TVA Browns Ferry: Local Blackout, On Emergency Power Due To Tornado 5

[racookpe1978]

This from

http://www.freerepublic.com,

repeating a story reported at the Times Free Press:

"TVA loses all power transmission lines ... Browns Ferry Nuclear plant forced into emergency shutdown"

Times Free Press ^ | April 28, 2011 | Pam Sohn

http://www.timesfreepress.com/news/2011/apr/28/tva-losses-all-power-transmission-lines-alabama-an/

Wednesday’s storms took out all of TVA’s electric power transmission lines in Mississippi and North Alabama, and forced Browns Ferry Nuclear Plant unto diesel backup power and into emergency and automatic cold shutdown.

Bill McCollum, the chief operating officer of Tennessee Valley Authority, said it may be weeks before power can be restored to all of the 300,000 customers whose power is supplied by the federal utility.

“With the level of damage we have, it will be — we hope it will be days until we get most of the customers back on, but it will be weeks before we’ve fully repaired all of the damage,” he said.

McCollum said the reactors, now being cooled by backup diesel power, are safe.

He said the spent fuel pools also are being cooled by backup diesel power and are safe.

The transmission lines are the monster power lines that carry electricity from TVA power plants to power distributors such as EPB and Huntsville Utilities."

 

[davefitz]

Yes, and the NRC is now questioning whether a 4 hr backup source is adequate in the case where a tornado has obliterated other sources of backup power after the 4 hr diesel tank has dried up. Perhaps a quick trip from a nearby armory with add'l fuel may help in some cases, but not all.

But once one considers the possibility of a tornado strike, then a nother question that may also follow is "what if the 250 mph tornado hits the SFP building?"

 

[trottiey]

That becomes a question of what frequency of accident are you prepared to accept. The marketing brochures say that core damage accidents should only happen once per 10,000 reactor-years, and that would imply that INES level 6 or 7 accidents should be much less frequent than that. But so far, core damage accidents have historically happened about once per 1000 reactor-years, and level 6 or higher has happened about once per 5000 reactor-years.

http://www.energypolicyblog.com/2011/04/27/reassessing-the-frequency-of-partial-core-melt-accidents/

The industry talks about a nuclear renaissance and a growth of up to 5000 operating nuclear reactors world-wide. If we extrapolate historical safety records, that might mean a serious accident once a year on average - probably not acceptable to the general public. We all hope that more modern reactors will demonstrate improved safety performance relative to the historical record.

It's fair to take a hard look at the design basis of old reactors to determine if they need to be replaced or upgraded.

Stress is a biological mechanism that improves strength at the expense of thought. It is counter-productive to solving technological problems.

 

[racookpe1978]

One issue nobody has addressed yet is the "lack of credibility" that 8x YEARS of the democrats saying "Bush lied, people died" + incomplete (and misleading and premature) TMI press releases + (incomplete and inaccurate and misleading) Japanese press releases + Chernobyl (lack of ANY press releases) + now 4 years of republicans knowing that democrat press releases on anything plitical from Washington about environment or energy or prices or taxes or medical care are lies = ZERO credibility of "government" or "official spokesmen."

And I have seen no particular evidence myself that the DOE - or other Washington agency led by the fed's is any more accurate. Now or in future accidents.

They need to release independent, publically-monitored site-fence radiation levels continuously after an accident. Nothing else will be believed.

 

[CastMetal]

Very few people would be qualified to interpret those radiation numbers (I don't claim to be one of them), especially in cases where there is a mixture of lower risk radioactive elements and those posing larger threats. Mass evacuations caused by scary sounding numbers on the local news can cause more damage than a few days low level radiation exposure. While I agree there needs to be more transparency for people to trust the government, throwing raw data to the media wolves would be poor judgement.

Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations

 

[davefitz]

I agree that control of information is probably the no 1 desire of modern governments; it seems to be the basis of steering the crowd. Witness the sudden loss of monitoring capabilities immediately after the Fukushima event, or better yet, witness the turnover in middle east governements following manipulation of "social media".

The way the system is now configured, either one has to put pressure on elected reps to provide more transparency (not so effective) or seperately provide independent and credible monitoring ( very effective- so it must not be allowed to occur).

I remember one time the latter method was used- perhaps 20 yrs ago, there was a wave of illness to swimmers at the NJ shore- the public asked for a state study of pollution from coastal sewer plants, and the state refused - so a coalition of physicians funded a separate study, and immediately the NJ state pre-empted that study by changing course and funding a state coverup/ study. Can't lose control of the flow of information.

 

[trottiey]

Settle down. This Browns Ferry tornado event doesn't even qualify as an accident on the INES scale. I see no basis for the allegations of cover up or information control in this case. Discussion of sewage plants and political rants do not belong in this forum.

You can get the raw Fukushima press releases here:

http://www.nisa.meti.go.jp/english/press/index.html

They're very comprehensive, and contain few errors. I think you need to accept that the more information is published, the more errors will slip through. There was a massive public outcry when Tepco got one measurement wrong in a chart of a hundred numbers in one press release out of hundreds. Obviously, the public cannot handle raw data.

Stress is a biological mechanism that improves strength at the expense of thought. It is counter-productive to solving technological problems.

 

[rmw]

trottiey,

Who are you - the forum police? Both posters who you critized are long time and respected members whose posts have contributed much to the fora on this site. The points they are making are germane as the political and media aspects of nuclear power (in our country at least) probably have more influence on the progress or lack thereof than the technical merits or lack therof of nuclear power.

This is the "other topics" forum and they have as much right to post their views of what is going oin in the industry as you do to call them a rant.

If you don't like their posts, just hit the RF and let management decide.

rmw

 

[trottiey]

rmw,

I guess you could RF my posts as well. But it sounds like you support my right to criticize others, just as I would support your right to criticize me. I am grateful that we share this common ground.

The transparency of the nuclear industry is important to me as well, which is why I spent so much effort during the Fukushima crisis to help others understand what was going on. I received many thanks for this work, both on this site and in real life, and I hope that I too have earned a measure of respect. But I always hope to win arguments on merit, rather than on any respect owed to me.

In this thread, I maintain that some of the arguments were off-topic. Maybe I should have said that they don't belong in this "thread," rather than "forum." But they sounded to me like the opening blows of a "My politician could beat up your politician!" kind of discussion that would occlude engineering issues. What would happen if an ardent Democrat had replied? There are already many internet forums dedicated to politics, but too few about engineering.

I agree that politics can often be germane to nuclear engineering. If anyone has evidence of political interference in the TVA Browns Ferry tornado blackout, or ideas to promote the transparency of this event, I encourage them to post; I would be interested in reading about them. The same would be true for any other reactor event, although I would hope they could be posted in appropriately-named threads.

Can we be friends? I've learned interesting things from our discussions, and I hope these can continue without acrimony.

Stress is a biological mechanism that improves strength at the expense of thought. It is counter-productive to solving technological problems.

 

[MikeHalloran]

>>>This Browns Ferry tornado event doesn't even qualify as an accident on the INES scale. I see no basis for the allegations of cover up or information control in this case. Discussion of sewage plants and political rants do not belong in this forum.<<<

The sewage plant story serves as an excellent example of how governments manipulate information flow so as to deceive the populace.

How soon would the Browns Ferry event qualify as significant if the tornadoes had also taken out local road and rail links and thereby made timely resupply of Diesel fuel impossible? Can the industry learn anything from near misses?

I understand that power production is a business, and that it is the business' duty to manipulate (the word seems harsh, but is accurate) design criteria applied by legislation so as to minimize business costs.

... However, I assert that the design basis for nuclear plants has so far been biased too far toward risk for economic reasons, witness the gap between achieved failure rates and marketing brochures, as you kindly explained.

Having, and being required to have, only a four hour supply of Diesel on site is just one example of how ineffective government's oversight of the nuclear industry has become, or maybe always was. Four hours is not enough time to even figure out what happened. ... or is happening; storms commonly last longer than that, and nobody in the nuclear industry or in government can or will make a decision in that kind of time frame.

So once again, the nuclear industry looks silly, stupid, venal or evil, depending on your perspective. Renaissance? Good luck with that.





Mike Halloran
Pembroke Pines, FL, USA

 

[vpl]

Mike

They have more than 4 hours worth of fuel.

Patricia Lougheed

******

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[itsmoked]

Yes but will the tank still be there after the tsunami?

Or tornado or hurricane?

Maybe they should bury them. Or one of them. Of course that has environmental possibilities too, but less than a meltdown(up).

Keith Cress
kcress -

http://www.flaminsystems.com

 

[MikeHalloran]

Point taken. I found a document suggesting they had tankage for 7 days of fuel as of a few years ago. The four hours came from a message above, apparently reflecting what the NRC actually requires. I couldn't find an indication of how much fuel was actually on site when the storm started.

Then I ran across a 2003 environmental report submitted as part of the licensing process. In that was a fairly exhaustive analysis involving SAMAs, or Severe Accident Mitigation Analysis. Each of which seems to be a suggestion for improving the reliability of the plant. There were hundreds. Apparently there's a computer model involved, sort of a FEMA type thing. The comments were interesting; I found some that had probabilities set to zero in order to produce a desired result in the math model. Others were evaluated on some pseudo-economic basis and classified as not cost-effective.

Systemic pencil-whipping is what I'd call it.

It just reeks of regulator/regulatee confusion about who works for whom.


Mike Halloran
Pembroke Pines, FL, USA

 

[vpl]

In general, diesel fuel tanks in the US are buried. I can't say whether that's true 100%, but it is at all the plants I've inspected.

US plants have survived both tornadoes and hurricanes without major problems, and definitely without any damage to the reactor core or spent fuel pool. There have been both direct hits of tornadoes and cases where the tornadoes took out the switchyard (so the plants had to go on the diesels). Generally they don't make much more than local news (if that), because nothing happens and the news organizations usually wants something exciting to report.

In regard to the hurricane, there was a nuclear plant in Florida who took a direct hit from hurricane Andrew. They did lose offsite power for a few days, but the diesels worked fine. That one might have made the news for a couple days ... but it was more on the lines of "there isn't power to the area because the darn nuke plant isn't running."

You might be interested in this follow up story on the Browns Ferry tornado:

http://www.timesfreepress.com/news/2011/may/06/nuclear-safety-shines-disaster/

Patricia Lougheed

******

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[itsmoked]

Interesting points all around.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[electricpete]

I am no nuclear spokesman. Just an anonymous voice who has worked at a nuclear plant and has an opinion. I think there is some perspective missing in the general discusions that have gone on since Fukushima event.

Take a look at how one US plant compares against Fukushima:

http://storage.cloversites.com/stpnuclearoperatingcompany/documents/PrRel 2-031611.doc

· STP’s two-unit facility was designed and constructed with multiple, redundant safety features. STP is one of the newest commercial facilities in the nation. Commercial operation began in 1988 and 1989. The first unit at the Fukushima Daiichi plant began commercial operation in 1971.
· The site’s safety features are unique; STP is the only commercial nuclear facility in the nation to have three separate safety trains or systems. These independent systems - electric power, pumps, valves, instrumentation - are available in each unit for redundancy.
· These independent safety systems are located in watertight, concrete buildings designed to withstand earthquakes, flooding and storm surges. Each diesel generator has its own fuel oil tank located in this earthquake-proof building.
· Each safety train includes essential safety equipment that will keep the reactor cool and covered. A diesel generator is part of each safety train and can provide the power for the essential safety equipment in the event of a loss of offsite power. Each diesel generator provides 5.5 MW and is designed to start within 10 seconds.
· This diverse train approach provides another level of redundancy to supply cooling and/or electricity to critical plant systems and components during a plant emergency.
· In addition, STP’s containment buildings are four feet thick and lined with steel to mitigate any potential issue in a worst-case scenario.
· Multiple offsite power sources are available at the STP site, including an emergency transformer from a power line independent from the main switchyard.
· The company also has a comprehensive and integrated Emergency Response Plan that is closely coordinated with local, state and federal officials. STP routinely tests and drills on all potential emergency scenarios to ensure that we are coordinated and aligned.

Note some difference:
3 redundant trains instead of 2
Diesels and storage tanks located in earthquake-proof, flood proof buildings. That means they don’t get washed away.
well-organized, trained, and integrated emergency response organization. Do not underestimate the importance of this one. While the workers at Fukushima have been heroic, I think the organization supporting them has been lacking.

Some will view it as spin. I view it as facts that seem to be overlooked.

What happened March 11? Natural disaster of unprecedented proportions. Richter scale 9 earthquake, 12 meter tsunami, loss of off-site power. Human toll was incomprehensible, more than 20,000 souls lost. How do the events at the nuclear plant compare? No deaths attributable. Very small levels of radiation for the general public, not much more than natural. Much less than the occupational radiation exporsure that I have received in my career, and I never considered it a risk. No deaths attributable unless you apply statistical wizardry of miniscule risk to a large population. For the people displaced, it's a very very big deal, but it’s not life and death.

If we have a comparable event in the US, I would worry about the tens of thousands of souls lost to the natural disaster, but I wouldn’t worry about the nuke plants. The very worst case, they perform similarly to Fukushima plants…. the consequences are ugly but not deadly. I certainly wouldn't expect even that much though, because of the many real differences discussed above.


=====================================
(2B)+(2B)' ?

 

[gmax137]

Re: four hours and seven days. The plant Tech Specs typically require seven days diesel fuel onsite in seismic, tornado-proof tanks. The station blackout rule (10CFR50.63) requires demonstration that the plant can 'cope' with loss of the emergency diesels and loss of the offsite AC power for a period (usually four or eight hours, depending on the characteristics of the site).

So, seven days diesel fuel, four hours without the diesels. It's two completely different things.

Re: underground diesel fuel tanks. Yes some are, some are not. Underground is good for tornadoes, maybe not-so-good for flooding (which can potentially lead to water in the tank through the fill connection or through the vent stack).

 

[rmw]

I am making a non-nucler comment in a nuclear forum:

Fuel tanks are normally placed underground (general statement irrespective of nuclear or non-nuclear application) to prevent the tanks from sweating during cool and cold weather. Since these tanks 'breath' with temperature change and level changes due to usage, above ground tanks will tend to 'sweat' inside as well as outside in cold weather in the vapor space area.

Diesel tanks are more susceptible to this as diesel fuel doesn't have the vapor pressure needed to help blanket the vapor space above the fuel as is the case with gasoline, for example.

Diesel tanks located above ground in climates where the ambient gets low enough to drop dew will just sit there and collect water out of the atmosphere hence the primary reason for burying them.

rmw

 

[itsmoked]

Thanks for clearing that up gmax137.
Though that spec sounds a bit like it was written by the power industry. The four hours being the time the direct drive turbine could keep running.

Sort of like, "Your truck has to be able to coast at least 100ft after the engine dies while moving at 60MPH".

That's interesting rmw. In CA it seems everyone is running away from buried tanks because of the triple expense and required monitoring. Maybe the temp variation is less here?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Browns Ferry in the news again. They got handed a red tag.

http://www.msnbc.msn.com/id/42974051/ns/us_news-environment/

Keith Cress
kcress -

http://www.flaminsystems.com