EOP introduction / SPTAs Flashcards
State the purpose of the EOPs and when it is considered applicable.
EOPs:
- EOPs provide guidance to place the plant in a safe condition when a reactor trip occurs or should occur.
- Also applicable to events that initiate in Modes 3 and 4 for which the Entry Conditions are met.
State the purpose of SPTAs and when they are implemented.
Standard Post Trip Actions (SPTAs)
- Entry point for all EOPs in Modes 1 and 2. (Normal entry point)
- Checks safety functions against acceptance criteria, along with contingency actions which can be performed to restore safety functions in jeopardy.
- Gives the operator a complete status of plant conditions and safety.
- Diagnostic Actions assist the CRS in deciding on ORP or FRP entry.
State the purpose of ORPs and when they are implemented.
Optimal Recovery Procedures (ORP):
- EOPs written to treat specific symptoms. (not a specific event)
- Entered from SPTAs after a trip or directly entered if initially in Modes 3 or 4.
- Simultaneous performance of more than one ORP is prohibited.
State the purpose of the FRPs and when they are implemented.
Functional Recovery Procedure (FRP):
- EOPs for undiagnosed and multiple events.
- Entered from SPTAs (modes 1 and 2) or directly entered if initially in Modes 3 or 4.
- May be entered directly after completion of the SPTAs if diagnosis of a single event is not possible.
- May also be entered from an ORP if an ORP had been initially selected but failed the Safety Function Status Check (SFCS) or the ORP is not mitigating the event. If the SFCS acceptance criteria are not satisfied at any time, then the operator is directed to evaluate the need to implement the FRP.
- Operator does not need to diagnose an event in order to establish and maintain a safe plant configuration.
State the purposes of the LMFRPs and when they are implemented.
Lower Mode Functional Recovery (LMFR)
- Places plant in a safe condition during events that occur during Mode 4, 5, or 6 with LTOP in service.
- Operator does not need to diagnose an event in order to establish and maintain a safe plant configuration.
- May be entered directly when the entry conditions are met, or when the CRS is directed by an ARP to enter the LMFR. During the course of an abnormal event the STA will check the applicable safety function status set. If the check reveals that any safety function is not being maintained, the CRS will direct entry into the LMFR.
Define Safety Functions, explain why they are important and what the order of importance is.
Safety Functions
- Condition or action that prevents core damage or minimizes radiation release to the public.
- Mitigates the consequences of any event and ensure proper plant control regardless of the event that is occurring.
- SPTAs check safety functions upon entry into the EOPs.
- SFSC section of each ORP gives the CRS a 2nd check of safety function status and confirms that the correct procedure is in use.
- FRP and LMFR provide an assessment of degraded safety function and directions for safety function restoration.
- Checked / controlled in order of priority (reactivity control, MVA, RCS inventory control, RCS pressure control, core heat removal, RCS heat removal, CTMT isolation, CTMT pressure / temperature).
State the purpose of SFSCs, who is responsible for them, who performs them and how often they are checked, performed.
Safety Function Status Checks (SFSCs)
- Review and assessment of the SFSC is the responsibility of the CRS.
- Normally assigned to the STA.
- Assign to 3rd RO when STA is not available.
- Checked every ~ 15 minutes while an ORP, FRP, or LMFR is in use.
- Any Safety Function not met shall be reported to the CRS and investigated immediately.
Describe the SFSC correction process if a symptom is adequately being addressed and if procedure guidance is inadequate.
- SFSC provides a correction process.
- If the procedure in use is adequately treating the symptoms, then the procedure is continued.
- If the guidance is inadequate, either because new symptoms appear that are not covered in the procedure, or because of improper plant response, then the operators exit the ORP, re-diagnose the event, and enter the correct ORP or the FRP.
What actions are required if a safety function is outside the acceptance criteria?
- If safety function outside the Acceptance Criteria: FRP should be implemented or a re-diagnosis. Unless all of the following conditions exist:
- Reason is known.
- Actions are available to readily return the safety function to within the Acceptance Criteria.
- CRS determines the recovery of the jeopardized safety function is imminent.
Whose concurrence is required to perform an EOP step in a manner other than it is written and under what condition is this allowed?
- If a step cannot be performed as written, and CRS wants to perform the step in another manner, then obtain SM concurrence.
Who should be informed if a contingency action is performed?
- CRS informed of all contingency actions performed
What is a continuous action step?
- Continuous Action Steps (Monitor, Maintain, Control): Start when reached, remain in effect until superseded by another step.
What are trigger steps and how are they designated?
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Trigger Steps (based on a setpoint or time frame):
- Performed when the specific trigger condition is met (pull forward as needed)
- Designated with an asterisk
What are hold point steps?
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Hold-Point Steps:
- Must be completed before continuing on with the procedure.
- Normally provide guidance for the main mitigating strategy of the procedure and require the full attention of MCR staff.
- Identified by a note identifying it as a hold-point step.
How are PAM instruments designated in the CR?
- Post-accident (PAM) instruments are indicated with a white border.
