Waihi Underground Explosive Principal Hazard Management Plan Approved by: SSE/ General Manager Approval Date:11/05/2021 Next Review: 08/04/2022 OceanaGold Waihi Document ID: WAI-400-PLN-007 Page 18 of 27 6.6.3 Testing Blast Fume Clearance Times The Ventilation Engineer will be required to undertake periodic gas testing to establish safe re-entry times as mining areas progress. All measurements taken must be accurately recorded in the ventilation logbook and all entries dated and signed as per logbook standards. All measurements recorded are to be reported to the Underground Mining Manager. 6.7 Other Explosives Use There shall be specific JHA’s developed for all other uses of explosives not covered in site procedures. This JHA shall be created by relevant site personnel and, when applicable, the explosives supplier. The JHA will give consideration to the following: • The storage and transport of explosives • Training and competency requirements • Specific explosive types • Guarding/barricade requirements • Environmental effects (vibration, noise etc.) • Infrastructure location and public access • Firing instructions • Emergency instructions including misfires 6.8 Atmospheric Electrical Activity During an electrical storm there shall be no activity involving explosives conducted on the surface. The magazine shall be evacuated and secured and not re-entered until 30 minutes after the last occurrence of thunder. The earthing connections on all magazine facilities shall be checked for electrical continuity at least every twelve months. There shall be no wiring in electric detonators while an electrical storm is in the vicinity. 6.9 Misfires A misfire is defined as: • Any hole or portion of a hole that has a signal tube, detonating chord or remnant explosives visible • Any hole, cut off, butt or remaining portion of a hole that is suspected to contain explosives • Any hole that has not been washed out or cannot be checked for any reason The Underground Shift Supervisor must be notified of any misfires immediately and all details recorded in the Misfire Logbook. If the misfire cannot be rectified during that shift, then the Shift Supervisor is to note the misfire location on the muster white board for the oncoming shift. Each heading and stope is inspected for misfires on re-entry as per site re-entry procedures. An electrically initiated complete misfire cannot be approached for at least five minutes. Misfires must be dealt with as per procedure and only by authorised personnel. The Underground Mining Manager must be notified immediately if any complete round misfires for an unknown reason or if there is any unplanned initiation of any explosive. For more information refer to the procedure for misfires; see Appendix I for document details. 7 CHARGING EQUIPMENT AND MAINTENANCE 7.1 Charging Equipment 7.1.1 Transport Explosives will be transported underground either in the charge cage (secured ANFO only), narrow vein loader (secured ANFO only) or in the back of an approved light vehicle. Any vehicle transporting explosives must be equipped with a flashing blue light, explosives signs, earth chain and a fire suppression system.
RkJQdWJsaXNoZXIy MjE2NDg3