AWE Aldermaston • Reading Berkshire • RG7 4PR www.awe.co.uk Ref : FOI2024-004 26th February 2024 Dear [Redacted] Further to our previous correspondence regarding your request for the following information: Can you please tell me: i) how many files, in total are in the Merlin database (I assume this could be in any relevant unit, bytes, pages, or number of document titles). ii) a description of the overall purpose and content of the Merlin database; iii) the security classification of the highest individual document, which will therefore be the security classification for the collection as a whole; iv) the required level of security clearance any official would need to have in order to access any part of this database, bearing in mind they must have sufficient clearance to view the highest individual document even to see other documents with a lower rating; v) the security classification of the lowest individual document; vi) if it's possible, a precise figure, or estimate, of how much of the Merlin database is at each level of security classification, ie 40% top secret, 60% confidential Your request has been handled as a request for information under the Freedom of Information Act 2000 (the Act). A search for the requested information within the Atomic Weapons Establishment (AWE) has now been completed, and we can confirm that information in scope of your request is held. We will address each of your questions in turn: i) How many files, in total are in the Merlin database? There are 28330 records listed in the database. ii) A description of the overall purpose and content of the Merlin database. The Merlin database was created in 2007 at the request of the Ministry of Defence and is held by AWE. The database contains records relating to historic technical and scientific documentation on the UK’s nuclear testing programme. It was developed to store relevant factual documentary evidence for the MOD to take into account when considering nuclear test veterans’ compensation claims but does not include medical records. iii) The security classification of the highest individual document. Secret Atomic iv) The required level of security clearance any official would need to have access. All officials accessing the database require Developed Vetting (DV). Under S 16 (advice and assistance), it may be useful for you to note that; DV clearance is one of the most comprehensive forms of security vetting and is what is needed if your position requires you to have substantial access to TOP SECRET assets. AWE Aldermaston • Reading Berkshire • RG7 4PR www.awe.co.uk v) The security classification of the lowest individual document. The lowest individual document is classified as ‘UNCLASSIFIED’, under S 16 advice and assistance this would be classified as ‘Official’ in the current administrative system which uses three classification tiers (OFFICIAL, SECRET and TOP SECRET) each provide a set of protective security controls and baseline behaviours. As the Merlin database is a standalone, read-only system protected from modification; the documents bear the original classification, with today’s equivalent determining how the documents are handled. vi) If possible, a precise figure, or estimate, of how much of the Merlin database is at each level of security classification. This information is not held, Under S 16 advice and assistance; it might be useful for you to note that it is not possible to search according to classification. Please remember to quote the reference number above in any future communications. If you have any queries regarding the content of this letter, please contact this office in the first instance. If you are unhappy with the way your request has been handled you have a right to request an internal review within 40 days of receiving this letter, by writing to [email protected] or our postal address: Information Requests Team, AWE Aldermaston, Reading, RG7 4PR. If you are still unhappy after an internal review has been completed, under the provisions of Section 50 of the Freedom of Information Act 2000 you have the right to take your complaint to the Information Commissioner’s Office. Please note the Commissioner will generally not consider a complaint until you have exhausted AWE’s internal complaints process. Yours sincerely, AWE Information Requests Team