Talk:Passive nuclear safety

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Page title

Someone please move this to either "Passively-safe" (with hyphen) or "Passive safety" (I can't, probably because my login is < 1 day old), as the current term "Passively safe" implies that the reactor is safe. What the term actually means is that the way the safety it has is achieved, is passive. It's a compound adverb, and it should be hyphenated for clarity. Check a (quality) grammar or style guide if you don't believe me. -- Curmudgeonlyoldman 04:07, 18 September 2006 (UTC)[reply]

The current page title 'Passive nuclear safety' is not a valid option, please see my comments on the page [1]. The term has never been in use outside Wikipedia, and again, gives a misleading impression to those who are unfamiliar with evaluation of safety in a nuclear/radiological setting. Perhaps it could be 'Passive (Nuclear safety)' or 'Passive safety feature (Nuclear)'. I have a feeling that the term should not need a page, because it should not be used like this. Again, I can't move the page, dunno why, isn't this 'the encyclopedia anyone can edit?!'. -- Yabbadabbadoo 09:35, 8 October 2006 (UTC)[reply]

Disagreement with the page title is not a reason to make a mess out of the article; it's sufficient to express your concerns at the talk page. It was previously at Passively safe which doesn't match any of naming conventions in sight, and I moved it to this title, which reflects that it is an aspect of Nuclear safety. Obviously, it is not meant as a neologism, but it merely expresses what the article is about. Perhaps a better title would be Passive safety (nuclear technology), I don't know. You couldn't move the page because your account was too new, which is a Wikipedia's safety measure to prevent inexperienced users to freely rename the pages, which can have numerous side effects if done improperly. Please follow the procedure on WP:RM if you think it should be renamed. Duja 07:55, 9 October 2006 (UTC)[reply]

Someone please change the title to "Passive safety (nuclear)" or similar. This IMHO seems the best option. Alternatively merge the content in Nuclear safety directly. Proliferation and weapons issues are an aspect of passive safety and nuclear technology. -- anonymous 04:50, 24 November 2009 (UTC)

History of the page

Instead of moving it to "Nuclear Reactor," it should have its own seperate page. Passive safety, which is more commonly known in academia as Natural Circulation, is a concept that is not in all nuclear reactors, especially the older ones. It is a specific safety technique that heavily utilizes hydrodynamics and isn't directly correlated with generating electricity (such as nuclear fusion or nuclear fission). There doesn't seem to be an article on "Natural Circulation," perhaps someone more knowledgable can create it. It would make sense for the article "Nuclear Reactor" to link to such a safety mechanism.

I too vote for a separate page. This topic is one that should be cited in many articles - also it is worthy of a lengthy article in itself. Containment building has a separate page for the same reasons. Simesa 16:55, 18 September 2005 (UTC)[reply]

I also concur, I will remove the merge notice. Reflex Reaction 15:16, 12 October 2005 (UTC)[reply]

Natural Circ is one way of achieving passive safety, but it is hardly the only one. Reactors, such as U-235 Pressurized Water Reactors have a negative temperature coefficient of reactivity - thus are passively safe with or without having a thermal driving head.Izuko 01:38, 12 December 2005 (UTC)[reply]

Laws of physics?

"[...]Some such reactors use the laws of physics to keep the nuclear reaction under control rather than engineered safety systems.[...]"

Someone has forgotten that the 'laws of physics' are merely a turn of phrase, not a reality.

Dude one: Wow, that was a killer jump man, how'd you do that??

Dude two: I like, totally used the laws of physics man!

Dude one: Kewl!!

It'd be nice to see this re-worded.

Resolved

Chris 06:03, 14 May 2006 (UTC)[reply]

Actually, such reactors (such as the pebble bed reactor) are better termed inherently safe rather than "passively safe". Simesa 18:45, 14 May 2006 (UTC)[reply]

So then what do we call the SLOWPOKE reactor which is licensed to operate unattended overnight? I would think the older term Fail-safe is the one that should be used, rather that 'inherently safe' or 'passively safe' --DV8 2XL 19:16, 14 May 2006 (UTC)[reply]

Relevant information?

I was thinking that the following line is nt really relevant to this particular article. "It is widely believed that such reactors will be important in the future of the industry, since their modularity allows for economies of scale via mass production while the passive-safety aspects address public safety concerns." It should probably be moved to the article on pebble bed reactors. 83.108.144.210 16:41, 21 July 2006 (UTC)[reply]

Article moved

I was bold and moved the article to "Passive nuclear safety". The old name, "passively safe" was clearly unacceptable, and Passive safety redirects to Car safety (which is IMO as it should be, as the most common readers' expectation). This title is in line with the main article, "Nuclear safety". Duja 09:46, 22 September 2006 (UTC)[reply]

What happened to all discussion after 2006???

A large amount of discussionj that occurred after 2006 is missing. Simesa (talk) 00:14, 1 April 2009 (UTC)[reply]

Whether the AP1000 is passively safe

Part of the Discussion that is missing is whether the AP1000 is a fully passively safe design. It turns out that the answer to that depends on the definition of Station Blackout (SBO) that is in use. The AP1000 requires either DC power or batteries to correctly position some valves that don't "fail safe". Inside the U.S., the NRC defines Station Blackout to be "Loss of all alternating current" (LOAC), so inside the U.S. the AP1000 would be defined as fully passively safe. Outside the U.S., whether the AP1000 is fully passively safe depeneds on the definitions in use. I have two sources, but one is 4 MB of text and I haven't read it all yet. Simesa (talk) 00:14, 1 April 2009 (UTC)[reply]

Suggested improved wording.

"The greatest departure from the old 'second-generation' designs is that many incorporate passive or inherent safety features which require no active controls or (human) operational intervention to avoid accidents in the event of malfunction, and may rely on pressure differentials, gravity, natural convection, or the natural response of materials to high temperatures."

The above quote from the article seems like gibberish. What about:

"Second-generation" designs incorporate passive or inherent safety features which require no active controls or (human) operational intervention to avoid accidents in the event of malfunction, and may rely on pressure differentials, gravity, natural convection, or the natural response of materials to high temperatures.

or should it be

"Third generation" designs improve on early designs by incorporating passive or inherent safety features which require no active controls or (human) operational intervention to avoid accidents in the event of malfunction, and may rely on pressure differentials, gravity, natural convection, or the natural response of materials to high temperatures. —Preceding unsigned comment added by 96.252.103.113 (talk) 04:44, 15 August 2009 (UTC)[reply]

Eligibility of CANDU Reactors??

How do CANDU reactors rate regarding passive nuclear safety? From reading the wiki and my knowledge from high school, the design of the CANDU is passively safe - but then again I'm a layman in these matters. 74.15.4.139 (talk) 12:23, 19 March 2011 (UTC)[reply]

Tritium

The tritium mentions in the article don't have anything to do with the passive safety as described in the lede. I'm moving them here for now to see if they can find a better home somewhere else. -- Limulus (talk) 18:47, 10 June 2012 (UTC)[reply]

---
During testing, it was observed that about 6–10% of the calculated 54 Ci/day (2.0 TBq/day) production of tritium diffused out of the fuel system into the containment cell atmosphere and another 6–10% reached the air through the heat removal system.^[1]

This Tritium mention is already in Molten-Salt Reactor Experiment article. -- Limulus (talk) 20:04, 10 June 2012 (UTC)[reply]

~~Inhalation of 70 GBq of tritium is equivalent to an adult human dose of 3 Sv ^[2] in which 50% of cases would be expected to die within 30 days.~~

Discussion of Tritium hazzards best suited to its article, where already somewhat discussed. -- Limulus (talk) 20:04, 10 June 2012 (UTC)[reply]

~~The fluoride salt molecular bond passive safety component failed to prevent tritium production from fission thus presenting a proliferation risk.~~

Wut? How can a molecular bond prevent fissioning of an atomic nucleus? Science fail. Tritium produced in small quantities by all reactors; not a notable proliferation risk AFAIK. Also, MSRE was an experimental reactor; only one in a government site for a govt that already had lots of nuclear weapons... and they used depleted lithium to make as little tritium as possible. Don't see the proliferation risk there, sorry. -- Limulus (talk) 20:04, 10 June 2012 (UTC)[reply]

~~The fluoride salt molecular bonds did not prevent tritium from leaking into the containment.~~

The tritium diffused through the metal itself AFAIK. -- Limulus (talk) 20:04, 10 June 2012 (UTC)[reply]

The fleet of BWRs and PWRs operating within the last 10 years in the United States have reported on 42 occasions a quarterly average daily tritium emission level of more than 22 mCi/day (70 GBq/day) from a power plant.^[3] During the first quarter of 2001 Palo Verde Unit 1 released on average 9 Ci/day (333 GBq/day) tritium gas.^[3] The passive safety component of water as neutron moderator failed to prevent excessive tritium gas (hydrogen with 2 neutrons) from being released from the plant as gas for dilution with air rather than water diluted tritiated water. Inhalation of tritium is absorbed at almost twice the rate as ingested tritium.^[2]

Again, not related to the concept of "passive safety", tritium in LWR best suited to another article, e.g. Environmental_impact_of_nuclear_power#Tritium where it's already discussed. -- Limulus (talk) 20:04, 10 June 2012 (UTC)[reply]

---

Source of Tritium mentions: four edits by an IP address user on 27 April 2010: [2] -- Limulus (talk) 20:09, 10 June 2012 (UTC)[reply]

References

^ R.B. Briggs (Winter 1971–72). "Tritium in Molten-Salt Reactors". Reactor Technology. 14: 335–42.
^ ^a ^b "USNRC Regulatory Guide 1.109 - Calculation of annual doses to man from routine releases of reactor effluents" (PDF). USNRC. October 1977. Retrieved 2010-04-27.
^ ^a ^b "NRC Effluent Database for Nuclear Power Plants". USNRC. Retrieved 2010-04-27.

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Mentioning core catchers?

Should it be mentioned? https://en.wikipedia.org/wiki/Core_catcher

--Tuxayo (talk) 04:14, 19 July 2021 (UTC)[reply]

[Briggs-1] R.B. Briggs (Winter 1971–72). "Tritium in Molten-Salt Reactors". Reactor Technology. 14: 335–42.

[nrc_effluent_doses-2] "USNRC Regulatory Guide 1.109 - Calculation of annual doses to man from routine releases of reactor effluents" (PDF). USNRC. October 1977. Retrieved 2010-04-27.

[nrc_effluent_record-3] "NRC Effluent Database for Nuclear Power Plants". USNRC. Retrieved 2010-04-27.

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