Russia Set To Extend Life of Nuclear Reactors Past Engineered Life Span 215
Harperdog writes "Yikes! Russia is extending the lifetime of nuclear power reactors beyond their engineered life span of 30 years, including the nation's oldest reactors: first-generation VVERs and RBMKs, the Chernobyl-type reactors. This goes against existing Russian law, because the projects have not undergone environmental assessments. 'Many of the country's experts and non-governmental organizations maintain that this decision is economically unjustifiable and environmentally dangerous — to say nothing of illegal. The Russian nuclear industry, however, argues that lifetime extensions are justified because the original estimate of a 30-year life span was conservative; the plants have been significantly upgraded; and extensions cost significantly less than constructing new reactors.'"
So does Canada. (Score:4, Informative)
Re:So does Canada. (Score:5, Informative)
As does the US, which has re-certified multiple reactors, including both at Nine Mile Point, which were re-certified for an additional 20 years after their initial lifespan.
Re:Well, (Score:5, Informative)
Except it does:
During life-extension projects, engineers determine which components are in need of replacement, and which can remain in service if maintained regularly. Some parts of a reactor, however, cannot be replaced -- including the reactor casing and its internal elements, the graphite stack (found in RBMK reactors), primary coolant circuits, primary coolant pumps, and biological shield systems. These parts are crucial for the safe operation of a reactor, particularly a first-generation reactor.
In the case of the Kola nuclear power plant in northern Russia, for example, the reactor casing should be replaced in order to ensure safer operation, but that cannot be done without building a new reactor. In addition, the proximity of the fuel assemblies to the steel walls in the VVER-440 reactor tank -- such as those used in two of Kola's reactor units -- results in higher neutron irradiation than in other types of reactors, so the walls of the VVER-440 become brittle more rapidly.
Re:Well, (Score:5, Informative)
Material decay under long-term exposure to radiation, most likely. Also, as new technology becomes available, they may expect the plant to be out-dated and no longer worth the necessary modifications to match newer standards after thirty years.
We do this too... (Score:5, Informative)
So far the US has granted extensions like this to more than SIXTY reactors. How many has Russia given out so far?
http://money.cnn.com/2011/03/15/news/economy/nuclear_plants_us/index.htm [cnn.com]
Re:So does Canada. (Score:5, Informative)
Design life span is a best guess.
Actual use reveals the true life span. Aggressive maintenance can stretch life span even further.
The same is true of small to medium sized hydro dams. They were so over-built that many of them have exceeded their design life. Some have doubled their design life without showing significant degradation, especially with new resurfacing technologies.
It is said that "Engineering is the art of finding the least safe design".
By which it is meant that engineers design to use the least materials, cost, labor, and still achieve a safe result.
When actual measurements and data are poor, or not available, engineers (the good ones) over build.
They design in extra safety factors, excessive strength. The result is you have Brooklyn Bridges, (a whipersnapper compared to the Ponte Fabrico [wikipedia.org] B52s, the aqueducts (some still in use) and similar very over-engineered projects.
That some reactors that were designed when the industry was in its infancy are still safe and suitable today is not all that surprising. People didn't push the envelope as often then.
But it remains to be seen expect that of future designs.
Re:We do this too... (Score:3, Informative)
The original article regarding the Russian reactors is talking about engineered lifespan, whereas your article is talking about license to operate. This is like the difference between renewing your car's inspection sticker and replacing your tires. One is a legal requirement and the other is a physical requirement. Neither article talks about this distinction, and I'm not sure that they're making it. The Russian plants were licensed for 30 years, and according to the article, their physical lifespan is also 30 years. The USA plants were licensed for 40 years, but that article doesn't make any mention about their engineered lifespans, and I don't know enough to say what the engineered lifespan of a USA vs. Russian plant is. It's certainly possible to keep machines working properly for many decades as long as they are designed that way. If the Russian reactors really do have irreplaceable physical parts that are expected to fail after 30 years, it would be madness to operate them after that time. However, this may not be the case with other reactors which have received license extensions.
Re:Insane (Score:5, Informative)
Sorry, that's a fairy tale.
1) There's no way a 'room which nobody knows about' can exist in a nuclear power plant.
2) Especially if it contains components from the freaking primary contour. And the secondary cooling contour is absolutely safe - you can drink water from it.
3) There's no way radiation levels can be large enough to cause significant irradiation in several minutes. Absolutely none at all - primary cooling water is radioactive, but not that much (it's continuously monitored).
4) Power plant operators after Chernobyl are _very_ careful. For a reason.
But what do I know? After all, I have actually worked on a Russian nuclear power plant.
Re:Well, (Score:3, Informative)
Most metals become brittle when irradiated.
Someone will be along with more details then I can recall offhand.
I would just design the plant to run with brittle metals from day one. Nothing that can't be solved with thicker walls (in many cases anyhow).
Modern reactors use a neutron shield that goes with the fuel basket. It can be replaced and greatly decreases vessel embrittlement by becoming the sacrificial element to first absorb/slow the errant neutrons.
The problem is with shutdown and startup. This needs to be done with control as things become harder and have less flex.
Re:Insane (Score:3, Informative)
That sounds, really, really, impressive and scary to the uninformed. But it's not actually. If your friend exceeded his quarterly allowed dose, it means he took the equivalent of a few transcontinental flights or chest X-rays. (I.E. practically nothing.)
No, you're not a sissy. Just badly misinformed and prone to EWW RAD1AT10N !1!11! syndrome.
Re:Well, (Score:4, Informative)
As I understand it, the RBMK reactors are already a long way from meeting modern safety standards. They have no containment building, they still have a positive void coefficient, the monitoring and control systems are quite limited despite being upgraded and this can't really be fixed, there appear to be a bunch of single points of failure that can't be fixed either, and so on.
Re:So does Canada. (Score:3, Informative)
Chalkriver is kept operational by political decree.
http://en.wikipedia.org/wiki/Chalk_River_Laboratories#2007_shutdown [wikipedia.org]
On December 11, 2007, the Canadian House of Commons, acting on independent expert advice, passed emergency legislation authorizing the restarting of the NRU reactor and its operation for 120 days (counter to the decision of the CNSC), which was passed by the Senate and received Royal Assent on December 12. Prime Minister Stephen Harper criticized the CNSC for this shutdown which "jeopardized the health and safety of tens of thousands of Canadians", insisting that there was no risk, contrary to the testimony of then CNSC President & CEO Linda Keen. She would later be fired for ignoring a decision by Parliament to restart the reactor, reflecting its policy that the safety of citizens requiring essential nuclear medicine should be taken in to account in assessing the overall safety concerns of the reactor's operation.
This reactor suffered 2 major emergency shutdowns since this incident already. Each resulted in many months downtime.
Basically, it's a reactor used for medical isotopes built back in the 50s kept limping along into 2nd decade when it should have been completely shut down and replaced. But that effort failed,
http://en.wikipedia.org/wiki/MAPLE [wikipedia.org]
so we are stuck with a leaking, 50+ year old machine.
Re:Well, (Score:4, Informative)
Modern updates greatly reduced the positive void coefficient. It used to be wildly positive (4.7), which allowed running unenriched uranium on a non-heavy-water reactor. Now it's around 0.7, which gives you a lot more room for error.
The controls are considerably upgraded: no more graphite tips on the control rods, more manual control rods, more neutron absorbers, no more safety overrides, and more.
There aren't many single points of failure, but the safety margin and redundancy is much lower than western designs. A PWR can be leaking like a sieve and still maintain adequate cooling; a RBMK can hit trouble with only a few broken pipes, and as you say, there's no way to mitigate it, since it's part of the design.
They actually do have some some containment. It's not a heavy-duty all-encompassing concrete bunker like a western reactor, but there are high pressure management channels, steam condenser pools, etc. Any routine blowout will be contained... Just don't pull a Chernobyl. :)
I'd say RBMK safety has been upgraded from "Insanely Irresponsible" to "Poor".