17 Tonkin & Taylor Ltd Hazardous Substances Technical Assessment – Waihi North Project - Storage and use of hazardous substances at Willows Road site and the Wharekirauponga Underground Mine Oceana Gold (New Zealand) Limited June 2022 Job No: 1015212.1000 vRev0 Figure 4.1: Proposed surface magazine layout indicating internal magazine offsets, positioning and NEQ Source: GSS 2021 4.2.2.2 Underground chambers The underground storage facility will comprise of six H.E. chambers each containing a maximum of 1,000 kg NEQ and one I.E. chamber containing a maximum of 100 kg NEQ, as illustrated inFigure 4.2. The location has been selected as a low traffic area of the WUG, with separation provided to other storage facilities. Figure 4.2: Magazine chamber layout including separation distances and proposed stored quantities’ Source: GSS 2021 Each of the seven underground chambers will be separated in order to mitigate risk of propagation between chambers. Two pathways of blast propagation underground are considered in Section 4 of the location assessment report attached as Appendix B. These scenarios and the minimum offset distance calculated are summarised inTable 4.2 below. Explosives storage facility exit I.E Chamber (up to 100,000 units or 100 kg NEQ) 6 x individual H.E Chambers (up to1,000 kg NEQ each) Explosives storage facility entry 10m
RkJQdWJsaXNoZXIy MjE2NDg3