Noting that it has certain concerns with regard to the recently-enacted US law on civil nuclear cooperation, India made it clear on Wednesday that it will 'walk out' of the deal if at any point it seems to undermine its national interest.

New Delhi, however, expressed confidence that the elements over which it has 'genuine' reason for concern, including conditional access to reprocessing technology and reprocessing of spent fuel, would be addressed in the 123 Agreement being negotiated to operationalise the deal.

The prime minister's special envoy on nuclear issue Shyam Saran said India has also conveyed to the US that it was not ready to accept any legally-binding provision on future nuclear testing in the 123 Agreement. He also emphasised that New Delhi would agree to fissile material control only under any multilateral framework.

He said India will retain the right to conduct nuclear test but would have to be prepared for repercussions such as snapping of the civil nuclear cooperation with the US since the waivers in the recent act do not apply to future detonations.

"There are concerns, of course... If at any point, it becomes apparent that it (deal) is something which would undermine India's national interest, we will walk out, no matter how much political investment has been made," he said while delivering a lecture on 'India-US Understanding on Civil Nuclear Cooperation and Future'.

Saran, who has been India's negotiator on the deal, said it has been New Delhi's endeavour throughout to ensure that its interest is not affected.

The deal will have 'tangible results if it works out the way we want it to be', he said, expressing optimism that India's concerns will be addressed in the 123 Agreement.

"We have to continue discussions on the 123 Agreement... There are certain important issues we need to look at and which need to be addressed. These are difficult issues," he said.

He, however, said that 'we have dealt with difficult issues in the past and so I am optimistic...The mindset on both sides is one of problem-solving and if this continues, there is room for optimism'.

The deal, Saran pointed out, will become a reality only after the 45-nation Nuclear Suppliers Group changes guidelines to allow civil nuclear cooperation with India and New Delhi concludes a safeguards agreement with the IAEA.

These measures cannot take place till the 123 Agreement, in the form India wants, is not signed with the US, he said.

He said India continued to lobby for support among the NSG countries and was now 'better placed' in the grouping, with several countries earlier having negative positions softening their stance.

But that does not mean that problems are over and 'we need to work with all members', he said.

Talking about the elements in the US law over which India has 'genuine reasons for concern', Saran identified these as conditional access to technology for reprocessing and heavy water plants and silence over end use of spent fuel.

On reference to conditional access to reprocessing technology, he said it 'does put limitations' and India wanted this to be removed.

But the US has a policy of not transfering reprocessing technology to any country and this provision is not discriminatory to India, Saran said.

He added that its practical impact on India will not be any great because this country's scientists have already built substantial infrastructure for reprocessing.

On the issue of assured fuel supplies, he said this provision will have to be incorporated in the 123 Agreement 'where it belongs'.

Referring to the concern over the law being silent on end-use of spent fuel, the special envoy said this ambiguity should be done away with.

He said New Delhi has conveyed to Washington that reprocessing of spent fuel will be critical in 123 Agreement and without that it will be difficult for us to carry the initiative forward.

On apprehension that reciprocity factor has been violated, he said New Delhi will not accept putting any civil nuclear facility under IAEA safeguards till 123 Agreement is signed, although progress of negotiations with IAEA will be conveyed to the US.

He also allayed concerns over the requirement of annual certification and reporting by the US administration to the Congress, saying New Delhi has nothing to do with it.

Saran described as advisory the provision in the law that US should ensure India does not stockpile nuclear fuel. He made it clear that permanent safeguards are linked to perpetuity of fuel supplies.

The US law may not explicitly recognise India as a nuclear-weapon state but it does accept that New Delhi has a strategic programme which it is unlikely to give up, he said, adding waivers in the act would not be needed otherwise.

He, however, pointed out that the waivers given in the US law were with retrospective effect and not applicable to any future nuclear testing by India.

He said if India conducts a nuclear test, 'there will be consequences as in 1998, when we took the step because of superior national interest despite realising the risks'.

Any testing by India, if the circumstances so warrant, will cost it not only the nuclear cooperation but other areas also due to possible sanctions, Saran said.

As India's economic reforms and development progress, there will be growing interdependence with the international community and as a result risks will also increase, he said.

On the provision that US will end the treaty if India were to conduct a nuclear test, he said as New Delhi was not ready to give any legal commitment in this regard, Washington also was doing the same.

He said India has been a votary of comprehensive ban on nuclear testing but has not signed the TBT because it is discriminatory.

He allayed fears that the deal will allow US to peep into India's nuclear programme, saying the strategic programme was out of its purview and even the safeguards for civilian facilities were to be undertaken only by the IAEA.

On what will happen to the agreement if the regime changes in the US, he said the bipartisan support given to the bill on it augurs well.