DE&S Policy Secretariat
Maple 0a, #2043
MOD Abbey Wood
Fred W P Dawson
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: Q1.
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. Q4.
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 website, http://www.ico.gov.uk
DE&S Policy Secretariat