CRD Malfunctions Flashcards
What is the procedure sequence for an asymmetric rod?
Perform rod position indication validation section to validate a true condition and then perform asymmetric rod section for applicable actions.
What are entry conditions for Asymmetric rod?
1) Greater than 5% asymmetry on PI panel or control rod asymmetric annunciator
2) Greater than 6.5% asymmetry and asymm fault and out inhibit on diamond panel and CRD withdrawal inhibited annunciator
What steps are performed to validate an asymmetric condition?
1) Monitor for changes in incore and excore quadrant tilt and power
2) Use rod position to compare api and rpi indication
3) Use trends to monitor rod position trending away from group
4) Use rod zone indicating switches and move applicable rod as desired to prove position.
5) Contact I&C to switch between the two alternate channels of indication and check position
What note is present in section 1 regarding zone indications?
What actions are required if all rod position indication is determined to be invalid? (API,RPI and Zone Ind Lights)
1) Enter TS 3.1.7 and declare rod inoperable
2) If safety rod enter 3.1.4 and 3.1.5
3) If reg rod enter 3.1.4
4) If APSR enter 3.1.6
What are entry conditions for dropped rod - reactor critical?
What is the definition for a dropped rod?
What actions are taken for dropped rod if power less than 2%? What actions taken if more than one rod drops and power greater than or equal to 2%?
1) < 2% -> S/D the reactor by inserting all reg rods in sequence and place in mode 3 per Power reduction and plant s/d or plant startup procedure.
2) >/= 2% and 2 dropped rods -> Trip Rx and perform reactor trip
What is consequence of recovering dropped rods from subcritical condition?
What actions are performed for single rod drop?
1) Ensure runback to 40%
2) Perform RPSD
3) Adjust ICS to maintain < 360 MW and < 40% NI Power to prevent Out inhibit and CRD Withdrawal Inhibited
4) When required to insert controlling rod group, operate in limit bypass
5) If safety rod dropped and required to bleed, ensure CV-1250 closed.
What is definition of rod inoperable?
What actions are required for dropped rod if out inhibit exists and desired to withdraw rods?
Place FW Loops and Rx demand to hand, diamond to manual and adjust to maintain Tave 578 - 580 deg F, less than 360 MW, and less than 40% NI Power.
What recovery rates are specified based on amount of time drop rod has been an issue?
1) If within 8 hours, recover at run speed with subsequent power escalation within limits (Att L).
2) If 8 - 24 hours, recover at run speed with power escalation as follows:
- 0 to 60%, less than or equal to 30%/hr
- 60 to 90%, less than or equal to 15%/hr
- 90 to 100%, less than or equal to 5%/hr
3) If > 24 hours then recover gradually (10% increments spaced 30 min apart) with power escalation < 3%/hr
If rod is considered asymmetric but not a dropped rod, what actions are taken if rod within 6.5% of group?
Transfer to aux supply, level rod to group average, adjust RPI, transfer back to normal supply.
What actions are taken for asymmetric rod > 6.5% from group?
1) Within 2 hours, attempt to recover rod by transfering to aux supply positioning and returning to normal supply
or
2) If > 1 hour, reduce power to 60% allowable power at 2%/min, If rest of group aligns then stop lowering power. Once < 60%, perform power peaking check, contact Rx engineering for ejected rod worth within assumptions, and I&C to adjust high flux trip setpoints = 70% of allowable power within 4 hours.
What are entry conditions for CRD Stator Temp High Section?
