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Tritium Leak At Vermont Nuclear Plant Grows
mdsolar writes "The tritium leak into ground water at Vermont Yankee has now tested at 775,000 picocuries per liter, 37 times higher than the federal drinking water standard. 'Despite the much higher reading, an NRC spokeswoman said Thursday there was nothing to fear. "There's not currently, nor is there likely to be, an impact on public health or safety or the environment," the NRC's Diane Screnci said in an interview. She had maintained previously that the Environmental Protection Agency drinking water safety limit of 20,000 picocuries per liter had an abundance of caution built into it. ... The National Academy of Sciences said in 2005 that any exposure to ionizing radiation from an isotope like tritium elevates the risk of cancer, though it also said with small exposures, the risk would be low. ' At what level should the NRC shut down the troubled plant?"
If the reactor doesn't produce much tritium, then wouldn't that imply that tritium would be a small proportion of the radioactive material released when a leak occurs... but it is detected early because it IS so mobile and easy to detect.
That is, the tritium itself is not the direct cause for concern, but rather an indicator that will lead to locating the real problem.
They are finding water near the condensate storage tanks. This is water that is supposed to be used for emergency cooling, replenishing reactor feedwater, and overflow for a couple systems. It is potentially contaminated. It draws its water from the potable water system (typically in most plants), which means that the water going in is supposed to be clean. They need to check if they have a leak in there causing potentially contaminated water to go into the site's potable water system. I'm sure that was already done, at my plant it would have been done already at least. Anyways, condensate storage tanks arent always located inside the plant. It is very likely thats where the leak is. I'm not completely sure why they are getting tritium of all things as in a BWR plant tritium usually isnt your biggest worry. Nuclear plants have a corrective action process that a plant uses to fix problems. Anyone at the plant can put something in the process, it is federally mandated, and its one of those things that an employee cannot lose his job over. The system is very effective and allows the plants to 'self-police'. Finding and fixing a problem like this when the tritium leak was low would have been a low priority fix because the tritium levels were under limits previously. One of the actions they took was likely to install the new wells to find if the leaks were worse near potentially contaminated systems, which they did and found out it was worse. Now they are likely elevating the issue internally, which is why it was reported again to the NRC. So far, the plant sounds like they legally/procedureally done everything right. They made a huge boo-boo by having a PR guy tell people they have no underground piping that could carry contaminated water, it makes me think that guy never took or paid attention during the BWR systems class. The plant cannot be expected to prevent all accidents, but they are expected to mitigate accidents and issues to a minimal risk of safety to the public and to monitor and fix equipment which has repeat failures (things they know are breaking). Long story short, They are going to get investigated, and if this problem has been here longer than they say it has, they are in a bit of trouble. I Tritium isnt terrible in the water, as long as it doesnt get into drinking water. It's in low amounts that it will be diluted easily if it reaches a main water supply. It's still not good, but there are MANY worse things that could have leaked.
One of the 10000 or so jobs I have over the years was working in a refinery for a few months. During that time some of the workers tried to find some pipes for maintenance. No one knew where they were. There were the design diagrams, the "as-builts" and numerous additions and removals by contractors upgrading and doing maintenance. Some new ones were out in, some ripped out, and others abandoned in place.
Metal detectors did not help, there was too much metal buried and scattered around.
The situation was so bad they resorted to dowsing. I'm serious!
Lately I've heard of small robots using GPS to travel a pipe and map it out. But with so many old plants and old pipes, it will be a long time before the situation is unsnarled.
putting the 'B' in LGBTQ+
Oh, the problem is by no means confined to this particular power plant. In fact, I'd argue that it is an extremely general problem, extending across the domains of system planning, document format design, library science, GIS, human resources, and others. It is also a very important problem to solve, or at least chip away at, if we want to continue to enjoy the fruits of highly complex technological civilization.
The people who design and build complex systems are always going to leave, retire, or die. Advances in medicine have modestly extended the time horizon on the last two of those events, and sufficiently large sums of money can reverse the first(though, in general, there seems to have been a trend toward people moving around faster than in times past).
Certain sorts of knowledge and experience are, at least without really creepy brain implants and other sci-fi stuff, basically impossible to capture. The muscle memory of a skilled technician moving through a complex series of manipulations, the emotional conditioning of a soldier continuing to function under extreme stress and danger, or the performance of a scientist or engineer(or, in more mundane cases, a support tech) who is so familiar with a system's parts that he can troubleshoot it as though by intuition.
Barring substantial advances in man-machine interfaces or assistive technologies, the best we can really do to try to capture these is to foster the correct funding and HR environments. This doesn't mean unlimited lavish funding for everybody, that would be unrealistic; but it does mean trying to avoid boom/bust or feast/famine cycles. You want a steady continuity, with new hires having time to absorb experience from veterans, rather than having a purge/binge cycle, where efficient, well operating systems are cut to the bone(because hey, if they can keep the lights on with 5 engineers, 10 is clearly just a waste, just in time is the future, man!) until they start to fall apart, and then a whole bunch of noobs are hurridly hired and forced to reverse engineer the pieces and get things running again.
Other aspects of institutional memory, while hard to capture, are at least in theory amenable to technological solution, if a serious and conscious effort is made to do things properly. Digital archivists and aggressive format standardization are one part of the puzzle. If your power plant/factor/whatever was CADed, your staff today should be able to call up the plans. If changes were made, they should be able to know when, where, what, why and who(similar, in principle, to the revision control systems used in software production). This is, admittedly, hard. It is quite possible that some 3rd party contractor CADed the place using an obscure, industry-specific CAD package from the 80s, and may or may not have shared the full specs with you. It is, however, necessary, and we as people with a stake in complex industrial society, need to do something about it.
The other half of the puzzle, since keeping records in sync with reality is extremely hard and is inevitably going to fail from time to time, probably lies in the development of embedded sensors, "smart dust", and suchlike projects. Ideally, we should not only have the records of what the world is supposed to look like; but be able to programmatically interrogate the world and determine how closely it is adhering to our records, both in the sense of "Hey, look, the tertiary Toxin Shunt is developing stress fractures, it should be replaced within the next 100 hours." and "Hmm, flow-rate readings on the 2nd street water main look off compared to water meter readings in the area, we should check for possible tree roots, leaks, unauthorized diversions, or other deviations from the design."
These are hard problems, and I don't actually suspect that the Vermont nuclear guys are unusually incompetent about it(though, losing tritium is more serious than just leaking water, so that is still kind of a problem); but this is an example of a very complex, very serious, and very important problem that we will have to come to a solution to. Complexity is hard; but if we want its benefits, we'll have to figure something out.
I would wonder how it is that Tritium is in the coolant. Unless it's the (primary?) coolant stage that's leaking, in which yes - fixing it is a bitch because the coolant is otherwise very hot and radioactive.
If you've got tritium in your (secondary?) coolant stage, you've got bigger issues.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
The problem is that underground plumes of bad stuff spread over time. If you discover the contamination before it gets dangerous and you stop the leak it may be that the levels in water that is used by people never gets above the regulatory limit. If you let it sit it won't be long before people are drinking water with many times the the EPA limit.
One thing that always bothers me about these environmental stories is that when some Chemical X is reported to be floating around, it's never 20% over the regulatory limit, or even twice the limit, it is always at least one order of magnitude too high. The regulatory limit may be conservative, but I really doubt it has a safety factor of 37 built in.
-- QED