Two separate reports have suggested it could be an ideal site for a new small module reactor (SMR).
About 300 workers are decommissioning the plant which began in 1995, two years after it ceased operating.
It is due to enter a care and maintenance period in 2016. Ninety redundancies were announced in April.
Darryl Williams from the Unite union said: "We would welcome anything that would keep local skills in the area."
A report by the House of Commons Energy and Climate Change Committee has called on the UK government to drive forward the development of SMRs.
Another report by the Institute of Mechanical Engineers also suggested Trawsfynydd as a location for a demonstrator reactor.
If the idea was given the go-ahead, it is thought the reactor could be up and running in 10-15 years.
A Welsh government spokesperson said it was a matter for the UK government, but that it would monitor the situation.
The Department of Environment and Climate Change (DECC) said: "We are undertaking a programme of work looking at the potential of SMRs."
Union leaders at the Trawsfynydd nuclear power station in Gwynedd have welcomed suggestions a new smaller reactor should be located there.