The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with Magnox Limited (MxL), the licensee for Bradwell site, against a strategy defined by the ONR Decommissioning Fuel and Waste (DFW) Programme. The inspection plan for Bradwell sets out a programme of regulatory inspections which includes a system based inspection (SBI) of the reactor primary circuit.
The purpose of this inspection was for ONR to consider the adequacy of implementation of the licensee’s safety case claims in respect of this system.
The two Magnox reactors at Bradwell site ceased generation in 2002 and the site was declared fuel free in 2006. The site is preparing to enter the quiescent phase of operations, known as care and maintenance, where structures, systems and components that remain will be maintained in a safe condition for an extended period to allow radioactivity to naturally decay. This is considered to lead to simplified and safer decommissioning at final site clearance.
The major components in each of the primary circuits are a reactor pressure vessel, six boilers, connecting ducts and associated valves. The system is important to nuclear safety because it contains a significant amount of the residual radioactive inventory on site, namely the reactor graphite core and activated metallic materials of construction.
The Bradwell nominated site inspector and I undertook a two day on-site SBI of the two Magnox reactors’ primary circuits at Bradwell. Our inspection comprised sampling safety case documents prior to the inspection, then on-site discussions with the licensee’s staff, a site inspection and reviews of system records and associated relevant documentation.
As part of our inspection we examined evidence for the adequate implementation of five licence conditions. These licence conditions (listed below) have been selected in view of their importance to nuclear safety and are defined within ONR’s formal process for SBI and we utilised ONR guidance specific to each licence condition during our inspection.
I judge that the safety system to be adequate.
From the evidence I examined during the inspection I consider that the licensee has adequately implemented its arrangements for compliance with Licence Conditions 10, 23, 24, 28 and 34. I consider that LC27 was not applicable to this system and so I have excluded it from the inspection scope.
I placed six actions on the licensee, which mostly related to what I consider will provide improvements to its management of the reactors’ primary circuits integrity. These were shared with and accepted by the licensee. I consider that none of the actions warrant me raising a regulatory issue on the ONR issues database.
In the areas I sampled during the intervention I considered that the licensee’s implementation of its arrangements for compliance with the Licence Conditions inspected were adequate.