The WRU already owns 50% of the Dragons but plans to take control of the region as well as the stadium.
Newport RFC and Newport County AFC also play at the venue and exact details of the deal are due to be announced on Wednesday.
It comes 11 months since the Dragons announced they were seeking investment.
Ex-Wales and Dragons lock Ian Gough told BBC Radio Wales if the takeover does not take place it will herald "the death of rugby in Gwent".
Importance of a deal
Dragons chairman Martyn Hazell has previously said he believed the deal between the Dragons and the WRU needed to be done quickly.
He stressed the importance of agreeing a deal by warning of the dangers for the region if no agreement could be reached with no viable alternative on the table.
Businessmen Hazell and Tony Brown have been putting money into the region since it started in 2003, a situation he said cannot continue.
"The future of the Dragons is that myself and Tony Brown can't keep pumping money into it. We're both turning 80 within the next few weeks and we can't keep doing it," said Hazell.
Newport RFC 'a key consideration'
The proposals are understood to mean the WRU taking complete control of the Dragons and the Rodney Parade ground.
Hazell and Dragons chief executive Stuart Davies have pressed for a 10-year guarantee under a lease agreement for the Dragons and Newport RFC to continue playing at the historic venue.
That will be among the details that supporters of both clubs are eager to learn and 75% of Newport RFC members must approve the deal.
"From our perspective it's important Newport and the Dragons will be looked after through the deal," said Davies.
"The continued playing of Newport RFC at Rodney Parade has been a key consideration.
"The assurance I can give Newport RFC is we have been protecting their interests."
Newport County could also be affected, though they have a tenancy contract at Rodney Parade until 2023.
Newport RFC play in the Welsh Premiership, the sport's second tier in Wales.
A group of Newport rugby supporters - Friends of Newport Rugby - has expressed concerns over some aspects of the proposed WRU takeover.
The Welsh Rugby Union (WRU) will announce details of the proposed takeover of Newport Gwent Dragons and Rodney Parade in the next 24 hours.