The planned re-entry to the Pike River mine has been narrowed to three options.
Mining specialists, Pike River Recovery Agency staff and family members of the 29 men killed in the 2010 blast were on the West Coast for a second workshop aimed at coming up with a plan for manned re-entry of the mine drift.
A panel of technical experts will now shift the focus to three scenarios which are now being developed further.
The scenarios include building a new two by two-metre tunnel around 200m long; drilling a large diameter borehole; and re-entering the main drift as it is with no second means of egress (exit).
The Pike River Recovery Agency was set up by the government earlier this year to plan a safe, manned re-entry and recovery of the drift access tunnel.
The aim is to try and find out what happened in order to prevent any further tragedies, to give the families closure and where possible, retrieve any remains found in the drift, the agency said.
The government is spending up to $23 million on the project.
Dinghy Pattinson, the recovery agency's chief operating officer, said he was confident they would get back in.
"Any mining activity has dangers or risks involved, so it's a matter of just identifying those risks throughout the whole process and having your controls in place," Mr Pattinson said.
"If there was any real danger then that would be a show-stopper, so at this stage all the risks identified - I feel confident we can manage them."
Last month a panel of technical experts met in Greymouth to begin a concept plan.
Anna Osborne, who lost her husband Milton in the accident, said she was still feeling good about the progress that was being made.
"We're really positive this is going to go ahead, listening to all the experts and having our own experts on board as well gives the families real confidence in the project going forward," Mrs Osborne said.
"It's nothing that couldn't have been done seven years ago."
Bernie Monk, who lost his son Michael in the explosion, said the battle for manned re-entry continued to be more than just about their individual loss.
"We've created something in New Zealand, where if people are prepared to roll their sleeves up and voice an opinion on something that it right, in our case to bring people home - that went to work and didn't come home - I think we're on the right road to set an example for other people, for the future of New Zealand," Mr Monk said.
The Paparoa Ranges. Photo: RNZ/Tracy Neal
Recovery Agency chief executive Dave Gawn said they had made bigger steps during this workshop.
"We still anticipate entering the mine before the end of the year, and we still think that's achievable. This workshop is only step number two in a number yet to take," Mr Gawn said.
He said among the steps was a detailed risk analysis of the preferred options.
The results of the today's workshop would be reviewed by an independent team, Mr Gawn said.
"After that, and once Minister [Andrew] Little is comfortable with where we're at, then we'll go on to the detailed planning process and the risk analysis."
That was likely to be late July or early August.
