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I was going to say that the greatest uncertainty, perhaps, was the amount of time that it would take to build and get into production of NPR just because of the uncertainties in safety review and technology that we are faced with. The other aspect was costs, and I think the construction costs were, perhaps, $2 billion, and all of the reactors fall into that category. Research and development might be anywhere from $100 to $500 million.

Senator JOHNSTON. Do you have an opinion as to which one would cost the most? Can you give us an opinion?

Mr. SCHOETTLER. No, I can't.
Senator JOHNSTON. Can you, Mr. Ahearne?
Mr. AHEARNE. No.

Senator JOHNSTON. Can anybody tell me? In other words, the cost is not a consideration in choosing one or the other. If we had to choose today, and you tried to add all the factors, would cost be a consideration, or you just don't know?

Mr. Salgado. I think the cost in our ballpark analysis is not a discriminator.

Senator JOHNSTON. What is the discriminator here?

Mr. SALGADO. I think the discriminator here is the reasonable assurance that we are going to be able to produce tritium for a given period of time, not for 2 or 3 years, but for 10 or 15 years from the facility we build. We have to have that kind of assurance because that is a commitment that we have to make to this country from the DOE standpoint, that there is an assured supply of tritium, either needed or have that capability not only from 1998 on, but for another 10 or 20 years beyond that, and that is the driving force, that we have the ability to maintain our nuclear deterrent if so needed.

Senator JOHNSTON. Obviously, the production of tritium between now and 1998 is not going to depend onthis new reactor. It is going to depend on the aging reactors over there at Savannah River.

If we were to make a choice right here today on which kind of reactor we were going to go to, you would say that cost is no discriminator, time is no discriminator, as I have gathered here, the discriminator is the assurance of the supply of tritium beginning roughly from 1998 on.

Mr. Salgado. I think there are so many assets and liabilities to each technology that I think the real issue that it boils down to, when the Secretary has to make a decision, is the confidence level to be able to produce the quantities of tritium that are needed for the national security of this country either through one reactor or two reactors. I think that is basically what the driving force in the decisionmaking process has to be.

TECHNOLOGY RELIABILITY Senator JOHNSTON. Do you have an opinion as to which one is the more reliable?

Mr. Salgado. More reliable?
Senator JOHNSTON. Which is the better choice?

LIGHT WATER REACTOR TECHNOLOGY

Senator JOHNSTON. Senator McClure.

Senator MCCLURE. Thank you very much, Mr. Chairman, and I agree with the statement that you have just made.

I am a little puzzled by one thing that came out of the ERAB report, Mr. Schoettler, and perhaps you can enlighten me. You have indicated that the WNP-1 light water technology could, perhaps, be a winner in terms of time. At least it is one of the two leading in terms of time, and yet there is nothing that has even been done with the light water reactor target producing tritium.

If I understand you correctly, you really can't address that question until one has been built, completed, and tested, then you can deal with questions of the safety code on the target. Yet, the completion of a plant is 4 years away, so you can't even start the verification work until you have completed the plant and put a target in and operate it. Is that not correct?

Mr. SCHOETTLER. That is correct, or the target would have to be put into some civilian reactor, and that was one of the risks for that light water reactor scenario.

Senator MCCLURE. But if it isn't put into a civilian reactor and tested there, then you lose whatever possible time advantage WNP-1 would have?

Mr. SCHOETTLER. That is correct.

Senator MCCLURE. Otherwise it would be sequential rather than going on concurrently.

Mr. SCHOETTLER. Excuse me. The time advantage of the WNP-1 is that it is approximately 63-percent complete. There are various schedules of completeness, but overall the average is 63 percent. It appeared that the plant could be completed on a shorter time scale, but then, you are correct, the target technology qualification testing would have to take place within the WNP-1.

Senator McCLURE. So it would depend upon our willingness or capacity, one or the other, or both, of being able to work the concurrent work on the target in a presently operating plant.

Mr. SCHOETTLER. That is correct.

Senator MCCLURE. I don't want to get into the uncertainties that are involved about the legality, or the legal questions surrounding WNP-1, I have lived with that for some years, and they still are unresolved.

I would also say that I don't want to get into the question of whether Senator Hatfield likes it or not, because he has already spoken for himself. I think Senator Adams has spoken for himself on that subject very forcefully. I gather that they have some idea that they would delay that process, or at least increase its hazardness. I think that that would be, perhaps, the minimum amount that I can say.

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PROBABILISTIC RISK ANALYSES

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Mr. Ahearne, what role do probability risk assessments have in safety analysis and licensing?

Mr. AHEARNE. At the present time the NRC does not have them as a formal part of the licensing process, but has encouraged all of the plants to go through these probabilistic risk analyses. The main thing that they do, they identify system weaknesses, vulnerabilities, where are problems that might be present that one had not expected. It has turned out to be very valuable, sufficiently valuable that most of the industry is now going forward to doing them.

Senator McCLURE. According to Department of Energy documents, HWR safety research at the Savannah River plants will take 4 years. If HWR is the chosen NPR technology, do you believe that these safety analyses should be completed before construction begins?

Mr. AHEARNE. I think that there are several types of safety analyses you are speaking about. There are analyses being done as was already mentioned by Secretary Salgado on the existing Savannah River plants, and PRA's, probabilistic risk analyses, are being done on those.

Those are safety analyses focused upon existing designs, existing plants, taking them where they are, as he mentioned, they are 30-yearold plants. Those are the kind of analyses that are going to have to be completed to give some high confidence that those plants could go up in power. Separate analyses would probably be required for a new design.

Senator MCCLURE. Is that because the new design would be sufficiently different from the older?

Mr. AHEARNE. It would be different. Obviously, you can capture some of the work that has already been done, some of the work will be directly applicable, but I don't think that automatically you can assume that the work being done for the older design is going to be applicable to the new design.

Senator McCLURE. In your opinion, are light water reactor codes easily adapted for use with heavy water technology?

Mr. AHEARNE. No.
Senator MCCLURE. You can't simply transfer the codes.

Mr. AHEARNE. The light water codes, it is not just the moderator which is a light water, they were really designed to handle the temperatures and the pressures, and the rest of the system fluid flow, and the type of fuel that exist in light water reactors.

The heavy water reactor is quite different, and I do not believe that it is a simple matter to take those codes and transfer them to a new reactor. One of the big issues that one has in any code work is to then validate the codes, and the more complex the code is, the harder time one has in validating; that is, to give confidence that the results of the codes are things that you want to believe.

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LIGHT WATER REACTOR TECHNOLOGY

Senator JOHNSTON. Senator McClure.

Senator MCCLURE. Thank you very much, Mr. Chairman, and I agree with the statement that you have just made.

I am a little puzzled by one thing that came out of the ERAB report, Mr. Schoettler, and perhaps you can enlighten me. You have indicated that the WNP-1 light water technology could, perhaps, be a winner in terms of time. At least it is one of the two leading in terms of time, and yet there is nothing that has even been done with the light water reactor target producing tritium.

If I understand you correctly, you really can't address that question until one has been built, completed, and tested, then you can deal with questions of the safety code on the target. Yet, the completion of a plant is 4 years away, so you can't even start the verification work until you have completed the plant and put a target in and operate it. Is that not correct?

Mr. SCHOETTLER. That is correct, or the target would have to be put into some civilian reactor, and that was one of the risks for that light water reactor scenario.

Senator MCCLURE. But if it isn't put into a civilian reactor and tested there, then you lose whatever possible time advantage WNP-1 would have?

Mr. SCHOETTLER. That is correct.

Senator MCCLURE. Otherwise it would be sequential rather than going on concurrently.

Mr. SCHOETTLER. Excuse me. The time advantage of the WNP-1 is that it is approximately 63-percent complete. There are various schedules of completeness, but overall the average is 63 percent. It appeared that the plant could be completed on a shorter time scale, but then, you are correct, the target technology qualification testing would have to take place within the WNP-1.

Senator MCCLURE. So it would depend upon our willingness or capacity, one or the other, or both, of being able to work the concurrent work on the target in a presently operating plant.

Mr. SCHOETTLER. That is correct.

Senator MCCLURE. I don't want to get into the uncertainties that are involved about the legality, or the legal questions surrounding WNP-1, I have lived with that for some years, and they still are unresolved.

I would also say that I don't want to get into the question of whether Senator Hatfield likes it or not, because he has already spoken for himself. I think Senator Adams has spoken for himself on that subject very forcefully. I gather that they have some idea that they would delay that process, or at least increase its hazardness. I think that that would be, perhaps, the minimum amount that I can say.

PROBABILISTIC RISK ANALYSES

Mr. Ahearne, what role do probability risk assessments have in safety analysis and licensing?

Mr. AHEARNE. At the present time the NRC does not have them as a formal part of the licensing process, but has encouraged all of the plants to go through these probabilistic risk analyses. The main thing that they do, they identify system weaknesses, vulnerabilities, where are problems that might be present that one had not expected. It has turned out to be very valuable, sufficiently valuable that most of the industry is now going forward to doing them.

Senator McCLURE. According to Department of Energy documents, HWR safety research at the Savannah River plants will take 4 years. If HWR is the chosen NPR technology, do you believe that these safety analyses should be completed before construction begins?

Mr. AHEARNE. I think that there are several types of safety analyses you are speaking about. There are analyses being done as was already mentioned by Secretary Salgado on the existing Savannah River plants, and PRA's, probabilistic risk analyses, are being done on those.

Those are safety analyses focused upon existing designs, existing plants, taking them where they are, as he mentioned, they are 30-yearold plants. Those are the kind of analyses that are going to have to be completed to give some high confidence that those plants could go up in power. Separate analyses would probably be required for a new design.

Senator MCCLURE. Is that because the new design would be sufficiently different from the older?

Mr. AHEARNE. It would be different. Obviously, you can capture some of the work that has already been done, some of the work will be directly applicable, but I don't think that automatically you can assume that the work being done for the older design is going to be applicable to the new design.

Senator MCCLURE. In your opinion, are light water reactor codes easily adapted for use with heavy water technology?

Mr. AHEARNE. No.
Senator MCCLURE. You can't simply transfer the codes.

Mr. AHEARNE. The light water codes, it is not just the moderator which is a light water, they were really designed to handle the temperatures and the pressures, and the rest of the system fluid flow, and the type of fuel that exist in light water reactors.

The heavy water reactor is quite different, and I do not believe that it is a simple matter to take those codes and transfer them to a new reactor. One of the big issues that one has in any code work is to then validate the codes, and the more complex the code is, the harder time one has in validating; that is, to give confidence that the results of the codes are things that you want to believe.

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