Office for Nuclear Regulation

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Sellafield Mox Plant: acknowledgement of receipt of plant modification proposal Overarching Strategy Paper for a new rod line (NRL)

Nuclear Site Licence 31G Licence Instrument No. 805

Permission requested

Sellafield Ltd (SL) has asked for the Executives acknowledgement of receipt of an Overarching Summary Paper (OSP) for the NRL at the Sellafield Mox Plant (SMP). The OSP outlines SLs safety case strategy for the project and allows ONR to identify where it may be appropriate to apply holdpoints.


SL intends to remove some existing equipment and re-position some internal walls to make room for a new rod filling and inspection line (Line 3). The NRL design will be based on an existing facility operating in France that uses a similar process to SMP and has been proven to be capable of delivering the required throughputt.

Assessment and inspection work carried out by ONR in consideration of this request

No assessment work has been carried out so far in relation to this request. An inspection for familiarisation purposes has been completed.

Matters that arose from ONR's work and outcome of ONR's consideration

Initial discussions led the ONR inspectors to form a view that SL should remove redundant glove boxes from SMP Line 1 before the new equipment is installed. This is not currently part of SLs project.

ONR identified that a formal holdpoint would be appropriate, requiring ONR's agreement before active commissioning can start.


ONR will need to satisfy itself that SL has an adequate safety case before nuclear matter is introduced into the NRL.


ONR should acknowledge receipt of the OSP. The ONR project officer should also write informing SL that it should obtain ONR's formal agreement to proceed before active commissioning is allowed to commence.