Published Papers

Analysis of a Screw Retaining Ring Closure Mechanism for a Type B(U)F Transport Package

Yiassoumis M, Britton R, Dingwall J, Zeng J & Longman G.  RAMTrans 2024.

A large cavity SAFKEG® has been developed by Croft Associates Ltd for the shipment of solid radioactive materials. Engineering challenges in ensuring O-ring compression, and hence leak tightness, of a screw retaining ring have been overcome as part of the design’s substantiation.

Validation of Impact Performance for the Croft SAFKEG® through Analysis and Testing

Britton R, Dingwall J, Jeenjitkaew C, Tait T & Yiassoumis M.  RAMTrans 2024.

A large cavity SAFKEG®, Design N° 4087A (Figure 2), has been developed by Croft Associates Ltd. for the shipment of solid radioactive materials. It has been designed to satisfy all safety requirements of a Type B(U) transport package, as specified within the IAEA SSR-6 [1] Transport Regulations.

Design and Analysis of a Large Cavity Type B(U)F SAFKEG®

Dingwall J, Britton R, Johnson M B, Tait T & Yiassoumis M.  PATRAM 2022.

Croft Associates Ltd has recently completed the design and development of a new, large cavity (Ø400 mm x 700mm), Type B(U)F transport package. The design is typical of proven transport containers; however, several novel features are incorporated to provide enhanced performance under Normal and Accident Conditions of Transport (NCT & ACT). In particular, a large screw ring closure mechanism has been developed to provide the structural and containment performance of the Containment Vessel (CV) closure.

Helium Leakage Testing of SAFSHIELD® 2773A with Silicone O-rings

McConaghy A, Dingwall I, Johnson M B & Shaw B.  PATRAM 2022.

The Croft Associates SAFSHIELD® 2773A is designed as a Type B(U) Package to the IAEA Regulations for the Safe Transport of Radioactive Materials [1].

Design Modifications to the HS Safkeg 3977A Package to Allow Transportation of Molybdenum 99 Contents

Tait T, Johnson M B, & Dingwall I.  PATRAM 2019.

The Croft Associates Safkeg-HS 3977A package, hereafter referred to as “HS”, is a general-purpose container for the transport of non-fissile nuclides and limited quantities of fissile nuclides as specified under United States Nuclear Regulatory Commission (NRC) general licences, for non-exclusive and exclusive use. The package has been designed for transportation of a variety of solid, liquid or gaseous contents by road, rail, sea and air. The package was originally designed in 2008 and tested in 2010 to provide substantiation for the initial license application. The HS consists of a single resealable containment vessel, (design No. 3978) fabricated from stainless steel with encased depleted uranium shielding, carried within insulating cork packing in an outer stainless-steel keg, (design no. 3977).

Design Modifications to the HS Safkeg 3977A Package to Allow Transportation of Molybdenum 99 Contents (Supporting Poster)

Tait T, Johnson M B, & Dingwall I.  PATRAM 2019.

Conceptual Design of Robust Shielded Box Transport Container Type B(U) Package Design

Johnson M B, Eccles P, Cowan P, Izatt C & Tso C.  PATRAM 2019.

In recent years, a number of the organisations responsible for managing the clean-up of the UK’s nuclear sites have adopted Robust Shielded Boxes (RSBs) for the packaging of higher activity waste (HAW). RSBs are thick-walled, ductile cast iron containers with a gross mass of up to 35 tonnes. They do not require remote handling and can use unshielded, personnel-accessible stores.

Design of a Transport Package to withstand Accident Conditions of Transport through the provision of International Paints Chartek 7 Intumescent Coating

Ballard V, Dillistone M, Fisher D, Tait T & Wickham D. RAMTRANS 2018.

In January 2017, Croft Associates were approached by an existing client with a very challenging project whereby they desired to accelerate the shipment of wasteforms between two UK licensed sites. A particularly challenging aspect of the project was the need for thermal management of the wasteform to prevent adverse degradation of package contents during transport and subsequent on-site storage.

Life Cycle Costing in Radioactive Waste Packaging: Reducing Costs Whilst Accelerating Clean-Up

Beattie C, Janicki M & Johnson M.  WM2016, 6-10 March 2016, Phoenix, Arizona, USA.

In recognition of the high up-front costs and potentially long timescales to alternative approaches to help accelerate hazard reduction and reduce such costs are being deployed. When considering such the cost of alternative approaches to waste packaging strategies, it is important that the complete waste life cycle is taken into account.

Innovative waste packaging and associated venting/hydrogen management

Chadwick C, Fisher D & Izatt C.  WM2016, 6-10 March 2016, Phoenix, Arizona, USA.

The original strategy for managing intermediate level waste (ILW) was developed in the 1980s by the UK Nuclear Industry Radioactive Waste Executive (NIREX), which is now the Radioactive Waste Management Limited (RWM), a wholly owned subsidiary of the Nuclear Decommissioning Authority (NDA). The strategy involved retrieving ILW, sorting and encapsulating it in cement based grout within thin walled stainless steel containers. The containers would then be transferred to a large purpose-built shielded ILW store on site, where they would be stored until the planned final deep geological disposal facility becomes available.

Designing packages for storage, transport and disposal of Intermediate Level Waste in the UK

Tait T & Vaughan R A.  RAMTRANS 2015.

Designers of packages for Intermediate level waste (ILW), to be supplied for use within the United Kingdom (UK), recognise the need to meet the separate regulatory requirements pertaining to on site storage, transportation and final disposal.

Evolution of packages for storage, transport and disposal of Intermediate Level Waste in the UK

Beattie C, Janicki M C & Vaughan R A.  PATRAM 2013, 18-23 August 2013, San Francisco, USA.

The paper describes the evolution of designs of containers for the long term storage, transport and disposal of ILW in the UK destined for the UK Geological Disposal Facility (GDF).

Safkeg-LS – Development and licensing of a small 6m replacement package

Marshall S & Vaughan R A.  PATRAM 2013, 18-23 August 2013, San Francisco, USA.

In 2007 the University of Missouri Research Reactor (MURR) contracted with Croft to develop two Type B packages in accordance with 10CFR71 [1]. These packages were required to serve the medical, research and industrial isotope market and to replace the 6M and 20 WC DOT Spec packages in use by MURR at that time

An overview of the development of IP-2 ISO freight containers

Hows R P & Vaughan R A.  PATRAM 2010, 3-8 October 2010, London, UK.

This paper records the establishment within the UK of the use of IP-2 packages for Low Level Waste (LLW) based on the design features and established ISO standards for ISO Freight Containers for which Croft was the prime mover.

IP-2 package containing plutonium contaminated slag pots

Hows R P, Marshall S H & Vaughan R A.  RAMTRANS 2009.

Croft Associates were approached by PC Richardson to carry out the licensing of an IP2 package containing Plutonium contaminated slag pots. This project provided several unique challenges for all those involved.

Helicopter drop test of Type B packages in the UK

Farrington L M & Vaughan R A.  PATRAM 2007, 21-26 October 2007, Miami, USA.

Testing was carried out in the UK in 1986 to demonstrate the ability of two Type B packages designed to pass the 9m drop test criteria in the IAEA SS6 1985 transport regulations, to provide a high degree of containment even under an extended drop test as might result from a package being released from an aircraft in a mid air incident at high altitude.

Thermal modelling of the Safshield 2999A package

Fry C & Vaughan R A.  PATRAM 2004, 20-24 September 2004, Berlin, Germany.

The SAFSHIELD 2999A is a general purpose container, designed by Croft Associates, for transporting small volumes of radioactive materials that require heavy shielding. It is intended for carrying materials as diverse as source capsules and accelerator targets.

Freight containers as IP-2 packagings

Hows R P & Janicki M C.  RAMTRANS 1994.

A range of standard freight containers has been designed and manufactured to meet the needs of users and the requirements of the 1985 Edition of the IAEA Regulations for the Safe Transport of Radioactive Material for Industrial Packages.  The development of freight containers as IP-2 Packagings (Industrial Package Type 2) is described.