Viewpoint by Tariq Rauf*
VIENNA (IDN) — Coming up to the one-year mark following the announcement of the AUKUS agreement on the supply of nuclear-powered submarines (SSNs) to the Royal Australian Navy (RAN), the International Atomic Energy Agency (IAEA) continues to struggle to deal with the challenge to the efficacy and credibility of the Agency’s nuclear safeguards (verification) system created by AUKUS.
On 9 September 2022, the IAEA Director General issued his long-promised report on “IAEA safeguards in relation to AUKUS” that is available to the Agency Member States but not publicly. The 5-page report is disappointing as it is covering merely procedural and administrative matters; it is deficient in outlining critical safeguards technical and implementation questions; and it advances some questionable interpretations regarding the nuclear Non-Proliferation Treaty (NPT).
This treatise will assess, in a preliminary manner, the IAEA report with a view to identifying critical issues and questions that require definitional and interpretation clarity, safeguards criteria and approach for naval nuclear propulsion in a NPT non-nuclear-weapon State (NNWS), and advance recommendations for further work and consultation with all interested NPT NNWS members of the Agency. The intention here is not to single out Australia or to question its NPT and Agency safeguards compliance, though trust but verify should be the universal standard; but to shed light on the many open questions and concerns about naval nuclear propulsion and safeguards in NPT NNWS.
Before proceeding further, I should like to note for the record that I have been dealing with the IAEA safeguards aspects of naval nuclear propulsion since 1987 and picked up again on the matter in September 2021 on the announcement of AUKUS. The various assessments published by me (inter alia here, here, and here) are exclusively my own views, not influenced by any States nor other parties.
These are meant to promote further discussion on and understanding of the complex issues concerning the “loophole” or “grey area” in comprehensive safeguards agreements (IAEA INFCIRC/153 Corr., paragraph 14) that relates to the “Non-Application of Safeguards to Nuclear Material to be Used in Non-Peaceful Activities”. Finally, my independent research and publications on this matter are not funded by any entity or party, nor is funding or endorsement sought for this purpose.
IAEA AUKUS Report
It is quite remarkable that the Director General makes some extravagant claims regarding the use nuclear material, in particular that: (a) “ It is inferred from the NPT (Articles I and II) that States are not precluded from using nuclear material that has been under safeguards in military non-explosive uses”; and (b) “Provisions rearguing the non-application of safeguards to nuclear material to be used in non-peaceful activities, e.g. in a non-proscribed military activity such as nuclear-powered submarines were included in para. 14 of INFCIRC/153 which has been used as the basis for negotiating safeguards agreements between the Agency and non-nuclear-weapon States party to the NPT”.
The IAEA report cites from the negotiating record of the special committee of the Agency’s Board of Governors (Committee 22/COM.22) that drafted INFCIRC/153 as the model safeguards agreement for NNWS party to the NPT. Unfortunately, now even after fifty years the Agency has not derestricted the proceedings on COM.22 and my request to the Director General for access to the records has remained unanswered.
This is in stark contrast to my time at the Agency when I would routinely approve access to Agency archives to bona fide researchers—one notable such instance was granting access to archives to the Nuclear Proliferation International History Project of the Wilson Centre in Washington that resulted in the publication in April this year of a book entitled, Inspectors for Peace: A History of the International Atomic Energy Agency.
Given the importance of the matter of the negotiating background and considerations relating to para. 14 of INFCIRC/153, it is essential that the full record of COM.22 is derestricted and made available to interested researchers, especially as half a century has elapsed.
The only other archival reference is the declassified negotiating history of INFCIRC/153 prepared for the US Arms Control and Disarmament Agency (ACDA)—established by US President John Kennedy after the 1962 Cuban Missile Crisis to provide independent advice to the US President. Unfortunately, ACDA was sacrificed in 1997 by US President William Clinton as he was blackmailed to secure Senate consent for ratification of the Chemical Weapons Convention—ACDA was finally abolished in April 1999.
I would not have been surprised if ACDA, had it survived, would have opposed exercise of para. 14 (INFCIRC/153) exemption of nuclear material from Agency safeguards, had it survived to this day. The ACDA negotiating history of INFCIRC/153 cannot be regarded as an official document for Agency purposes as it is the work of a Member State and thus cannot be compared for reliability and authority to the Agency’s records of COM.22.
Now as regards the “inference” that NPT Articles II and III do not preclude States from using nuclear material that has been under Agency safeguards in military non-explosive applications”; though that has long been the view, the “inference” has to be documented and validated.
The negotiating record of the NPT that used to be kept in the Library of the UN Department for Disarmament Affairs at the Palais des Nations in Geneva seems to have been misplaced the last time I personally checked several years ago.
The only other reliable but unofficial negotiating history of the NPT is the three-volume publication Mohamed Shaker, The Nuclear Non-Proliferation Treaty, Origin and Implementation 1959–1979, that provides little insight into the matter of non-proscribed, non-peaceful or non-explosive military activities in NNWS. Mohamed Shaker was a young Egyptian diplomat in Geneva at the time and wrote the tome for his degree work in Geneva.
In the late 1960s and 1970s reportedly there was interest in nuclear ship propulsion and the Otto Hahn (German) and Mutsu (Japanese) nuclear-powered commercial vessels, I am informed, were subject to IAEA inspections.
A reliable record must be found that supports claims that naval nuclear propulsion outside of NPT safeguards was part of the negotiations on the Treaty. What is clear is that there was consideration during the mid- to late-1960s of a NATO Multilateral Force (MLF) that envisioned multinationally crewed nuclear-armed naval platforms under NATO aegis, that might have included nuclear-powered ships and submarines; however, the MLF never materialized and the proposition was shelved as it could not be condoned under a nuclear non-proliferation treaty.
Finally in this particular context, it is beyond the mandate of the Agency’s Secretariat or IAEA Member States to “infer from the NPT”; that is exclusively for States Parties to the Treaty.
Another historical anomaly is that I cannot find a reference in the final document of the First NPT Review Conference (1975), or for in the outcome documents of subsequent review conferences, in which the States Parties formally accept, adopt or endorse INFCIRC/153 as meeting the intent and purposes of NPT Article III.1. I stand ready to be corrected on this specific matter.
This should be a matter of concern, as one would have expected States Parties to have endorsed INFCIRC/153 as providing the “structure and content” for safeguards required pursuant to Article III.1—especially as INFCIRC/153 was finalized in 1972 and approved by the Agency’s Board of Governors as providing the model for safeguards agreement between the IAEA and NNWS party to the NPT.
If indeed it is the case that NPT States Parties have never formally endorsed INFCIRC/153 as the model agreement for safeguards required pursuant to Article III.1, then the case is moot that States Parties have accepted the INFCIRC/153 para. 14 provisions as allowing for exemption from mandatory IAEA safeguards of nuclear material to be used in non-proscribed non-peaceful activities.
Returning to the IAEA report, it correctly asserts that, “The Director General recalled that under a comprehensive safeguards agreement (CSA), a State undertook to accept Agency safeguards on all nuclear material in all peaceful nuclear activities within its territory, under its jurisdiction or carried out under its control anywhere. He also noted the provision in the CSA regarding the non-application of safeguards to nuclear material to be used by States in certain non-proscribed military activities” (all emphasis here and later by this author).
The report states further that, “The Agency’s aim is to ensure that the safeguards measures and approach to be used in the context of naval nuclear propulsion under AUKUS will enable the Agency to attain the technical objectives established for Australia. The Agency’s capability to develop suitable verification measures and approach in the context of naval nuclear propulsion under AUKUS is enhanced by Australia having in force and implementing the AP [Additional Protocol]”.
The Director General informs that, “In its letter to Australia [of 24 September 2021], the Agency reminded that country that, in accordance with modified Code 3.1 of the Subsidiary Arrangements (General Part) to the CSA, Australia was required to provide early design information for any new facility as soon as it had decided to construct or authorize construction of such a facility, including in connection with its plans to acquire nuclear-powered submarines. Australia was also required, under its AP, to provide to the Agency information on its general plans for the succeeding ten-year period relevant to the development of the nuclear fuel cycle (NFC), including those related to NFC-related research and development activities, when approved by the appropriate authorities in Australia. Australia, in its reply dated 31 January 2022, informed the Agency that it had yet to take a decision “to either construct or authorise construction of any nuclear facility in connection with the acquisition of nuclear-powered submarines”. Australia reiterated that it remained “fully committed to meeting its obligations and commitments”, including those related to reporting, under the NPT, CSA and associated Subsidiary Arrangements, and the AP”.
The IAEA report further notes that, “In the annual update of the AP declarations for 2021, Australia submitted to the Agency on 10 May 2022 a declaration relating to the AUKUS partnership in which Australia reported that a framework for the disclosure and use of information relevant to naval nuclear propulsion among the three partners in AUKUS had been established to enable Australia to determine the optimal pathway to deliver conventionally-armed, nuclear-powered submarines. Australia further informed the Agency that, as of March 2022: no activities listed in Annex I of the AP had either been conducted or were planned; no transfers of equipment/material listed in Annex II of the AP had either taken place or were planned; and no decision had been taken to construct or otherwise acquire any nuclear reactor or other nuclear facility in connection with AUKUS. Australia stated in this declaration that it “does not intend to undertake enrichment of nuclear material or reprocessing of nuclear fuel in support of the nuclear powered submarine program””.
In addition, the IAEA report states that, “In a letter to the Director General dated 21 July 2022, Australia, on behalf of the AUKUS parties, stated, inter alia, that the AUKUS parties sought an optimal pathway to deliver a conventionally-armed, nuclear-powered submarine capability to Australia. According to Australia, their approach is framed by four key elements:
(i) with regard to the nuclear fuel cycle, Australia stated that it “will not pursue uranium enrichment or reprocessing in relation to this initiative” and has “no plans to undertake nuclear fuel fabrication as part of this effort”;
(ii) “it is proposed that Australia would be provided with complete, welded power units. These power units are designed so that removal of any nuclear material would be extremely difficult and would render the power unit, and the submarine, inoperable. Further, the nuclear material inside of these reactors would not be in a form that can be directly used in nuclear weapons without further chemical processing, requiring facilities that Australia does not have and will not seek”;
(iii) Australia stated that it was “already engaging the IAEA regularly with respect to the development of a suitable verification approach to confirm the non-diversion of nuclear material from Australian nuclear-powered submarines. Developing the detail of the verification process will take some time, but we have already confirmed our approach will operate under Australia’s CSA and its AP”; and
(iv) “Australia will work with the IAEA to continue to implement and deepen additional safeguards measures outside of the nuclear-powered submarine program to maintain international confidence that there is no undeclared nuclear material or activity in Australia. Those measures may include enhanced use of transparency and access under Australia’s CSA and AP, and, where relevant, the voluntary development of new measures with the IAEA””.
Safeguards and Naval Nuclear Propulsion
The matter of IAEA safeguards and naval nuclear propulsion was discussed at some length at the Tenth Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), held at United Nations headquarters in New York on 1-26 August 2022. The conference was unable to agree on a final document and thus came to an inconclusive end. The matter of naval nuclear propulsion was considered in Main Committee II (non-proliferation and safeguards). The draft final document of the Review Conference went through three draft versions, but the final version was considerably weakened as noted below:
NPT/CONF.2020/CRP.1 (22 August 2022) (paragraph. 36): The Conference notes that the use of nuclear material in non-proscribed military activities provided for under comprehensive safeguards agreements, in particular with respect to the topic of naval nuclear propulsion, has generated interest among States parties to the Treaty regarding, inter alia, arrangements to ensure that such nuclear material will not be used for the production of nuclear weapons or other nuclear explosive devices. In this regard, the Conference notes the importance of the IAEA’s consideration, in consultation with the States concerned, of arrangements related to naval nuclear propulsion and for continuing dialogue and transparency in accordance with the rules of the relevant bodies.
NPT/CONF.2020/CRP.1/Rev.1 (25 August 2022) (paragraph 36): The Conference notes that the use of nuclear material in non-proscribed military activities provided for under comprehensive safeguards agreements, in particular with respect to the topic of naval nuclear propulsion, has generated interest among States parties to the Treaty regarding, inter alia, verification arrangements to ensure that such nuclear material will not be diverted to nuclear weapons or other nuclear explosive devices.
In this regard, the Conference recognizes that the States concerned should continue to engage with the IAEA on the issue, in line with the relevant safeguards agreements, and that the IAEA Director General should report relevant developments to the wider IAEA membership in accordance with established practices of the IAEA’s policy-making organs.
NPT/CONF.2020/CRP.1/Rev.2 (25 August 2022) (paragraph 36): The Conference notes that the topic of naval nuclear propulsion is of interest to the States Parties to the Treaty. The Conference also notes the importance of transparent and open dialogue on this topic. The Conference further notes that Non-Nuclear-Weapon States that pursue naval nuclear propulsion should engage with the IAEA in an open and transparent manner.
The reason for citing the draft recommendations of the NPT Review Conference is to show that the final version called for a “transparent and open dialogue” on this matter at the IAEA. Reportedly the States that negotiated the text on naval nuclear propulsion at the NPT review conference included Australia, Brazil, China, the UK and the US. It is hoped that these States shall in fact follow through on this recommendation at meetings of the IAEA Board of Governors and General Conference and further that the Agency reports on the matter in an open and fulsome manner.
Now reverting to the IAEA report on “IAEA safeguards in relation to AUKUS”, portions of which are excerpted in the preceding section; it notes that several “technical meetings” have been held between the Agency and the three parties to the AUKUS agreement, but no details or information is provided on the safeguards approach to and safeguards objectives for naval nuclear propulsion.
At present, in addition to Australia, Brazil too has informed the Agency about its indigenous naval nuclear propulsion programme – see my earlier article, Nuclear Submarines and the Non-Proliferation Treaty: Brazil Gets a Jump on Australia? Thus, the IAEA is grappling with naval nuclear propulsion at two levels: (i) importation of naval nuclear propulsion technology (reactors) and nuclear fuel by Australia; and (ii) indigenous development of naval nuclear propulsion fuel cycle (fuel and reactors) by Brazil. In both cases exemption from full-scope safeguards will be sought by the respective parties, even though in the case of Brazil under the Quadripartite Agreement (on safeguards implementation in Brazil), naval nuclear propulsion is characterized a “peaceful activity”.
Notwithstanding the differences in approach between Australia and Brazil on acquisition of naval nuclear propulsion technology, the critical safeguards concerns and procedures essentially remain the same.
The Agency already has indicated that uranium enrichment technology for naval nuclear propulsion cannot be exempted from safeguards as the technology per se cannot be considered as a “non-peaceful activity” or a “non-proscribed military activity” as envisaged under paragraph 14 of the comprehensive safeguards agreement (INFCIRC/153 Corr.).
On 20 August 1987, the IAEA in response to my enquiry stated that, “processes such as enrichment or reprocessing to produce materials for use in such an activity would not themselves be considered as non-proscribed military uses and would therefore be subject to safeguards in the NNWS [non-nuclear-weapon State] concerned” (reproduced from Aurora Papers 8).
Hence, in Brazil uranium enrichment for naval nuclear propulsion would be subject to safeguards under IAEA safeguards pursuant to the 1991 Agreement between the Republic of Argentina, the Federative Republic of Brazil, the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials and the International Atomic Energy Agency for the Application of Safeguards, Quadripartite Agreement, reproduced in IAEA INFCIRC/435 which also serves since 30 July 1999 as Brazil’s safeguards agreement under the NPT (IAEA INFCIRC/435/Mod.3 dated 2 March 2000).
As for Australia, the IAEA report as referred above notes that Australia will not pursue uranium enrichment or reprocessing for naval nuclear propulsion; has no plans to undertake nuclear fuel fabrication as part of this effort; and would be provided with complete, welded naval nuclear propulsion power units (reactors).
The Problem
As I have previously argued, the problem the IAEA is facing concerns what has been referred to above, i.e., the exemption from safeguards of naval nuclear propulsion reactors and nuclear fuel. Not only is there not any definition or interpretation of the INFCIRC/153 Corr. paragraph 14 exemptions, nor of what is meant by “non-peaceful” and “non-proscribed” military activities, and there is no understanding of, or procedures to, implement paragraph 14 provisions.
Referring again to the IAEA response on 20 August 1987 to my enquiry that, “To the Secretariat’s knowledge there is no formal definition of “non-proscribed military activity”. We understand that at the time of preparing INFCIRC/153 naval propulsion was considered as the most likely use … [and that the drafters of INFCIRC/153] favoured a narrow construction of the term “non-proscribed military activity”, (reproduced from Aurora Papers 8).
Thus, for any States to take it upon themselves to interpret and to define possible paragraph 14 exemptions, with or without the IAEA Secretariat’s involvement, cannot command confidence without adequate consultations involving interested Member States and international experts. All IAEA Member States are equal under the Agency’s Statute, and all States with INFCIRC/153 (Corr.) type safeguards agreements in force have an equal stake in how the structure and content of comprehensive safeguards agreements are concluded and implemented even taking into account the differing levels and extent of their respective nuclear fuel cycles and activities.
Drafting and subsequent changes and amendments, interpretations and practices of Agency safeguards agreements traditionally have been considered in consultations involving all interested IAEA Member States in accordance with the Agency’s Statute. Such consultations involving all interested Agency Member States were carried out for the development of INFCIRC/66, INFCIRC/153 (Corr.) and INFCIRC/540 (Additional Protocol) safeguards measures and for the rescission of and modifications to Small Quantities Protocols (SQPs) for States with comprehensive safeguards agreements, before they were brought before the Board for approval. At the 2005 IAEA General Conference, Director General Mohamed ElBaradei stated that, “Since February [2005], the Secretariat has been consulting with Member States on this issue [SQPs], with a view to identifying possible remedies”.
To further reinforce this point, it should be recalled that in 2005 the IAEA Board established a special committee (Committee 25) to consider further strengthening measures for safeguards (as proposed by the US). The Director General’s report to the IAEA General Conference in 2006 stated that, “In June 2005, the Board of Governors established the Advisory Committee on Safeguards and Verification within the Framework of the IAEA Statute, otherwise known as Committee 25. Committee 25 was established, with an initial two-year mandate, to consider ways and means to strengthen the safeguards system and to make relevant recommendations to the Board”.
In the annual Resolution on safeguards adopted on 22 September 2006, the General Conference in the resolution’s operational paragraphs:
“8. Acknowledges the work of the Advisory Committee on Safeguards and Verification within the Framework of the Agency’s Statute in accordance with the Board’s decision in June 2005, in whose work all Member States may participate, to consider ways and means to strengthen the safeguards system, and to report thereon, with recommendations, to the Board, and appreciates the Secretariat’s efforts in supporting that work;
9. Attaches great importance to the Committee’s making every effort to take any decisions or make any recommendations by consensus within the Agency’s statutory responsibilities”.
Thus, it is abundantly clear that it has been the IAEA’s established practice to consult with Member States and to seek their involvement and approval for any and all substantive matters concerning the Agency’s safeguards system, as regards amendments, changes or interpretations. Such good practice enables buy-in from all Agency Member States and leads to uniform acceptance of procedures and obligations, and thus provides a common agreed foundation for the Board to approve individual safeguards agreements as well as changes or interpretations drawn up on the basis of the agreed standardized texts.
Thus, past practice clearly establishes that no Agency Member State or group of such States can unilaterally take up discussing significant aspects of safeguards implementation, with or without Secretariat involvement that will lead to critical alterations or limitations that have implications for the Agency’s safeguards system.
Hence, the point here is that implementation of paragraph 14 derived safeguards exemptions necessarily must first be discussed in consultations or negotiations involving all interested Agency Member States to arrive at common understandings that can be put before the Board for its consideration and approval. Neither Australia or AUKUS, nor Brazil, is being singled out; the matter is bigger and broader than them and concerns all Agency Member States.
Conclusion
This discussion clearly shows that the IAEA’s nuclear verification/safeguards system is facing an unprecedented challenge in dealing with the naval nuclear propulsion programmes of Australia and Brazil. Exempting nuclear material and nuclear reactors for naval use from safeguards will result in creating within the NPT/IAEA regime new arrangements under which a State can operate two parallel nuclear programmes, one under and one outside IAEA safeguards.
This would weaken the uniformity of the structure and implementation of comprehensive Agency safeguards in NPT non-nuclear-weapon States (NNWS).
Both Australia and Brazil in exercising relevant provisions for safeguards exemptions would be creating a big gap as regards significant quantities of enriched uranium naval nuclear propulsion use – 200 to 250 kg of up to 97.3% HEU per boat for a total to 1.6 to 2.0 metric tonnes that is 1600 to 2000 kg in the case of Australia; the quantities in Brazil’s naval nuclear fuel cycle cannot be estimated given lack of information. Recall, that for safeguards purposes, the IAEA calculates a Significant Quantity (SQ) as 25kg of HEU even though with modern designs a nuclear warhead can be fabricated with as little as 5 kg.
Another important consideration is that the Agency’s Statute prohibits it being involved to “further any military purpose”. Now, it could be argued that in exempting significant quantities of enriched uranium naval fuel from comprehensive safeguards for a State’s navy, the Agency could be furthering a military purpose – that of facilitating military operations by nuclear-powered naval ships or submarines — even though this does not involve Agency projects.
Thus, there could be an inherent tension or contradiction between the Agency’s Statutory obligations and the provisions of IAEA/ABACC comprehensive safeguards agreements. The drafters and negotiators of the text of INFCIRC/153, in hindsight, seem to have been blissfully unaware of this possible tension with the Statute when they were drafting the provisions of paragraph 14.
There is an Agency document dealing with this matter, GOV/INF/433 (1983) that also must be derestricted by the Secretariat, as should all other documents addressing directly or indirectly the matter of naval nuclear propulsion and non-proscribed non-peaceful activities — what does the Secretariat have to hide in this context?
Should Australia or Brazil, or any other NPT NNWS, be able to exercise exemptions from NPT/IAEA/ABACC comprehensive safeguards without prior understanding of, and agreement on, the modalities involved and prior approval of the Agency’s Board of Governors beggars belief. The only practical and rational way forward is for the IAEA Board of Governors and interested Member States through open-ended working group consultations to arrive at a clear and common understanding on how to interpret and implement exemptions on a non-discriminatory and uniform basis; and further to consider whether to close off this loophole” for good. And, for the IAEA Secretariat to derestrict any and all documents pertaining to the negotiation of INFCIRC/153.
Should the INFCIRC/153 (Corr.), para. 14 provisions for exemption from safeguards of naval nuclear propulsion be exercised, that would add yet another layer of discrimination in the NPT to that between nuclear-weapon and non-nuclear-weapon States by creating a new category of NNWS with significant quantities of (weapon-grade) nuclear material out of NPT safeguards.
My recommendations are as follows:
- The IAEA Board of Governors needs to establish an open-ended working group, or consultations mechanism, to examine in detail the issues in particular, inter alia, definitions of: non-peaceful activities; non-proscribed military activity; period of non-application of safeguards; arrangement for non-application of safeguards; temporal and procedural provisions; reporting arrangements; classified knowledge of the military activity; the use of the nuclear material therein as used in paragraph 14 (INFCIRC/153/Corr.). And definitions of: special procedures; non-proscribed nuclear activity, the period or circumstances during which the special procedures shall be applied; reporting arrangements; classified knowledge of such activity or relate to the use of the nuclear material therein, as used in paragraph 13 (INFCIRC/435) Quadripartite Agreement. There are several precedents of the IAEA Board previously having established open-ended working groups on safeguards implementation matters such as on “93+2” strengthened safeguards, additional protocol, SQPs, and the Advisory Committee on Safeguards and Verification (Committee 25) in June 2005.
- The IAEA Secretariat needs to be fully open and transparent and forthwith derestrict and make publicly available all documentation and records pertaining to the negotiation of INFCIRC/153 as well as to naval nuclear propulsion. The cloak of secrecy must be lifted forthwith.
*Tariq Rauf is former Head of Verification and Security Policy Coordination, Alternate Head of IAEA NPT Delegation, Office reporting to the Director General, International Atomic Energy Agency (2002-2011), responsible for safeguards and nuclear security, Director General’s annual report on the Application of Safeguards in the Middle East and for the IAEA Forum on the Experience of NWFZs relevant for the Middle East. Prior to joining the IAEA, he prepared the early drafts of the Central Asian NWFZ Treaty, and assisted Mongolia in formulating its nuclear-weapon-free status legislation and UN recognition. He is involved in the work of METO as a pro bono technical expert on matters pertaining to a Middle East NWFZ. Personal comments are 1presented for purposes of discussion and information. [IDN-InDepthNews – 13 September 2022]
Image: (Left) US Navy Virginia-class SSN, courtesy of General Dynamics Electric Boat Public Affairs, Creative Commons Licence 040730-N-1234E-002); Right: Royal Navy Astute-class SSN, courtesy Royal Navy MoD.