The uranium sector will benefit from United States President Barack Obama's guaranteed loans for the construction of new nuclear reactors, Energy Resources of Australia Ltd (ERA) says.

Mr Obama unveiled the $US8 billion ($A8.66 billion) plan in February, which will underpin the construction of two new nuclear reactors in the American state of Georgia - the first in the US in nearly 30 years.

ERA chief executive Rob Atkinson said the move "can only do the uranium industry a world of good".

"When you've got a country such as America putting a clear stake in the ground, as nuclear energy is going to be a key cornerstone of their energy mix, that is hugely significant," Mr Atkinson told AAP on Tuesday.

"It really will go a long way to not only ensure that more ... reactors are brought on stream in America, but an awful lot of other countries will also follow the lead that America has taken.

"Key leaders are putting their commitments out there, saying nuclear power is an important and key part of their energy mix, going forward, which is going to have a clear and positive effect on uranium miners."

Rio Tinto Ltd-controlled ERA said in its March quarter report on Tuesday that production tonnages and grades at its Ranger uranium mine in the Northern Territory had fallen.

However, the fall was in line with guidance provided in January that flagged a similar second quarter result due to the sequence of areas being mined at the maturing open pit and maintenance activities.

"In January, we said that the first half of the year was going to be lower grade because of the (mining) sequence," Mr Atkinson said.

"With the mine reaching old age, the good-quality ore is at the bottom of the mine and we'll certainly be mining that in the second half of this year.

"So I fully expect the grade will go up, but over the life of the open pit and certainly with the stockpiles, the grade does gradually go down."

While the open pit is almost exhausted, ERA expects it will be able to maintain steady production levels for some time by using a proposed heap-leach facility to allow it to recover material that was previously considered too low grade, Mr Atkinson said.

"It gives us another 20,000 tonnes of potential material ... very much complementing the (existing processing) plant.

"We're going to be mining purely from the stockpiles and purely from the heap leach."

A $36 million detailed feasibility study on the heap-leach facility is underway.

The mine's longer-term future hinges on the 34,000 tonne Ranger 3 Deeps discovery, east and adjacent to the Ranger 3 operating pit.

Mr Atkinson said the development of Ranger 3 Deeps was several years away.

Studies on the resource are expected to be complete by mid-2010, to be followed by a decision on the development of an exploration decline.

Mr Atkinson said softer prices for uranium on the spot market would have only a small effect on expected average sale prices achieved by ERA during the first half of 2010, given it sells most of its product on long-term contracts.

Shares in ERA were down $1.17, or 5.94 per cent, at $18.52.