Tuesday, 17 September 2013

Latest update on Carbon 14 at Chatham

This post includes the the responses from the MOD and the Environment Agency (EA)

FOI request to the Environment Agency 11 August

Dear sir

                the MOD in response to a recent FOI request (ref 1)  has said that  0.95 GBq of Carbon 14 was disposed of by burial at Chatham Dockyard.  The MOD had previously disclosed that the waste buried was short lived Cobalt 60. Has the EA been informed of this new information, if so what action is the EA taking to ensure the MOD provide updated risk assessment and ensuring that the burial site meets Regulatory standards.   I feel that this is important, in that unlike other radioactive waste disposal sites, this site is in an urban area about to undergo redevelopment (ref 2) . Background information (ref3).


1: Request for Information under the Environmental Information Regulations 2004 Further to my letter of 26 July 2013, I am now in a position to provide you with a substantive response to your request for information regarding nuclear waste disposal at Chatham Docks.

2: The Chatham Waters development

3:  Chatham an urban nuclear waste dump and a lasting legacy of the nuclear submarine programme

Environment Agency (EA) Response 30 August

"Thank you for your enquiry in respect of a radioactive waste burial at Chatham, Kent.

We have been aware of the authorised disposal of waste from the site at Chatham where the 
Ministry of Defence (MOD) operated part of the site as a submarine refuelling facility (both as Her Majesty’s Inspectorate of Pollution (HMIP) and now as the Environment Agency).

HMIP was originally made aware that the wastes disposed of were primarily based on Cobalt 60 and that MOD’s environmental monitoring programme has also been based on Cobalt 60. We have recently (in 2012) been made aware of the presence of Carbon 14 and earlier this month (August) of a maximum estimated activity - about 0.95 Giga Becquerels of Carbon 14 disposed within this waste. MOD disposed of approximately 9000 cubic metres of waste at this site. Assuming the maximum activity of Carbon 14 this indicates an estimated activity concentration of about 0.04 Mega Becquerel per cubic metre or 0.032 MBq per tonne. 

You asked what action we are taking to ensure that the MOD provide an updated risk assessment. In answering this we have taken into consideration current legislation and not legislation in force when the disposals were made. If MOD or any other operator were to dispose of these wastes at the activities they contain today such wastes would be classed as “Out of Scope” under the Environmental Permitting Regulations 2010 (Exemption Orders) – less than 10 Bq/g for Carbon 14 and 1 Bq/g for the previously declared Cobalt 60. As such the material or waste that was disposed would not be classified as radioactive waste. 

The basis on which the numerical values and waste disposal criteria have been developed are mainly related to the radiation dose which might be received by a member of the public. For out of scope values the criteria adopted for artificial radionuclides are based on a radiation dose of 10 microsieverts per year to a member of the public. These dose criteria have been selected on the basis of representing an appropriate level of risk below which regulation is not necessary In this particular case disposal made historically by the MOD at Chatham would now meet the criteria for being out of scope of regulation and regulatory control. Radiation impact assessments conducted take into account a wide variety of possible pathways and assume that no controls are placed on the disposals. Therefore we do not need to revisit the MOD risk assessment at this time.      

In addition we have with discussed with MOD how these wastes were actually buried and 
ultimately capped when the site was closed. As your question also referred to the adequacy of controls it may be of interest to you that the disposal of what was then classified as Low Level Waste at the Chatham burial ground was subject to a number of conditions as stated in the approval certificate. These included a condition that the waste should be capped with at least 1.5 metres of non-radioactive earth and that the specific activity of the waste (and material used for capping) must not exceed 3000 micro curies per cubic metre (111 MBq/m3). These are similar regulatory requirements that would be placed on a landfill site receiving out of scope waste today and at the end of its life or when capping a completed landfill cell.

The site is still owned by MOD. We have not been involved in detailed discussions with the MOD over the future of this site or any redevelopment. At this time there is no further engagement expected between ourselves and the MOD. If the MOD were to sell this land then the impact of any redevelopment would be a matter for the developer. If approached we would recommend that the developer contacts the MOD for information on the material buried, location and radioactive inventory. Any redevelopment might then need to take account of the specific type of development. "

The Environment Agency is to be commended on providing this information in particular the 
information about risk and dose. It is worrying that at no stage did the MOD provide this 

The EA is silent on the issue that Carbon 14 was disposed of  without proper consideration of the risks.  It is notable that the EA only had knowledge of carbon 2012

" We have recently (in 2012) been made aware of the presence of Carbon 14 and earlier this month (August)"

The MOD knew about the Carbon 14 in 2000

14 August the MOD was asked

" Dear Ministry of Defence, 

I note in a recent answer to an FOI MOD have stated that a maximum of 0.95 GBq of Carbon-14 was buried by the MOD at Chatham. 

Could you please provide me with details of the calculations and assumptions used to arrive a this figure and also information about the statistical uncertainty of the figure. 

Could you provide me with information about the updated risk assessment for the burial site to take account of Carbon 14. 

Could you provide information why Carbon 14 has not been included in the environmental survey reports.  

Also whether or not the MOD has now informed the Environment Agency that Carbon 14 was also disposed by burial at Chatham when the original agreement from the then HMIP was for Cobalt 60. 

Could you tell me if the MOD has provided any information about the radioactive waste burial site to the developers of the adjacent land. If so what information has been provided."

The latest reply from the MOD  9 September

"Your request is being dealt with under the terms of the Environmental Information 
Regulations (EIR) 2004. I can confirm that the Ministry of Defence does hold information 
within the scope of your request. The time limit for this request, however, needs to be 
extended from the initial 20 working days. Under the EIR, a public authority may extend 
this period if it reasonably believes that the complexity and volume of the information 
requested means that it is impracticable either to comply with the request within the earlier 
period or to make a decision to refuse to do so. In this case, I am writing to inform you, that 
we must extend the time limit for responding by a further 20 working days. I will write to 
you again no later than 7 October with a substantive response."

This calls into question the information provided by the EA because the MOD has provided no 
information on the  "details of the calculations and assumptions used to arrive a this figure and 
also information about the statistical uncertainty of the figure"

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