NUCLEAR TRANSPORTS IN BRITAIN:

written By

This guide is produced as a quick reference to identifying the make-up of the rail transports which convey spent nuclear fuel from UK’s nuclear power stations to Sellafield for reprocessing. Though largely a UK guide, a section on overseas fuel transports is included. Also provided are document references for sources of further information.

The guide provides some detail not only of the rail freight companies which haul the nuclear flasks, and the routes and timings of the train movements, but also the different railway rolling stock which go to forming the transports and, most importantly, the make-up of the fuel rods and the flasks which contain them. Whilst observers may be familiar with the cream coloured nuclear transport ‘cabins’ hauled by rail through our towns, cities and countryside, they may be less familiar with the nuclear flasks and their hazardous contents which are concealed from public gaze by the innocent-looking cabins.

Brief information on the fabrication of nuclear fuel, its use in reactors and its final reprocessing at Sellafield provides a background to the nuclear fuel cycle which results in the rail transports that provide the life-blood for BNFL’s reprocessing operations. The guide also contains an outline of the radiological hazards of such transports, the safety tests to which the flasks are subjected, the methods of flask documentation and the regulations which govern their movement.

The Authors

CORE (Cumbrians Opposed to a Radioactive Environment) traces its 1980 origins directly back to the issues of spent fuel transports – specifically Japanese fuel being shipped through the port of Barrow-in-Furness. With two full-time campaigners CORE’s remit has widened over the years to cover all BNFL activities. A major part of today’s campaign is aimed at the two reprocessing plants at Sellafield, their radioactive discharges and resultant environmental contamination, the production of nuclear wastes, the health detriment and risk of major accident.

CORE is uniquely placed to monitor the wide range of transports which converge on Sellafield from near and far. Extensive surveillance over the years has provided the information contained in this guide. A more comprehensive publication is currently under production.

CONTENTS

1. Conventional Nuclear Fuel for Reactors.

Nuclear fuel is fabricated from natural uranium imported from overseas by BNFL who operate a uranium enrichment plant at Capenhurst in Cheshire and a fuel fabrication plant at Springfields near Preston. Natural uranium is composed largely of two elements – Uranium 235 (U235) and Uranium 238 (U238). Whilst this is suitable for making fuel for Britain’s ageing Magnox reactors, it has to be enriched before it can made into fuel for the newer Advanced Gas-Cooled Reactors (AGR). The enrichment process entails removing, via a series of centrifuges, some of the U-238 which is less fissionable, thereby increasing the proportion of the more fissionable U-235 and thus enriching it. AGR fuel will normally be enriched to between 3% and 5%.

The amount of fuel in a reactor depends on the reactor type, and normally the fuel will stay in the reactor for 3-4 years. During this period, fissioning of the uranium takes place creating other radioactive elements as it does so, including plutonium. Whilst the industry claims that the plutonium and the uranium which has remained '‘unburned’ are re-useable, the remaining fission products are categorised and treated as nuclear waste.

Once the fuel has served its time in the reactor it has become ‘spent’ and is removed from the reactor and pond-stored at the power station for a number of months or even several years to allow cooling and the decay of some short-lived radioactivity. Following this period of wet-storage the fuel is then ready to be transported to Sellafield. This is where the separation of Plutonium and Uranium first takes place in anoperation known as reprocessing.

Spent fuel transports from the UK’s nuclear power stations form the majority of movements to Sellafield and are undertaken almost wholly by use of the railway network on a regular weekly basis. BNFL operates two Magnox power stations, Calder Hall at Sellafield and Chapelcross in Scotland, each with four reactors. Along with all UK Magnox stations, their spent fuel is reprocessed at Sellafield in building B205. Spent fuel from Chapelcross is the only UK fuel to be transported to the Sellafield site entirely by road.

Other Magnox power stations currently operating within the UK are Bradwell, Dungeness A, Hinkley Point A, Oldbury, Sizewell A and Wylfa. Those at Hunterston A, Berkeley and Trawfynydd are closed, the latter two being decommissioned. All Magnox stations are now operated by BNFL Magnox and remain in the public sector following privatisation which saw AGR stations transferred firstly into the hands of Nuclear Electric and Scottish Nuclear, and then to British Energy who also operate UK’s only Pressurised Water Reactor (PWR) at Sizewell B. AGR power stations are Dungeness B, Hartlepool, Heysham 1, Heysham 2, Hinkley Point B, Hunterston and Torness, and their spent fuel is contracted to be reprocessed at Sellafield’s THORP plant.

Periodically transports of spent submarine reactor fuel, usually one flask at a time, arrive at Sellafield on Ministry of Defence flatroll wagons. The fuel is stored on site. Transports of overseas spent fuel arrives by train from Barrow Docks.

After 40 years of nuclear power the realities of managing the spent fuel from power station reactors have to be faced. There are 2 basic options for the industry, the first being to store it in above ground stores where it can be managed, monitored and retrieved. The second is to send it to Sellafield for reprocessing .

The reprocessing of spent nuclear fuel is carried out at British Nuclear Fuel’s Sellafield site in West Cumbria. Sellafield has two reprocessing plants, the Thermal Oxide Reprocessing Plant (THORP) which deals with the UK’s AGR spent fuel, and the B205 plant which reprocesses the fuel from the older Magnox power stations.

THORP is also able to reprocess spent fuel from Pressurised Water Reactors (PWR) and Boiling Water Reactors (BWR). Currently fuel from these reactor types is imported from abroad with overseas customers accounting for around two-thirds of THORP’s orderbook. The largest overseas customer is Japan, followed by Germany, Switzerland, Italy, Spain, Sweden and the Netherlands. The UK’s only PWR station is Sizewell B which intends to wet store its spent fuel for 20 years.

On arrival from UK’s AGR and Magnox power stations, spent fuel is unloaded from its transport flasks underwater and placed in storage ponds adjacent to the two reprocessing plants. After a period for cooling, the fuel is transferred to the first stage of the reprocessing plant where it is cut up into small lengths and dissolved in boiling nitric acid. The highly radioactive dissolved liquour is transferred to the chemical separation area of the plant where, as the name suggests, a series of chemical processes separates the dissolved fuel into its three constituant parts – plutonium, uranium and High-Level Waste (HLW)

The end-product of plutonium is stored at Sellafield with over 50 tonnes now stockpiled. The uranium is stored at one of several BNFL sites in the north west. Of around 40,000 tonnes of uranium ‘recovered’ by reprocessing only around 5% has actually been re-used as new fuel in reactors The HLW is eventually ‘vitrified’ into blocks by mixing it with a glass matrix and then stored at Sellafield for eventual disposal. The remaining nuclear wastes which arise from the operation, in the form of the chopped metal fuel casings and operational sludges are encapsulated in cement and stored in drums at Sellafield for eventual disposal. The low level wastes are pumped into the Irish Sea in liquid form, with the gas wastes being discharged to the air, and the solids taken to BNFL’s licenced waste dump at Drigg just south of Sellafield.

Nuclear trains rumbling across UK are a fairly familiar sight these days, but the cream coloured transport ‘cabins’ hauled in the twighlight hours through towns, cities and countryside conceal the real nuclear cargo - the spent fuel flasks. Because the flasks are generally loaded into their transport cabins at the reactor site, there is seldom any chance to see the flasks themselves. The exception to this is the imported foreign fuel which, having been unloaded at Barrow docks, is transported by rail to Sellafield unprotected by any cabin.

The transport cabins, padlocked for the journey but which open on a ratchet system, contain/conceal a single flask – either for AGR or Magnox fuel. Both flasks look alike, being cuboid in shape, white in colour and having roughly similar outer dimensions. The flask is constructed as a single-piece forged carbon steel container with a separate lid which is bolted on. Heavy fins on the outer surface are for cooling purposes, increasing the effective heat transfer area of the flask.

Magnox flasks are usually identified with a two-digit number prefixed with the letter E – for example E59. AGR flasks are either type MkI or MkII and are similarly identified with a two-digit number prefixed with an E and suffixed with the letter A – for example E41A.

A visual difference between the Magnox flask and its AGR counterpart is that the latter will usually have a prominent shock absorber fitted over the flask lid during transport.. Apart from that the essential difference between the flasks lies in the internal structural design whereby the higher gamma and neutron radiation from AGR fuel requires increased lead shielding.

Flasks for transporting Magnox and AGR fuel are almost identical. The diagram below shows a typical transport flask, in this case for Magnox fuel, and shows the fuel rods packed horizontally inside the flask in a skip.

Standard Magnox fuel comes in the form of a rod measuring approximately 1 metre long, 5 centimetres in diameter and weighing between 10-12 kilogrammes. The fuel rod is contained in a casing fabricated from magnesium alloy, hence the name Magnox. Prior to dispatch to Sellafield, and with the ‘fins’ mechanically removed, the rods are transferred from the power station cooling pond to an open-top fuel skip which is then fitted into the transport flask. The skip forms a snug fit within the flask which is then filled with water which serves as coolant for and shielding against the highly radioactive fuel.

Magnox Rod (pic3)

Prior to dispatch the steel lid is secured with 16 high-tensile bolts (each of 5cm diameter) and the outer surfaces are checked for contamination and decontaminated if necessary. A radiological survey of the flask is undertaken to ensure that the regulatory limits for transportation are not exceeded, though as a later section of this guide shows, the decontamination programme leaves much to be desired. When fully loaded with 200 Magnox rods each transport flask will weigh around 50 tonnes, with the fuel itself weighing around 2 to 2.5 tonnes.

Unlike Magnox fuel, AGR fuel is not in ‘rod’ form but consists of fuel pellets packed inside a fuel pin. The pins are themselves then contained in a moderator (graphite) sleeve.

Each sleeve contains 36 fuel pins, and 20 sleeves are placed in a skip which is then fitted inside the flask. In total, a flask will therefore hold 720 fuel pins.The sleeve is around 1 metre long and weighs around 43 kilogrammes. Fully loaded, an AGR flask will weigh around 60 tons In all other respects AGR fuel is prepared and loaded into the transport flask in a similar way to Magnox fuel.

AGR Fuel (pic4)

AGR Flask with skip to hold assemblies upright (pic5)

With the spent fuel placed in the transport flasks and ready to be dispatched to Sellafield, the regulations governing the transport then come into play. There are a bewildering range of rules and regulations which are outlined briefly below.

The principal Regulators are the International Atomic Energy Agency (IAEA) who, in 1959 were charged by the UN Economic and Social Council with drafting recommendations on the transport of radioactive substances. In 1961 the IAEA published the IAEA Regulations for the Safe Transport of Radioactive Materials, with Safety Series 6 becoming established as the regulatory bible for all such transports. These regulations have been adopted by the United Nations and are incorporated into the regulatory texts of organisations concerned with international transports and into the national regulations of numerous countries. They are periodically revised to take account of technical advances, operational experience, radiation exposure to the public and transport workers.

In the UK, the ultimate responsibility for the safety of radioactive materials in transit lies with the Scretary of State for the Environment,Transport and Regions who appoints a Government Materials Transport Radiological Advisor who heads the Radioactive Materials Transport Division, Department of Transport which is designated as the ‘Competent Authority’ in the UK. The Competent Authority is responsible, amongst other things, for ensuring compliance with the regulations, the inspection of transport operations and the auditing of radioactive material transporters – design, manufacture and operation.

For Rail transports in the UK, the principal regulations are contained in:

For Road transports, where spent fuel is transported from the power station to the nearest railhead, there are a number of regulations, the principle regulation being:

International regulations governing transports by road, rail and air in Europe include:

Every ‘package’ containing radioactive material for transportation is subjected to a range of tests laid down by the IAEA. The aim of the tests is to ensure that the necessary safeguards are built into the design of the flask, and the conditions under which it is transported, so that it will withstand severe accident conditions without presenting a significant radiological hazard. Flasks are subjected to four main tests:

The Impact (Drop) Test involves the free-fall of a flask from a height of 9 metres onto an unyielding target. The test covers not only the accidental free-fall of the flask, but also the force impact of a collision whilst the flask transport is in motion.

The Penetration (Punch) Test involves the free-fall of a flask from 1 metre onto a 15cm diameter bar. The bar is based on an equivalent section of rail section.

In the The Fire Test a flask is engulfed in a uniform flame temperature of 800 degrees C for 30 minutes – and then allowed to stand for 3 hours before any firefighting measures are applied.

The Water Immersion Test involves firstly the immersion of a flask in water to a depth of 15 metres for 8 hours and secondly, the resistence to a pressure equivalent to immersion at a depth of 200 metres for 1 hour.

It is easy to see why extensive criticism continues to be levelled at this range of tests, calling into question the effectiveness of tests on flasks containing such toxic and radioactive material. Flask tests are carried out in a particular sequence which raises doubts as to whether the flask and its contents would survive adequately if the test sequence was changed. Added to the limitations of the tests themselves are the concerns that they are sometimes partly undertaken via computer modelling, or on scale models of flasks. This raises the question whether these forms of testing are indeed sufficient to guarantee radiological containment under the most severe conditions It is useful to list some of the test shortcomings:

For the Drop Test, a 9 metre drop is clearly inadequate when transport flasks routinely cross railway bridges over 40 metres high. The free-fall speed from 9 metres equals an impact velocity of around 30mph. Spent fuel transports travel regularly at speeds of up to 45mph, and in the event of a collision with another train the closing speeds of the two trains will be even greater. In similar vein, the Penetration Test is now interpreted to cover an attack on the flask’s outer surface by a penetrating missile. Given the advancement in modern armour-piercing shells and the explosive and shock potential, the test is insufficient.

Examples of transport fires show up further test weaknesses. The 1984 railway petrol tanker fire in Summit Tunnel near Manchester, burned for 4 days reaching temperatures of 8000 C. The average ship fire is reported by Lloyds Insurers to burn well in excess of 800C and to last significantly longer than 30 minutes. At sea, flasks will be shipped over areas of the ocean well in excess of 200 metres, and the ability to raise a flask submerged at 200 metres or more, within one hour, remains highly questionable.

The limitations of these tests , whether on UK or European flasks, was highlighted in 1998 when it was revealed that a flask type NTL11 regularly in use between Germany and Sellafield had failed three successive drop tests (from 9m) early in the year. The first test was undertaken by BNFL at the Winfrith nuclear installation in Dorset on 13^th February 1998 – using a quarter scale model. As a result of the 9m drop, the bolts which secured the flask-lid sheared. BNFL repeated the test at Winfrith on the 5^th and 6^th March

and on both occasions the bolts broke and the lid shifted.

Concerns over these significant test failures were heightened when a German State Energy Minister announced that it was at least 15 years since the NTL11 flasks had been tested, yet observations at Barrow showed that around 20 of these flasks had passed through Barrow docks during 1997, the last on 2^nd February 1998 – eleven days before BNFL’s first drop test.

An NTL11 Flask arriving at Barrow on 2nd February 1998 (pic7)

Perhaps the best known flask test was that carried out by the CEGB at Old Dalby in the mid 1980’s when a Magnox flask, placed on a railway line, was ploughed into by a 140 ton diesel locomotive travelling at 100 mph. The flask remained reasonably intact, an outcome still used today by the nuclear industry as evidence that the flasks are sufficiently robust to withstand the worst accident. In retrospect, and deemed to be little more than a publicity stunt, the test had many shortcomings. Firstly the flask was shunted along the ground for a considerable distance before coming to rest – with badly buckled cooling fins. The outcome may well have been different had the flask been pushed into an unyielding object such as a steel or concrete railway bridge or tunnel abutment. Secondly, no sequential fire test was undertaken, and thirdly no test was undertaken to demonstrate the impact effect on the spent fuel rods that would have been inside the flask (substituted by 2 tons of steel bars). Magnox fuel rods are known to be fragile and the fuel cladding relatively brittle. Had the cladding failed, the highly radioactive and deadly fission products contained in the fuel would have escaped into the flask’s cooling water and, if the flask had been ruptured or the lid displaced, released into the atmosphere.

11. Flask Classification, Labels and Documents.

Initial classification divides dangerous materials into numbered categories which indicate the principal hazard. Radioactive materials are Class 7. Packages containing radioactive materials fall into 4 main categories; Excepted Packages, Industrial Packages, Type A Packages and Type B Packages. Spent fuel flasks are classified as Type B Packages.

The design of Type B Packages must be approved by the Competent Authority of the country in which the package was designed. A sub-classification for Type B Packages was introduced in 1973. Until then, each country through which the flask was transported had to issue its own approval, known as Multilateral approval (M). This led to complications and delays to transports and the concept of Unilateral (U) Approval was introduced. A Type B Package therefore became either Type B(M) or Type B(U), the latter indicating the designer country’s unilateral approval in respect of the Type B criteria, and hence its validity in any other country.

For transport of spent fuel by rail a Dangerous Goods label must be clearly displayed on each side of the wagon carrying the flask, indicating the principal hazard present and the Emergency Code which identifies the product and the source from which specialist advice may be obtained. The buff coloured label with red graphics and text is secured to the side of the rail wagon itself by means of a sturdy spring clip. Behind the label other documents relating to the flask and its contents are secured in a waterproof envelope.

The label shows the flasks destination code 10202 (Sellafield) and The Com Code 095 which identifies a full flask. The railway wagon number is shown in the lower right corner. The handwritten flask number is E61A, the A identifying AGR fuel.

When empty flasks are returned from Sellafield to the power stations, the Dangerous Goods label is overstamped with "Discharged Flask" and the new destination code displayed – Hartlepool nuclear power station for instance carries the number 14252 and Hinkley power station 81921. A small green label sometimes seen on the side of the flask wagon indicates that the wagon is being returned for repair.

As well as the Dangerous Goods label, other labels fixed to the flasks and cabins provide information on the radiation dose from the ‘package’. For Class 7 (Radioactive) materials the hazards identification labels are diamond-shaped. Based on radiation protection controls, four different labels (7A to 7D) are used depending on the radiation dose from the ‘package’. Label 7C Category III Yellow (the top half of the diamond label is yellow) is generally seen on spent fuel transports and whose definition by Department of Transport Regulations includes:

Labels 7B and 7C both show a rectangular box in a lower section of the label in which is contained a Transport Index (TI) value. This TI value is used to decide how many packages can go into a conveyance and how far they should be stored away from occupied areas.

The maximum dose rates (a measurement of how much damage the radiation is expected to cause to the human body) for label 7B are shown as 0.5mSv (at flask surface) and 0.01mSv/hr (at 1 metre distance), and for 7C as 2.0mSv/hr and 0.1mSv/hr. Within these limits, the TI value is calculated by multiplying the radiation dose figure (1 metre from the flask surface) by 100. A radiation dose of 0.1mSv/hr at one metre from the surface of the flask would be allocated a TI value of 10.

As a general indication, the National Radiological Protection Board (NRPB) show a TI value for UK spent fuel flasks (Magnox and AGR) as being ‘low’ – in the order of 0.4 to 0.9 with some AGR flasks being over 1. Different flasks carrying different fuel types can have TI values of up to 10, whilst those containing higher burn-up fuels reaching a TI value of 50.

Clearly then, a glimpse of the TI value written on the label will give a useful ready-reckoning of the radiation risks from the flask’s contents

A set of travel documents has to accompany each transported flask. They are fixed on the transport wagon itself usually in an envelope behind the Dangerous Goods label. The documents include a Consignment Certificate, a Combined Consignment Note and Declaration Form and a Packing Sheet.

Between them the forms provide details of the sender power station, the recipient, flask number, package type, weight, TI value etc. The Packing Sheet gives information on the number of fuel rods or fuel elements contained in the flask and the amounts and types of radioactive material in the fuel.

12. Radiation Doses from Transport Flasks.

As the governing body on the transport of radioactive materials, the IAEA require periodic assessments of radiation doses to railway workers and members of the public to be undertaken. Such assessments are made in the UK by the NRPB. Legislation regulating contamination on flasks transported by rail is the Packaging, Labelling and Carriage of Radioactive Materials by Rail Regulations 1996 (RAMRail) made under the Health & Safety at Work Act 1974, implementing European Council Directive EC/96/49.

Radiation from the flasks comes from two principal sources – the flask contents and the flask itself. The spent fuel contents emit neutron and gamma radiation at varying levels

depending on the type of fuel in the flask (Magnox or AGR). Exposure to the neutron and gamma radiation to a member of the public will depend on the type of flask used, the distance between the flask and the individual, the length of exposure at that distance and the number of times such exposure occurs.

The NRPB assessments, generally published in the form of memoranda or reports, fall under two main headings. 1] Memorandum – Radiological Consequences resulting from Accidents and Incidents Involving the Transport of Radioactive Materials in the UK, and 2] Radiation Exposure from the Normal Transport of Radioactive Materials within the United Kingdom. They are available from the NRPB Publications Department.

A 1995 NRPB report which covered all flask types in use on the UK rail network concluded that, amongst other findings a) AGR flasks emit much higher radiation dose rates than Magnox fuel, b) that neutron and gamma radiation was emitted in a 90 degree cone rather than a plane beam, c) that radiation doses from a static flask to members of the public positioned at the boundary of a marshalling yard were around 5 microSieverts per year, and less from a transient flask and d) doses to railway workers in marshalling yards were less than 100 microSiverts.

As a rough guide, the radiation dose from one chest x-ray is equivalent to 50 microSieverts.

The second exposure pathway comes from the surface of the flask itself. Radiation from flask surfaces results either from the flask’s immersion in the power station (or reprocessing plant) cooling ponds whilst loading the fuel, with subsequent failure to properly decontaminate the flask, or from residual radiation which becomes trapped and adheres to the under-surface of the flask’s paint. Under various transport conditions this radiation is transferred to the outer surface of the flask from where it is emitted. This is known as flask ‘sweating’, a well documented problem for many years.

Early in 1998 all transports of spent fuel from European power stations to Sellafield and to the French La Hague reprocessing plant were halted when significant radiation levels were found on a number of flasks in transit – and on the railway wagons carrying the flasks. The safe limit imposed by the IAEA for flask surface contamination is set at 4 Bequerels (Bq) per square centimetre.

This is known as the Derived Working Level (DWL). The discovery of levels of 13,400 Bq/sq cm on German flasks being transported to France in 1997 led to an immediate ban being imposed. These illegal levels, known to have existed for many years by the nuclear industry but kept hidden from governments and the public, have resulted from a combination of flask sweating and poor decontamination practices.

Initially denying that the UK industry was in any way involved in the transport of flasks with illegal surafce levels, BNFL finally admitted that European flasks had been found to be contaminated up to 15 times the permitted level at Barrow docks, and 25 times permitted levels at Dunkirk. For UK flasks a parliamentary answer revealed that between 1995 and 1998 11 flasks had arrived at Sellafield from UK power stations in excess of permitted levels and that 42 empty flasks being returned to UK power stations from Sellafield were recorded as being above permitted levels.

Hazard Labels attached to the flask transport cabin.
The higher the TI value, the higher the radiation dose.

The transport of spent fuel to Sellafield, and the return of empty flasks to the power stations, has been undertaken in the past by a succession of rail freight carriers. Privatisation of the freight business in recent years has brought about some rapid changes and the old brand-name freight companies have disappeared, leaving the contracts to haul spent fuel to be fought over by emerging private companies.

Looking to expand and diversify their business and spotting a niche in the market, BNFL formed its own rail freight company DRS. Registered with Companies House as number 03020822, the returns filed in February 1996 showed BNFL’s Legal Director as being Company Secretary and included among the five Company Directors were the Director of Magnox reprocessing, the Assistant Director of Production at THORP, and two Directors of BNFL’s shipping company PNTL.

Effectively ending Trans Rail’s monopoly – and subsequently that of the England, Wales and Scotland Railway company (EWS – with their distinctive maroon and yellow locomotives), BNFL’s wholly-owned subsidiary company DRS purchased an initial batch of ten Class 20 locos. Five of these were refurbished by Brush Traction at Loughborough during 1995/1996 and painted in the new company livery (Dark blue with light blue roof and yellow ‘nose’), the remainder being kept in store or used for spare parts. Since then a further five Class 20’s have been brought along with six of the heavier Class 37’s. Most of these latter puchases are now also refurbished.

The 21 DRS locomotives form a sizeable fleet, and BNFL’s intentions were clearly to take over all the spent fuel flask haulage business in the UK. They will also have had an eye on the future transport of nuclear waste destined for the UK’s planned underground nuclear dump.

DRS Class 20. They normally travel in pairs (pic8)

By 1998 however, with safety licensing and contract problems, DRS had little nuclear work to do and it was not an uncommon sight to see a majority of the fleet dormant in Sellafield’s sidings. The early years of DRS work has been largely confined to hauling foreign flasks from Barrow docks to Sellafield, collecting nitric acid on a weekly basis from Runcorn for use in the reprocessing plants, and taking regular consignments of containerised low-level nuclear waste to BNFL’s licensed dump site at Drigg, just a few miles south of Sellafield.

In early 1999 the rate of longer distance nuclear business has picked up as contracts have passed hands from the EWS freight company to DRS. In January, DRS locos hauled nuclear flasks for the first time to Bridgewater, Somerset (serving Hinkley power station). They also hauled flasks from Sizewell in Suffolk and Dungeness in Kent via London’s Willesden Junction, and from Heysham power station on the Lancashire coast to Sellafield. Other sightings have included what is thought to be a ‘route learning trip’ on the Settle to Carlisle line (see below).

With so little revenue-earning business available, and with a large fleet to maintain, it is not surprising that DRS should have turned its attention to other work. The trial haulage of milk tankers from Penrith in Cumbria to London’s Cricklewood depot is an example, whilst the haulage of passenger charter trains, and on one occasion the Royal Train, are others – though the latter perhaps had more to do with the company’s public relations image than anything else. That this clean and friendly image is vital to DRS (like the Yellow Pages ‘we’re not just here for the nasty things in life’) is confirmed by plans for 1999 for DRS locomotives to be used in April to haul a ‘Settle Excursioner’ trip from Banbury to Carlisle via the scenic Settle to Carlisle line, and in May a ‘bucket and spade’ excursion from Herford North to Skegness. Doubtless there will be more.

The Class 20 diesel locomotives were built largely in the late 1950’s and 1960’s and prior to their purchase by DRS had been used on Railfreight coal duties in the Midlands. The current fleet is numbered consecutively from 20301 to 20315. The 73.5 ton Class 20’s measure 14.25m from buffer to buffer, are equipped with English Electric 8SVT MkII engines and are listed as having a maximum speed of 75mph and an Air and Vacuum braking system.

The Class 37’s are numbered from 37607 to 37612, measure 18.75m in length, have a maximum speed to 75mph and weigh in at around 107 tons.

DRS intends to work locomotives out of three depots. Currently only two are established – at Sellafield itself and in the Kingsmoor Yard at Carlisle.

At Sellafield, the company’s home base provides the facilities for routine maintenance of the locos and other rolling stock as well as the mashalling of the incoming and outgoing flasks. At Carlisle, similar facilities are available, and the Kingsmoor Yard is used as a collection point for flasks coming to and from the power stations in Scotland and from Hartlepool. It is understood that any major overhaul of DRS locos will be carried out under contract with Brush plc at Derby. Drivers recruited for DRS are generally all ex-British Rail.

The establishment of the third depot, at Cricklewood in London, currently hangs in the balance as BNFL’s inept and less than honest attempts to get a licence for the yard have met with increasingly stiff opposition from local residents who object to a nuclear presence in their communities and the marshalling and parking of spent fuel flasks close to their houses. In the past the marshalling of these transports has been done in the neighbouring Willesden Junction by EWS who hold the depot licence for those sidings. Whilst mediated meetings between the newly formed local residents group, BNFL, the local MP and local authority continue in tandem with negotiations between DRS and EWS for the lease of part of the sidings at Willesden and/or Cricklewood, the marshalling of spent fuel transports continues to be undertaken at Willesden.

All Magnox and AGR flask transports are made on ‘FNA Nuclear Flask Transport Wagons’. Around 50 such wagons are in use and all display the identification letters FNA followed by the weight and a 6-digit serial number starting 5500**. FNA indicates the type of wagon (Flatroll), the type of cargo (Nuclear) and the braking system (Air).

Currently wagons numbered between 550009 to 550060 are in use, the lower numbers having been built as long ago as 1976/78.

Other railway wagons are inserted in a variety of combinations between the locomotive and the flask wagons, and between the flask wagons themselves. Known as spacer wagons, these can be several different types but are usually the hopper type wagon (used for coal and aggregates) or a simple flat wagon. The ‘spacing’ arrangements of these wagons between flask wagons appears to be dictated by the way in which a complete transport is made up – ie the addition of extra flask wagons already accompanied by spacers at various marshalling yards around the country, with some consideration also being given to the overall weight distribution of the completed transport.

A train which may start with just one flask from one power station may end up at Sellafield with up to 10 or more flasks and an equivalent number of spacer wagons. Until recently, all transports of spent nuclear fuel flasks had to be accompanied by a brake/guards van. The discontinuation of this practice has led to increased concern that the ability of railway staff accompanying the nuclear trains to act effectively after a rail accident has been severely compromised.

Unlike the diversification offered by the road network, nuclear transports by rail are largely limited to a standard rail network. Over time, small changes to these rail routes have been made but in general the same network has been utilised for many years.

The movement of nuclear flasks from power stations is undertaken almost wholly by rail. Some power stations do not have a direct rail link to the mainline network and the flasks start their journey by road. Other power stations have spur lines running from inside the stations to the mainline. In some cases these non-mainline connections are relatively short whilst others are of considerable distance.

When transported by road to the nearest rail point flasks are loaded, by a gantry crane straddling the line , onto the waiting railway wagon/s.

Reproduced with permission from M.Rawlinson, Freightmaster Publication.

Local Transport Systems from Power Stations.

It can be seen from the railway map that some flask journeys to Sellafield are relatively short – the trip from Heysham taking just a few hours. Transports from the distant power stations such as Sizewell and Dungeness take very much longer and are started the day prior to flask delivery to Sellafield. For these longer journeys ‘layover’ sites are required where the transports can wait for their allocated travel slot on the main line network. These layover sites are in addition to the larger marshalling yards where flask transports from different power stations are collected together to form a final transport to Sellafield.

Layover sites have included Falkland, Ayr for Hunterston, Carnforth for Heysham, Tonbridge for Dungeness, and Warrington and/or Carnforth for all complete transports travelling from the south-east and south-west power staions.

Also shown on the map are the marshalling yards where complete transports are formed.

These are located at Willesden, Bescot, Warrington and Carlisle, and serve as focal points on the network.

Official timetables for the movements of rail freight are classified as ‘Private and not for publication’ and are hard to come by. However the timing of transports from power stations has hardly changed over the years and the departure and arrival times at the power stations and Sellafield are well known and confirmed by regular observations. What is more difficult is tracking the transports through railway stations en route, as a number of factors determine whether the transports run on time - or at all.

Experience has shown that approximate times can be gauged from old official timetables, but intrepid nuclear train-spotters will need considerable patience to catch a transport passing through a particular station. Passenger rail traffic has preference over freight traffic and any delays to the passenger system will have a knock-on effect on flask transports. The increasingly frequent signalling problems, and the general failure of rolling stock all add to the uncertainties surrounding the scheduled timetable. Though official timetables may show a specific departure time from a power station, if there is no fuel to be transported on that day then there will be no transport. For example, scheduled departures of fuel flasks unloaded at Barrow Docks for Sellafield depend entirely on whether nuclear ships carrying foreign spent fuel have actually docked and unloaded

In general terms, spent fuel to Sellafield travels towards the end of the week whilst empty flasks are returned to the power stations from Sellafield in the early part of the week.

Reproduced with permission from M.Rawlinson, Freightmaster Publication.

The H code (Headcode) in the timetable helps Railtrack keep track of the trains. The first figure 7 denotes train type the (freight). The following letter denotes the destination area referred to, and the last two numbers identify the particular 7= 45mph train. The FO (Friday only) shown to depart from Bridgewater on Thursday also includes the flasks from the south-east power stations.

In general, spent fuel flasks leaving the south-east power stations are collected together at Willesden in London, where they are formed ready for an overnight departure to Bescot. This transport is then added to the Bridgewater train and the flasks from Oldbury. The whole train then leaves Bescot around 0620 on Friday morning to Bescot. This transport London is then added to the Bridgewater train and the complete the journey to Sellafield. The empty flasks are distributed in exactly the same way, splitting at Bescot and Willesden.

Reproduced with permission from M.Rawlinson, Freightmaster Publication.

The 'Friday' train arriving at Sellafield with nine flasks. (pic12)

16. Sellafield Railway Sidings.

Incoming flask transports to Sllafieeld, whether approaching from the north or south, all have to pull through the mainline Sellafield railway station. Transports arriving from the south – usually a large number, of flasks pull directly onto the station platform and once the points are switched the train is shunted backwards to a further set of points just south of the site railway gate. Once BNFL’s railway staff are available to open the entrance gates, the transport then pulls into the Sellafield sidings frontwards and once inside the locomotive is decoupled and will exit the plant.

Transports arriving from the north will either pass directly through the Sellafield mainline station to a point south of the sidings gate, and will then be reversed into the sidings.

The sidings themselves are secured behind a security fence topped with razor wire – as is the whole Sellafield site. A footpath – part of the Cumbrian Coastal Way, runs between the fenced-off sidings and the main railway line. It is not uncommon to see well over a dozen empty flasks in the sidings being formed up to make the return journeys to the individual power stations. The sidings also contain a number of DRS locos, BNFL’s own small shunting engines which shunt the flasks around the Sellafield site, other flasks that are used only for internal site work, and a selection of spacer wagons waiting to be linked up to empty flasks due for return.

When full flasks arrive in the sidings they are almost immediately shunted off to their final destination – either the THORP plant (for AGR and foreign fuel) or to the Fuel Handling Plant which stores the Magnox fuel. These individual sidings cannot be seen from outside the plant, but an internal site bus tour provided by BNFL for tourists gives a good view of the flask handling areas for both reprocessing plants.

Whilst the shunting procedures are carried out by railway staff, further procedures for the movement and handling of flasks at THORP and B205 are carried out by BNFL staff under a series of written instructions relating to flask and wagon movement, radiation monitoring and non-radiological safety related activities. For THORP, under Section 16 of the ‘Ponds [East River] Site Railway Instructions (the Sellafield site is divided in two by the River Calder), the responsibility for the flask wagons lies with THORP’s operators once the flasks are parked 50ft from the plant’s rail bay door, and becomes the responsibilty of the Site Railways again once the shunting loco is recoupled for movement away from THORP.

Monitoring of incoming flasks takes the form of ‘swabbing’ areas of potential contamination (the lid-joint, valves etc). If any ‘action level’ is exceeded at any of these points a full flask survey must be undertaken. Once the flask has been cleared and unloaded from the transport wagon, the wagon itself is then surveyed. Further monitoring is undertaken on the flask as it moves within THORP to have its lid unbolted and the spent fuel assemblies removed.

The docks at Barrow-in-Furness, Cumbria, have played host to all spent fuel flasks arriving from Japan since the 1970’s, and more recently to flasks from Europe. The 230 acre dock complex is operated by Associated British Ports (ABP) from whom BNFL lease the Ramsden Dock as their nuclear flask terminal.

Ramsden Dock consists of a single quay along which two ships can be berthed end to end, though ships are sometimes double berthed to accommodate up to four ships. A crane, running on twin tracks and traversing the length of the terminal is used for flask unloading. From the main railway line which serves Barrow, a spur line leads directly into the terminal. Once unloaded from the ships and secured onto the railway wagons, the flasks are hauled the one hour rail journey north to Sellafield – a route identified on an IRA ‘hit-list’ in the 1980’s.

Staffed by a manager, security staff, port operatives, technicians and administrative staff, BNFL’s terminal has provided regular business for the port which is also home to Britain’s nuclear submarine building programme (currently the Trident submarines) and other defence related ships.

Until the mid 1990’s spent fuel from BNFL’s European customers was imported through Dover on the ro-ro ferry Nord pas the Clais, operated by P & O. Following high-profile Greenpeace campaigns at the port and concerns about the safety of ferry bow-door systems, BNFL transferred the European business to one of their own ships and re-routed the transports from Dunkirk directly to Barrow via the Itrish Sea. All shipments of spent fuel from overseas, and the return of empty flask, is carried out by a company specifically formed for the task.

Formed in 1975, PNTL has BNFL as a majority shareholder (62.5%) with remaining shareholders drawn from a number of Japanese power utilities and from the company COGEMA who operate the French reprocessing plant at La Hague. Operating a fleet of six ‘dedicated’ ships, PNTL’s registered office is at BNFL Headquarters at Risley near Warrington. Shipping agents for PNTL are the Barrow based company James Fisher & Sons.

The six ships are registered with Lloyds Register as nuclear cargo carriers. Because of the ‘double-hull’ construction, sophisticated location and communications systems, the ships and their trained crews are considered by BNFL to provide a safe means of sea transport. Five of the ships are used for the Japanese transports, taking around 42 days to complete the Far-East voyage of 15,000 miles via the Panama Canal. Named after a variety of birds, these ships are named Pacific Swan, Pacific Crane, Pacific Pintail, Pacific Sandpiper and Pacific Teal. The sixth ship, the smallest in the fleet and used for European transports is the European Shearwater.

Though early transports from Japan and Italy saw the import of Magnox spent fuel, a majority of imports today consist of spent fuel from PWR and BWR reactors in Japan, Germany and Switzerland. These fuels are destined for Sellafield’s THORP plant and are actively cooled during the voyage. An assortment of transport flasks is used, all very different in size and shape to the standard Magnox/AGR flasks used in the UK. A further difference with these when transports is that hauled from Barrow to Sellafield, the flasks remain uncovered.

A range of different flasks pass through Barrow docks, with perhaps the Excellox series, shown below, being the most frequent visitor. The Excellox 6 can carry 7 PWR fuel assemblies (each around 5m long) from Europe, whilst the Excellox 7 will take 7 PWR or 17 BWR assemblies from Europe and Japan. The flasks weigh around 100 tonnes and are almost 7m long.

Several other flasks, identified below,are also seen fairly often in Barrow. Like the Excellox flasks, they are very different from the AGR and Magnox flasks used in the UK.

CORE
(Cumbrians Opposed to a Radioactive Environment)
98 Church St
Barrow-in-Furness
Cumbria
LA14 2HT

Tel: 01229-833851 Fax: 01229-812239

Email: info@core.furness.co.uk