If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Apollo 11 Lunar landing - 40th aniversary
In rec.photo.digital.slr-systems DRS wrote:
"Chris H" wrote in message In message 4a6ffc56$0$9720$5a62ac22@per-qv1-newsreader- 01.iinet.net.au, DRS writes [...] Two accidents due in large part to poor design is not an argument against nuclear per se. Any fair dinkum analysis of the non-carbon emitting power sources inevitably bring nuclear into the equation. Just ask the Germans and the Danes where they get their electricity when the sun doesn't shine and the wind doesn't blow. And the French..... The trouble is that whilst the US is good at making Nuclear weapons it is not very good at making nuclear power stations. 3 mile island could very easily have been a Chernobyl. No, it couldn't. No Western reactor uses positive feedback designs. A nuclear chain reaction of the kind used in nuclear power stations is inherently a positive feedback process. -- Chris Malcolm |
#2
|
|||
|
|||
Apollo 11 Lunar landing - 40th aniversary
"Chris Malcolm" wrote in message
In rec.photo.digital.slr-systems DRS wrote: "Chris H" wrote in message [...] The trouble is that whilst the US is good at making Nuclear weapons it is not very good at making nuclear power stations. 3 mile island could very easily have been a Chernobyl. No, it couldn't. No Western reactor uses positive feedback designs. A nuclear chain reaction of the kind used in nuclear power stations is inherently a positive feedback process. Which is not what I was talking about and you should know it. The Chernbobyl nuclear power plant used graphite-tipped control rods. When the core overheated and the water coolant flashed into steam that graphite *increased* the nuclear reaction rate as the control rods were inserted. As the core got hotter more water flashed, etc. It was a positive feedback loop not possible with Western designs. |
#3
|
|||
|
|||
Apollo 11 Lunar landing - 40th aniversary
In message 4a7179c1$0$9740$5a62ac22@per-qv1-newsreader-
01.iinet.net.au, DRS writes "Chris Malcolm" wrote in message In rec.photo.digital.slr-systems DRS wrote: "Chris H" wrote in message [...] The trouble is that whilst the US is good at making Nuclear weapons it is not very good at making nuclear power stations. 3 mile island could very easily have been a Chernobyl. No, it couldn't. No Western reactor uses positive feedback designs. A nuclear chain reaction of the kind used in nuclear power stations is inherently a positive feedback process. Which is not what I was talking about and you should know it. The Chernbobyl nuclear power plant used graphite-tipped control rods. When the core overheated and the water coolant flashed into steam that graphite *increased* the nuclear reaction rate as the control rods were inserted. As the core got hotter more water flashed, etc. It was a positive feedback loop not possible with Western designs. But different failures are. 3 mile island could have been much worse. As it was the press blew it up into something worse that it actually was -- \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ |
#4
|
|||
|
|||
Apollo 11 Lunar landing - 40th aniversary
Chris H wrote:
In message 4a7179c1$0$9740$5a62ac22@per-qv1-newsreader- 01.iinet.net.au, DRS writes "Chris Malcolm" wrote in message In rec.photo.digital.slr-systems DRS wrote: "Chris H" wrote in message [...] The trouble is that whilst the US is good at making Nuclear weapons it is not very good at making nuclear power stations. 3 mile island could very easily have been a Chernobyl. No, it couldn't. No Western reactor uses positive feedback designs. A nuclear chain reaction of the kind used in nuclear power stations is inherently a positive feedback process. Which is not what I was talking about and you should know it. The Chernbobyl nuclear power plant used graphite-tipped control rods. When the core overheated and the water coolant flashed into steam that graphite *increased* the nuclear reaction rate as the control rods were inserted. As the core got hotter more water flashed, etc. It was a positive feedback loop not possible with Western designs. But different failures are. 3 mile island could have been much worse. As it was the press blew it up into something worse that it actually was It could have been much worse but not because of "positive feedback". Nine seconds into the incident the rods went in and the fission reaction was shut down. The major problems were the result of an operator mistakenly turning off two of the primary coolant pumps an hour or so into the incident. By the way, a fission reactor only operates on "positive feedback" when it is run at a level above criticality, below criticality there is no "positive feedback". |
#5
|
|||
|
|||
Apollo 11 Lunar landing - 40th aniversary
DRS wrote: Which is not what I was talking about and you should know it. The Chernbobyl nuclear power plant used graphite-tipped control rods. When the core overheated and the water coolant flashed into steam that graphite *increased* the nuclear reaction rate as the control rods were inserted. As the core got hotter more water flashed, etc. It was a positive feedback loop not possible with Western designs. It is not possible in some western designs. Similar problems are in many of the reactors that use control rods to slow down neutrons. After the Chalk River near meltdown (Graphite control rods) in the mid 50's AECL started designing CANDO reactors that used heavy water to moderate the reactions. When the water boils or disappears the reaction essentially stops after a burst of high energy neutrons. The primary reason for heavy water is this fail safe property. w.. |
#6
|
|||
|
|||
Apollo 11 Lunar landing - 40th aniversary
In rec.photo.digital.slr-systems J. Clarke wrote:
Chris H wrote: In message 4a7179c1$0$9740$5a62ac22@per-qv1-newsreader- 01.iinet.net.au, DRS writes "Chris Malcolm" wrote in message In rec.photo.digital.slr-systems DRS wrote: "Chris H" wrote in message [...] The trouble is that whilst the US is good at making Nuclear weapons it is not very good at making nuclear power stations. 3 mile island could very easily have been a Chernobyl. No, it couldn't. No Western reactor uses positive feedback designs. A nuclear chain reaction of the kind used in nuclear power stations is inherently a positive feedback process. Which is not what I was talking about and you should know it. The Chernbobyl nuclear power plant used graphite-tipped control rods. When the core overheated and the water coolant flashed into steam that graphite *increased* the nuclear reaction rate as the control rods were inserted. As the core got hotter more water flashed, etc. It was a positive feedback loop not possible with Western designs. But different failures are. 3 mile island could have been much worse. As it was the press blew it up into something worse that it actually was It could have been much worse but not because of "positive feedback". Nine seconds into the incident the rods went in and the fission reaction was shut down. The major problems were the result of an operator mistakenly turning off two of the primary coolant pumps an hour or so into the incident. By the way, a fission reactor only operates on "positive feedback" when it is run at a level above criticality, below criticality there is no "positive feedback". There is always positive feedback. Below criticality the gain is less than one, past criticality the gain is greater than one. -- Chris Malcolm |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Apollo 11 Lunar landing - 40th aniversary | Alan Browne | Digital SLR Cameras | 486 | August 6th 09 07:03 PM |
Apollo 11 Lunar landing - 40th aniversary | Chris Malcolm[_2_] | 35mm Photo Equipment | 6 | August 1st 09 09:33 PM |
Apollo 11 Lunar landing - 40th aniversary | Atheist Chaplain[_3_] | 35mm Photo Equipment | 0 | July 30th 09 07:00 AM |
Apollo 11 Lunar landing - 40th aniversary | J. Clarke | Medium Format Photography Equipment | 1 | July 25th 09 11:42 AM |
Apollo 11 Lunar landing - 40th aniversary | Bill Graham | Medium Format Photography Equipment | 3 | July 24th 09 08:55 AM |