This is an HTML version of an attachment to the Freedom of Information request 'Chatham Carbon 14'.

DE&S Policy Secretariat 
Maple 0a, #2043 
MOD Abbey Wood 
BS34 8JH 
[email address] 
Fred W P Dawson 
Our Reference:  
via: request-172609-
[email address] 
Date: 8 November 2013 
Dear Mr Dawson, 
Further to my letter of 4 November, I am now in a position to provide you with a 
substantive response to your request, in which you ask for additional information about the 
presence of Carbon-14 (C-14) at the Chatham Docks site. 
As I confirmed in my letter of 9 September, the Ministry of Defence (MOD) does hold 
information within the scope of your request. I shall address each of your questions in turn: 
Could you please provide me with details of the calculations and 
assumptions used to arrive at this figure (0.95 GBq of Carbon 14) and also 
information about the statistical uncertainty of the figure. 
Some of the information we hold was previously provided to you in the MOD’s email of 9 
October 2009, in response to your Request For Information (RFI), reference 18-09-2009-
162855-001.  This confirmed that a methodology known as the Mass Balance Hypothesis 
was used to estimate the quantity of C-14 present at the Chatham site.  It also confirmed 
that the quantity of C-14 in radioactive waste arising from the Naval Nuclear Propulsion 
Programme is divided between the different ultimate waste stream types, and at the 
Chatham site these waste streams comprise “hard trash” and “soft trash”.   
Our records also show that this hard and soft trash is estimated to contain 1/50th of the C-
14 found in boat resins. The boat resins from Chatham contained 47.52 GBq of C-14 and 
thus the hard and soft trash generated at Chatham is estimated to contain 0.95 GBq of C-
14. A proportion of the hard and soft trash was disposed of at the Chatham burial site with 
the rest disposed of at other locations. When this estimate was made, the information on 
the proportion disposed of at the Chatham burial site was not readily available.  Therefore 
the total quantity of C-14 in hard and soft trash across all locations was used as the 
maximum value of C-14 disposed of at the Chatham site. 
The Mass Balance Hypothesis uses a best estimate approach in calculating C-14 in 
ultimate waste streams.  This is because the variation in basic data could be up to a factor 
of ten and thus no meaningful statistical uncertainty could be applied to the value of 0.95 

Could you provide me with information about the updated risk assessment 
for the burial site to take account of Carbon 14.  
I again refer you to the MOD’s email of 9 October 2009 in response to your RFI, reference 
18-09-2009-162855-001.  This email states that the MOD does not hold information about 
the updated risk assessment.  After a further search in response to this current request, I 
can confirm again that the MOD does not hold information relevant to this question.  
Outside of EIR, however, I can confirm that we understand that the Environment Agency’s 
(EA) position is that they do not “see any need to revisit the MOD risk assessment at this 
Could you provide information why Carbon 14 has not been included in the 
environmental survey reports. 
The information we hold was included in the letter sent on behalf of the Director General 
Ship Refitting (Submarines), which was released as part of the MOD’s response of 9 
October 2009 to your RFI, reference 18-09-2009-162855-001.  This letter confirms that 
Cobalt-60 (Co-60) is viewed as the dominant risk, and so it can be assumed, therefore, 
that the presence of C-14 at the Chatham site is not of enough significance to warrant 
inclusion in environmental survey reports. 
Outside EIR, however, we can confirm our understanding that the EA acknowledges that 
C-14 monitoring is not necessary based on current regulatory requirements.  This is 
because the level of C-14 present at the site is significantly below the minimum level for 
monitoring of 10 GBq.  There is no regulatory requirement, therefore, to conduct 
environmental survey reports for C-14 specifically. 
Also, whether or not the MOD has now informed the Environmental Agency 
that Carbon 14 was also disposed by burial at Chatham when the original agreement 
from the then HMIP was for Cobalt 60. 
In summary, the answer to this question is “yes”. 
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. 
I can confirm that the MOD does hold the following information that is relevant to this 
The Chatham low level radioactive waste repository was formally approved by Her 
Majesty’s Inspectorate of Pollution (HMIP), now Environment Agency.  Approval by 
certificate was granted with conditions of timescale of future tenure and use issued 
in 1980’s, the navy is now searching the archives for this certificate.  Without this 
we are unable to progress at the moment. The continuing monitoring regime data is 
sent to EA and may well  be available directly from their website as it is deemed to 
be in the public domain.  We will however follow up enquiries with DSTL who carry 
out the monitoring in order to establish the way forward. 

As you will be aware, however, there are provisions in EIR under which some information 
is exempt from release.  It has been judged that a small amount of additional information in 
scope of this request is subject to Exception 12(5)(e), “confidentiality of commercial or 
industrial information”.  As with all EIR exceptions, this is a qualified exception, and so an 
assessment of the balance of public interest in releasing or withholding the information has 
been carried out. 

The factors considered in favour of release include the MOD’s commitment to openness 
and transparency in its commercial activities. The factors against release include prejudice 
to the commercial interests of, and relationship between, the MOD and the developer, 
which would be caused by the MOD releasing details of the developer’s commercial 
activities before the developer discloses them itself.  This would, in turn, harm the MOD’s 
ability to achieve best value for money for the taxpayer. The MOD considers that the 
balance of public interest rests in withholding this information under Exception 12(5)(e). 
If you are not satisfied with this response or wish to complain about any aspect of the 
handling of your request, then you should contact me in the first instance. If informal 
resolution is not possible and you are still dissatisfied then you may apply for an 
independent internal review by contacting the Deputy Chief Information Officer, 2nd Floor, 
MOD Main Building, Whitehall, SW1A 2HB (e-mail [email address]). Please note that 
any request for an internal review must be made within 40 working days of the date on 
which the attempt to reach informal resolution has come to an end.  
If you remain dissatisfied following an internal review, you may take your complaint to the 
Information Commissioner under the provisions of Section 50 of the Freedom of 
Information Act. Please note that the Information Commissioner will not investigate your 
case until the MOD internal review process has been completed. Further details of the role 
and powers of the Information Commissioner can be found on the Commissioner's 
DE&S Policy Secretariat