Mr. WEAVER. Let us stop for a moment and go off the record.

[Discussion off the record.]

Mr. MILLER. When you get beyond the 28th and start talking about the number of calculations being made about various things, there were so many people making them that I was not aware of all of them. I was an inplant guy at that time, and my opinions are not the ones you should take to make a judgment.

Mr. WEAVER. We are taking them all.

Mr. SCOVILLE. I guess the point of my question was really this: When you were deciding which procedure-you said there were many procedures you could pursue to get rid of the bubble. Was the fact that it was contemplated by some that oxygen was being produced and the bubble might explode a significant factor in making the determination as to what procedure you were going to follow?

Mr. MILLER. No; you would take gas out with the same procedure, take it out using that system the way Bill and I described.

Mr. SCOVILLE. To your knowledge-and I understand you may not know this was the theory of producing something that Met Ed came up with or did it come from the NRC?

Mr. MILLER. I do not believe it came from either. I think it came from a separate consultant that they both had talked to personally, possibly an expert on hydrogen and oxygen.

Mr. SCOVILLE. Thank you.

Dr. MYERS. Were you concerned that water in the containment or the fact that sodium hydroxide had been sprayed might have caused equipment or degradation of equipment, of instruments, such that you might lose control at some point?

Mr. MILLER. NO; the reason for that would be that we were designed to pump that whole tank into the building.

Dr. MYERS. Pump the tank into

Mr. MILLER. If you had a loss, a LOCA, a loss of coolant accident, the whole 500,000-gallon tank goes in the building. You have a safety tank on the outside of the building with boric water in it. You put that water in to keep the core down, keep the core cool. You would pump 500.000 gallons of water right into the building.

Dr. MYERS. But with that water going into the containment, would that cause disruption of the 480-volt power supply or cause equipment failures or whatever?

Mr. MILLER. You would have had enough instrumentation left to operate what you needed to at that point.

Dr. MYERS. So you were not concerned that the conditions in the containment, whether by rising water levels or the fact that sodium hydroxide or the fact of radiation or temperature or whatever, might cause loss of instruments or equipment?

Mr. MILLER. If I had to pick, we could have lost pressurizer level and steam generator level, which would have complicated the operation for us.

Dr. MYERS. That is one reason why I think some people were concerned, if you lost control of that equipment inside, that then you would know less of what was going on and you would not be able to

Mr. MILLER. That is true. At the time, during the day on the 28th, though, we had only pumped 20 feet of that tank into the building, and

we did not feel we were at a level-I did not feel where we were at a level where we were going to cover those instruments yet on the 28th. Subsequent to that, we had small leakages which accumulate over hours and months to the point where the building had more and more water in it, and then the concern became a lot more of a concern, because we now were controlling the thing or reading those instruments, and we were looking at backup ways of telling what those levels were. On the 28th, though, we had not put enough water in where I had that concern that day.

Dr. MYERS. Did you know where the equipment was, so that at what level the water might be where it would start to interrupt certain things?

Mr. MILLER. Yes.

Mr. CHENEY. One other question, if I might. When we toured the facility last Monday, we were told, as I recall, that one of the condensate pumps tripped and that that started the whole sequence of

events.

Mr. MILLER. I do not know that we have determined that. I do not think we have determined the source.

Mr. CHENEY. What the initiating trip was?

Mr. MILLER. That is right. I know the feed system stopped pumping water. We know that the main feed pumps both tripped.

Mr. WEAVER. What you are saying is something there may have tripped before that?

Mr. MILLER. Or a valve.

Mr. ZEWE. Something resulted in that condensate pump causing it to trip.

Mr. CHENEY. What was suggested to us was the possibility of some kind of a break in the power supply.

Mr. ZEWE. That is not true, to my knowledge.

Mr. MILLER. Remember, from the plant design standpoint, this equipment is in the nonnuclear portion of the plant. It does not have the quality assurance because it is not safety-related.

We know we lost the feed system, and the plant should have been able to handle that from a reactor standpoint. I do not think the company has gone back and decided what the really initiating point was. Mr. CHENEY. So in your mind, we really do not know that?

Mr. MILLER. That is right.

Mr. ZEWE. They are still looking today at it. They are still trying to gather information and postulate just why that condensate pump tripped and what the motor failure was that initiated it.

Mr. WEAVER. As to Henry's last question about the possibility of instrumentation being eroded by the various chemicals, we read in the paper that days before you were supposed to get into the final cold shutdown, the last instrument failed. That was the quote in the newspapers.

Mr. MILLER. On the day of the incident, like I told you, that was not a concern. In the following days, we had a level in this pressurizer. We had a level in there and we wanted to keep a level in there, because you could keep steam on top and maintain pressure.

The level instrument that says how high the level is in there, they failed one at a time, and we eventually had the last one fail.

Mr. MILLER. They failed because of either radiation or liquid level in the building. They are down in the basement. But we had anticipated that could occur and we had made evaluations of what we would do with the system. We had alternate ways of looking at that level other than the direct reading.

Mr. WEAVER. But it does bring out what Henry said. Instruments did fail because of it.

Mr. MILLER. But we, by that time, had devised backup ways, and also, we could have taken that vessel solid again and still maintained the coolant.

So the concern was that, OK, we are going to have to-it is going to be a little harder to operate.

Dr. MYERS. But if you had kept it solid, would you have continuedat that point, would you have continued to pump?

Mr. MILLER. We might have. We might have shut it off and used natural circulation. Natural circulation probably would have been better because that is one more piece of equipment. The pump could have failed, too, and then you would have had to have used natural circulation.

Mr. WEAVER. Gentlemen, I want to thank you very, very much. Mr. CHENEY. It has been very, very helpful.

[Whereupon, at 3:55 p.m., the hearing was adjourned.]

ACCIDENT AT THE THREE MILE ISLAND NUCLEAR

POWERPLANT

TUESDAY, MAY 15, 1979

U.S. HOUSE OF REPRESENTATIVES,

COMMITTEE ON INTERIOR AND INSULAR AFFAIRS,

Washington, D.C.

The committee met at 9:50 a.m. in room 1334, Longworth House Office Building, Hon. James Weaver presiding.

Present: Representatives Weaver, Carr, Markey, Vento, Marriott, Edwards, and Cheney.

Staff present: Messrs. Myers, Burnam, Terrell, Reis, Scoville, and Chakoff.

Also present: Messrs. McMillan, Deddens, Nelson, Ellis, Bergson, Edwards, Benitez, Edgar, and Stang.

Mr. WEAVER. The task force will be in session.

We are very pleased that members of the firm of Babcock & Wilcox, the engineering firm that designed the Three Mile Island unit 2, as well as other pressurized water reactors in the United States, are here to give us their responses to the various questions that have been raised by the Three Mile Island unit 2 accident. We have a series of questions prepared by staff, and that is the format that I intend to follow, unless you have some remarks you would like to make at the outset. If you do, please go ahead.

Identify yourselves for the record, and we want to welcome you and thank you for coming.

STATEMENTS OF JOHN MCMILLAN, VICE PRESIDENT, NUCLEAR POWER GENERATION DIVISION, BABCOCK & WILCOX CO.; AND JAMES DEDDENS, MANAGER, PROJECTS MANAGEMENT GROUP, BABCOCK & WILCOX CO., LYNCHBURG, VA.

Mr. MCMILLAN. Thank you, Mr. Chairman.

My name is John McMillan. I am vice president of the Nuclear Power Generation Division of the Babcock & Wilcox Co. Our division has the responsibility for the design, development, manufacture, and support of the startup and the operation of the commercial nuclear plants, which includes a number of contracts, including the Three Mile Island 2 nuclear steam system and the nuclear fuel for that plant.

I have with me Mr. James C. Deddens, who is manager of project management. He was my deputy and was in charge of the Lynchburg operations at the time. On March 28, when the incident occurred, I was out of town and he was acting on my behalf, and I thought it would be appropriate for him to be here, since I understand you have some ques