A trip to Chernobyl

[KokomoBusa]

by hafnium i assume you are refering to the natural piosions? and that there are many ways to control the k effect, we personally use recirculation pumps to change the moderator density for fine control, or control rods for course. we also have sodium pentaborate for emergencies. as far as supercritical goes, the introduction to nuclear power manual defines it justas i stated before. btw, the soviet reactor used a horrible design that used graphite as the moderator. (heard it on the radio)

natural poisons???? You should listen closer to the radio chief...you just restated what I said since all those control methods are used for reactors designed as supercrit... Only difference is, the control rods that you mention....you don't seem to realize they're made of hafnium.

 

[KokomoBusa]

baleibec, i think you're trying to hard to impress folks with Nuke know how...you should go back to the original statement...all plants in the US are supercrit assembly, it's a fact, it's safe...chernobyl was a subcrit assembly...it's a face, it's gone. Nuff said

 

[KokomoBusa]

World Nuclear Association

 

[Powers739]

by hafnium i assume you are refering to the natural piosions? and that there are many ways to control the k effect, we personally use recirculation pumps to change the moderator density for fine control, or control rods for course. we also have sodium pentaborate for emergencies. as far as supercritical goes, the introduction to nuclear power manual defines it justas i stated before. btw, the soviet reactor used a horrible design that used graphite as the moderator. (heard it on the radio)

So you are on a GE BWR design plant...

 

[UncleSteve]

very sad situation and it never had to happen. A fault of having the human equation involved.
I pray it is never repeated anywhere in the world.
The poor people how had to live and die that day, weeks, months, and years that followed, the people who deal with it today. God bless the heroes that gave their lives for others.

 

[mrsBusawhipped]

Wow! I have goose bumps. I remember as a senior in HS, I thought the world was coming to an end. If this could happen in USSR then it could happen here too. Very scary times. I think History channel had a show on Chernobal a few years back and it was just chilling what happened there and how those people suffered even years afterwards.

 

[Powers739]

If this could happen in USSR then it could happen here too.

I know never say never, but there are huge differences between physical plant designs and nuclear operating "culture" between USSR and US, even more so in today's "Nuclear Culture".

There are several defense in depth measures taken to ensure that we protect the public.

I recommend doing a little research to help understand what the industry does to protect the public and maybe that will help the uneasy feeling you may have.

A good place to start is the NRC: Home Page

If you have any specific questions PM me and I will do my best to help...

 

[baleibec]

QUOTE=KokomoBusa;1743121]baleibec, i think you're trying to hard to impress folks with Nuke know how...you should go back to the original statement...all plants in the US are supercrit assembly, it's a fact, it's safe...chernobyl was a subcrit assembly...it's a face, it's gone. Nuff said [/QUOTE]
not trying to impress anyone, heck i dont even know y'all??? i believe where i got ahead of myself is when it was initially called a supercritical reactor, since the fuel initially has to be irradiated in order to start the chain, then continues to be supercritical untill an neutron adsorber or poison slows the reaction to critical (what i was stating is that was where a unit stays at steady power= critical) sorry if i stepped on any toes.:moderator:

 

[baleibec]

So you are on a GE BWR design plant...

correct, we are running 3 GE bwr's

 

[MR X]

WOW, I am at a loss for words .
I seen some pictures of Chernobyl in RIDER mag of a bike tour there , Wow.

 

[mrsBusawhipped]

I know never say never, but there are huge differences between physical plant designs and nuclear operating "culture" between USSR and US, even more so in today's "Nuclear Culture".

There are several defense in depth measures taken to ensure that we protect the public.

I recommend doing a little research to help understand what the industry does to protect the public and maybe that will help the uneasy feeling you may have.

A good place to start is the NRC: Home Page

If you have any specific questions PM me and I will do my best to help...

I am 40 yrs old now and have learned a few things over the years. One is, if humans are involved, there is ALWAYS a chance for error. I am not against nuclear power, but like anything accidents can happen. We just need to be prepared for the consiquences.

WE have come a long way since this incident too.

NRC: Fact Sheet on the Three Mile Island Accident

 

[J.Busa]

Quick question. With all the talk of finding alternative fuels and possibly using "nucular" (G.W. talk) power in the future, are the plants we are currently using creating large amounts of "nucular" waste, and what is being done with that waste currently???

So if we do add more plants in the future, will this waste disposal be alot bigger problem than the current pollution problems we have now with oil and coal plants???

 

[KokomoBusa]

Quick question. With all the talk of finding alternative fuels and possibly using "nucular" (G.W. talk) power in the future, are the plants we are currently using creating large amounts of "nucular" waste, and what is being done with that waste currently???

So if we do add more plants in the future, will this waste disposal be alot bigger problem than the current pollution problems we have now with oil and coal plants???

There's a HUGE misconception about Nuclear waste. Most plants consist of a primary and a secondary loop. Only the primary loop is irradiated and it's shielded to keep the bad zoomies out of the people space. Once the reactor is shut off there's a period of time allowed for all decay chains to finish up...not sure how long, not more than a couple days if civi plants are anything like naval. After that grace period the space is relatively safe. The yellow drums of green fluid is movie land stuff. And most core fuels that aren't being subjected to an influx of thermalized neutrons undergo very few reactions as they have an incredibly long half life minimizing the radiation emitions from them.

civi pro's welcome to edit.

 

[Powers739]

I am 40 yrs old now and have learned a few things over the years. One is, if humans are involved, there is ALWAYS a chance for error. I am not against nuclear power, but like anything accidents can happen. We just need to be prepared for the consiquences.

WE have come a long way since this incident too.

NRC: Fact Sheet on the Three Mile Island Accident

You are correct, if there are humand involved there is a chance for error. But since we KNOW humans are involved we do what we can to prevent errors. That's why we use Human Performance (Hu) tools to minimize the odds of making a human error, and we continue to strive for excellence and perfection.

As far as being prepared for the consequences, that too is pratices and drilled with the Emergency Response Organization (ERO), with contingency plans already in place. There are quarterly drills and annual drills which are graded by the NRC.

Your nuclear worker (and employer) spent a lot or time (and money) in training and drills.

We can't afford another incident...

 

[GMbusa]

What is the Elephants foot?

 

[Powers739]

What is the Elephants foot?

It was a glob of melted fuel and fuel cladding, it was the shape and size of an elephants foot.

 

[Powers739]

Quick question. With all the talk of finding alternative fuels and possibly using "nucular" (G.W. talk) power in the future, are the plants we are currently using creating large amounts of "nucular" waste, and what is being done with that waste currently???

So if we do add more plants in the future, will this waste disposal be alot bigger problem than the current pollution problems we have now with oil and coal plants???

The nuclear waste you are referring to would be that of the spent fuel. The utilities have been funding a project for long term storage of the spent fuel at Yucca Mountain (Nevada)... now there is a story of the Goverment mismanaging large amounts of money (funded by the utilities with reactors) and we still don't have the repository. So, in the mean time the spent fuel is stored on site until the repository is operational. Which may never happen.

The low level rad waste would go to regional repositories like Barnwell NC. Not that big of a deal with low level waste.

I can't answer if it's going to be a bigger problem than the current pollution problem. I can answer, probably not in our lifetime, but we still need to considerate of the earth for our children, future children and mankind in general.

I do know they are working on reprocessing (recycleing) the spent fuel.

 

[Powers739]

There's a HUGE misconception about Nuclear waste. Most plants consist of a primary and a secondary loop. Only the primary loop is irradiated and it's shielded to keep the bad zoomies out of the people space. Once the reactor is shut off there's a period of time allowed for all decay chains to finish up...not sure how long, not more than a couple days if civi plants are anything like naval. After that grace period the space is relatively safe. The yellow drums of green fluid is movie land stuff. And most core fuels that aren't being subjected to an influx of thermalized neutrons undergo very few reactions as they have an incredibly long half life minimizing the radiation emitions from them.

civi pro's welcome to edit.

Waste isn't coming from the cooling loops... it's the spent fuel that is in question. But you are correct about how a Pressurized Water Reactor (PWR) works with a primary and secondary cooling loop in order to provide barriers to the outside world. The primary loop is contained within the Containment building, the loops transfers heat to the secondary loop by Steam Generators (big radiators that make steam from the heat given off by the primary loop, physical barriers between the two loops), everything is recycled hence the name LOOP! What heat polution you would see coming off the plant is that of the secondary being cooled off after it was sent throught the turbine and to the condeser, where there is another loop (circulating water) which takes the heat away from the condeser (spent steam which condenses back to water to be pumped back into the Steam Generators) by another type of radiator (another seperate loop) to remove the heat to enviroment (river, ocean, cooling tower). The enviroment is several loops away from the primary coolant, giving Defense in Depth...

 

[KokomoBusa]

The nuclear waste you are referring to would be that of the spent fuel. The utilities have been funding a project for long term storage of the spent fuel at Yucca Mountain (Nevada)... now there is a story of the Goverment mismanaging large amounts of money (funded by the utilities with reactors) and we still don't have the repository. So, in the mean time the spent fuel is stored on site until the repository is operational. Which may never happen.

The low level rad waste would go to regional repositories like Barnwell NC. Not that big of a deal with low level waste.

I can't answer if it's going to be a bigger problem than the current pollution problem. I can answer, probably not in our lifetime, but we still need to considerate of the earth for our children, future children and mankind in general.

I do know they are working on reprocessing (recycleing) the spent fuel.

what fuel do civi plants use? is it U-235? Maybe the core remains isn't a big deal in the navy because the reactors are small and the remains are minute. As far as spent fuel the decay chains of U-235 lead to stability rather quickly, so i'm guessing you'd use a different fuel or the fuel cells are much larger and the critical mass is still a HUGE amount. I'm not starting an arguement, I've justn ever been in a civi plant and i'm curious as to the differences.

 

[Powers739]

what fuel do civi plants use? is it U-235? Maybe the core remains isn't a big deal in the navy because the reactors are small and the remains are minute. As far as spent fuel the decay chains of U-235 lead to stability rather quickly, so i'm guessing you'd use a different fuel or the fuel cells are much larger and the critical mass is still a HUGE amount. I'm not starting an arguement, I've justn ever been in a civi plant and i'm curious as to the differences.

No argument, just discussing stuff...

The commercial side, the fuel assembles are much larger than those used by the Navy. Enriched U-235 is used, one fuel assemble is around 12-14' long, which consists of fuel pins, which actually hold the fuel pellets, a fuel assembly may have around 100 pins. Depending on the design, the plant may have up to 500 or more fuel assemblies. Usually, 1/3 of the assemblies are replaced during the refueling outage. The fuel is designed to run between 18 or 24 months, again depends on design and operating liscense.

These numbers will vary depending on the design of the unit. Just giving a little idea on what you are looking at...