System T5

• A(1) - Monitor against goals 
• A(2) – Monitor against PC 
• A(3) – Periodicity - Every refueling cycle not to exceed 24 months
• A(4) Online Risk Assessment
• B(1) – Scope of what falls under M-Rule (SR)
• B(2) - Scope of what falls under M-Rule (Non-SR)

• During the 1980’s the NRC started to consider the need for a rule to address the maintenance of nuclear power plants
• NRC had indications that a lack of effective maintenance could adversely affect overall plant safety.

To improve reliability and availability of equipment

To ensure the effectiveness of the maintenance program

Establish and Monitor goals of performance criteria (reliability and availability)

• Data monitoring/trending to take corrective actions
• Shift focus to balance LRS/HRS

• 1. Scoping
• 2. Risk Ranking
• 3. Develop PC
• 4. (a)(2) Monitoring
• 5. (a)(1) Monitoring
• 6. (a)(3) Assessment

• Form
• SR/Non-SR
• SR components:
•     Important in an accident
•     Relied upon to mitigate an accident
•     Used in EOP
•     Could cause a reactor scram

• 1.      Quantitative – criteria set based on calculations
• 2.      Qualitative – Considerations not based on calculations
• 3.      Expert Panel governed by different procedure, includes:
• a.       Engineering
• b.      *PRA
• c.       *Maintenance
• d.      *Operations
• e.       Work Management
• NOTE:  * Required to attend if scoping or determining ranking

• 1.      PC – Always a(2)
• 2.      Goals – Always a(1)
• 3.      Use PRA if it is modeled
• 4.      HRS – Monitor Reliability and Availability
• 5.      Plant Level:
• a.       Reactor Trip
• b.      Unexplained reduction in power >20%
• c.       Unplanned Safety Function Actuation

• 1.      Reliability – PVAR Reviews
• 2.      Availability – M-Rule Coordinator

• 1.      PC or a(1) goal is inappropriate
• 2.      Monitoring data is incorrect
• 3.      Not Maintenance Related
• 4.      Condition is corrected, CAs are complete and effective
• 5.      For exceeding a(1) goal, existing corrective actions correct the cause
• 6.      Degraded structure still meets its design basis

• 1.      Periodic (every refueling cycle (18 months) not to exceed 24 months)
• 2.      Asses balance between reliability and availability

• A component failure that causes a required function to be lost.
•     Identified by system engineers, tracked by M-Rule Coordinator
•     Equipment that is unavailable is made available again when it is in the logs.

• A(2): (good) 
• Reliability – PVAR Reviews
• Availability – M-Rule Coordinator 
• A(1): (bad)
• Exceeding performance criteria (a(2))
• Exceeding goal – must go to expert panel (a(1))
• Exceeding plant level performance criteria
• Maintenance Rule Repetitive Functional Failure (MRRFF)
• Significant Declining Trend

• 10 CFR 50.65
• Reg. Guide 1.160 Rev. 2 - Committed to in 1.8
• NUMARC 93-01 Rev. 3
• 70DP-0MR01, Rev. 34