NUCLEAR INSTRUMENTATION Flashcards
(18 cards)
What action is required if SR or IR SUR exceeds 3 DPM?
Trip the reactor and go to EOP-001.
What is the minimum overlap required between Source and Intermediate Range NIs?
1 decade overlap.
How many Source and Intermediate Range NIs are required to be operable unless 2 of 4 Power Range NIs are >10%?
1 Source and 1 Intermediate Range NI.
What type of detector is used for Source Range NIs?
Fission Chamber.
What happens to Source Range NI count rate if voltage discrimination fails low?
Count rate goes up closer to CRD out-inhibit.
At what count rate does the RB Evac alarm activate and reset for Source Range NIs?
Activates at 40 cps rising and resets at 30 cps.
What is the CRD out-inhibit threshold for Source Range NIs?
2.0 DPM rising with reset at 0.5 DPM.
What type of detector is used for Intermediate Range NIs?
Compensated Ion Chamber.
What happens to Intermediate Range NI readings if compensation voltage fails low?
Readings go high closer to CRD out-inhibit.
What does “overcompensated” mean for Intermediate Range NIs?
It results in non-conservative readings.
What is the interlock threshold for Intermediate Range NIs?
3.0 DPM rising with reset at 0.5 DPM lowering.
What type of detector is used for Power Range NIs?
Uncompensated Ion Chamber.
Why is compensation not required for Power Range NIs?
Neutron flux is high relative to gamma.
What functions do Power Range NIs feed into?
High flux, flux/flow/imbalance, flux/pumps, turbine trip, and FWP trip.
When must Nuclear Instrumentation be calibrated during normal operations?
If there is a Δ 2% from heat balance.
How is Power Imbalance calculated?
Top Half – Bottom Half.
What indicates undercompensated Source Range NIs?
Intermediate Range coming on-scale with Source Range NI not yet at 1e4 counts.
What is the relationship between Source Range 1e4 cps and amps?
1e4 cps corresponds to 10-11 amps.
