risk and hazard reduction and waste management working … · 2017. 9. 12. · sixep contingency...

Risk and Hazard Reduction and Waste Management Working Group

Minutes for the meeting held on Wednesday June 21st 2017 (Meeting #18)

Attendees Craig Ashton LLWR Dave Banks Copeland Borough Council Nick Barron Gareth Cosslett SL Thomas Dowd (Secretary) Lena Hogg (Chair) Copeland Borough Council Simon Kellet SL Peter Manning Beckermet Parish Council Alan Parry SL David Saul LLWR Stephen Tandy EA Martin Walkingshaw LLWR Felicity Wilson Copeland Borough Council Henry Wormstrup Rob Yetts LLWR Apologies Richard Griffin Cumbria County Council Brian Hough NDA Bob Jones Ponsonby Parish Council Bernard Kershaw Cumbria County Council – Resilience Unit Mark Nicholson Cumbria County Council – Resilience Unit Phil Reeve SL Alan Smith Allerdale Borough Council Christine Smith Allerdale Borough Council Jane Tideswell Cumbria County Council – Resilience Unit Ian Winchester Cumbria County Council – Resilience Unit

Risk and Hazard Reduction and Waste Management Working Group, part of the West Cumbria Sites Stakeholder Group

Minutes for the meeting held on Wednesday June 21st

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1. Welcome and Introduction The Chair welcomed all to the meeting. The minutes for the previous meeting were accepted.

2. Review of Actions There were four outstanding actions:

15.2 The Chair to take comments regarding better articulation to the wider public, and more engagement between the WCSSG and the G6, to the next WCSSG main meeting. 16.3 The Secretary to arrange for a presentation from RWM at a meeting of the Working Group. 17.1 The Secretary to liaise with the Chair regarding an update on the Sellafield Site Effluents Stream. 17.2 An update from LLWR to be arranged for the next meeting of the Working Group.

15.2 – The Chair will pass on these comments to Rosina Robinson (SL) to find a way forward, rather

than mentioning it at the next WCSSG main meeting. This is a new action [Action 18.1]. Action 15.2

is closed.

16.3 – This has been arranged for the next meeting (September 20th 2017 (Meeting 19)). Action

closed.

17.1 – The relevant update was given at this meeting. Action closed.

17.2 – The relevant updates were given at this meeting. Action closed.

3. Sellafield Effluents Strategy Alan Parry (Head of Strategy and Technical, Decommissioning, SL) and Simon Kellet (Effluents Lead,

Decommissioning, SL), gave a presentation on the enterprise level approach to effluent management

at Sellafield.

3.1. Presentation – Alan Parry/Simon Kellet Alan Parry explained with the aid of a diagram how the Sellafield site effluent routings are

configured.

The demands placed on the site’s effluent routings will change significantly in the near future,

due to the ramp-up in FGMSP retrievals, the start of MSSS retrievals, the completion of the

MOP, the end of reprocessing, and the onset of POCO.

There is been a move from each individual plant having its own retrievals stream towards an

integrated effluents strategy.

SL has carried out an extensive review which has shown that the SIXEP Effluent Stream is robust

to the imminent and ongoing challenges it faces.

However, there are a number of risks which need to be managed (both in the individual

facilities and at an enterprise level).



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SIXEP Contingency Plant (SCP) will replace key sections of SIXEP Sea Discharge Treatment Plant

which are at risk of failure before the planned end of SIXEP operations. The plant will be

brought into operation in 2024.

Alan explained how tactical planning, R&D, scenario modelling, and integrated flowsheeting are

being used at the enterprise level. An example is predicting how much effluent will come out of

each MSSS compartment.

£2 million is being invested in the current financial year in R&D and modelling towards effluent

risk management.

Simon Kellet introduced the Combined SIXEP Effluent Stream Programme Timeline and

highlighted some key details.

o The baseline strategy for MSSS effluents has changed due to it now being

processed via the Alternative Intermediate Level Waste Approach (AILWA),

rather than via the now abandoned Silos Direct Encapsulation Facility (SDP),

which has brought the start date forward from the mid-2020s to the late-2010s.

o This timeline shows in a Gantt chart format when it is expected that particular

facilities will have an effluent stream.

o It also shows key decisions facing FGMSP, MSSS, and SIXEP.

Simon explained the Sellafield Integrated Modelling Approach.

o A number of inconsistencies/anomalies across the SIXEP donor flowsheets have

been identified and work carried out to standardise flowsheets.

o Modelling is being used to assess the impact of planned retrievals operations

and to ensure that the effluent stream doesn’t cause an operational bottleneck.

o An example timeline was provided, showing the typical stages to a sensitivity

assessment using an integrated modelling approach – an initial Sellafield

Operational Research Group (SORG) model, followed by an MSSS process model,

SIXEP Activity Management Project (SAMP), ion exchange bed model, and

Overall Effluent Strategy (OES) model can be expected to take a total of ten

weeks to create.

Simon Kellet gave a brief overview of decisions and learning from experience (LFE) relating to

FGMSP.

o At present sludge is transferred from the pond via the Sludge Packaging Plant

(SPP1) to Buffered Storage Vessels (BSVs), with the supernate1 being returned to

the pond.

o Once the Effluent Distribution Tanks (EDTs) are commissioned, they will offer a

new effluent route to SIXEP.

o Pond visibility has become a problem of late due to sludge being kicked up by in-

pond operations. R&D is being used to look at possible sludge-settling aids.

o Three key pending FGMSP effluents decisions were highlighted:

Will SPP1 supernate pose a threat to SIXEP?

Does pond purging mitigate algal blooms?

Should SIXEP be utilised for Redundant Settling Tanks (RSTs) sludge? 1 When a solution undergoes precipitation, the solid at the bottom of the vessel is known as the precipitate.

The remaining precipitate-free liquid remaining above the solid is known as the supernate.



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Simon summarised the LAEMG effluent stream.

o The Enhanced Actinide Removal Plant (EARP) has been running since the mid-

1990s on consistent, relatively well-understood batches of LA effluent, generally

sent as part of long campaigns.

o As reprocessing draws to a close, there will be shorter campaigns and more

variable feeds.

o Significant investment has been made into R&D including provision of a test rig

at NNL Workington, which is looking at ways to better understand and expand

the EARP operating envelope.

o A Low Active Effluents Working Group has been set up to develop cross-

programme working.

3.2. Questions/Discussion 1. Henry Wormstrup – Does this mean you are now going ahead with “SIXEP 22” and

“MASWEP3 2”? If so, when will the new plant(s) come online?

Alan Parry – Yes, the current target is the 2023/2024 financial year.

2. Henry Wormstrup – Is it new build or change of use?

Alan Parry – Some aspects of the new plants will be new build, others are change of use.

3. Henry Wormstrup – Is there now more risk to SIXEP than when it first opened?

Alan Parry – There isn’t necessarily any greater risk, but the different challenges associated

with future operations present different risks. For example pre-treated clinoptilolite4 has a

different risk profile to non-pre-treated clinoptilolite.

4. Peter Manning – Do future plans rely on somehow emptying Bulk Storage Tanks (BSTs)5?

Alan Parry – Retrievals have been decoupled from downstream treatment, leaving enough

2 “SIXEP 2” is the SIXEP Contingency Plant (SCP).

3 MASWEP is the Medium Active Solid Waste Encapsulation Plant – currently this is a pair of 200 m

3 storage

tanks for spent ion exchange and sand filter material within the SIXEP building, with the encapsulation stage unbuilt. 4 Clinoptilolite, often known as clino, is a natural zeolite which acts as the ion exchange material in SIXEP.

5 Vessels containing used clinoptilolite.



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space in the BSTs to continue to retrieve6.

5. Peter Manning – When you speak of things “challenging capability”, does this refer to

volumetric capability or to discharges?

Simon Kellet – Discharges.

Henry Wormstrup – Does this mean there will be an increase in discharges?

Simon Kellet – Yes there could be an increase in discharge levels, within EA limits.

Henry Wormstrup – Could the EA representative pass comment on this?

Stephen Tandy – The EA is taking a balanced view to this. The EA will be regulating in

accordance with principles of Best Available Techniques (BAT) and As Low As Reasonably

Achievable (ALARA).

Craig Ashton – It’s worth noting that SL has made significant investments to reduce its

discharge limits to very low levels of impact. Any increases associated with clean-up and

decommissioning are likely to be very low compared to the overall levels of reduction that

have been achieved to date and are still to occur when reprocessing operations cease.

Lena Hogg – The Group appreciates that it is sometimes necessary to have a short-term

increase in risk for a long-term decrease.

6. Peter Manning – Is the annual discharge limit still 20 µSv?

Craig Ashton – Sellafield’s discharges collectively provide a critical group dose of ~26 to 27

µSv·yr-1. These are set to reduce to below 20 µSv·yr-1 following the cessation of reprocessing

operations, after which Sellafield’s discharges will be dominated by clean-up and

decommissioning activities.

7. Henry Wormstrup – The public understanding is that “near-zero discharges” means that

Sellafield would have zero discharges after 2020.

Stephen Tandy – After the meeting I can gather some information from the EA and provide a

definition and explanation of the term “near-zero discharges”. [Action 18.2]

6 It is planned to introduce the capability for processing fresh clino arisings for long term storage before the

BST and other contingency storage capacity is exhausted. The current stocks of clino and sludge waste in the BSTs and MASWEP A will be retrieved and processed separately. There is currently a study (SIXEP Waste Management). Delivery of the projects will follow SCP and facilities should come on stream around 2030.



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8. Lena Hogg – If effluent sent to the EDTs/SIXEP was going to challenge discharge limits, could

it be stopped?

Alan Parry – Yes there will always be the option to stop operations.

9. Henry Wormstrup – Can a copy of the presentation be made available to members?

Alan Perry – Yes, but it will need to go through Document Security first. [Action 18.3]



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4. Plutonium Contaminated Facility Decommissioning Rob Yetts (PCM Programme Delivery Manager, LLWR) gave an update on Plutonium Contaminated

Facility Decommissioning at LLWR.

4.1. Presentation – Rob Yetts The presentation focused mostly on magazine decommissioning.

Magazines are underground concrete bunkers originating from ROF Drigg. During the 1950s

and 1960s PCM originating from the Sellafield site was stored in some of the magazines.

A programme to decommission these magazines was launched in 2008.

An Accelerated Decommissioning Programme commenced in 2013, which saw the

throughput almost doubled by switching from day shifts to 12-hour 7-day shifts. This

removed four years from the end of the schedule and saved £20 million for the NDA.

Currently air-fed suits must be worn for work inside magazines (a C5 area), and work is being

done to roll back the contamination classification to C3.

A particularly troublesome part of the magazines is an area known as the “void”. Notable

challenges associated with the void include:

o Different access configurations

o Unsuitable ground conditions

o Water ingress

o Varying slab thickness

One successfully decontaminated magazine has been deliberately left undemolished so that

it can be used for training and simulations.

Rob also spoke about legacy drums. These drums originated at Springfields, containing

reactor bed materials from experimental fuels. Radiologically-speaking they are

unremarkable, but there are historic concerns that they may contain hexafluoride. Chemical

analysis has confirmed this isn’t the case.

In the last 12 months, an alliance has been formed with Springfields, and they may be able

to take back the legacy drums and reprocess the material contained therein. The plan is to

analyse each individual drum and then, if possible, send on to Springfields.

4.2. Questions/Discussion 1. Henry Wormstrup – Why don’t you advertise your successes?

Rob Yetts – We publicise things at the local level through Cath Giel and her team.

2. Henry Wormstrup – What will happen to the ventilation systems?



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Rob Yetts – Metal recycling where possible. Where the contamination levels prohibit this,

the material will follow standard PCM disposal routes.

3. Peter Manning – When do you expect the demolition of magazines to be complete?

Rob Yetts – March 2019.

4. Felicity Wilson – It seems there is a widespread misunderstanding of the term “magazine”,

due to their different and more widely known context at the Sellafield site. Perhaps LLWR is

understating its achievements by using this term.

5. Repository Development Programme Vision David Saul (Repository Development Programme Manager, LLWR) gave a presentation regarding the

Repository Development Programme (RDP).

5.1. Presentation – David Saul The RDP Vision is “At the end of this programme we will have provided sufficient safe and

secure disposal capacity at the Repository for all suitable radioactive waste and closed the

site such that the environment and local population are protected now and in the future.”

The RDP will implement the 2011 Environmental Safety Case (ESC). Planning permission was

granted in 2016, and the estimated duration for the whole programme is 114 years (to

2130).

The RDP is split into twelve tranches. This presentation focused mostly on Tranche 1.

RDP Tranche 1 consists of three inter-related work packages:

o Repository Development Enabling Works

The construction of roads

Ecological mitigation

Tree clearances (trees will be replanted)

o Vault 8 Closure Project

The voids between Half Height Isofreight containers (HHISOs) will be filled

with a gravel type material

The uppermost containers will be topped up to fill the ullage space where

required

Containers currently stored in Vault 9 will be transferred to Vault 8 and

stacked up to a maximum height equivalent to eight HHISOs

A cut-off-wall will be constructed along the north and west sides of Vault 8

o Final Capping

Profile material will be placed on top of the trench cap adjacent to Vault 8.



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An additional 2 metres of material (surcharge) will be placed over and

above the profile fill and this will be will be monitored to assess the

performance of the trench cap under a loading equivalent to the final cap.

Any settlement is expected to take place within 2 years; subsequently this

additional material will be moved to provide the profile fill for Vault 8.

The final engineered cap will then be installed.

During the two year settlement period work will be undertaken to enhance

the remaining interim trench cap.

David showed an animation of the Tranche 1 works starting from the present day and

ending with the completed final cap (ca. 2130).

5.2. Questions/Discussion 1. Peter Manning – What will be the final height with the cap on?

David Saul – 33 metres AOD.

2. Peter Manning – How confident are you in the waste volume estimates?

We use the latest data from UK RWI and take account of current and future waste forecasts.

The programme is under constant review to ensure that any changes to the waste volume

estimates can be dealt with appropriately.

6. Waste Management Services Projects Supporting Sellafield Ltd. Dr. Craig Ashton (Head of Waste Management Services, LLWR) gave a presentation on the LLWR

Waste Management Service projects that support Sellafield Ltd.

6.1. Presentation – Craig Ashton In total 159 WAGR boxes were made, of which:

o 36 are already disposed of within Vault 8;

o 34 have less than 4 GBq·t-1 α and 12 GBq·t-1 excluding the box itself;

o 27 have less than 4 GBq·t-1 α and 12 GBq·t-1 including the box itself;

o 27 are expected to decay to less than 4 GBq·t-1 α and 12 GBq·t-1 including the box

itself within the next 10 years; and

o 35 boxes which are expected to remain above LLW limits for at least the next 10

years.

Sellafield currently has around 10,000 steel drums containing AGR graphite. Future arisings

are likely to double this number. The Dismantling Waste Store is full, and some of these

drums are being stored in the Engineered Drum Store (EDS). The main hazardous isotope is 60Co, which means that some of the AGR drums are thought to have now decayed to LLW

levels.



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o If these drums were taken to LLWR, it would save SL an estimated £400 million and

would accelerate high hazard risk reduction.

o However, it would also take up 75% of LLWR’s 14C capacity headroom.

Craig showed a breakdown of the different waste categories in the UK. In particular he

highlighted the Waste Management Hierarchy and its applicability to the treatment of ILW.

The mixing of wastes solely for the purposes of reclassification is prohibited under The

management of higher activity radioactive waste of nuclear licensed sites: Joint guidance

from the Office of Nuclear Regulation, the Environment Agency, the Scottish Environment

Protection Agency and Natural Resources Wales to nuclear licensees rule 183. However

perhaps in the future there will be a change of policy on this, which would enable lower-end

ILW to be mixed with lower active wastes to produce a product suitable for LLW disposal.

Craig introduced an interesting point regarding how waste is classified. Due to the focus on

activity rather than dose rate, a container of 224Ra with an activity of, say, 12.01 GBq·t-1

would be classed as ILW, while a similarly sized container of 60Co with an activity of 11.99

GBq·t-1 would be classed as LLW, despite these two hypothetical containers having dose

rates of 8 µSv·hr-1 and 2 mSv·hr-1 (250 times greater), respectively.

In the future there might be changes to the regulatory framework that would remove such

apparent anomalies in waste classification.

6.2. Questions/Discussion Due to significant time constraints there was unfortunately and regrettably no time for a discussion

of this presentation.

7. Any Other Business Felicity Wilson remarked that there is no community representation on the G6, and wondered

whether there could be community representation. This fits in with Action 18.1.

It was asked when the next NDA update would be. The Secretary confirmed that a couple of NDA

presentations are planned for the September meeting (Meeting 19).

Dave Banks and Felicity Wilson expressed their congratulations that Dorothy Gradden of Sellafield

Ltd. had been named in the Queen’s Birthday Honours List to receive an OBE. It was agreed that the

Secretary should send a congratulatory letter to Dorothy Gradden, on behalf of the Working Group.

[Action 18.4].

The next meeting (Meeting 19) of the Working Group will take place on Wednesday September 20th

at Cleator Moor Civic Hall, from 13:00 until 15:00.

8. List of actions arising 18.1 The Chair to pass on comments regarding better articulation between the Working Group

and the G6 to Rosina Robinson (SL). 18.2 Stephen Tandy to provide further information on the definition of near-zero discharges. 18.3 The Secretary to arrange for the Sellafield Effluents Strategy presentation to be distributed.



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18.4 The Secretary to send a letter of congratulations to Dorothy Gradden.

9. Distribution 1. Attendees.

2. Those in apologies.

A copy of these minutes will be made available on the WCSSG website.



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10. Key to abbreviations 14C Carbon-14 60Co Cobalt-60 224Ra Radium-224 AGR Advanced Gas-cooled Reactor AILWA Alternative Intermediate Level Waste Approach ALARA As Low As Reasonably Achievable AOD Above Ordnance Datum BAT Best Available Techniques BEIS Business, Energy and Industrial Strategy Bq Becquerel BST Bulk Storage Tank BSV Buffered Storage Vessel C3 See C3 and C5 C3 and C5 Plant contamination levels. C3 is a lower contamination level than C5. C5 See C3 and C5 CA Carlisle postcode area ca. Circa EA Environment Agency EARP Enhanced Actinide Removal Plant EDT Effluent Distribution Tank ESC Environmental Safety Case Fax Facsimile FGMSP First Generation Magnox Storage Pond G6 A collaboration of BEIS, EA, NDA, ONR, SL, and UKGI. HHISO Half Height ISO Container hr Hour ILW Intermediate Level Waste ISO International Organisation for Standardization LA Low Activity LFE Learning from experience LLW Low Level Waste LLWR LLW Repository MASWEP Medium Active Solid Waste Encapsulation Plant MOP Magnox Operating Plan MSSS Magnox Swarf Storage Silo NDA Nuclear Decommissioning Authority NNL National Nuclear Laboratory OBE Order of the British Empire OES Overall Effluent Strategy ONR Office for Nuclear Regulation PCM Plutonium Contaminated Material POCO Post Operational Clean Out R&D Research and Development RDP Repository Development Programme ROF Royal Ordnance Factory RST Redundant Settling Tank RWM Radioactive Waste Management SAMP SIXEP Activity Management Project SCP SIXEP Contingency Plant



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SDP Silos Direct Encapsulation Plant SIXEP Site Ion Exchange Effluent Plant SL Sellafield Ltd. SORG Sellafield Operational Research Group SPP1 Sludge Packaging Plant 1 Sv Sievert Tel Telephone UK United Kingdom UKGI UK Government Investments UK RWI UK Radioactive Waste Inventory WCSSG West Cumbria Sites Stakeholder Group WAGR Windscale AGR t Tonne yr Year

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