Australia’s navy chief has left the door open to keeping some of the existing Collins-class submarines in the water until 2050, amid uncertainty about the exact schedule for acquiring new nuclear-propelled submarines.
The government is already planning to extend the life of the six Collins class submarines by 10 years, with the extensive refitting work set to cost between $3.5bn and $6bn.
But the navy chief, V-Adm Michael Noonan, indicated on Friday that a “potential” option was to refit them a second time to further extend their life.
Given the first Collins-class submarines were commissioned in the late 1990s, that option could see them used until they are about 50 years old.
Australia is planning to acquire at least eight nuclear-propelled submarines under the Aukus partnership announced last month, but the first of these are not likely to be in the water until the late 2030s.
The South Australian senator Rex Patrick accused the government of being “extremely reckless” with national security amid the latest revelations.
He suggested Australia faced a worse outlook than 2009 when a decision was made to increase submarine numbers from six to 12 because of rising regional concerns.
“We now have an even worse geostrategic situation and yet the plan on record will see at least one of our six Collins class submarines retiring before a first nuclear submarine has arrived.”
At a shipbuilding committee hearing on Friday – the first since the $90bn French deal was dumped – senators explored concerns about Australia facing a “capability gap” while it waited for the new submarines to be ready.
Noonan played down that concern. He said the Collins class submarines would each undertake a life-of-type extension (LOTE). Each extension would take two years to complete, and would “essentially give 10 years’ life to that submarine”.
The first submarine would begin to be upgraded between 2026 and 2028, giving it a capability to 2038.
“And then we will see the second one, with an extended life as well,” Noonan told the Senate’s economics references committee.
“And I don’t write off the opportunity for us to further upgrade these submarines beyond that period of LOTE.”
Labor senator Kimberley Kitching asked: “So we’re going to have Collins class in the waters until 2040, 2050?”
Noonan replied: “Potentially, yes, Senator.”
The inquiry heard that the first submarine under the now defunct French deal would have been expected to be operational about 2034 or 2035.
Labor – which has backed the Aukus plan – said the evidence raised many questions for the government, including whether the Collins class submarines would be able to withstand multiple upgrades of this type.
Labor’s defence spokesperson, Brendan O’Connor, asked: “If enhanced submarine capability is critical to our national security, why would we still have 50-year-old Collins Class vessels in 2050?”
Later in the hearing, however, Noonan expressed some caution about the use of the Collins class submarines into the 2040s and beyond.
“My assessment is we will be able to continue to operate the Collins class submarines very successfully through the 2020s, through the 2030s,” he said.
“But as we get into the 2040s and beyond, the areas of operation that we seek to operate in … will make any conventionally powered submarine at a higher risk of detection due to its requirement to surface and snort in order to charge its batteries.”
The Australian government has set up a taskforce, with 89 members and growing, whose job over the next year and a half is to work with the US and the UK on “identifying the optimal pathway to deliver at least eight nuclear-powered submarines for Australia”.
Noonan accepted that this “means that there is not yet a follow-on capability under contract”.
It remains unclear precisely how much the Australian government will have to pay to settle contracts with France’s Naval Group and another defence contractor, Lockheed Martin.
Greg Sammut, the general manager of submarines at the defence department, said there was “no break fee” but “there will be costs associated with termination”, which may not be known until early to mid next year.
Sammut defended the department’s handling of talks with Naval Group, after the scrapping of the French contract triggered an extraordinary diplomatic rift that saw France temporarily recall its ambassadors from Canberra and Washington in protest.
Sammut said his team had been made aware on the afternoon of 15 September that an announcement was to be made the following day in relation to the submarine program – but had not been aware of the content of the announcement.
He said his team had been aware that contingency planning was under way – but not the specific deliberations. “We were kept separate from that. We continued to work with Naval Group in good faith on the program of record that remained in place,” Sammut said.
In a letter dated 15 September – and obtained by Guardian Australia under freedom of information laws – Royal Australian Navy Commodore Craig Bourke cautioned Naval Group that its achievement of a key contractual milestone did “not provide any authorisation to continue work”.
Asked why that line was added to the letter, Sammut said: “We wanted to be very clear that that was subject to government approval … We were very clear that the decision to enter the next design phase rested with government.”
The also inquiry heard the Australian Nuclear Science and Technology Organisation was consulted in March about a plan to buy nuclear-powered submarines, about six months ahead of the surprise announcement.
Ansto’s chief executive officer, Shaun Jenkinson, said he was asked about the organisation’s ability to support the endeavour.
“Initial conversations started in March and we had a number of consultations between then and the announcement,” he told the inquiry.
At the same hearing, the chief executive of the Australian Radiation Protection and Nuclear Safety Agency, Carl-Magnus Larsson, said his agency was briefed on the plan at the end of June or beginning of July.