ML19309G278
| ML19309G278 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/30/1979 |
| From: | Zewe B METROPOLITAN EDISON CO. |
| To: | |
| Shared Package | |
| ML19309G275 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8005050500 | |
| Download: ML19309G278 (9) | |
Text
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'INI STAFF INTERVIEW Bill Zewe 0623 Hrs. March 30, 1979 Conducted By:
R. Long and D. Reppert LONG:
Bill, could you identify yourself and your job function?
ZEWE:
I'm Bill Zewe and I'm Station Shift Supervisor.
LONG:
And you were the Shift Supervisor during the turbine trip the other morning?
ZEWE:
Yes, I was.
I was in the Unit 2 Control Room in my office at the rear of the Control Rcom at the time of the trip.
LONG:
Could you back up about an hour or so before the trip and identify what you were doing and then just go on from there? To the best of your recollection, describe the events.
ZENE:
The plant was operating normally about 98% power and everything was operating quite nomally. We were at a normal electrical line-up, normal primary line'-
up, nomal secondary line-up. The only problem that we had in the plant at the time was that we had been trying to transfer for several hours the resin beds in No. 7 polisher to the receiving tank down at the condensate polisher
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skid and we had an operator there that was working on trying to free up the resin clog in the line, and with moderate success up to this point.
I was in my office, I just finished reviewing some papers and I was just about to leave to go out to see how the operator was doing. The last time I looked at my watch just before the trip it was almost exactly 4:00.
I was just about to gather up my papers and leave whenever I heard the alams out in the Control Room, looked out the window which I do for every alam and I noticed that we had every alarm, just about every alarm, on panel IS which was it monitors most of the ICS parimeters for feed water limited by reactor, reactor limited by feedwater, BTU limits, etc. Most of these were lit, you know, and I jumped up and I could see that both the Control Room operators were up at the panel, one was by the primary panel and the other was over by feedwater. As soon as I seen that, I jumped up and just as I got through the door, I looked and I seen that we had a turbine trip and I took about another step or so and got up to about the first few desks there and then the reactor tripped. So I just yelled out to carry out actions for a reactor trip and I went over to the page to announce to the plant that we had a turbine trip and a reactor trip.
It was my shift foreman who was at the polishers at the time so that he could come back into the Control Room and that the other operators could take action on the trip.
So as soon as I announced that, I went right over to the panel there and I told the operator to verify the turbine trip and to verify the emergency feed and then I went over to the primary panel and the operator there was looking at pressurizer level and primary pressure and I said well let's start the A makeup pump and then catch the shrink from the pressuri:er level.
So the pressuri:er level was heading down so we put on the A =akeup pump and opened up the one high pressure injection valve to 16 B to try to catch the shrink on a normal trip and up to this point, I didn't know at this point that we had an abnomal condition at all because it just looked like a normal trip on loss of feed. 'Ihe turbine tripped because we s
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sure turned right away after the trip. You put on the makeup pump to get the pressure from shrinking too low.
LONG:
You've been on shift before when there had been a turbine reactor trip?
ZEWE:
Oh, yes.
I have had a couple of them before. So then we started to recover pressurizer level, it got down to somewhere under 150 inches and then it started to recover. Just about this time, which was,ust about a minute into it, the operator was having trouble with the emergency feed and he yelled down that the emergency feed valves, the EFV-12's which isolate the automatic valves were shut and I said, "Nhat do you mean they're shut?" and he said, "They're shut." So, he grabbed them just as I got there to open them up right away so that we could establish some feed. Then it was just a few seconds that the 'rimary pressure went down further and then we hit the point of high pressure (njection.
This, too, I didn't think was too unusual because putting on the emergency feed at the plant that was already cooling when it's certain no colder water is generated and push pressure a little lower.
So, then at this point, the pressurizer level was still coming up and we had pressure leveled off at somewhere around 1100 or 1200 psi and had pressurizer level coming up and had control of it, then I wanted to bypass ES so that we secure the makeup pump and shut the high pressure in-jection valves after we verified that everything had lit off for the high pressure injection. The other operator was still trying to get the emergency feed Icvels up around 30 inches.
REPPERT:
You're still talking about minutes now?
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ZEWE:
Yes, we're five minutes into it maybe. The time span here I really can't pin down to fractions in minutes or anything like that.
REPPERT:
But it still would have been in the first ten minutes?
ZENE:
Yes. And then while he was trying to do that, establish the feed, there at the steam generators, I wanted to be sure that the steam generator didn't go dry. The steam generators as I recall never got less than ten inches the whole time and I was watching. My shift foreman was up in the Control Room so that it was the four of us standing there after about a minute.
I told him to get the pressurizer level and to handle the primary side for the make-up system there with my one Control Room operator and my other Control Room operator was handling the feedwater.
An aux operator called after we re-started one condensate pump and said we had a real bad leak, on the suction side of the COP 2A.
We had no condensate pump running, no booster pump run-ning and no feed pump running. The hot well level was going high.
I also called over to the shift supervisor from Unit 1 and he was in the Control Room at this time then too and I instructed the couple of NRC engineers that had been in Unit 1 that ran over to help out to start to call some people to get some help. To call the unit superintendent, the unit superintendent technical support, my shift foreman was saying the pressurizer level was still coming up.
So, I said try to go to max letdown to try to let de-to hold the pressuri:er level and then we thought the pressurizer level in-struments were failing so we checked all three pressurizer levels.
He had prior to that anyway and they read all pretty closely the same and then we checked the computer, compensated computer level, and then we checked the inverse of the DP on the computer, too.
I sent an operator down to the aux-
f./ ri OV iliary building to check that out too and the hot well was out of sight high and the operator had called about the leak on COP-2A.
It looked like Fred was holding the level at about 390 or so.
Holding it the pressure was still fairly steady.
I felt that the pressure was low because we had had problems with the pressuri:er heater breakers in the M-20 area there where the relief valves are on.
Once it gets real hot and humid there that we have had a problem with. tripping our breakers.
We've had a limited pres-suri:er heater capacity before. The operator yelled, that he couldn't get the valves shut and there was water everywhere.
So, I r6shed down there since we had so m ny people up there.
So, I went down there and I still didn't know yet why we had lost feed for sure.
When I'm down the leak at the valve is right beside the condensate polishers and I looked and all the polishers were J
isolated. Just before we left the Control Room, the operator had started the condensate pump, but we didn't have any suction pressure to the booster pu=p to try and get it going because I want to try to reject the hot well so that we didn't flood over and lose backing to the backing pumps from a high hot well level.
So, when I got down and seen that polishers were isolated, I thought that was probably what caused the loss of feed was that somehow the polisners had isolated themselves and had isolated the suction to the booster pumps aad also isolated the discharger to the condensate pumps and that's why the line blew.
But I don't know that for sure at this point so that I wanted to try to open up the bypass around the polishers so that we could reject the hot well down. So then I was down there for several minutes and then we finally got COV-12 partially opened to where we could open it from the Control Room. We had tried earlier to open it from the Control Room
- but the motor wouldn't drive it open.
So then I ran back up to the Control C,
Room and George Kunder was there at this time looking at the pressurizer level with Fred Scheimann and Ken Bryan.
LONG:
About what time would have that been?
ZEWE:
I'd say 20 minutes maybe, a half hour at the most. George would probably recall when he got there but I really wasn't paying much attention to the time when I got up there.
I noticed before I went down that the drain tank had a high temperature and :ero pressure. The running pump had a very low discharge pressure means that we had ruptured the RC drain tank.
So, before I had left to go down to get that polisher job, I had asked Ken Bryan, the other shift supervisor, to check the discharge temperatures on the relief valves but they didn't look abnormally high since the electromatic had lifted.
It was about 228 or 230 degrees and they had been running about 170 or 180 so I figured it was still wam from when it lifted because it didn't indicate that it was still open which we found out later that it was passing by, but at this time I did not know. George and I and Ken along with the Control Room operators, were trying to figure out why we couldn't get the level back down.
It just didn't make sense and then the RB pressure was coming up and we were up to just about 2 pounds at this time and I figured that was from the RC drain tank. At this point the only radiation monitors that we had ab-normally high were the intermediate letdown monitors which have a very low set point, and they are very susceptible to background and they are right by the RB sump itself. We figured that the water from the drain tank was going into the sump because we did get the running alam on the computer and we had the primary operator check the reactor building sump level and it was high.
It was at six feet which is the maximum reading so we had him put the s
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sump pumps in "off" so that they wouldn't automatically transfer water to the reactor building sump to the misc waste holdup tank that was done like 45 minutes after the trip.
So that is just some of the side things that was happening also.
LONG:
Somewhere in there you must have decided that this was an unusual circum-stance.
You know when you began to get that feeling that hey this is not...
ZEWE:
As soon, well before, I left the Control Room whenever the pressurizer levels still came up and came up to like 395 and then we got it down to about 390 and it was just waivering around there. Something was wrong.
I couldn't put my finger on it and Ken was there, the other shift supervisor, and we just couldn't come up with why so that's why I checked all the other instruments and then was when I not only informed George Kunder and Joe Logan and everybody that we had a trip, but to ask them to come on in that I needed some more eyes either it was something I was missing or so unusual that I couldn't put it together.
So then George and them were there and then we kept going over in our minds, you know, what it was.
So we said well we have to leave the pressurizer levels actually high but how else can we get water into it.
It took us a good while to look over things and get everything else to say we don't it doesn't seem true.
So, then we initiated high pressure injection and stopped the letdown.
Because we said that maybe we're actually down and it is just a fake pressurizer level high.
Then we and then couple of our people showed up about this time and another shift supervisor. The discharge temperatures of the relief valves, RCRV2 was still high than the other ones.
So we went and shut RCV2 to block valve f r the o
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electromatic and the pressure in the building took a market drop down. Just L
prior to that we had a pressure differential between the B steam generator and the A steam generator which was about 250 to 300 pounds.
I thought that maybe somehow we had a leak off one of the steam generators that was pres-surizing the building.
So we went and isolated the B steam generator and as soon as we did that the RB pressure stopped going up and took a slight downward trend.
I thought maybe we had found the source of pressure in the building but whenever we shut RCV2, pressure came down very markedly.
It took a rather large drop.
So, we were sure that the electromatic had been leaking by and that was what caused us to depressurize at that point. Some-where around here we still had reactor coolant pumps running and the RC temperature was beginning to come up and then we were looking at the tempera-ture pressure curves from the coolant pumps and we started to get abnormal fluxuation in our flow instruments from the reactor coolant pumps.
So, I decided to stop two reactor coolant pumps at this time. We were about, I think it was somewhere around 540 degrees average temperature at this point.
We secured two of the coolant pumps and then the flow came down to about 50%
and stayed like that for I'm not sure for how long but a couple of minutes anyway and then the flow started to fluctuate some more. Then we secured l
all the coolant pumps and then we kept on feeding with the high pressure in-jection pumps at this point.
We kept on going without the coolant pumps l
and then I had the operator raise the steam generator level toward 50% and -
I thought, well, we probably don't have a problem with B, the level in B was still up somewhat yet.
But since we isolated RCV2 and the pressure dropped down markedly, then we went later on and fed up the B steam generator, too.
In the A we had to raise level to about 50% to increase natural circulation. We had quite a hard time trying to hold the level in the steam generators using the emergency feed because the EF-V11's valve didn't really 1
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respond to holding 21 feet or 50% on the operating range and we were re-sorting to taking more manual controls to do this and also even the EFV 11 valves, the throttle valves for the leveler, were leaking by and causing the level to go higher, so we ended up throttling on the header isolation valves, the EFVSA, B valve. So then we were like this for awhile just feeding up trying to get natural circulation going.
LONG:
So, you were trying to get natural circulation?
ZEWE:
Right.
Before we actually went into this before, we tripped the pump, Mike Ross, he is the Supervisor of Operations from Uniti, showed up because we had called him earlier and shortly thereafter Joe Logan came in too, the unit superintendent. Then we were still evaluating it and then we ended up to where we went to feed the B steam generator, after I had had it isolated, and shortly thereafter we tried to start the r,eactor coolant pump again and tried to get some circulation because the temperature, the T hotlegs were now trying to start the reactor coolant pump to see if we could get some circula-tion and we tried to start one pump, the breaker closed, but the pump was only going 100 amps and we weren't really sure that the pump was running.
So, we tried the second reactor coolant purp in the A loop this time and it started but it also dropped off to 100 amps and it wasn't pumping anything.
So, we just went ahead and secured it after that. Then...
LONG:
About what time was that? Do you know?
ZEWE:
No.
This was like, you know, quarter after six or six thirty because it was after we started to fill the B OTSG and we jogged the pump and we began to
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get all the radiational alarms in the auxiliary building and the E HB build-gins. This we declared a site emergency, it was about ten of seven there in that neighborhood.
I declared a site emergency because the radiation levels were going up, and it was getting worse and we really didn't know at that time exactly where the activity was coming from and then we had a report that the aux building drains were backing up and that the water in the drains were the source of the radiation going out the station vent. All our radiation monitors in the building showed this.
Also, once I fed that B steam generator, we had our off gas monitor come up in a very high range indicating that we now had a primary and secondary leak in the B steam generator.
So, we isolated the B steam generator again.
We went on like this for awhile..
LONG:
It was your decision to initiate the site emergency?
ZEWE:
Yes, George Kunder was there too, and Joe Logan was there, Ross was there, l
and it was a collective decision, you know, to go ahead and declare the site emergency.
So,'I announced that and that was the exact time. We went to carry out the procedures, you know, of the site emergency and make the notification to the evacuation and everything. Then shortly after that Gary Nd11er showed up, the Generation manager here at the site, and he took charge as the emergency director from Joe Logan and. George Kunder who had been there earlier.
Then we just then tried to evaluate the situation and see where we were and then we hadn't determined about this point that we had transferred the bubble into the loops from the pressurizer. We then tried to come up with ways to try to transfer the bubble back to the pressurizer, and we started to get problems and lose some of the pressuri:er heaters because they were shorting out.
We were spraying down to try to reduce some of the pressure by
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using the electromatic valves straight to the building and watching the
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building pressure. We had tried first to press up and to compress the steam bubble without much success the first time and then we went back and then tried to depressurize it and try to float the core flood tanks on the system.
And to keep the high pressure injection flow but at a reduced rate while trying to reduce pressure by way of venting to the building.
We then were venting by the spray valve.
We had it open. We had the electromatic open and we had the pressurizer vent open trying to get pressure down so that we could du=p the core flood tanks and then reduce the pressure and hopefully get down to the neighborhood of 300 pounds to put on the decay heat removal. We were unsuccetsful in trying to come down so then we finally later on in the afternoon then we came up and closed the electromatic and the vent and then pressed up to try to compress the bubble again from the hot legs.
Compress it into the reactor coolant pump to get circulation.
It was just about that point that I left that night.
LONG:
About what time was that?
ZEWE:
I left about 6:00 or 6:30 that night, I guess it was. We were just about solid in the pressurizer when I left and I was in the Computer Room looking at the level. We had the high pressure injection pumps on just compressing up the system.
LONG:
You indicated that several things as you talked didn't work properly. Any of the equipment you can think of?
(-IENE:
Well, the only ones that I can remember that were either malfunctioning or
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weren't right were the polishers did isolate themselves and we found out-later that we had excessive amount of water in the air system which would have caused the polishers to isolate themselves. The EFV 12 's, A and B, of course, were shut and they should have been open.
REPPERT:
Have you any idea how they got to be closed?
ZEWE:
WeII, my idea is that the last surveillance that was done on the emergency feed pumps, and I am not sure when it was done, but I think it was done within a week of the problem that we had ' Wednesday.
It was done on the emergency feed system which requires you to have the valves shut for the particular surveillance test.
It is just my guess that it was shut since then and we just failed to notice it.
I'm not sure just when the test was exactly because I just followed mainly the surveillance that are due and upcoming rather than those that had been completed but if I recall that was to be done not too many days prior to it.
But I am not sure of the exact date, but I feel that maybe then was when it was shut and it was never reopened and nobody noticed it for some reason.
That is just my guess at this point.
LONG:
Did you use any procedures anywhere?
ZENE:
Yes, as soon as we had the trip we pulled out the emergency procedures to follow the reactor trips and the turbine trip and also the high pressure in-jection and we followed those and then we also pulled out the site emergency whenever we declared the site emergency, etc.
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o But at the onset of it, it was just an unusual trip after the first two minutes. As far as the radiation levels or anything else goes, we really had no problem declaring a site emergency or anything else until about quarter to seven, whenever we got the water into the auxiliary building.
That is still in my mind, I don't know why or how we got so much water that was standing in the aux building floor or because the sumps backed up.
Everyone thought at the time that it was the reactor building sump pumps overflowed into the aux building.
But that isn't true because we had that off, and the Control Room operator who reported to me that the aux operator said that it was high so I said, "have Terry Dougherty shut off the pumps so that we don't flood out the aux building". He related that to Terry and Terry got back to us that it was shut and then he had walked around the building for quite some time after that and after the pumps had been secured and the floor drains weren't coming up.
Right now I still haven't found a very good explanation for how we got so much of that high contamina-ted reactor coolant into the aux building which resulted in the problem with respirators that we are now wearing.
It was mainly caused from the water from the auxiliary building, either a relief in the makeup system which did not go to the reactor coolant bleed tank must have lifted blowing water onto the floor.
It wouldn't have taken much to overflow the sump tank because the sump tank wasn't very far from overflowing when we came on shift. We were just waiting for the evaporator to give the one process some more water.
But it wouldn't have taken a great deal to do that but it wasn't from the reactor building sump. We didn't really have any indication of any of the other tanks like the bleed tanks or anything else overflowing, so I feel it must have come somewhere from the letdown makeup system either a b
relief in the letdown system or a relief downstream in the makeup pump some-where that was putting water into the aux building sump.
LONG:
When you began to see the high radiation levels just before 0700, what kind of procedures happens to initiate samplings? Is that part of the plan out of your hands, in terms of environmental sampling or in-plant radiation monitoring, are there some special things that happen there?
- EWE:
Well, once we recognized the magnitude of the radiation level that we were starting to see, I announced to all the stations that I was declaring a site emergency in Unit 2 and then once we do that we sound the alarm for the site emergency. That keys all the personnel to proceed to the emergency control station for either to be deconned er to be used to help to rectify the situation. At that point, then it strictly followed the site emergency plans themselves and I, as shift supervisor, am the emergency director until I am relieved by a senior member and they were already there at that point. We had already had three or four emergency directors there that took charge so really they were there before that point.
I just had the responsibility then of the plant operations and as directed by the supervisor of operations who was Mike Ross, Gary Miller was there in about five or ten minutes of the site emergency and he declared that he was the emergency director and that Mike Ross was responsible for the plant operations and Joe Logan and George Kunder and Mike were the input contacts for his functions as the emergency director and everything from there on in was pretty much as automatic as we had trained for, contacting the agencies, etc. and getting the repair parties available for any work, the on-site team and the off-site team, etc. to monitor the relief and to feed back the levels to make a further detemination.
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LONG:
How about the inter-action that went on in the Control Room between you and the CR0 and the shift foreman, the auxiliary operators? How would you...
ZE!?E:
In this point in time, you mean? After the site emergency was declared?
10NG:
No.
Back towards the.. back at the beginning? How would you characterize their actions and the communcation that went on?
ZEWE:
Well, we talked between ourselves and tried to resolve the problem or try to figure out what the problems that we had and we listened to each others ideas and then we tried to plan accordingly to try to systematically try to find out exactly from the indications that we had where the problem was and what to do about it.
We just used the auxiliary operators strictly to look at this, isolate this and go do that. We were just trying to evaluate the situation and try to look at every aspect.
It was hard to determine what the best move should be made next.
REPPERT:
When the general emergency was declared, Bill, what...?
ZEWE:
The general emergency was declared about a half hour later. About twenty after seven.
REPPERT:
Based on what kind of radiation levels?
ZEWE:
That was strictly when Gary Miller called it.
I heard it as they announced it, but frankly at that point, I was busy doing other things for Mike Ross under his direction and I really didn't get back at what point in the general
-f emergency are we at.
But as far as I know, at that point we did not meet the specified criteria for the general emergency that I knew of for at that point in time.
I think we went to it early but just in a safe direction that we still didn't have control of the situation as far as the possible releases to the public goes. We went one step further in the planning.
LONG:
You may have made some recommendations to Mike Ross or any of the other fellows that came in.
Did that happen and how did they respond?
ZEWE:
Well, George and Mike and Brian Mehler and Ken Bryan, were most helpful in trying to assess the situation and we were all pretty much just working as a team trying to advise each other and just more brain power, if you will, and more eyes to look at more things and try to come up with something more to go on.
Something more positive.
It wasn't a case of one person only listen-ing to one person, we were listening... The two control room operators had some pretty good ideas that we tried also and then Mike had some good ideas.
So, we just listened to everyone and then just based on the informa-tion and the suggestions and then just tried to do the best' that we could.
It's always the same case really because certainly don't ignore any sugges-tion that could be good and. they are pretty highly trained people and their words all had a lot to say.
LONG:
Let me make sure I understood that you are the one who asked the BSW people to notify the other station people that you needed help.
Is that right?
' EWE:
Exactly.
LONG:
So it was your decision to get out to George.
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ZEhE:
Right.
Plus I celled the Unit 1 shift foraman and told him to call some other people. 1 hey are the actual ones that called Miller and Mike Ross, and then the guys from Unit 2 who were calling Logan and George Kunder, etc.
George is really the best bet that I used first because he only lives about two miles from here, probably a mile and a half maybe, so George was here in the matter of about fifteen or twenty minutes at the most.
LONG:
Then the notifications to the state agencies, Gary Miller took care of this?
ZEhE:
Right. That is all made from the engineers that come up to the Control Room on the site emergency or general emergency they are assigned certain duties. They notified the agencies then.
I had nothing to do whatsoever wi*', any of that.
LONG:
You clearly have a pretty complete picture, more so than any of the others?
ZEhT:
We did have one other failure come to think of it, too, that I failed to mention.
We did have a problem starting the A makeup pump one time. When-ever we were going back on high pressure injection mode, we did have a problem once in getting the A makeup pump to start, so we just went to the B and C makeup pump then. That was the only other failure that we had besides the other ones that I mentioned so far.
We also tried to reduce the RB temperature prior to this.
We had went to emergency river water booster pumps to try to cool the reactor building and to fast speed on all our fans.
We tried to cool the atmosphere.
i LONG:
Anything else that you can think of what would help fit the puzzle together?'
ZEhE:
Not really.
END OF INTERVIEW WITH BILL ZEhE.
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