Talk:Three Mile Island accident

Closure date

https://www.pennlive.com/news/2018/09/three_mile_island_closure_loom.html gives the closure date as September 20, 2019, but notes attempts to postpone this... community support for it to stay open for obvious local economic benefits (ie jobs), and environmental concerns of its replacement by fossil fuel. Some other news:

• https://www.bloomberg.com/news/features/2018-06-05/a-meltdown-didn-t-kill-three-mile-island-but-shale-probably-will
• https://www.pennlive.com/news/2018/10/nuclear_safety_advocates_call.html
• https://www.pennlive.com/news/2018/09/three_mile_island_closure_loom.html
• https://www.pennlive.com/politics/index.ssf/2018/05/one_year_later_officials_still.html confirms September 2019 but not the actual date

Article just needs an update... I'll do it when I find time but feel free to help! Andrewa (talk) 23:38, 21 February 2019 (UTC)

closure data should be accompanied with the fact that clean-up of nuclear waste has not been done or even started. Fulber (talk) 01:27, 29 December 2019 (UTC)

Opinion instead of lesson

The whole section "Lessons learned" is about the personal opinion of some Charles Perrow. The assertion of Perrow that the accident was "unexpected, incomprehensible, uncontrollable and unavoidable" is falsified by the facts stated in the introduction of the page about "ambiguous control room indicators". Indeed, the lesson learned is that there must be (i) more reliable control room indicators; (ii) more automatic reactions of the system and less reliance on the judgment of the operators. Perrow suggest that such a complex system cannot be improved, which is historically falsified by the improvements made as a lesson learned. --Dominique Meeùs (talk) 18:58, 10 March 2019 (UTC)

Thousand separators

From Wiki: "Numbers consisting of long sequences of digits can be made more readable by separating them into groups, preferably groups of three, separated by a small space. For this reason, ISO 31-0 specifies that such groups of digits should never be separated by a comma or point, as these are reserved for use as the decimal sign."

Ummmm, OK. If there are such "long sequences of digits" in the text, by all means, go ahead and edit them. Or as for help if for some reason you are unable. No one here is particularly comma penurious. In fac,t, we often stum,,,,,b,,l across,,, them ... ourselves. SkoreKeep (talk) 20:13, 30 July 2019 (UTC)

Someone appears to have changed some titles

I am not a wikipedia editor, nor do I know what the titles should be, but I'm relatively sure a header should not read "trans people" — Preceding unsigned comment added by 2600:1700:3040:31A0:1D54:58D7:84DA:C22D (talk) 02:43, 8 February 2020 (UTC)

Thanks, it was a rapidly changing IP. Fixed and blocked. Acroterion (talk) 02:47, 8 February 2020 (UTC)

A Commons file used on this page or its Wikidata item has been nominated for deletion

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:

• Carter TMI-2.jpg

Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 00:37, 7 February 2022 (UTC)

A Commons file used on this page or its Wikidata item has been nominated for speedy deletion

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for speedy deletion:

• TMI Both Units in Operation.jpg

You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 00:52, 23 May 2022 (UTC)

Removal of public domain information

The user https://en.wikipedia.org/wiki/User:Diannaa removed content derived from a PDF in the Nuclear Regulatory Commission's publicly available document database. That document is therefore considered public domain and free for all to use. The content should be restored. NRC OPA (talk) 17:43, 30 June 2022 (UTC)

Should add new section describing why PORVs fail particularly on B&W reactors

A new section or additional information could be added to the article describing cause of of PORV failure. B&W reactors for economy had a small pressurizer, and consequently routine turbine trips resulted in high pressurizer water level, resulting in the PORV opening. In short the PORV would open routinely. Pressurizer spray of course turns on before the PORV opens, so the PORV gets steam with entrained water droplets. Thats what causes the freight train sound, beats the crap out of the PORV valve with its reversing flow path, and guarantees PORV failure. Plus back then nobody had really thought out what would happen when a pressurizer went solid. Probably a small steam dryer is needed between the pressurizer and the PORV. On new facilities it could be better to build this steam dryer inside the top of the pressurizer. Shutting off presserurizer spray should be evaluated 209.150.58.4 (talk) 01:01, 3 October 2022 (UTC)

Interesting frankciufia@gmail.com 71.172.19.246 (talk) 00:02, 7 October 2022 (UTC)

Babcock & Wilcox's PORVs previously failed 11 times. Normal usage in present systems destroys PORVs. Water droplets from the pressurizer spray are entrained in the exiting steam act like bullets and destroy PORVs. It sounds like a freight train! To my knowledge this is still not addressed: PORVS are still not tested for water droplet steam nor is a simple small cheap passive steam dryer installed. One steam dryer is a lot cheaper than a PORV. PORV failure should be considered a serious accident.

BTW this article has come a long way. Early revisions imparted "the fundamental cause of the accident was operator error". The fundamental cause of the accident was several unrecognized design errors, and not operator error as per initial NRC report. The operators were convenient fall guys. Whether or not the system has a small or large pressurizer, a steam dryer (simple water droplet separator) should be on the PORV valve input side. Otherwise the PORV valve is beat to crap by water droplet steam. 2603:7000:4EF0:9B0:B54B:EDE1:AAD5:F94F (talk) 19:37, 24 June 2023 (UTC)

ROUTINE PORV FAILURE: (1)If PORV valves open regularly have a bigger pressurizer. (2)Each Steam Generator has a built-in steam dryer. Pressurizer steam should be treated the same. (3)Stopping pressurizer spray prior to PORV opening should be considered. 2603:7000:4EF0:9B0:C3B:4684:2103:2FF (talk) 19:30, 3 August 2023 (UTC)

Yes, yes, and yes. On your no 1: B&W used a smaller pressurizer than the original Westinghouse design to save money. As a result of the small pressurizer routine turbine trip transients would cause the PORV to open! Which leads to PORV failure. This means the PORV will fail during 'normal' reactor operation! B&W had a large history of PORV failures, but their solution was to replace PORVs many times instead of addressing why PORVs were failing.

No mention of any of the workers.

The day of the accident Ron Fountain entered a high radiation environment to unjam a valve of chillwater. The valve was on the 2nd level but the elevator wasn't working. He ran causing him to hyperventilate. Fountain received the most REMs of any worker.

Kevinfountain (talk) 08:12, 18 July 2023 (UTC)

Yes, what about Houser? The guy who said the sample looked like Alka-Seltzer and showered for 8 hours to be decontaminated? Bucky winter soldier (talk) 13:09, 18 October 2023 (UTC)

Include NUREG 0600

NUREG 0600 is a better source than many of the books used here. It is what I consider a primary source Several items that are mentioned in NUREG 0600, not mentioned here or wrongly stipulated here.

1. The EMOV (PORV) valve was leaking. The leakage was wrongly calculated p(rocedure was wrong) and was more than 1gpm. The NPP was not allowed to be operated longer than 72 hours with a reactor cooling leakage of more than 1 gpm. 2. Because of the leakage the statement that the operator should be able to see the closure of the EMOV by checking the temperatures downstream is not true. This temperature was way up while normal 'closed'. After closure it would take 10 minutes before the valves (Fail safe valves in front of EMOV) would go back to normal temperature, but the EMOV valve remained higher in temperature for more than 40 minutes in case of a normal closure. Typically the EMOV should have been opened for only 31 seconds. Even without leakage it would have taken a lot more time to discover that the EMOV was still open. [Outside comment: PORV probably was leaking because it was beaten to crap by water droplets in previous openings ]2603:7000:4DF0:9340:9151:1EBF:5994:3533 (talk)BG 3. The temperatures were used to determine that the EMOV was open, and this the reason that the operators closed the EMOV finally after 80 minutes. Only because these temperature should be dropped by now.

4. TMI-2 Did receive NRC report on Besse incident (10 copies) but training staff didn't use it. 5. Training staff considered the idea that pressure could drop and pressurizer could fill as something that could never happen. So it was never trained to the staff. In such case the pressurizer level was considered focus. 6. Operators consider the response of the reactor to a turbine trip as severe. So it was common that ES were activated, and also common to shut them down. The ES activation, the failure of the rupture disc, the radiation alarm, even high - all these had happened before so none of them was sufficient to raise an alarm. (literally fromn NUREG 0600) Actually, only the continuous running of the sump pumps could have triggered an early indication that reactor coolant was being lost

7. In case of power failure, the EMOV would stay open. This was changed after an incident, but this change was not carried out according to procedure. No safety analysis was done afterwards, no training was given to operators. Originally there wasn't even a light indicating that the EMOV was open.

Comment: Thanks. Design didn't consider the consequences of an open EMOV or solid pressurizer. A serious Westinghouse design oversight was made much worse by using a smaller pressurizer. Can't blame the situation on the operators when the designers didn't consider these problems.2603:7000:4EF0:9B0:4526:FA2E:9B0:47A6 (talk)BG

8. The operators were forced to close down the RCS pumps, because the procedure required it. These procedures were written with pump failure /seal failure in mind, and not with the situation that actually occured. So when vibration exceeded the limits, the operators had to change to HPInjection cooling of the core.

This list is not even complete. Blackbird69b (talk) 08:45, 17 October 2023 (UTC)

Joseph Mangano and the Radiation and Public Health Project (RPHP)

I have just cleared up the sentence about 'their' findings a little. The current sentence and its citations is a mess. Presently it states that RPHP is citing Mangano but neither the article from Mangano in Bulletin of the Atomic Scientists nor the article from The Guardian draws this link - so presently WP:OR. The whole muddled mess of sources risks WP:SYNTH. I have removed the statement of Mangano's credentials that I thought was taking up rather too much space and gave him WP:UNDUE weight.

Overall, I'd say that if editors want to cite Mangano in Bulletin, then cite Mangano in Bulletin and stop beating around the bush with these RPHP people.

All the best, ~ El D. (talk to me) 14:39, 19 December 2023 (UTC)