Enclosure 1 ~ THE INVOLVEMENT OF TH E ROYAL NEW ZEALAND NAVY IN THE BRITISH NUCLEAR TESTING PROGRAMMES OF 1957 AND 195 8 J A B Crawford, Research Officer (History) ~ ~ ~ t HEADQUARTERS NEW ZEALAND DEFENCE FORC E WELLINGTON, 1989 ~ ~ ~ ~ TABLE OF CONTENTS Page Glossary ii - iv Chapter I Introduction 1 - 16 Chapter II : The 1957 Test Series 17 - 48 Chapter III : The 1958 Test Series 49 - 58 Appendices : I The positions of HMNZS ROTOITI and PUKAKI 59 - 61 ~ during Operation Grapple Nuclear Test s II The time spent by HMNZS ROTOITI and 62 - 63 ' HMNZS PUKAKI at Christmas Island afte r the Grapple X Tes t III Map of Christmas Island 64 Bibliography 65 - 68 i ~ l ~ 1 1 GLOSSARY ~ Absorbed dose : Some of the energy of ionising radiation is transferred to the matter through which it passes . The absorbed dose is the amount of energy transferred to a unit mass of material (1 gray (q .v .) = 1 joule per kilogram) . Activation: Some of the neutrons released in fission are captured by atoms in the surrounding materials, e .g . soils, structural materials or atmospheric gases . Many of the resulting atoms are radioactive and are known as activation products . This process of producing radioactive materials is known as activation, producing 'induced radioactivity' (q .v .) . Air burst : A nuclear explosion at such a height that the expanding fireball does not touch the earth's surface . Alpha radiation : Some radioactive elements, particularly those with a high atomic number decay by emitting a positively charged particle, the ~ alpha particle, which is identical with the nucleus of a helium atom . ~ Alpha radiation has very little penetrating power, but it may present a serious hazard if alpha emitters are inhaled or ingested . ~ Background radiation : The naturally occurring radioactive isotopes in the surroundings and in biological tissue produce a background radiation . Cosmic rays also contribute to the background radiation . Background reading on instruments : Unavoidable reading on any instrument measuring radiation, usually caused by background radiation and instrumental effects . Beta radiation : Some radioactive elements emit from the nucleus charged particlesof low particles, mass called bet whicha are identical to the electrons in the atom . Fission products generally emit negative beta particles . Beta particles have a penetrating power intermediate between that of alpha and gamma radiation . Contamination : The deposit of radioactive material on or within structures, land, people or animals following dispersal of the radioactive material, e .g . by a nuclear explosion or dust raising activities . Decontamination : The removal or reduction of contaminating radioactive material from persons, equipment, structures or areas . Dose : The amount of energy delivered to a mass of material by ionising radiation passing through it . ~ Fallout : The descent to the earth's surface of particles contaminated with radioactivity, following the dispersion of radioactive material into the atmosphere by a nuclear explosion . The term is applied both to the ~ process and, in a collective sense, to the particulate matter . The early fallout consists of the particles which reach the earth's surface within ~ 24 hours . The delayed fall-out consists of smaller particles which may be carried by wind to great distances and even completely around th e Y earth many times before descent . Fast neutron : Neutrons p roduced by neutron reactions or resulting from fission of fissile materials but which have lost relatively little of their initial energy as a result of collisions with atoms . Film badge : A plastic holder containing a piece of film usually the size of a dental X-ray film . The film is subsequently developed and the degree of darkening is a measure of the radiation dose received . The film holder usually contains various metal filters to provide some discrimination for different types and energies of radiation . Fireball : Almost immediately after a nuclear explosion the residues and surrounding materials form an intensely hot and luminous mass, the fireball . This expands and rises rapidly, cooling in the process . Fission : The process whereby the nucleus of a heavy element, e .g . uranium or plutonium, splits into two nuclei of lighter elements (fission products : q .v.) accompanied by the release of substantial amounts of energy . ► ~ Fission products : The complex mixture of substances produced in the process of nuclear fission . The primary fragments produced in fission are themselves radioactive, and decay through a succession of radioactive isotopes until a stable form is reached . ~ Fusion: The process in which the nuclei of light elements, in particular the isotopes of hydrogen, deuterium and tritium, combine to form a nucleus of a heavier element accompanied by the release of substantial amounts of energy . Fusion reactions can only be initiated by very high temperatures in excess of about ten million degrees Celsius ; in thermonuclear or 'hydrogen' weapons such temperatures are provided by a boosted fission explosion . Gamma radiation : Most radioactive elements emit from the nucleus electromagnetic radiation called gamma rays . Gamma radiation is penetrating and can cause radiation exposure many tens of metres from external sources . It is also the radiation that is most readily measured by monitoring equipment such as film badges and dosimeters . Gray : The SI unit of absorbed dose (q .v.) . The gray replaced the rad (q .v .) as the unit of absorbed dose (1 gray = 100 rad) . Ground zero : The point on the ground surface at, or directly below, the ~ initiating point of a nuclear explosion. Induced radioactivity : The radioactivity of nuclides produced from ~ naturally stable nuclides, as the result of nuclear reactions with neutrons . Radioactivity is induced in materials close to a nuclear explosion by the absorption of the neutrons given off by the explosion . ~ i ~ iv Milliroentgen : The one-thousandth part of a roentgen . Rad : The former unit of absorbed dose (q .v .) . It was defined as the absorption of 100 ergs per gram and is equivalent to 1/100 of 1 gray . Roentgen : The old unit exposure to X-rays or gamma radiation . It is defined as the quantity of radiation that will produce 2 .58 x 10-4 coulomb s per kilogram of dry air . An exposure of 1 roentgen is roughly (equivalent to an absorbed dose of 1 rad (q .v.), or 0 .01 gray (q .v.), in soft tissue . Thermonuclear : The process of fusion of light nuclei at a very hig h temperature, such as occurs in hydrogen bombs . X-radiation : Electromagnetic radiations of energy between that of ultraviolet and gamma rays . Much of the initial release of energy from a nuclear explosion is in the form of thermal and X-radiation which is dissipated in the immediately surrounding media as heat to generate the fireball. Yield : The effective energy released immediately in a nuclear explosion . The residual nuclear radiation associated with the fission products, which amounts to about 10 per cent of the total fission energy, is not included in the yield . Yield is usually expressed as TNT equivalen t ~ - the quantity of TNT that would release the same amount of energy if exploded . Yield is usually given in kilotons or megatons, one kiloton of TNT being defined arbitrarily as 4 .18 x 1012 joules . ~ i ~ ~ ~ ~ ~ 1. CHAPTER I : INTRODUCTION ~ . ~ In order to understand how the Royal New Zealand Navy came to a small but significant in the Unite d play part Kingdom's nuclea r testing programme in the Pacific during 1957 and 1958, it is necessary to appreciate the extent to which New Zealand's foreign and defence policies then centred on the Commonwealthl . Th e t New Zealand Government supported the production and testing of atomic and thermonuclear weapons by the United Kingdom because it believed that this would materially enhance the security of New Zealand and the rest of the Commonwealth2 . It was therefore hardly surprising that the New Zealand Government should direct the Armed Forces to assist in the British nuclear testing programme, indeed the RNZN contribution to the programme was simply a somewhat unusual facet of the close Commonwealth defence relationship which dominated much of the Armed Forces' plans and activities 3 The threatening state of international affairs during the late 1940s and 1950s made the development of atomic and later thermonuclear weapons by the United Kingdom a matter of vita l national policy4 . Central to the success of the atomic weapons L programme was access to suitable test sites . In 1952, after considering various options, the British Government reached agreement with Australia for the use of the Monte Bello Island s ~ . i 2 off the north west Australian coast, as the site for Britain's first atomic weapon test5, which was successfully conducted on the 3rd of October 19526 . The Royal New Zealand Air Force played a minor part in monitoring radioactive fallout from this test, which was known as Operation Hurricane . Three aircraft based at Whenuapai made flights to the north and south of Auckland while another aircraft made a return flight to Suva . Apparently all but one of these aircraft "collected significant radioactivity"7 . The Royal Commission into British Nuclear Tests in Australia, however, concluded that "the air sampling operations out of Townsville [by the Royal Australian Air Force] and New Zealand collected filter samples having a level of radioactivity which would produce very low radiation exposures for the aircrew ; aircraf t 3 contamination levels were well below permissible levels" . Operation Hurricane was followed by further tests at th e Monte Bello Islands in 1956 and in South Australia at Emu Field in 1953 and at Maralinga in 1956 and 19579 . Five New Zealand officers were members of the Indoctrinee Force which took part in the atomic tests at Maralinga in 1956 known as Operation Buffalo10 . During the following year two New Zealand officers observed the Operation Antler tests at Maralinga11 .