Taranaki

Nuclear Weapons Testing Range, Maralinga, South Australia, site of 12 hydronuclear experiments at Taranaki in 1960, 1961, and 1963 (Vixen B Trials) in which 22.2 kg of plutonium was dispersed, having been ejected 2,500feet vertically into the atmosphere. Cooper etal. 1994... 

Higgins M. D. (1996a) Crystal size distributions and other quantitative textural measurements in lavas and tuff from Egmont volcano (Mt Taranaki), New Zealand. Bull Volcanol. 58, 194-204. 

The plutonium contamination close-in at Taranaki is mainly in three forms, viz. as a fine dust, as small sub-millimetre particles, and as surface contamination on larger fragments (Bums et al., 1986). In the trials, the plutonium was dispersed in narrow plumes, the main ones extending to the west, north-west, north and north-east of Taranaki. The most extensive of these is the north-west plume, which can be detected crossing West Street between Fifth and Tenth Avenues (Fig. 10.10). In the central area... 

Fig. 0.11. Map of the Taranaki area and major trial sites. The sites of high volume air samplers and the contours of activity are indicated.

A wide-ranging ground survey of Taranaki area was conducted by the Australian Radiation Laboratory (ARL) over the period 1984 to 1986. Field measurements employing thin sodium-iodide detectors and single-channel analysers were used to provide a qualitative indicator of plutonium (Cooper et al., 1985), and quantitative data were obtained by gamma-ray analyses of soil samples (Cooper et al., 1985 Bums et al.,... 

With the exception of a few measurements to the north-west, these data were confined to the area of the former test range, viz. the Taranaki site and sampling points along the major north-south and east-west tracks on the range. 

In-situ gamma-ray spectrometry used by Johnston et al. (1989) was capable of detecting surface deposits of americium at surface densities as low as 0.05 kBq m (corresponding to 0.4 kBq of plutonium in the north-west plume). The results indicate that the plumes extend well beyond the limits of the Maralinga range and traces of the north-west plume persist to beyond 80 km from Taranaki (see Fig. 10.11). 

Bums, P.A., Cooper, M.B., Duggleby, J.C., Mika, J.F. and Williams, G.A., Plutonium-contaminated fragments at the Taranaki site at Maralinga, ARL/TR075, July 1986. 

The Synfuel gas-to-gasoline complex is sited within 180 hectares of land at Motunui, Taranaki. It is designed to convert 52-55 PJ per annum of natural gas into 570,000 tonnes (14,450 barrels per stream day) of high octane gasoline. 

New Zealand s two largest gas fields are the Kapuni and Maui fields. The Kapuni field has estimated recoverable gas reserves of 419 petajoules (PJ) and is on-shore in Taranaki whereas the Maui field with estimated recoverable gas reserves of 5193 PJ is 33 km off the coast of Taranaki. 

The Synfuel plant is sited within 180 hectares of land at Motunui, Taranaki... 

The first 4000 tonnes of blended gasoline was sent to the Ministry of Energy tank farm near Port Taranaki in early November 1985. The results of quality tests of this first batch of gasoline were within specification and were as follows ... 

In the two decades since I.C.I. introduced the low-pressure methanol process others have gained increasing shares of the market. Major competitors include Lurgi, Mitsubishi Gas Chemicals and Haldor Topsoe. All have their own variations of the co-precipitated Cu-ZnO catalysts. Recently, Alberta Gas Chemicals has constructed several 1200 tonne/day plants one at Medicine Hat, Alberta and the other at Taranaki near the Synfuels methanol-to-gasoline plant in New Zealand. The Alberta Gas Chemicals plants use catalysts under licence. 

An early activity on the project was the selection of a site out of the forty-three sites previously surveyed and deemed suitable. A composite team of Mobil and Bechtel personnel supported by New Zealand consultants narrowed the selection first to three sites, then to one by August 1980. The criteria for site selection were many and varied. The most significant were proximity to the natural gas pipeline, to a reliable source of water, to a centre of population which would provide the necessary infrastructure in support of plant operation, and to the Port of Taranaki for shipping the gasoline product and for reasonable transportation access for preassemblies. A clear and level site to minimize civil works was needed as well as a location that would not have an overwhelmingly negative environmental impact on the area. 

The area of Taranaki surrounding Mt. Egmont is overlaid by volcanic ash which does not provide good bearing strength for equipment foundations. As a result all major foundtations are supported by piles, a total of approximately 7000 being installed. 

New Zealand Synthetic Fuels Corporation Ltd (Synfuel) operates a 1650 tonne per day gas-to-gasoline facility at Motunui, Taranaki. The facility consists of two identical 2200 tonnes per day ICI licensed... 

Fig. 5.48 Ternary plot of relative abundance ofC29, C30 and c31 17ct-hopanes (22S + 22R) in New Zealand coals (shaded area shows province of coal-sourced oils in Taranaki Basin after Killops et al. 1998).VR = vitrinite reflectance.

Killops S.D., Raine J.I., Woolhouse A.D., Weston R.J. (1995) Chemostratigraphic evidence of higher-plant evolution in the Taranaki Basin, New Zealand. Org. Geochem. 23, 429 15. 

Killops S.D., Allis R.G., Funnell R.H. (1996) Carbon dioxide generation from coals in Taranaki Basin, New Zealand implications for petroleum migration in southeast Asian Tertiary basins. Am. Assoc. Pet. Geol. Bull. 80, 545—69. 

The relatively high heat flow in parts of the Taranaki Basin appears to have accelerated the natural gas generation process in which 8 C(CH4) is initially much more negative than the source organics (—27 to —29%o) but becomes more positive with increasing maturity of the soince rocks. This results in a range of 8 C(CH4) values from —32 to - 8%o. 

Isotopic equilibrium between 2 and CH4 does not appear likely in Taranaki. In TVZ apparent isotopic temperatures are higher than reservoir temperatures but show fair correlation. This may relate both to a hydrocarbon maturity effect and to a source effect but this does not fiiUy explain the 8 C(CH4) and S C(C02) distribution within some fields. 

Fig. 1. Location of the Taranaki natural gas fields, Taupo Volcanic Zone (TVZ) and the subducting Pacific plate. WK, Wairakei RK, Rotokawa MK, Mokai NM, Ngatamariki BR, Ohaaki-Broadlands RO, Rotorua TT, Tikitere KA, Kawerau.

With this new equilibrium data it seems appropriate to include a revisit of the carbon isotopic data from CO2 and CH4 in the TVZ and Taranaki systems to look at the factors controlling this data and the relevance of isotopic equilibrium temperatures calculated for the 4 C(C02-CH4) system. 

Surface heat flow estimates in the Taranaki Basin (Eunnell et al, 1996) range from 47 mW m in the SE to a maximum of 74 mW m near New Plymouth (where the subduction zone has a depth of ca. 200 km) before decreasing again further to the north-west. The heat flow estimate for the Maui field is 64 mW m. ... 

Fig. 2. Stratigraphy of Taranaki Basin hydrocarbon formations. Adapted from King and Thrasher (1996).

The chemical and isotopic compositions of gases from hydrocarbon systems of the Taranaki Basin reported by Hulston et at. (2001) show wide variation. The most striking difference between the souA-eastern and western groups of gases is the helium content and its isotopic ratio. In the south-east, the Kupe South and most Kapuni natural gases have low total helium concentrations of 10-19 and a minor mantle helium input of 0.03-0.321 a (where... 

Table 1. Summary of heat flow and o results for Taranaki hydrocarbon CO2 and CH4 gases...

Fig. 4. (a) 6 C(CH4) vs. relationship for Taranaki natural gases helium isotopic ratios... 

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