Question 1

  It would be helpful to have a note setting out actions taken by UKAEA in response to points raised inDr Walker's report.

  Dr Walker's report was one of a number of useful inputs to UKAEA plans for upgrading the fuel and waste plants in the Dounreay Fuel Cycle Area (FCA).

  UKAEA considered the findings of Dr Walker's report together with its own study of the condition of the fuel cycle and related plants, and a review of the plants carried out by NNC under contract. As a result, a major improvement programme was prepared for both the fuel cycle and waste plants and is now being implemented. The planned upgrades have been prioritised; the most urgent tasks have been identified for 1998-99, and appropriate sums included in the budget. Thirty-eight projects have already been completed, and 119 are in progress.

  The table attached summarises the key concerns contained in Dr Walker's report, and the actions taken by the UKAEA to improve performance in these areas. The Committee is asked to note that:

1.  The detail and prioritisation of the improvement programme will be reviewed in the light of the HSE/SEPA Audit of Dounreay undertaken during June 1998, and expected to report shortly.

2.  NII expressed satisfaction with the progress to date, in both the written and oral evidence to the TIC hearing in Thurso on 15 June.

3.  Safety of the Dounreay plants is subject to continual review by UKAEA and NII, to ensure public and occupational safety.

PLANT DESIGN AND ENGINEERING CONDITION

  1.  Containment

  Improvements planned in all buildings identified by Dr Walker, for example the clearance of the D1203 "amber" area, the decommissioning of lab 33, containment of process pipework and the DC3 roof bulge in D1206 are all underway.

  Overall four projects are already complete and 20 projects are in progress.

  2.  Ventilation

  Standards for each plant have been documented to allow specification of appropriate systems, for example the reviews of ventilation in D1200 are complete and the improvements to the space extracts in D1203 and the upgrading of fans in D1206 and D1234 are underway.

  Overall three projects are already complete and 15 are in progress.

  3.  Shielding

  Plans for removal of radiation sources, and improvement of shielding quality, for example the cleaning of the D1204 pond and the removal of radiation sources from various areas in D1206 are underway.

  Overall one project is complete and eight projects are in progress.

  4.  Instrumentation

  Instruments have been identified for improvement/replacement, for example the Criticality Detection and Alarm System (CIDAS) has been replaced.

  Overall one project is complete and 16 are in progress.

  Long-standing temporary shielding

  See (3) above.

  Waste management strategy

  No further ILW is planned to be disposed to the wet silo after the end of 1998. Much waste cleared from active handling facilities and Waste Posting Cell now operational, as are both 6021 flasks. Detailed waste strategy under development.

  Outstanding Post Operational Clean out (POCO)

  A number of POCO tasks are now underway, eg the clear-out of the legs of the caves in D1217.

  Lab 33

  The decommissioning process has now begun.

  Operating plant in care and maintenance

  The recent decision on the future of commercial reprocessing means that some plants are no longer required and will undergo POCO, then decommissioning.

  Safety cases

  The programme of safety case review and revision has been accelerated.

  Project categorisation

  A new system of prioritisation has been introduced in the UKAEA; safety-related projects have the highest priority.

  Maintenance procedures

  More than 6,000 maintenance instructions have been produced and are in place, leaving only a handful still to be completed.

  Suitably Qualified and Experienced Persons (SQEPs), Duly Authorised Persons (DAPs) and training

  A new UKAEA policy on SQEPs and their training has been introduced.

  Authority to Operate (ATO) holders and Safety Working Parties (SWPs)

  The number of ATO holders has been increased. SWPs are now incorporated within the line management structure advising the Group Manager.

  Nuclear Site Licence Conditions and the Corporate Safety Instructions (CSIs)

  Descriptions have been prepared of how Licence Conditions are met within UKAEA's safety systems.

  Interface management

  Team-building initiatives have been carried out. A number of contractors have been recruited into UKAEA (see Question 8).

  Question 3

  It would be helpful, following Q28, to have the details of the existing contracts for reprocessing irradiated fuel, indicating the source, nature and length of the contract, the volumes concerned, any irradiated fuel still to be delivered to Dounreay, and arrangements for return of waste in each case. It would also be helpful to have a note on the significance in volume and technical terms of the carbide fuels (Q35).

  The attached table[9] lists all existing contracts for reprocessing irradiated fuel at Dounreay showing the source of the fuel, the nature of the contract and processing time involved, the amounts of fuel, whether any has yet to be delivered and the arrangements for return of waste in each case.

  Carbide Fuels

  Most of the fuel awaiting treatment at Dounreay is in the form of uranium-plutonium oxide. The remainder is uranium-plutonium carbide. 1.7 tonnes of the carbide fuel is irradiated; the rest is unirradiated (0.7 tonnes)*. For comparison, total quantities of irradiated and unirradiated fuel awaiting treatment at Dounreay are 14 tonnes and 12.8 tonnes respectively.

  Carbide fuels were developed for fast reactors because they offered the prospect of higher power generation in a smaller volume and therefore better economics than the more normal uranium-plutonium oxide fast reactor fuel.

  The Georgian material does not include any carbide fuel.

  Carbide fuel needs to be reprocessed—direct disposal is not a realistic option because the chemical reactivity of the carbide material could produce flammable gas in a repository. However, they are more difficult to reprocess than oxide fuels.

  To date, no-one has reprocessed either irradiated or unirradiated carbide fuel on more than a laboratory scale. Three options have been identified for processing the carbide fuel:

(a)  blend with larger quantities of oxide fuel, and co-process through the normal route;

(b)  convert to oxide in a furnace, and then reprocess through the normal route used for oxide fuels;

(c)  use an alternative dissolution process.

  These options are currently being evaluated. Should option (a) prove to be safe and technically acceptable, installation of a new dissolver would make it possible in principle to carry out this work in D1206 at Dounreay without additional plant.

  *Note. In addition, there are 4.1 tonnes of unirradiated uranium carbide breeder material. This contains natural/depleted uranium. The current intention is to oxidise the material to stable uranium oxide, suitable for storage and disposal.

Not printed.

  Question 4

  It would be helpful to have an indication of the likely end-users of the fuel to be produced from the LEU and irradiated HEU.

  The unirradiated HEU from Georgia will be used to make uranium targets for irradiation in Materials Test Reactors to produce molybdenum 99 radioisotopes which decay ultimately to produce technetium 99, an important diagnostic source used in nuclear medicine. The end users are doctors worldwide treating patients who are suspected of having cancer. Only technetium-99 produced from HEU is licensed for worldwide use as a diagnostic in nuclear medicine, as it avoids potential side effects from other radioactive materials.

  The HEU recovered from the irradiated HEU once reprocessed, unirradiated LEU and recovered LEU will be blended at Dounreay to produce fuel elements for Materials Test Reactors (ie the type of reactor used to irradiate the targets as described above), in Western Europe or Canada.

  Attached is a letter from Dr S E M Clarke, of the Department of Nuclear Medicine at Guy's and St. Thomas' Hospital Trust, confirming the value of technetium 99.

  Thank your for your fax and our subsequent telephone conversation. I can confirm that the processed molybdenum is vital in the production of 99m Tc used for 90 per cent of Nuclear Medicine diagnostic procedures in the UK. Nuclear Medicine imaging is available in most hospitals in the UK and is used to investigate a wide variety of disease processes including bone problems for spread of cancer to the bones, clots in the lungs, heart disease, kidney disease in both adults and children, and thyroid problems.

  The main source of molybdenum at the present time is from Canada and there have been two occasions over the past six years when the supply of molybdenum to Europe including the UK has been at risk due to industrial action in the Canadian company. I was involved with writing letters to the Department of Health at the time of the first incident and I know that the second episode was discussed in the European parliament. Alternative sources of molybdenum are therefore essential to ensure a secure supply for clinical purposes.

  Question 5

  It has been suggested that D1206 would require "reconfiguration"—in addition to the investment in a new dissolver and plant upgrade—to deal with the irradiated HEU from Georgia since it normally deals with MOX fuels. It would be helpful to have clarification.

  The UKAEA will treat the very small quantity of irradiated HEU from Georgia (0.6 kg) either in the D1206 reprocessing plant or by a laboratory process in D2670 (the Marshall Laboratory).

  A few straightforward changes to the arrangements for cutting up the assemblies and removing the fuel prior to dissolution would be required if the Georgian material were processed in D1206 together with some changes to the chemical process for dissolving the fuel.

  Question 6

  It would be helpful to have a note on the future reprocessing of irradiated HEU targets, indicating where it is to be carried out; with what product; and the nature (length, finance, conditions etc) of the contract with the ECN reactor at Petten.

THE TARGET PRODUCTION CYCLE

  Dounreay plants fabricate HEU into targets which is sent to the reactor at Petten in Holland. The targets are irradiated in the ECN reactor. After irradiation, the reactor operators separate targets chemically into three main products:

(1)  Molybdenum 99 radioisotopes which are used to produce technetium 99 for use in medical diagnosis.

(2)  Radioactive waste which is retained by the reactor operators.

(3)  The unburned uranium-235 including some residual waste which is returned to Dounreay for re-use. Any resultant waste from processing will be returned to the reactor operators.

  UKAEA also supply purified HEU metal to AECL Canada who fabricate their own targets.

THE CONTRACT WITH ECN

  UKAEA has a contract with ECN (Holland) for the manufacture of up to 5,000 targets. ECN raise purchase orders against the contract as the demand on them requires. The contract itself is for an unspecified period but there are mutual break clauses at 10 months notice. The price paid by ECN covers transport costs, target manufacture, recovery of HEU and leasing the HEU, and profit.

  Of the current order for 2,394 targets, 1,890 targets containing 9.6 kg of HEU have been delivered to ECN and, of that, 3.7 kg irradiated HEU has already been returned to Dounreay for recovery.

  The remaining production and a further order for 2,268 targets depends on the outcome of the current NII/SEPA safety audit at Dounreay.

  Question 7

  Following the exchanges in oral evidence, it would be helpful to have a response from UKAEA on its latest views on the balance of advantage between reprocessing and storage.

INTRODUCTION

  1.  In his evidence to the Trade and Industry Committee on 15 June, Dr John McKeown, Chief Executive of UKAEA, outlined some primary factors which led to UKAEA proposing to continue to reprocess Prototype Fast Reactor (PFR) fuel at Dounreay rather than attempting to make a case for long-term storage. This note summarises the strategic factors which support this policy.

OPTIONS CONSIDERED

  2.  In broad terms, three types of treatment can be considered for PFR fuel[10]:

(a) Surface storage followed by direct disposal;

(b) Surface storage followed by reprocessing; or

(c) Early reprocessing followed by storage, reuse and disposal of the materials arising.

(a) Surface storage followed by direct disposal

  3.  Surface storage followed by direct disposal is an option being pursued for spent fuel from thermal power reactors. Countries such as Sweden and Finland have proposed long-term storage for irradiated thermal reactor fuel to allow the radioactivity of fuel to reduce prior to direct disposal in an underground repository. In the UK, Scottish Nuclear Ltd proposed in the 1990s to build dry-storage facilities at Torness for its irradiated fuel, with the aim of eventual direct disposal. However, UKAEA understands that currently the majority of spent fuel from thermal power reactors in the UK is scheduled to be reprocessed.

  4.  A key factor in determining the feasibility of direct disposal is the nature of the fuel and the amount of fissile material it contains.

  5.  Most commercial reactor fuel is in the form of metallic uranium (Magnox) or ceramic uranium oxide (AGR, PWR), containing less than 5 per cent U235 and—after use in the reactor—a small proportion of plutonium. The low fissile material content of this fuel means that it poses a relatively minor security risk and raises relatively little concern relating to criticality.

  6.  By contrast, the Dounreay PFR used uranium/plutonium oxide or carbide fuel. The plutonium content ranges from 20-33 per cent.

  7.  Approximately 50 per cent of the PFR fuel is unirradiated and is classified as a special nuclear material which is subject to the highest levels of security on non proliferation grounds. The majority of the PFR fuel is irradiated and, although requiring proper security measures, is categorised at a lower level of security than unirradiated fuel, as it is more difficult to use for non peaceful purposes.

  8.  Studies have confirmed that surface storage of both irradiated and unirradiated PFR fuel would be technically feasible for timescales of 50 years or more, with tight security arrangements and storage arrangements designed and monitored to prevent the possibility of criticality.

  9.  Direct disposal of irradiated or unirradiated PFR fuel following a significant period of secure surface storage, would require demonstration over a timescale extending to half a million years or more that:

—  a critical mass would not form and start a chain reaction as a result of the contents of fuel elements coming together in the repository due to the long-term degradation of barriers intended to contain the material.

—  there is not an unacceptable risk that the plutonium could be recovered for non peaceful purposes. This is more significant for unirradiated PFR than for irradiated fuel, as the material could be more easily used for non peaceful purposes.

—  a containment system could be established and demonstrated to prevent the release of unacceptable amounts of radioactivity into the environment whilst the spent fuel remained radioactive.

  10.  Direct disposal of the unirradiated PFR fuel at Dounreay (which amounts to 12.8 tonnes) poses particular difficulties in that it is special nuclear material which requires secure confinement for very long periods of time to avoid diversion for non peaceful uses.

  11.  Direct disposal of irradiated PFR fuel faces the same challenges in making a safety case and avoiding criticality, however security considerations are less significant as the radioactivity makes it more difficult to use for non peaceful purposes.

  12.  Whilst in principle the irradiated PFR fuel could be diluted and packaged with other materials for safe direct disposal, this process has not yet been demonstrated. In the event of the safety case for disposal of PFR fuel identifying factors which preclude the material being accepted for a UK national repository, the whole costs of a separte repository for PFR would fall on the UKAEA and thus on the the UK taxpayer.

  13.  The total quantity of plutonium in PFR fuel amounts to only a small percentage of the total stock of civil plutonium in the UK, putting into perspective the risks of following a unique to PFR solution. Since the UKAEA plutonium is only a small percentage of the UK civil stock, UKAEA considers it to be an unacceptable commercial risk to pursue what may be a unique solution for this material.

 (b)   Surface storage followed by reprocessing

  14.  It would be feasible to store PFR fuel for a period of 50 years or more with the aim of eventual reprocessing. However, this option would be inconsistent with the principle of sustainable development since it would require future generations to reconstruct reprocessing facilities similar to those currently available at Dounreay, to discharge this generation's responsibilities.

 (c)   Early reprocessing followed by storage, reuse and disposal of the materials arising

  15.  Reprocessing spent PFR fuel results in four main products:

(i)  Plutonium and uranium;

(ii)  Low Level Waste (LLW) for disposal at Dounreay or Drigg;

(iii)  Intermediate Level Waste (ILW) in a form appropriate for storage and subsequent disposal to an eventual UK national repository;

(iv)  High Level Waste (HLW) for interim cooled storage in vitrified form followed by disposal to an eventual UK national repository.

  16.  Reprocessing would convert the UKAEA PFR fuel into forms which are the same as those produced by reprocessing fuel from Magnox and AGR reactors in the UK. This would allow UKAEA to be part of a UK-wide solution which would share costs with the other UK nuclear operators. Separation of plutonium from PFR fuel would allow the UKAEA's plutonium to be managed with the rest of the UK's national civil stock, whether reused in MOX or other types of advanced reactor fuel, or dealt with via an agreed, common disposal route.

CONCLUSIONS

  17.  Surface storage of PFR fuel is feasible but direct disposal to a UK repository would be a high risk option. UKAEA judges there is insufficient evidence or experience available to allow this option to be established as technically feasible and consequently that it is not consistent with the principle of sustainable development.

  18.  Storage followed by reprocessing may be feasible, but not consistent with sustainable development as it would require future generations to construct facilities to process the fuel.

  19.  Adoption of either of these options could leave a problem unique to the UKAEA PFR fuel for future generations to solve. The solution could require very significant research and development, and the production of a unique safety case. It would also introduce the potential to require the construction of facilities unique to this fuel. The costs and risks would fall to the UKAEA and so to the UK taxpayer.

  20.  Early reprocessing of PFR fuel would allow it to be disposed of via the same route as other UK nuclear materials, greatly reducing the risks, bringing economies of scale, and avoiding costs associated with a unique solution.

  Question 8

  Details, as given in the briefing, on the numbers and specific functions hitherto contracted out and recently taken back into direct employment, together with an overall view of numbers of staff and functions contracted out and retained over recent years, would be helpful.

  UKAEA has or is about to take back in house the following functions and staff numbers following a reassessment by UKAEA in discussion with NII of the scope of the core competence UKAEA requires as site licensee.

(a) Seven Radiological Protection Advisors, two of whom were recruited from AEA Technology who had taken the function with them under contract at the time of their privatisation in 1996.

(b) Three radioactive material transport personnel (two drivers and a supervisor) from Johnson Controls Limited (JCL). These staff had been part of the UKAEA's Facilities Services Division (FSD) sold in 1995 to Procord, which subsequently became JCL.

(c) Six staff from AEAT who controlled contractors to UKAEA.

(d) Seven staff from the Management Support Contractors W S Atkins/AEAT.

(e) 20 operational staff for high security nuclear work in D2670 (The Marshall Laboratory) which had previously been operated under contract by AEAT. (five of the staff recruited have come from AEAT).

  Previous "divestments" at Dounreay were:

—  284 staff to what became AEAT (privatised in 1996),

—  132 people divested as part of the sale of UKAEA's Facilities Services Division in 1995 to Procord,

—  and 19 staff divested on the sale of Plant Decommissioning Services to Rolls Royce Nuclear Engineering in 1997 in order to increase competition in the decommissioning market.

  Question 9

  The Committee has asked for an explanation of why the UKAEA was unwilling to allow the release of Dr Walker's Report until 12 June, and specifically which parts of it the Authority regarded as commercially confidential.

  Prior to 12 June neither NII nor any Government Department requested UKAEA to publish Dr Walker's report.

  It is our understanding that NII regarded the report as a working document intended "to produce a dialogue". Such documents are understood not to be unique to Dounreay and are not normally published as their role is to facilitate the regulatory dialogue.

  In its evidence to the TIC on 15 June 1998, the NII Chief Inspector expressed the view that the Dounreay site was "not unsafe".

  Against this background, UKAEA did not agree to other requests for the report's publication. The contents were known to its producer, our regulator, who was protecting the public safety interest, whilst its style and content could damage UKAEA's commercial position.

  The denial of requests for a copy of the report must not be equated with complacency about the Dounreay plants. Improvement measures were being implemented at the time as confirmed by NII evidence to the TIC that it was "satisfied that Dounreay management were addressing the problems".

  The announcement that UKAEA would not be seeking any further commercial reprocessing contracts made on 5 June by Government Ministers changed the status of the report. That is why the UKAEA agreed to the publication of the report on 12 June following a Ministerial request.

16 July 1998

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10   PFR fuel includes materials arising from the manufacture of fast reactor fuel, the PFR fuel itself and some associated experimental fuels.

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