Term
Lev Con
Describe the runbacks that Lev Con components have an input into. |
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Definition
-Runback to minimum (30%) if feedwater flow is less than 20% of rated for 15 seconds.
-Steam blow >55.4% rated and RFP or Cond pump trips the recirc pumps runback to 50%. |
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Term
Lev Con
Describe the effect that Lev Con components have on the rod worth minimizer. |
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Definition
-Puts RWM in service <20% steam flow.
-Takes RWM out of service >20% steam flow.
-Turns RWM ON less than 35% steam flow.
-Turns RWM OFF > than 35% steam flow. |
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Term
Lev Con
Describe the effects that Lev Con components have on hydrogen water chemistry. |
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Definition
| HWC isolates when < 30% steam flow. |
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Term
Lev Con
Describe the element control inputs and uses. |
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Definition
-3 element control: Monitors steam flow, feed flow, and Rx level.
-Used durning normal operations.
-1 element control: Monitors Rx level only.
-Used when < 30% (steam/feed flow inaccurate) (40% by procedure).
-Also as a sub for 3 element upon failure up to 100%. |
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Term
Lev Con
Describe when an auto transfer to 1 element occurs. |
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Definition
-Steam flow indicators differ by more than 270,000lbm/hr.
-Feed flow indicators differ by more than 570,000lbm/hr.
-Failed sensor on feed or steam flow. |
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Term
Lev Con
Describe the failure modes of the FRVs and element controls. |
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Definition
-Loss of air to FRVs (<75#) they fail as is.
-Can operate in 1 or 3 element control. |
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Term
Lev Con
Describe the failure mode of the low flow valve and element control. |
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Definition
-Loss of air (<75#) fails open.
-Loss of power fails closed.
-Can operate in 1 element only. |
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Term
Lev Con
Describe the power supply to Lev Con system. |
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Definition
-Dual power from Y-30 and Y-10.
-Loss of one power has no effect on the system except an annunciator. |
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Term
Lev Con
Describe the selection of Rx level control. |
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Definition
-Can select either A or B detector or median.
-Median selects the median of the 3 inputs. |
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Term
Lev Con
Describe the indicated values on the Rx water level inputs into Lev Con. |
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Definition
-Feedwater: 0" to +60".
-Safeguards: -50" to +50". |
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Term
Lev Con
Describe the deviation from setpoint of Rx water level. |
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Definition
-Programmed to lower level by 3" from setpoint (only see 3" due to level being sensed outside steam seperator).
-Will get 7" in the steam seperator area due to diff pressure.
-Total of 10" at 100%.
-10% to 100%.
-Prevents carryover and carryunder. |
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Term
Lev Con
Describe the low flow controller band and power limit. |
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Definition
-In auto can only control level between +15" to +40".
-Can control level <20% power. |
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Term
Lev Con
Describe bias control. |
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Definition
-Set a bias on the FRVs.
-Bias should always by 0 or negative. |
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Term
Lev Con
Describe the FRV control band. |
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Definition
| -In auto the FRVs are clamped between +30" to +40". |
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Term
Lev Con
Describe level sensor failure and what happens. |
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Definition
-If narrow (feedwater) or safeguard level differ by 10" from median then auto switch to median.
-Also get alarm. |
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Term
Lev Con
Describe flow signal failures and what happens. |
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Definition
-If feedwater or steam flow fail out of range then switch to single element.
-If feedwaters differ by 570,000lbm/hr or steam flows differ by 270,000lbm/hr then switch to 1 element.
-Also get alarm. |
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Term
Lev Con
Describe what happens on loss of control signal to FRV. |
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Definition
| -If input signal and output signal of FRV controller differ by 27% or more than the valves lock-up. |
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Term
Lev Con
Describe the failure of the master controller or low flow controller setpoints. |
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Definition
-Master controllers clamped at +30" low and +40" high in auto.
-Low flow controllers clamped at +15" low and +40" high in auto. |
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Term
Lev Con
Describe the Rx pressure input failure. |
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Definition
| -Get alarm if the inputs differ by 75#. |
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