Nuclear Engineering Services Limited

• Concept Design & Optioneering
• Final Design including Substantiation
• Detail Design.

A requirement was identified for a facility to be introduced for the remote handling/removal/replacement of critical submarine reactor components. A machine exists for the safe handling of the components however the interface between this machine and the submarine is required to be designed. NES were awarded the contract to design and substantiate the interface platform arrangement. The scope of work included for the production of a final design scheme drawing, associated calculations that satisfy the required criteria and constraints, and this is also demonstrated in the production of a Technical Substantiation Report. 

The physical arrangement consisted of three main areas: platform structure, alignment guides, and restraint system. The platform itself is a circular plate of approx. 2m diameter that is suitably profiled to engage with the existing interface structure. Within the platform are two access holes into which 2 m+ lengths of guide tube are inserted upon removal of the appropriate shield plugs. The bottom of each guide tube incorporates a telescopic tube that engages with the submarine component both in height and alignment. The restraint system (steady) is a fabricated assembly consisting of a top and bottom plate spaced 755 mm apart by introducing two rolled and seamed tubes of 1m internal diameter, with additional stiffening webs as appropriate. The profiles of these plates are such that the tubes align over the guide tubes below and extend beyond the platform in two areas. The nominal plate size of the steady is 1.5m x 3m with suitable features on the top face for coarse alignment and retention of the handling machine. In operation each individual sub-assembly was to be installed separately with a maximum weight constraint of 1.6 tonnes.

The design was produced using Pro-Engineer Wildfire with both the modelling and the final design drawing becoming deliverables. The design evolution involved the Client at all stages, including his attendance at an internal design review such that design iteration was minimised. Other deliverables included the substantiation calculations that were produced using MathCad 2000 and substantiated the design against high integrity lifting philosophy, structural assessment against normal operations and anti-toppling of the handling machine. Finally, the Technical Substantiation Report was produced in Word and successfully demonstrated that the design satisfied the intended specifications.