# LC15 -- Periodic Review

## Condition

Licence Condition 15 requires the licensee to carry out a **review of the safety case at regular intervals**, comparing the current safety case against modern standards to identify any reasonably practicable improvements that could enhance safety.

## Key Requirements

- Safety cases must be reviewed periodically (typically every 10 years, though ONR may specify other intervals)
- Reviews must benchmark the existing safety case against current standards, good practice and relevant operating experience
- Where the review identifies that improvements are reasonably practicable, the licensee must implement them
- The review must consider changes in the facility condition, regulatory expectations and state of knowledge
- Findings and any resulting action plans must be documented

## Relevance to Decommissioning

Decommissioning programmes frequently span **decades** -- some UK sites have projected end dates extending 100 years or more beyond final shutdown. Over such timescales:

- **Standards evolve.** Dose limits, waste classification criteria, environmental protection requirements and engineering codes may all change. Periodic review ensures the decommissioning safety case remains aligned with current expectations.
- **Facility condition changes.** Ageing of structures, corrosion, and changes in waste inventories mean that the assumptions underpinning the original safety case may become invalid.
- **Knowledge improves.** Characterisation data accumulated during early decommissioning phases may reveal hazards not previously recognised.
- **Regulatory expectations shift.** ONR and the environment agencies may issue revised guidance or Technical Assessment Guides.

Periodic review under LC15 provides the formal mechanism to capture these changes and ensure the safety case for ongoing decommissioning remains adequate.

## Docket Cross-References

- Chapter 6, Section 6.5 -- Key Nuclear Site Licence Conditions

## See Also

- [LC14](LC14.md) -- Safety Documentation (the safety case being reviewed)
- [LC35](LC35.md) -- Decommissioning (decommissioning arrangements subject to review)