Thursday, 12 May 2011

Nuc Subs Disposal

At the beginning of December 2010 the Ministry of Defence (MoD) released >> new information relating to its Submarine Dismantling Project << (SDP). The Project has the long term aim of dismantling 27 of the Royal Navy's nuclear powered submarines – from Dreadnought to Vengeance – and is currently considering how and where to do this. The latest releases from the MoD for the project include an update of the Strategic Environmental Assessment (SEA) Scoping Report and a Site Criteria and Screening Paper 
The latest documentation sheds further light on where the MoD hopes the dismantling process will take place; where the intermediate level radioactive waste (ILW) generated by the process might be stored; and the methods which could be used to dismantle the submarines.

Where

MoD states that three high level options are available when deciding where submarine dismantling should take place. The vessels could be dismantled at a new facility built on a greenfield site, or at a facility on a previously developed brownfield site, or at an existing nuclear site. According to the MoD these sites must be in the UK for defence and security reasons.

By screening against various criteria, MoD has concluded that there are significant cost, schedule and risk implications in choosing a greenfield or brownfield site as the location for dismantling. Although these options will not be discounted from further consideration and will be included in the SEA as generic options, the screening report comes to the conclusion that:
“use of an existing nuclear licensed or authorised site has significant cost and performance advantages over the development of new facilities, be they on greenfield or brownfield sites.” 

The screening report goes on to assess 25 named sites against a set of specific criteria. All but four of these sites fail to meet primary screening criteria (the need to be located on the coast and have sufficient physical capacity to undertake dismantling work) and are thus not considered suitable for undertaking SDP activities.

Two sites are assessed as failing to meet secondary criteria: HMNB (Clyde) at Faslane (where submarine dismantling would be incompatible with site operations and operational safety) and Barrow-in-Furness (where there is considered to be inadequate port access and incompatibility with site operations).

This leaves two sites that meet all of the initial screening criteria: Devonport Royal Dockyard, Plymouth, and Rosyth Royal Dockyard, Fife.  These two sites have been proposed as potential locations for submarine dismantling.

Storage 

MoD has yet to identify a disposal route on the UK for the ILW which will be produced by the dismantling process. The two MoD indicate that the volumes of waste that the project will produce are unlikely to justify the building of a new storage facility on value for money grounds.  A better option would be to share an existing store - most likely owned by the Nuclear Decommissioning Authority (NDA)

The NDA has challenged the well established practice within the civil sector of storing ILW where it is produced, and MoD seems keen to take a similar approach to waste storage. This raises the possibility that the interim storage site for waste from the SDP could be located away from the dismantling site, requiring the transportation of ILW by rail or road.

The waste produced by the dismantling is eventually intended to be stored at the planned national Geological Disposal Facility (GDF) for radioactive waste, which is not expected to be available until 2040 at the earliest. Storage facilities for the SDP waste are seen as providing a interim solution to the problem of what to do with the waste until the GDF comes into operation.

Method

Three technical options for the submarine dismantling process are considered in the SEA scoping report. These are cutting out and storing the reactor compartment intact; cutting out the reactor compartment and removing the reactor pressure vessel, and then dismantling the remaining reactor compartment components; or fully dismantling the reactor compartment.

The method chosen to dismantle the submarine has implications for the design of the storage facility which will be needed to keep the waste secure. The first two options would mean that full and complete dismantling of submarines would be delayed until the GDF eventually becomes operational. The MoD state that the technical options for the dismantling process are currently under review.  

At this stage in the project government agencies are being invited to give their views on MoD's proposals and their potential environmental impacts.  The general public will be consulted on the proposals later this summer.  NIS is concerned that, by formulating proposals before the public has been consulted, MoD is running the risk that it will be accused of having made key decisions on how and where redundant submarines will be dismantled regardless of public opinion.

No comments:

Post a Comment