Glossary entry (derived from question below)
English term or phrase:
control power was lost
English answer:
power to the control system(s) failed
Added to glossary by
Tony M
Jun 4, 2016 06:31
8 yrs ago
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English term
control power was lost
English
Other
Nuclear Eng/Sci
All the inside containment isolation condenser valves would keep their position when the AC power was lost, but they would close, by design, if the control power (i.e. DC power) was lost to the protection system — for the line break situation — that would have sent ‘close signal’ signals to those valves.
I have two problems regarding this sentence. Firstly, I cannot understand what control power is, and what it means when control power is lost to something, in this case "protection system".
I have two problems regarding this sentence. Firstly, I cannot understand what control power is, and what it means when control power is lost to something, in this case "protection system".
Responses
4 +7 | See explanation | Tony M |
Change log
Jun 9, 2016 09:27: Tony M changed "Edited KOG entry" from "<a href="/profile/1642331">Masoud Kakouli Varnousfaderani's</a> old entry - "control power was lost"" to ""See explanation""
Responses
+7
10 mins
Selected
See explanation
'control power' is the power that is used to control the valves: the implication is that the AC power is used to actually drive the valves (presumably motorized ones), but the valves are 'controlled' (told when to open or close) using a DC control signal.
So the AC supply must have been OK, otherwise the valves wouldn't have moved at all; but failure ('loss') of the power supply going to the protection system would result in loss of the DC control signal, which would cause the valves to close automatically by default.
Sounds like a 'fail-safe' system that wasn't!
So the AC supply must have been OK, otherwise the valves wouldn't have moved at all; but failure ('loss') of the power supply going to the protection system would result in loss of the DC control signal, which would cause the valves to close automatically by default.
Sounds like a 'fail-safe' system that wasn't!
4 KudoZ points awarded for this answer.
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