pressurizer went into a tank. That tank filled and the rupture disk blew, sending the radioactive water out into the containment building where sump pumps routed it to an auxiliary building (crapping it up) (this is also all in the TMI article). My understanding is that one of the many post-TMI modifications fixed this, but I'll have to research that more.
However, the second sentence does appear to be substantially correct. My understanding was that the holdup volume was engineered to accomodate the releases from a major accident, but I could be wrong and I didn't find a source to confirm or deny this. Certainly the stack height is engineered - again no source found yet. Both should be researched and mentioned. Simesa 09:15, 1 June 2007 (UTC)
Which second sentence are you referring to? But yeah, there were issues that caused gases to be released, and those were related to complexities of the entire system - though I don't think people should find this any more assuring. You have to suppress the steam generated sooner or later, just the ability to contain the impact from the entire vaporized coolant system doesn't mean you've established long term safety. I think all of the new designs call for both a steel and concrete containment building which lets natural circulation cool the core indefinitely. I imagine that you wouldn't have to seep air to the atmosphere, but I don't know if that applies for most currently operating plants. -Theanphibian (talkcontribs) 01:02, 13 September 2007 (UTC)
  • If you wish to claim that the containment building CAN prevent all radioactive gases from escaping, fine. But while it might be ABLE to do so, the presence of the containment building has NOT prevented it in all cases. I added back this TRUE statement with a factual reference from the NRC itself. It is important to make clear what the containment building CAN and CANNOT do. To only put in what it can do and then imply that it can do more than it can is wrong. Argue all you want but the facts are that TMI had a containment building, yet radioactive gases did enter the atmosphere. While the release of the gases might not be a failure of the containment building, it is wrong to imply that because one exists, that no radioactive material can ever be released. Fanra 17:16, 29 October 2007 (UTC)
    • Well said. The containment isn't an innovation that would prevent release of radioactivity regardless of what the other systems in the plant do, quite the opposite - it's only a small part. I hope the article reflects this correctly now. -Theanphibian (talkcontribs) 19:38, 20 January 2008 (UTC)