Extending Technical Specification Completion Times via Risk Managed Technical Specifications (RMTS) - MTA-PRA-002
| Administrative Items | |
|---|---|
| Date | 2/1/2025 |
| Functional Area Where Benefits Will Be Realized |
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| Reference Implementation Guidance |
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| Industry SME | EPRI Risk and Safety Management Program
Contact: NuclearPlantMod@epri.com |
| Previous Implementation |
This methodology has been implemented at several nuclear plants. Please contact the EPRI SME for additional information. |
| Implementation Enablers |
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| Applicability |
Reactor Type: BWR, PWR Regions: United States and others that adopt similar guidance as NEI 06-09, Rev 0A and TSTF-505, Revision 2. |
| Keywords |
Risk‑Informed Applications; Technical Specifications |
| Business Case Analysis Cross-Reference |
N/A |
Description
The Nuclear Energy Institute (NEI) Risk‑Informed Technical Specifications Task Force has addressed several generic initiatives to further risk‑inform station Technical Specifications, including Initiative 4b, entitled Risk‑Managed Technical Specifications (RMTS). The key feature of this program is the ability to calculate a flexible risk‑informed completion time (RICT) as an alternative to the allowed out‑of‑service time in current Technical Specifications.
RMTS may allow plants to extend maintenance completion times beyond the time duration specified in the Technical Specifications, avoiding either a plant shutdown or an expedited justification for enforcement discretion. Additionally, the additional time can provide the opportunity to complete the maintenance in a more thorough manner, providing substantial operational flexibility and significant cost savings.
Benefits
Benefits Estimate
Level 2 – Savings are greater than $1 million per year but less than $5 million per year (inclusive).
Benefits Description
When fully implemented an RMTS program may provide the following benefits:
- Under a Risk‑Managed Technical Specifications program, a nuclear power plant may use its PRA to determine the safety impact of removing equipment in the plant Technical Specifications from service as the plant configuration changes over time.
- Extending completion times enables maintenance to continue beyond the times specified in the Technical Specifications. Once equipment is restored to service, the action statement in the Technical Specification LCO is exited.
- This PRA application therefore allows restoration and maintenance activities to be continued beyond the times that would normally be permitted, potentially avoiding plant shutdowns. It also allows for voluntary entry into a RICT to support planned maintenance. An added benefit is that the additional time can provide the opportunity to complete the maintenance in a more thorough manner, providing substantial operational flexibility and significant cost savings.
- For emergent equipment failure, RMTS/RICT can lower organizational stress as the option exists to enter a RICT and avoid either a plant shutdown or an expedited justification for enforcement discretion.
Costs and Schedule
Cost
Level 2 – Implementation cost is between $1 million and $5 million.
Schedule
One to three years.
Scope Context
Benefits and costs will depend on the scope of implementation and frequency of use. Benefit estimates above are based on industry experience and will likely occur in discrete events where shutdowns are avoided or a RICT is intentionally entered to execute particular maintenance evolutions at‑power. Cost estimates assume the plant has a reasonably mature PRA model, but may require some updates to meet the technical adequacy requirements for the program. Licensing costs are also included to gain approval for participation in the program.
Risks
No unique risks beyond standard project risks associated with implementing changes at nuclear power plants.
SWEEP Score
| Category | Level | Description |
|---|---|---|
| Cost | 2 | Implementation cost is between $1 million and $5 million. |
| Savings | 2 | Savings are greater than $1 million per year but less than $5 million per year (inclusive). |
| Payback | 0 | No identified payback period because either the savings were achieved by event avoidance, or the technology or process improvement is an enabler. |
| Technical Readiness | 3 | The program is ready for wide operational deployment. |
| Licensing Readiness | 1 | Regulatory changes are required for implementation. |
| Implementation Proficiency | 3 | The program can be implemented by all sites. |