Dr. Helen Caldecott yesterday on The Accidental Armageddon http://www.theage.com.au/daily/990620/news/news22.html

snippet:

There are 433 non-military nuclear power reactors in the world, 103 of them in the US. All depend on an intact coolant system. In most reactors, integral components of the cooling system are computerised. So if any date-dependent fixture breaks down, the reactor could melt down within minutes.

How to deal with this? Even if the reactor is taken ``off line'' - that is, the fissioning process is stopped on 31 December and the cooling system fails on 1 January - it will still melt down within two hours. Indeed, even if the fission reaction were to be stopped today, the core would still be so hot in six months that it would melt down within 12 hours if the coolant system failed.

But there's more. The circulation of coolant water is also dependent on an external electricity supply and an intact telecommunications system. If the millennium bug causes power failures and/or telecommunication malfunctions, reactors will be vulnerable. Because of this possibility, each US reactor has been equipped with two back-up diesel generators. But at best these are only 85 per cent reliable. So, in the event of a prolonged power failure, the back-up diesel generators will not necessarily prevent a nuclear catastrophe. And 67 Russian-built reactors are even more vulnerable, because they have no back-up generators.

What is more, the Russian electricity grid is itself at great risk because, as one might expect, the political and economic turmoil in that country means the Y2K problem has hardly been examined. There are 70 old nuclear reactors on old Russian submarines moored at dock in the Barents Sea. If they were to lose the electricity grid powering their cooling systems, they would melt.

About 80 per cent of France's electricity is nuclear generated. Its government has announced it will close its nuclear power plants for four days over the New Year. But this will not stop meltdowns if the external electricity supply is lost and the coolant fails to reach the intensely hot radioactive cores.

---------- Looks like from this NRC page that there is a continuing need for coolant for at least 5 years, as that is the time before the rods could be placed in dry casks.

http://www.nrc.gov/NRC/NUREGS/SR1628/part06.html#_1_3

See: 5.8 Spent Fuel Pools

Even after the nuclear reactor is shut down, the fuel continues to generate decay heat. Decay heat results from the radioactive decay of fission products. The rate at which the decay heat is generated decreases the longer the reactor has been shut down. So the longer the spent fuel has been out of the reactor, the less heat that it gives off. Storing the spent fuel in a pool of water is a way to provide an adequate heat sink for the removal of heat from the irradiated fuel. In addition, the fuel is located far enough under water that the radiation emanating from the fuel is shielded by the water to adequately protect the workers from the radiation. .....

5.8.4 What would happen if there were a loss of heat-removal capability or water in a spent fuel pool when it was fully loaded?

Depending on the amount of time since the reactor last operated, it would take several days for the temperature of the water to rise to boiling from the constant temperature that it is normally maintained. After sufficient time, the heat generated by the fuel would be insufficient to even cause boiling in the pool. The longer the time interval since the last batch of fuel was moved from the reactor to the spent fuel pool, the longer it would take for the water to reach the boiling point. After approximately a week or more from the onset of boiling without mitigating action, the water level in the spent fuel pool would drop to a level at which it would no longer provide adequate radiation protection for workers. If the water level were allowed to fall lower than this level, dose rate levels would continue to increase, and at some point the fuel pool would boil dry. This would cause very high radiation levels in the vicinity of the spent fuel pool. The NRC has found that, after sufficient time has elapsed since the fuel was last used to generate power, even under the worst case, of a catastrophic immediate loss of spent fuel pool coolant, no offsite doses to the public in excess of Federal limits would occur. The NRC staff is preparing a draft guide (DG-1069), which discusses fire protection in the spent fuel area. ....

5.9.3 What is a dry-storage cask, and how does it keep the fuel from melting or from causing a nuclear reaction (criticality)?

Dry storage involves sealing used or spent fuel above ground in airtight steel (or in steel and concrete) containers or casks that provide both structural strength and shielding. .... They will receive spent fuel that has been cooling in the reactor's spent fuel pool for at least 5 years. ---------

QUESTION:

So.. doesn't the plant have a continuing need for power to maintain safe conditions in the spent fuel pools? And if power is lost and backup generators fail, or power stays off longer than the generators can provide power...???

-- Anonymous, June 21, 1999

Answers

"About 80 per cent of France's electricity is nuclear generated. Its government has announced it will close its nuclear power plants for four days over the New Year."

Haven't heard this before. Exactly what are they going to *close*? Tours to the public?

-David Binder

-- Anonymous, June 21, 1999

Linda:

I would love to read the French statement regarding the plant shutdown; please include a link. The closest I could find was this webpage: http://info-france- usa.org/america/embassy/nuclear/n2f2/index.htm

From what I read here, the most digital (thier words) of the French reactors passed five days worth of testing.

Re: Spent fuel pools Search this newsgroup for 'fuel pools', you'll get a ton of info. Including me asking the same question. I looked into it in depth, and you have nothing to worry about. If your search doesn't help, ask again and I'll tell you what I know.

-- Anonymous, June 21, 1999

70 year old reactors would pre-date many if not all of the computer problems. There is some discussion as to whether Russian nuclear power is modern enough to be a problem... Does anyone have any ideas on this?

-- Anonymous, June 21, 1999

Reporter,

I dont mean to interrupt here but in the interest of accuracy, I believe the number 70 in Lindas post related to the current number of submarines at anchor. Not to the age of the reactors. At least I hope not anyway. 70 year old reactors would tend to diminish the Y2K issue a bit. at least for me.

-- Anonymous, June 21, 1999

linda,

great find. i am attempting to locate dr. haldicott and verify the comments regarding france's intention to take the nukes off-line.

if this is indeed true... we have a precedent. if the french are not willing to entertain the risk of an incident[and 80% of their power is generated by nuclear] than why should we be expected to suffer the risks.

the french as a nation are not known for taking a proactive stance. i have friends that are french and live in paris, lyon, and cagnes sur mer. when last speaking to one of them regarding y2k i was told that the french 'attitude' regarding y2k was 'what will be will be.' this is not unusual. i was also told they were more suited to handle the problem as they had not removed themselves as far from the land as the americans.

vell, mah ree ahn, zees iz zomtheeng that ve havf bought up on ourzelves.

so this type of behavior, at least to my mind and from my experience, is totally atypical.

if they are indeed turning them off it shows a willingness on the part of their government to put the people of france ahead of the almighty dollar.

-- Anonymous, June 21, 1999

Although Helen Caldicott has some great points and concerns, she is off base on reactors melting down within a couple of hours even six months after they are shut down.

Her credibilty gets hurt with each issue she raises. And she hurts it herself.

-- Anonymous, June 21, 1999

To nucpwr -

Re the French shutting down nukes - I did a AP/UPI/REUTERS search and turned up nothing. I would like to see it too. The reference to it was in Dr. Caldecott's remarks in the snippet of article I posted.

Re the spent fuel pools - thanks for the tip on searching old posts. I haven't read them ALL yet, but have yet to find any that say that extensive cooling is NOT needed. Several point to the back-up power provided by the generators (2) which may have fuel for up to 60 days. But I have found nothing to suggest that freshly shut down plants, with their still active rods, don't require a long period of cooling - needing some sort of external power. If you know of specific information, please point me in the right direction. Thanks so much.

Otherwise it looks (to me) like we are okay IF the nuclear plants have no Y2K issues... or failing that we are okay IF the grid stays up, or failing that, we are okay IF the generators work, and IF the power comes back on before the generators fail or run out of fuel.

http://www.nrc.gov/NRC/NUREGS/SR1628/part06.html#_1_3

-- Anonymous, June 21, 1999

>The circulation of coolant water is also dependent on an external electricity supply and an intact telecommunications system.

I'm not a nuke person, but could someone explain to me (or ask the good Dr.) how the circulation of coolant water is dependent on a telecommunication device? What device is she referring to? What is the sequence of events leading from telecom device failure to loss of coolant water circ.?

-- Anonymous, June 21, 1999

"The circulation of coolant water is also dependent on an external electricity supply and an intact telecommunications system."

I'm assuming she means that the electric power is dependent on telecommunications - not that the cooling system is directly dependent on telecommunications. (but don't know myself either)

-- Anonymous, June 21, 1999

Caldecott is a well known social and political activist out on the fringes. She is not regarded as an authority on technology, much less Y2K. The entire article is full of absurd false statements. If I hadn't known of Caldecott, I would have thought it to be a ruse. Regards,

-- Anonymous, June 21, 1999

To Factfinder - reguarding the absurd false statements - could you be more specific? I am mainly concerned here with her statements about nuclear power plants, in particular about the need for external power to maintain the cooling pools. Her statements seem to be in line with those on the NRC website about how plants are decommissioned. Do you know Caldecott's statements about the need for power to maintain cooling pools to be false? And if so, are the NRC statements also false? Thanks for any clarification you can provide.

-- Anonymous, June 21, 1999

Linda,

It's been a long time since I've diagrammed a sentence, but I really don't see that in her writing. If it is what she meant, I hope her mom & dad didn't spring the bucks for a doctorate in English.

-- Anonymous, June 21, 1999

I knew I wouldn't just get to let this article go ignored as it should be. As requested Linda:

FactFinders review of Helen Caldicotts article, The accidental Armageddon

Excerpts from the article are in quotes, followed by my commentary in brackets.

There are 433 non-military nuclear power reactors in the world, 103 of them in the US. All depend on an intact coolant system. In most reactors, integral components of the cooling system are computerised. So if any date-dependent fixture breaks down, the reactor could melt down within minutes.

[The last two sentences above are absolutely false. In most US reactors, systems required for the safe shutdown of the reactor, including the coolant system, are NOT controlled by digital computers, most are of the analog design. I know this from experience, and the NRC has stated this as well. Additionally, safety systems related to core cooling are designed with redundancy. Emergency cooling can be obtained a number of ways, depending on the specific design, such as injection from pressurized cooling tanks, via cooling pumps powered by redundant power sources (including diesel generators). And by the way, the pumps can be operated by manual controls (ie, non-computer controlled push-button switches which turn on the pumps, open valves, etc). Additionally, the few safety systems with digital devices are typically for monitoring, not controlling, and only minor y2k bugs have been found in those to the best of my knowledge (e.g., ICCM/RVLIS). I do believe that the NRC has stated that for the plants reviewed by them for Y2K, no y2k bugs have been found in safety systems that would have prevented safe shutdown of the plant. The bottom line is that y2k bugs in integral components of the cooling system are very improbable.]

How to deal with this? Even if the reactor is taken ``off line'' - that is, the fissioning process is stopped on 31 December and the cooling system fails on 1 January - it will still melt down within two hours. Indeed, even if the fission reaction were to be stopped today, the core would still be so hot in six months that it would melt down within 12 hours if the coolant system failed.

[I am not an expert on the decay rate and dont have the appropriate reference docs at home, but I have seen figures that tend to support the above times given. In the past others in this forum have posted detailed information on this. so you can search the forum. Again, emergency cooling systems for the core are redundant, so this should be systems  both would have to fail. However the entire premise upon which this paragraph is based  failure of the coolant systems due to a y2k bug in integral components of the cooling system is invalid, as I have shown above.]

But there's more. The circulation of coolant water is also dependent on an external electricity supply and an intact telecommunications system. If the millennium bug causes power failures and/or telecommunication malfunctions, reactors will be vulnerable. Because of this possibility, each US reactor has been equipped with two back- up diesel generators. But at best these are only 85 per cent reliable. So, in the event of a prolonged power failure, the back-up diesel generators will not necessarily prevent a nuclear catastrophe.

[US reactors are equipped with to back-up emergency diesel generators ( EDGs) to provide for emergency power in the event of a loss of offsite power, telecommunications was never a factor in this. You may speculate that communications may lead to a loss of offsite power, but this was never considered in the decision to incorporate EDGs, to the best of my knowledge. If someone has evidence otherwise, please come forward. In speaking of US reactors equipped with EDGs, the statement that at best these are only 85 per cent reliable is absolutely false. Reliability criteria requires 95% - 97% or better reliability for each EDG (the lower figures may even require accelerated testing). I dont have the industry averages in front of me, but I do believe they are better than 98%. A 95% reliable EDG has a 5/100 or 1/20 chance of failure. Now thats for EACH EDG. Since they are redundant, two 95% reliable EDGs would yield a probability of failure of 1/20 * 1/20 = 1/400. Put another way, with two redundant EDGs at 95% reliability, the overall reliability for providing power for emergency cooling is 99.75%. Now this is a worst case, and from the industry data I last saw, there were no units with two EDGs that were this bad. More typically you would see 98, 99% or 100% (no failures in last 100 starts) for each EDG. Now here I will stop to say that even though this sounds like very good reliability (and it is), when you consider all of the EDGs and reactor units involved, I personally do not believe that it is good enough, since the potential for a dual failure somewhere, sometime, coincident with a loss of offsite power event, increases with each reactor unit operating. It has been my postion for many years that alternative power supplies should be employed. This notwithstanding, Calcott drastically overstates the situation by providing a very erroneous reliability figure and not accounting for the overall reliability of emergency power due to the redundant design. Now then, the question should be asked, what is the potential for a y2k bug to prevent the EDGs from supplying power to the emergency cooling pumps? For most EDG controls I have worked with and from the industry information I have seen, not many nuke EDGs use computerized control systems, although a number of them have computerized monitoring of EDG parameters. I do know of a few that have digital controls, but the ones I have seen y2k information on indicated no problems that would affect operation (this would be the y2k smoking gun I have never found but promised to let you know of if I ever do. Again, the probability of a nuke plant EDG failure due to a y2k bug appears quite small if existent at all.]

About 80 per cent of France's electricity is nuclear generated. Its government has announced it will close its nuclear power plants for four days over the New Year. But this will not stop meltdowns if the external electricity supply is lost and the coolant fails to reach the intensely hot radioactive cores. 

[I have not heard this in the news, but havent watched the news lately. With 80% of their electricity from nuclear (this sounds right), I hardly think they would intentionally shut ALL the nukes down over the four day period. Electricity de France supplies 90% of Frances electricity and operates the nukes, the y2k page is here , but it is not available in English, so one of you multilingual types who can translate the French please report back. ]

Every nuclear reactor should be fitted urgently with back-up alternative electricity sources, such as solar or wind power. This is not an impossible task, and it could be achieved if the US showed the same level of commitment as it has displayed in the Kosovo crisis.

[This would be funny if not so absurd. Can anyone imagine what a 4-6 Megawatt NET solar panel system, or wind mill system complete with batteries would involve and cost??? And what about the potential for y2k bugs in these systems? Why not check for bugs in the EDG systems we have, which is what we are doing! For alternate supplies for real loss of offsite power threats (i.e., local line loss, faults, tornadoes, etc, but not y2k), I recommend a third EDG or small combustion turbine (one day, it is my dream to see EDGs replaced by ultra-reliable and affordable fuel cells  these may not be far away).]

Dr Helen Caldicott is secretary of the Our Common Future party, and founding president of Physicians for Social Responsibility.

[FactFinder is a nuclear industry insider working on y2k in software and embedded systems who believes that to presenting the facts to the best of his ability without hype or exaggeration is socially responsible, and that dis-information as contained in the reviewed article is not. After evaluating/testing/reviewing industry data on hundreds of software applications and computerized power plant components, he has concluded that Y2K can be a serious problem in some mainframe software financial and other date important software applications. In the large majority of software applications and embedded systems, however, y2k bugs are typically (but not always) minor date bugs that do not affect the primary functions, and the embedded system Y2K threat is turning out to be the embedded system Y2K annoyance. As always, there are exceptions to any conclusion, and thats what we look for.]

-- Anonymous, June 21, 1999

70 year old nuclear reactors? Let's see, that would be 1929, some 15+ years before fission was achieved. Got to hand it to those French.

-- Anonymous, June 21, 1999

Caldicott is a saint. I have loved her for years. **Thank you** for this post, Linda. I saw her speak & have some of her books, which inspired me greatly in pursuing ecological & anti-nuclear political work.

If ANY of her questions or statements are off-base, I would be very surprised. She is a rarestly Intelligent Warrior -whose public declarations should be addressed very seriously. I find it hard to believe that she would officially make these comments - - if the issues were not extremely problematic & most accurately portrayed.

-- Anonymous, June 21, 1999

Thanks FactFinder for your detailed response - much more helpful. Do we agree that electricity is necessary for maintaining the cooling pools? And that electricity can be provided by the nuclear plant - or if the nuclear plant is shut down, the electricity can be supplied by the grid - or if the grid goes down the electricity can be supplied by backup generators. But power IS required to keep the pools cool or if power is lost for long enough (depending on how "hot" the rods are) a "BAD THING" could happen. I think I will leave it there.

-- Anonymous, June 22, 1999

Forgot something... thought it might be helpful to post a link to what the NRC said about STATION BLACKOUT:

http://www.nrc.gov/NRC/NUREGS/SR0933/SEC2/a44r1.html

-- Anonymous, June 22, 1999

Yes Linda, electricity is needed to run the pumps for core cooling. Your mention of "cooling pools" inclines me to think that you may also be refering to the cooling necessary for the spent fuel pool (a totally different scenario than the cooling required for the core, i.e., reactor coolant, emergency core cooling, etc.). The spent fuel pool contains a large volume of circulated water to cool the fuel cells. Electricity is needed to run the pumps here as well, but in a total loss of all power (the station blackout), I believe that someone has already mentioned that we could use any means available to to keep an inventory of water in the pool, from fire hoses, manual pumps, to buckets. Regards,

-- Anonymous, June 22, 1999