ML20136H070
ML20136H070 | |
Person / Time | |
---|---|
Site: | Three Mile Island ![]() |
Issue date: | 12/13/1984 |
From: | AFFILIATION NOT ASSIGNED |
To: | |
References | |
SP-I-TMIA-029, SP-I-TMIA-29, NUDOCS 8508200142 | |
Download: ML20136H070 (21) | |
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. :. Sen. Hart Briefing.
4 TMI Observation Center a 1e on March 29, 1979 h .
DIECKAMP: ....the 50% or majority owner and the operator of the i Plant.- The gentlemen on my left here is Walter Creitz
( who is the president of Metropolitan Edison and this j is Jack Herbein who is the Vice President of Generation and the man directly responsible for the operation of {
the Three Mile plant.- We understand your interests.
We know that you face demands for information, for t answers. I have only one,-two thoughts that I would like to convey. It is the policy and intent of the company to be totally open about this matter, to keep the public informed and to cooperate fully, with all-the governmental agencies _that are involved. I would only urge you to be a bit sympathetic with our problem in the sense that we still have a monumental task ahead of us to fully dig into all of the' facts that initiated the incident and the manner in which it progressed and the full ramifications of it. I think while we will be, Mr. Herbein will be giving you an outline of our current best understandin~g of the status of the plant and our observations or our current conclusions.about what kind of events probably occurred. I must emphasize the prob-able because we have not had that chance to verify all of the facts and all of the data. And I think"I must again say that we think it would be counter-productive if premature speculation caused the public to begin to lose confidence in the credibility of the operation that will be ongoing now in terms of the full explora-tion of this accident and its meeting. So, if there are f any questions from you, I'll.be happy to entertain them.
Otherwise, I'll turn it over to Jack Herbein to proceed.
SENATOR HART: Let me just say a word perhaps on behalf of all of us.
Senator Simpson and I are representing the Senate Committee on Environment Public Works and particularly the Nuclear.
f Regulatory Subcommittee. Of course, Senator Heinz and j Congressman Ertel have a medior constituent interest.
Other members of Congress were invited but were unable.
to come. I think our purpose here is two-fold. One.
to get'a factual or data base, so that we understand'
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what the present. situation is and second to determine f .
to the degree possible preliminary how government agencies <
have responded and particularly the interface between the Nuc1 car Regulatory Commission and the utilities and J
.so forth to date. Speaking'only'for myself,'I think in terms .of our handling of pres _s inquiries, we'll have to deal with those individually /and not collectively. I have no interests at all_in; pointing any fingers. I think it frankly would be premature for our committee-to undertake any kind of hearing or investigation until things.get,under control here. So, I think that we're primarily here to find out how what has happened. How the-agencies have.all private and publicly have dealt g 8508200142 841213 PLR ADOCK 05000289 .c PDR. h 0- -
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with each other to date. Then, we'll just have to each individually respond to questions that we need. ;
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-DIECKAMP: Well, we appreciate your sensitivity and we hope that j we can indeed assist you in that mission. Perhaps in l
!. the light of your one comment, Senator, let me introduce Mr. Richard Baumer, who I understand will be the senior 4 NRC man on the site. ,
TXURERT In the interest of brevity, I think we've all had a ,
an awful lot of information flowing at us. You deter- '
> dpIWr . mine how much of that you want to repeat. I think there's, to degree, what is on the public record is accurate. I think you can presume we know that and we'll go from there.
. If you want to start from the beginning, please do so.
. HERBEIN: Well, if you'll turn to the left here I think using this
! ........... schematic, we can give you a plant status as we understand it now; briefly run through the sequen.ce of events again that we can qualify it's as we understand
' it, we still have a lot of homework to do. It is probably.
better to say too little than too much. After I finish i going dowr. the p~lant status and what we think the key sequence of ~ events were to get us to where we were today, then certainly we'd entertain questions. With regard to the interface, the Nuclear Regulatory Commission, the state agencies, the Civil Defense, I think it's been
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good. Some areas perhaps could-have been improved, primarily communications. But, I think-things are going along fairly smoothly at this point. We presently are
- in a stable cond.ition with the reactor plant here in red.,
We've got the reactor coolant pump running removing '
decay heat from the core. Emergency injection systems
- stand ready. If there's .a problem within the pump, we
! can continue to inject and provide the necessary core coolant. In the auxiliary building which supports this red loop and clean-up systems and tankage and storage capability, we are releasing some radiation to the envi-i ronment. Approximately ~ 8,000 gallons of ' spilled coolant
- on the auxiliary building floor, some leakage through j
- pump seals, some gas releases have taken place we think i j in the auxiliary building. We have been and are contin- '
uing to on a periodic basis vent ' low 1evels of radiation !
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out of the ventilation exhaust systems in the auxiliary building to the environment. This morning we've seen levels of 4 to 5 MR per hour on site. At the site boun-dary, we've seen background and nothing higher. - I think early this morning there was one time-when we possibly i had 4 to'5 MR per hour off site.. .I don't think over the last 3 or 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> we've gotten anything that's that order
" -l l- of magnitude. Luckily, the ' sequence of events started -l 4 yesterday morning about 4 o' clock when we lost a feed -
)
4 pump indicated here in the steam water loop supply....
l
-3 HERBEIN: Two of these pumps, both of them tripped, and the
. a 6 Continued) suction valves came unplugged. When that occurred, there was naturally heat rejection which took place in the primary, increased the high pressure situation where the control rods dropped in the core automatically on that reactor trip at about 2350 lbs.
QUESTIONER: Could you give us some time sequences here as to how (interrupted by Mr. Herbeln) ,
HERBEIN: The thingI'lls talk about now occurred within about i
the first five minutes. When the reactor shut itself down, the fission chain reaction, of course, was term-inated here in the fissionable fuel area. The heat
- source imarily-stopped with exception of decay heat in the assembly. The pressure continued to rise as one ould expect in the sudden rejection and shut-down of the secondary plant. The valve on the top of the pressurizer which we term an electromatic relief valve ~ opened.at the proper set point and discharged its contents into a receiving tank in the lower regions of
- the reactor building. That valve, we think at this point, didn't reset where it'was supposed to. It basically lifts at about 2350 lbs. and should reseat some hundred lbs. less than that. It didn't reseat. It continued i to discharge reactor coolant contents into a receiving drain tank in the lower regions of. the auxiliary building.
. ... . .in turn, some of that contents got pumped out of the reactor building over into the auxiliary building and at that point, the receiving tank there overflowed.
. . . .three to four ' inches of coolant that we've got on the floor. We continued to depressurize the plant through this open electromatic relief because it didn't reset at the' required set point. We got down to 1600 lbs. and the safety injection systems automatically j
initiated and they injected four points shown here on the discharge ...... primary' reactor coolant pump. That system 4
actuated as was expected automatically as we had discharge
, through all four points. The system continued to de-4 pressurize through this open electromatic relief valve and at roughly 1200 lbs. we had'to shut off the reactor coolant pumps to prevent damage. These pumps are'not allowed to operate with the low suction pressure and 1 the temperature ' combinations outside of their relevant I design configurations. So we shut off two. pumps and the l pressure continued to drop, we shut off four. j QUESTIONER;. At what point was tnis?
4 At this point we're possibly five or six minutes into HERBEIN: -
the incident.
QUESTIONER: That was a manual operation?
HERBEIN: That .was a manual operation to protect the' reactor coolant pump. At this point, and this is where we still have more homework to do, we 'did initiate . emergency feed to steam
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l HERBEIN: . generater because of the interruption and. then the (Continued) initiation of the emergency feed. We may have caused
' a shocking consideration here that could cause a breach i of tubes in the "B" steam generator. That linkage between the primary and the secondary side of the "B" steam generator ultimately turned up in the condensate system, the sy, stem here. When this boiler war isolated, the other one still received we think potentially radio-activated feedwater, such that in subsequent steam venting operations off of this point we released some iodine and l .
radioactivity to the plant atmosphere and in turn was ,
4 swept offsite by the wind. We think that happened; we're l not positive. We continued with these pumps off and i emergency injection here through the discharge points '
which there are four for approximately two hours. We were unable to start these pumps because of the in-adequate suction pressure. It's possible that during this initial two hours of cooling that we vapor bound i the inlet and outlet piping systems of the core and
- as a result of that we were not able to restart these pumps. At least that's the way it appeared for the first two hours and then subsequently as the evolution evolved 'during the remainder of the day. There may ,
have been, and we're fairly certain of this, some pump fuel failures in the upper regions of the core because the drop of steaming effect took place to a lack of complete removal capability because we were not using 4
the emergency injection systems. Now this first beRan to show up on our radiation monitors in the auxiliary building at about 10 minutes of 7:00 yesterday morning.
When we saw the levels indicated on the monitors, we initiated the site emergency plan, which.is required 4 when we see these abnormal radiation levels on plant 4 monitors. We at that point notified the local Civil Defense and dispatched our onsite-offsite monitoring teams. They made an initial pass around the site and found no evidence of radiation being emitted. We con-tinued to watch the situation and at roughly 7;30 we got a high-level alarm in the reactor building at 8 R
- per hour and at'that point our plan requires that we
. initiate a general emergency, whereby there's potential for offsite radiation exposure. It was initiated and through calculations saw that perhaps on the western reaches i
. , of Three Mile Island across the river someone could perhaps receive a radiation dose. We dispatched a helicopter
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with a portable radiation monitor and a technician to
- -the western shore and at that point had nothing detected.
j So the initial sweep around the site and the sweep off--
- shore a mile and a half to the west initially indicated that at 7
- 30 'there were no offsite releases.- We con-tinued through the morning to survey'the plant environ-ment and the territory immediately surrounding the plant, the highway and of course down towards Middletown, the j direction predominantly that the wind was blowing. About 5 minutes of 11:00 we did detect some radiation levels-offsite. At that point we had 5 to 7 in some cases 10
- MR per hour. I put that in perspective an average' person i~
. , ; .' HERBEIN: . in the U.S. to sunlight, dental x-rays and granite
,(Continued) buildings, TV and so forth picks up about 200,so 200 MR in a year. We were seeing on the order of i
10 MR an hour at some locations. When the wind was l sporadic, shifting at a velocity of l'to 2 or 3 miles an hour, we didn't see very stable radiation level readings at any particular point.
QUESTI'ONER: At what point was the NRC notified in this process?
HERBEIN: In accordance with the plan when we declared the site emergency.
l QUESTIONER: At 7:10 to 7:207 HERBEIN: Within that time.
Continuing then when we began to. detect the-levels of radiation offsite, it was felt that possibly this venting operation on the one steam generator that was in service 3 was the cause. As soon as we felt that that was the cause, we stopped that venting operation. .We continued through
] the day to try and get these pumps started which we indi-d cated we felt they were vapor bound. Finally last. night around 9:00 we got a pump started and began to stabilize this situation, which previous to that was receiving four injections through four points being spilled out through l; the electromatic which at this point we left open with one ........ through the core. We left the electromatic
- . open and injected from our borated water storage tank
- l. approximately'150,000 gallons into the reactor building
- basement. That water is still there, it's radioactive and levels are about I think 10 R per hour. We've got 3 radiation monitors in the reactor building and one in the dome we'think is giving us a faulty reading-because it was exposed to moisture. That's reading I think between 80 and 100 R per hour.
QUESTIONER: Is that the one that at one time was reported to be at 6,0007
- HERBEIN
- That's right and if you use the factor of 100 that's -
available with lead shielding,'one could say that'it was' 80 or it was 8,000. I don't believe that's accurate. We '
have 2 other meters in there, one reading 10 R per hour, r the other reading about half to one R per hour. We believe that those are the accurate readings. At this point we are not'sure. Again, i_t's supposition.
i As.I indicated last night, we get this pump running.' we're at load now. The next level would be to step down from this pump to a high-volume low-pressure pump. We don't j
want to get there hastily. We are at a stable' condition now, we would 'like ~to get a better understanding of the i
fuel temperatures. We see in 5 assemblies that possibly some temperatures that are above that of the average of r the other 172. We want to be careful before we-step to
- that next: lower. level; be sure we' understand what we have.
i We're working with Babcock and Wilcox and our own Engineering Department to assess that situation. We believe that we've -
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.: . . HERBEIN: identified the major pathways that the offsite (Continued)- radiation leakage is coming from the auxiliary
, . v. building. We indicated some problems with gas; some other problems due to leakage along the point shaft seals down into the reaches of the auxiliary building. We hope to tonight or tomorrow tb- have terminated the majority of the offsite >
releases. To date our exposure to plant personnel has been on the average of 56 MR per individual.
L . Some individuals haven't received any exposure. We
- had one individual in an incident that occurred
!. over the past 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, we found out today received j a tenth of a R over the allowable quarterly dose.
! He received 3.1 R over the last two days.
j Gentlemen, that pretty well encapsulates the best
- I can about in 10 minutes what happened, where we j are and I'll throw it to questions.
QUESTIONER: Are you still venting through your pressurizer into
. the auxiliary building at the present time?
} HERBEIN: No we're not. That path has been r.losed off and a j high pressure -in,j ection.
QUESTIONER: What are the present pressure and temperature readings?
! HERBEIN: The present temperature is roughly 280 degrees with the pressure between 700 and 1000 pounds in'the vent system.
i QUESTIONER: Is that figure not higher than it was yesterday when you cite the 700 to 8007 Wasn't that coming yesterday?
i 1he pressure is invariable and we through the system i HERBEIN:
- operation can vary that pressure between 500 and 1500 pounds. The thing to look at is_the temperature, and 4
I think-that temperature's been coming down from the i
4 340 to 343 that we had last night on 'down to the 280 that we're experiencing now.
4 QUESTIONER: What's your decay rate on your temperature at the present time?. What's it reducing per hour?'
! HERBEIN: I've heard 13 degnees an hour. I Agaitt, I don't know that we're
- going at that rate now. On the whole thing,.getting an understanding of the fuel temperatures that we have here.
- Again, five assemblies have been fixed. Temperature is around 500 degrees. The other assembly temperature is
- . around 300 degrees. We want to understand that' differently before we step down to the decay heat.
i- QUESTIONER: As-I understand it, the problem started with the feedwater i
trip. .
4 1 HERBEIN: That's right. The valves on these two pumps here went shut. The pump shut off.' Loss 'of feedwater here. Pressure i . built up in the primary system. High pressure trip on the reactor.
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.- QUESTION: Have you had problems with the feedwater pump before?
4
. <HERBEIN: We have tripped feedwater pumps before. Yes, sure. I 4
don't know that this particular is similar to one that we've experienced before. Plants of this type _ do typically, on occasion, trip a feedwater pump. We tripped both of i them. That is not normal where you lose both.
QUESTION: Have you had any significantly different experience between this reactor, number 2 and number 1 with respect to your feedwater trip?
i HERBEIN: No. On our first reactor we had difficulties with the feedwater pumps tripping during the first half year of .
the operation till we straightened: some of the complicated controls here.
1 QUESTION: When was the last time it tripped?
HERBEIN: The feedwater' pump tripped on Unit 17.
i QUESTION: No, on this one?
l HERBEIN: Onthisreactor?'k.wouldsaywithinthelastfourmonths
- we have had feedwater pump trip possibly two or three.
QUESTION: Have you been able t'o determine whether any portion of the core may have heated more than another portion of the core such as through the bubble (interrupted by Mr. Herbein) l HERBEIN: Not directly. We do associate these increased temperatures l in the fivu fuel assemblies with assemblies that perhaps heated more due to a different level of cooling than the other 172 received.
QUESTION: Enough to perhaps rupture but not to come to th'e melt 1 situation?
4 HERBEIN:. I don't know if we've got rupture or if.we've got melt
- , or i'f we've got both. . Whatever has happened we have
. reached ........................ on some of the fuel
. ........ That's why we had the high radiation levels
- -in the spilled coolant that's in the basement' of the reactor building. .
QUESTION: You acknowledged early remarks that there was a problem-with communication. Would you expound on that? Was it a problem we had on the receiving end because of receiving six or eight or ten different explanations or communications as to what was happening?. Ranging- from problems of broad-casting that there was no release at all of any type of
.......... materials to high levels.
, HERBEIN: And depending when people got their information and when that in turn was released to the public, I can understand how there would be conflicting stories'because the situa-tion was rapidly changing. With regard to the communica-tions, I just heard that at the press conference this
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HERBEIN: morning, some of the Civil Defense people from the York /
, .(Cont.) Lancaster area indicate that they were upset because the Dauphin County people didn't cut them in better. We typically get a hold of the Dauphin County group, Civil Defense. That's..................for getting into the Civil Defense . network.
- We ............. .....ca11 the state duty officer. He was called at 7:02. We also called Ken Molek(?) .
QUESTIONER: You did that at ten minutes of seven.
HERBEIN: As required by our plan..
QUESTIONER: I understand. The plan that you talk about is the original plan filed with the license application. Is that correct?
HERBEIN: Yes sir, the emergency plan.
QUESTIONER: Does that only call for u. plan rules for communication and notification when it reaches "X" level? Is that correct?
HERBEIN: That is true. Yes sir.
QUESTIONER: Was there any reason to feel that you did not have any-thing to worry about at 4 A.M. when this occurred that should compel you to communicate at that time?
HERBEIN: The fellows called me at, I think, 6:30. They called Gary possibly a half hour before. We at that time didn't feel that we had failed fuel or that we were into an out of the normal plant transient which one would expect from a new plant. I was very surprised when we got the word of the radiation levels over in the auxiliary building which in turn initiated the site emergency.
QUESTIONER: Are you saying that when the trip thing occurred to which Senator Heinz alluded that there isn't a likelihood of release of materials that cannot be projected?
HERBEIN: We did not project.
QUESTIONER: And ordinarily the state of that would not project that?
HERBEIN: We didn't feel at the time that kind of a projection would have been in order.
QUESTIONER: Assuming from now on, would you recommend that when a trip like that occurs that indication and notification should be in order?
HERBEIN: I think in retrospect I'd have to say yes.
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QUESTIONER: Would you go back to.the decision to shut down the pump in the reactor system, and walk through that very carefully?
i ;
j HERBEIN: The decision to shut down this pump was predicated on the jl net positive suction head requirements. In other words, I
for the existing temperature at the time, the allowable
- suction pressure at this time, I think the temperature i was probably around 530 degrees and the pressure was about 1200 which on the limits of the allowable operating
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pump emblem . . . . . . . . . . . to shut the pump off.because the pressure was continuing to decrease. If we would allow that pump to run ........................then we would
- not only damage the...............but also the pump seal j and would thereby provide the additional path of pressurized j leakage out on that pump path.and we didn't want that to happen.so, we shut the pump off.
QUESTIONER:. If that had happened, what would have occurred that didn't
- occur anyway? Core meltdown?
i HERBEIN: I think we had'some fuel failure, some rod melting, some 1 core melting if you will, possibly another source of leakage into the reactor building in addition to the ones
! which we've identified through the electromatic. There i have been cases where, I think, other reactors of this .
type, where the seals were failed on pumps like this and j .. a significant amount leakage occurred went out the pump shaft out into the building. I think that's happened on j certain tasks.
1 l QUESTIONER: I'm puzzled as to why those pumps aren't designed to with-i stand the kinds of pressures that they were under in this i
incident and consequently, why it had to be shut-down.
They are probably technical. explanations. I just don't l
understand it. It seems to'me that the tolerances that should be built into these systems should accomodate the i very situation that happened here. Why did the pump fail, 1
I guess, is the question? Or why did it need to be pro-tected? Why didn't it do its job?
- HERBEIN
- It needed to be protected so that later on we could use -
it as we are now to remove the: heat from this system. Sir, I really don't have a good answer to your question. I
, think that's the kind of thing that we need to look at in
- j. cur subsequent investigation.
i QUESTIONER: Jack, there's a point there about the design...... pump * -
. going from wet ,to dry a very ,significant difference to
. the design criteria and the very importance of the seals.
v>
Is that part of it? .
HERBEIN: Yes.there certainly is. It's designed to pump water and when~you get the ....... situation it just is not designed to move up and you put the range . . . . . . . operation we typically
(
HERBEIN: shut this top off and then go down to another kind
! . (Continued) of pump at a low pressure situation. That's why we were talking about going ........ . l
- t
} QUESTIONER: But even given the fact that had the pump kept operating,
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a bad situation would have occurred. Was not the decision
- to shut the pump down, did that also not lead to .....
(interrupted by Herbein)
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HERBEIN: I don't think so sir. If we had not shut that pump off, i
it would have shut itself off and would not have been able to run. ..... rotating element would have sized to '
j -the point that it wouldn't spin anymore and we would not have j been able to pump subsequent. -
l 2
) QUESTIONER: Where was the pump on the ECC system?
i
- HERBEIN: . . . =. shut it on instamatic, but three of them around . . . . .
- injecting-at four points; one here, and of course there j are actually four heads of the
- points into the reactor. '
If we look up here,.we get a better feel for what these pumps actually look like. Two boilers here which of course are shown.over there with the red-blue interface.
The pump's right here. Normal flow of reactor coolant system. Hot water ...... operation. 'How water coming at here at 600 degrees coming off the bottom of the -boiler
. after it's made steam by passing through the tubes at 550 degrees being discharged into the reacitor, going down along the core barrel making a bend, coming up through a '
i flow distributor plate through 177 fuel assemblies, j picking up about the same 50 degrees of heat that is given up here in the generator. SSS in, picking up 45. 600
- through here and repeating..Four points of injection off .
- these pumps, and these are the ones.that we first shut l i down two in one loop and moved over and shutdown two in l l the next loop. The injection emergency core cooling systems j injecting through four points; one here, here, here and
! here.you see mounted on the discharge.
I QUESTIONER: At what point were these two shut down, and then when were these two shutdown?
j HERBEIN: I would say within'five minutes.
y .
! QUESTIONER: Why was that done? Why were these shutdown?
I*
i HERBEIN: For the same reason. The low pressure situation experienced here shut the pumps off to save them. The pressure continued j.. to' drop, shut the pumps off here. Go with the high pressure injection cooling.
i .
QUESTIONER: In other_ words, if you had not done what you had done these-
. pumps could freeze? q l
i HERBEIN: That's right. j l
l
. . . _ . m -__ _ . _. _ _ _ . _ _ _ . .._._ _ _ _ _ _ .
11 i-i QUESTIONER: And then they would be unable to do what they are doing 1
right now.
HERBEIN: That's right, sir. We felt that.,
QUESTIONER: One thing, when you cut out all four of your main, I guess you call them main feed pumps, at that point you are going to an emergency system.
- HERBEIN: That's right. Yes, sir. The emergency system had already
- actuated and was in (interrupted by Questioner).
1 QUESTIONER: . . . . . . At that point obviously . . . . when you cut these off j' HERBEIN: They had already actuated. It actuated at 1600 and we didn't shut these pumps off until 1200.
i j QUESTIONER: Now when you did that, at that point, do you not have an l' emergency in the plant and is that a normal....you know. 3 Certainly you expect certain failures during a normal operation of the plant. By having four of your feed pumps out at the same.. time, isn't that a ....wouldn't you con-
- sider that an emergency situation because you are on all l emergency pumps at that point?
- HERBEIN: No sir. Not really. The plant is,-at least theoretically.
l J
(interrupted by Questioner),
l, QUESTIONER: You have no backup system at that point, do you?
1 1
i HERBEIN: , Well the backup system of course is in actuation, but I there is another backup system known as the core flood '
tank system here and then there are again low pressure injection pumps -that serve as a still further. backup system. So, we were not without backup systems. What we felt would happen with these pumps shut off was the induce-ment of natural circulation whereby because of the steam removal from the steam generator we-'.d create a temperature differential and cause water to naturally flow. Hot water here sinking as cold and going back into the. core, without' the benefit of any motor power. It's the natural circulation setup that we felt was going to occur with these four pumps shut off. As it turned out, we didn'.t get that natural cir-.
culation because , as we see it, vapor binding in these what we call " candy. canes".-
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QUESTIONER: And you tried to turn these back on?
HERBEIN: We did, two times and each time we tried to turn them on, the amperage indication flow of current to the motors showed .
about 100 amps; a factor of 10 below what we should have seen I if we were pushing water. That indicated to us that we were just rotating in a gas phase steam environment, so we didn't want to damage the pump, so we shut it off.
. l
, i QUESTIONER: Now you had a pressure on your pr'essurizer. You had a electromagnetic .....
HERBEIN: Pressurizer over here. The electromatic....This is the spray. Actually there are three locations here with
. . . (interrupted by Questioner) .
QUESTIONER: Three separately actuated valves?
HERBEIN: Two of them are code mechanically oporated valves. One of them an electromatic which receiv u an electrical sig-nal at roughly 2350 and it opens and discharges to a tank contained here in the basement of the building.
QUESTIONER: And it reseats at 2250?
HERBEIN: Approximately, sir, yes.
QUESTIONER: And when it didn't rescat, is there any way to remotely rescat that valve, to do it manually?
1 HERBEIN: There is a way to close the valve. When you look at the
~ indication and now we are into the kinds of details that begin to get takg because we haven't done all the home-
- work that Herman indicated we need to do?
QUESTIONER:
....seem essential, because you've got. contaminated flow .....
HERBEIN: The signal to the valve is indicated, not the position ,
of the valve. So if someone would look it would appear that the valve were closed; however, that's only in '
order to the valve, and that's what we think we have.
We think we had in order to the valve a green light indicating the valve should go shut. It's possible.... 1 (interrupted by Questioner). '
i QUESTIONER: You have nothing on the valve itself which indicates l whether the valve is in a closed or open position, l only in order to the valve? j l
HERBEIN: That's true.
QUESTIONER: You have no followup system which comes back and indicates to you the actual position of the valve?
HERBEIN: I don't think there is a PI on the electromat.
QUESTIONER: Have you ever had some other shutdown of the pumps and the injection of emergency cooling in the other reactor?
HERBEIN: Yes. We've (interrupted by Questioner).
, QUESTIONER: Since it went commercial?
HERBEIN: Yes. Back in 1974 we did have a period where that the system de-pressurized, the injection lit off as it was j supposed to keep the level up in this surge tank or l l
i
... . . _ . .- - -.-~. -. . . . . - . . - - . - - . - . - - - . - - - -
U. . I. HERBEIN: pressurizer if you will. This device right here which ,
- '(Continued) actually rides through this pipe, connects to the system l
[ . -
and of course it's this tank with electric emergent heaters that keeps the steam bubble up here at 670 degrees, and
- that in turn with the saturation pressure then forces down ,
j through this pipe through the whole system and keeps the l
. whole thing at 2000-2100 lb. level, so we don't have any l j boiling. Now, this level had gone low on Unit 2 occasionally, l and on Unit 1 occasionally, and the injection systems did i
- light off at low pressure points and have injected in the l systems. That part has occurred. Also in Unit 1, we have in the past experienced an electromatic relief discharge ,
to the drain tank and I think on two occasions on the first
[. - reactor we discharged out of that valve into the drain tank, ,
ruptured the drain tank. So that occurrence is not something r that was completely unique. We experienced some of these
~
kinds of problems in the past.
QUESTIONER: -.Where then was the divergence, at what point?
- j. HERBEIN: I think the combination of events where this valve continued
- to depressurize did not reseat, pulled the pressure down
, past the injection point, past the point where these pumps j . operate and that with the continued loss of volume from this ,
system and the corresponding probable transfer of a steam bubble or a vapor binding condition in these candy canes, we got into the situation where we couldn't initially relight these pumps, so we had to rely on the high' pressure injection in the four points that I described.
-QUESTIONER: ~ May I ask one question? ~I had a report that somebody then i cut off your emergency injection systems. 'Is that correct?
i l HERBEIN: We tried from, I think 7-8 o' clock on through to maybe 2 i
- o' clock, to force this system solid and we could tell that ;
I we were vapor bound here. No matter what we do raising the I
pressure to try ed get this system solid,. we weren't getting j anywhere. So we said, let's take another tact. Perhaps if we can reduce the pressure and re-draw the steam bubble over j near the pressurizer, maybe then we can get some pressure con--
trol with our heaters and restore +hings to normal operation.
i to get our reactor coolant pump's running. The period of i time that those pumps were turned off, if they were turned i off, was minimal. Again, it was trying...(interrupted *by l Questioner).
i j QUESTIONER: Why do you.say "if" they were turned off, don't you know,
- because you were consciously either.doing that or not,
! were you not? Was there a design to try and turn them j off?
- HERBEIN: When you say turned off, Gary, did we pinch back on the j dische.rge of th,e makeup pumps or. did we shut all four injection pumps?
!~ GARY: . We're looking at a period of 7 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.- Initia11y'when
- the operator.got this transient, he had a pressurizer level i
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. - 14
. GARY: which would call for pinching back cause you had control.
, (Continued) If this pressurizer level went out, then you could continue. I don 't know the exact flow . . . . . , but once 3 we were at that point, then I kept telling them to keen the injection on.
HERBEIN: What he's saying is that when we were at a point not associated with~the draw down pressure, but where we were trying to get this solid, we wanted to stay around 2000 lbs., we didn't want
'to go up over the electromatic setpoint up around the 2300 lb. region, possibly we'd be activating the codes at 2500, so when the pressure went up and that this valve was open, then possibly we did .....back on the high pressure injection.
QUESTIONER: In the other problems that you had either with Unit 1 or 2, have you ever had to shut these ECC pumps down to protect them?
HERBEIN: We've had to shut these reactor coolant pumps off and bottle the steam generator and allow the natural circulation process to take place to remove heat from the core. We've done that.
Where we had natural circulation induced with no pumps. The flow in other wor.ds through here and up through here and back into the core, with no motive power.
QUESTIONER: When you had your failures before and you had your unseating of your basically relief valves safety valve, whatever you want to call it; your electromatic valve, how did you know that that reseated other than just the pressures probably came back up in your tank. Do you have a measure of pressure in that tank? ,
HERBEIN: We do have a measure of pressure in that tank. We also have a measure of pressure in the tank down below. We could tell with the decrease in pressure in the tank down below that this valve had reseated.
QUESTIONER: Did you ever have failure of that valve in the other incidence to reseat?
HERBEIN: Not to the degree that I think that we've experienced here, sir.
QUESTIONER: A valve either reseats or does not. You may have a leaking position (interrupted by Mr. Herbein)
HERBEIN: It may reseat after 100 lb. blowback, 200 lbs. or it may not reseat at all.
QUESTIONER: Or it may leak.
HERBEIN: Yes sir. That valve has leaked on Unit 1. ..
QUESTIONER: A continual leak through all ranges of pressure?
HERBEIN: Yes sir.
l
3 l 1
, , - QUESTIONER: The company is in a public.........according to one news count with your engineers over the existance of a valve or a seal. I saw, I think in a New York Times account, one of your spokesman, I don't know who it was, talked about a failure of a valve or a seal, Babcock 6 Wilcox
- says, accordi.ng to some spokesman in Virginia, that did not exist.- Do you know what this is referring to? This morning's New York Times.
4
- 1 Jack, I_think that what happened is the reporter took it
! to mean the pumps in the primary system. Then the reporter gh k-j _ called B6W and said "What about the pumps?" And they I
really don't have any valves (interrupted)
HERBEIN: It's difficult because the feed pump over there, the secondary blue pump, the blue one in the lower center,
- that started the whole incident. That pump tripped, so
- someone could think that that pump failed and get that j pump confused with these pumps. If someone asked Babcock j 4 Wilcox "Do you have a feed pump in the secondary loop?",
they would say "No."
j QUESTIONER: Could you estimate clenn-up costs? Or procedures at this l point?
4 9
] HERBEIN: I can't sir, no.
QUESTIONER: Is there anyone here that can?
2 DIECKAMP: I don't think we can. I think that we have to be str t i forward enough to expect the plant to be out for an ex i-period of time and it will be a considerable task to clean-up.
4 Beyond that, we just cannot quantify ........
i QUESTIONER: Along that line, what do you do about the contaminated water?
HERBEIN: Well,t$ere'sseveralthingsI'msurethatourexpertsare looking at. We can solidify it as it is without concentrating '
{
it. That basically means take it and mix it with cement,'a l mastic type of substance and ship it off site. We could '
probably ship it off site as a liquid in its present form.
One of the other things we could do would be to bring in package evaporators, concentrate the radioactivity in a j bottle if you will,-taking pure distillate, keeping it in tanks, sampling it suitable,' discharging distillant to the river and then disposing of the concentrates. These are
- some possible options that are available. I'm not sure what i we are going to do. I think that one thing that we do is to i wait for.the levels in the 150,000 gallons in the auxiliary building to decay somewhat before we try and do anything with j it. -
QUESTIONER: Are there any regs governing what you should do with the water?.
- HERBEIN
- There are regs certainly that govern us with regard to the 4
exposure we can give the operators to handle it, the regulational 1
4 5
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A a.
, }iERBEIN: with regard to shipping it over the road. There are regu-(Cont.) lations with regard to where it can be buried and there are only certain kinds of people that are in that business.
There definitely are certainly discharge limits on the distillant that would be processed to the river. Yes, very closely governed by the Nuclear Regulatory Commission
. regulations.
j QUESTIONER: I,think we want to hear from the.NRC representative here L briefly. .Let me ask Mr. Dieckamp. It's been speculated in the past that if an incident of this sort occurred, i that the level of radioactivity involved and the damage
- involved might make it prohibitive to even reopen the plant
- .at all. 'Is that being discussed?-
J DIECKAMP: I don't think we have any indications at this point that t would suggest that. =I really do not think so. One can think of 3
. situations within the reactor vessel where one might have a te .diti
! situation. But, we have no evidence to date that we're at I that point. And again, we're in this very early stage and i as we're able to analyze the system and regain access, begin 1 to open things up,. take a look at them, this will be a j developing story.
s l HERBEIN: It's a step by step process. The first thing that we've got l to do is go to that auxiliary building and get that four to five inches of water, 8,000 gallons, ~off the floor and get it into tanks. We're going to have to do things with the I
water that's in the basement of the reactor building. After
- that' clean-up process, we're going to have to inspect our fuel assemblies that are enclosed in the reactor. To do that -
l we'll have to flood the cavity, or remove the head, flood the
- cavity and look at each (end of that side of tape) 1 DIECKAMP
- . . . . . . . . . . .(flipped to second side of tape. Missing first
! part.) I don't know if it was mentioned earlier, but it is-i down. . It has been .down for its annual refueling. We will i
not be restarting it until we are quite_ confident we know
- what the problem was and we understand whether we have a t similar probability in it or not.- So it is in a. cold standby '
l position and will stay,there for some indefinite time until ,
j we're able to fully analyze it. . i j QUESTIONER:* Another question if I might. You hate this water in your i auxiliary building ~on the floor, four or five, whatever
] iit is. Do you have tanks to put that in?
4
.HERBEIN: .
Yes, we do. We had some low level. liquid in a tank that I we are in the process now of transferring now into the Unit .1 reactor. That will free up space for the majority of what's
'on the floor..
i 4
QUESTIONER: What are you talking about? .How long a time till you get this j sort of thing'(interrupted by,Mr. Herbein)~
'HERBEIN: I'm estimating,.but I would say two days. Again, we want to go slow.- We're just not in 's hurry. We want to plan every step.
I l
l QUESTIONER: If.it is agreeable with my colleagues here, we might hear from the NRC on some of these issues if you'd care to.
NRC: ' What would.you like, the ah..?
l QUESTIONER: Well, I think.the chronology of your involvement, any l i- response you might have to the briefing we just received. i I
! .NRC:
I think our involvement has been pretty much as follows.
i Notification was early yesterday morning and the regional 1 office . in the King of Prussia, sections of the . . . . . . . .
L offices were notified. They dispatched ..... people who i were qualified to look at the systems aspects, radiological j and point of. health and safety aspects, and tried 'to set up i'
an information gathering which eventually is still going on j at this point and time. Early yesterday morning we initiated p our incident response center at headquarters in Bethesda and 4
this has been manned continuously ever since. We've had
- open lines to the plant here, to Babcock.6 Wilcox and to j regional representatives. . Has mainly been one of trying j to determine the gross status of the plant. I think you can appreciate that so much information, so many facts 3 coming in. It's difficult for us, particularly time and j distance wise to draw any conclusions except that I think...
1- - appreciate what the operators are trying to do, the direction
. they're taking. This is certainly correct to try and reduce the pressure and temperature in getting down to the decay i heat removal. It's difficult not being in the actual plant
{ and control room to determine the best way to do that. I l
i
. think that they've indicated 'a number of factors prevented a'perhaps more normal and orderly approach to those things. '
i I myself and seven others arrived here about noon today and are trying to set up a committee office, if you, will to
~
l j simulate the information that would become available to l
- let our representatives back in Washington know where things i
- stand. i
! QUESTIONER: ........ clarify content. levels in the atmosphere? Could
} you clarify the reports that are being given from the company?
NRC: Yes, sir. Our inspection enforcement'is independently monitoring airborne samples or taking environmental samples and so on (interrupted) They should be able to talk about that.
QUESTIONER: Do you have any reports on those?
NRC: Mr. P(?), the inspection reports on. . . . . . . . . They're asking.
p about verification of airborne or environmental samples as -
i far as radioactivity.is concerned. .......... is in charge of the environmental monitoring ~1ab that we have on site here -
i right now.
............: We do have a mobile lak here ............. as a daily protective
-system. In: fact, we have been counting most of the samples that
! have been now taken in .the environment . ... .of the high radia-tion background.. . . .and they can't detect the~ lower levels of j activity that we can on the........particular sample. So we're k
.-n.,v, - . . - - , . . _ . - , , , . _ . ,
- -~. -- .. - . . . .
4
.c . a
............: involved in doing that. We are also taking some independent samples of our own, we have taken some independent radiation j surveys; we're also taking a few spot checks of such things l j as soil, water... I QUESTIONER: Your readings differ appreciably from those of the utility? !
- , NRC
- No. As a matter of fact we have had a man go along right with the utility on ..... survey team efforts. I think yesterday ~
evening when we first arrived there was some varied.. .. . what t
the facility had been finding and what we found on our way in.
We pointed that out to licensee and then he sent....out in
! that direction and came out with some higher levels than had i been recorded. That was the only .........
i.
f QUESTIONER: What are the levels right at this moment as far as-you are concerned, at this moment?
i NRC: We are talking about radiation levels now. The charcoal cart-ridges that we have pulled .... sampling radlowise in the atmosphe QUESTIONER: They are whrd.? ,
NRC: Charcoal cartridges. You take an air sample, you pull the air through a charcoal cartridge and remove and concentrates the radio iodine that we have at present. 0.K., we have done that l
and we have yet to find any radio iodine in the environment. -
I What we are finding is nomal gas xenon 133 and 135. This is
- giving the radiation levels.which we are observing around the '
! site and offsite.
QUESTIONER: What does that mean as to danger to the citizens?
[ NRC: Most people involved in this area in the emergency plane would be more concerned with the radio iodine with complications of j
1-the thyroid of adults and particularly infants and gives higher specific dose to that organ. The other dose.that you would get from the nomal gases is essentially a whole body dose'. This is I the same as direct radiation. It's not concentrated in any orgaa 1 To that' extent it's less of a hazard. . . . .to measure you are l thinking of direct radiation exposure. Does that answer your question?
4 QUESTIONER: Not fully. The radiation, the whole body radiation...
- NRC
- It's like an.x-ray. ,
- . QUESTIONER
- Yes, I understand that. At what level of' danger or non-danger
- is it now? How can we report that back.to the people?
NRC: 0.K. ,I - think tlne are some people from the State here. Maybe
. I could characterize'it well in a couple ways. One EPA came out with protective action guidance, if you will, where they
.t have deemed approved to take certain actions. O.K. The State has the distinctly.in'a ....., correct me if I'm wrong, having adopted these protective actions. They are in the range of~
. _._ __u- _. - ___ _a. ._ ._.a. ~_ __ . ~ ,
4 NRC:. one R to S R.whole bodies. O.K., the IcVels which are now
, .. ,.(Continued) being observed are in the low MR range, that is one-thousandth of one R. New, these levels integrated on an hourly basis will then add up to some total and so far, I have just a rough pro-4 jection that.....on it, it's very rough; I haven't seen anything I'd like to see yet, the levels fall out way below the protected
- actions. If that gives you a handle, ther. characterize it as
........ There's another quick rule of thumb might be natural
- background which is about 100 MR for the year roughly, i.
f QUESTIONER: Have we found out if there is any serious problems as far as
! the NRC concerned in terms of getting information or relating to the utility licensee?
k NRC: None that I know of sir. We're .directly tied in to the Unit 2 Control Room from our region 1 office and also our headquarter's office and also response centers. . . . . in format i on . . . . . . . . . . .
- available.
- . HERBEIN
- Working closer. Bill's been an assistance to us in the accounting areas af communications.
j .........: May I have the s.tatus also to doing our own samples. We j '
have D.O.E. Teams from Brookhaven and Venice working for
- us .............. samples also.
] . QUESTIONER: Have you come up with any readings (interrupted) l ,
.........: No, our's correspond with what the NRC and the utility have j been getting.
I QUESTIONER: Do the NRC people here on the site have any substantial
- quarrel with the way the licensee utility has managed this j
situation?
] NRC: I don't think'so at the time, sir. As I said before, it's l l a gross situation ............................... decay heat l
{ removal. ......certainly the appropriate way of doing it. l
{ as procedurely as normal and is possible with...... We i i have great lack of information if there was anything to ,
quarrel ..... I think it would take a great deal of detailed i i
look into the information to first of all, assess what did i
- - . go on and secondly, if this is what you're suggesting, to.
determine whether or not things should have been done differ-ently or could have been done differently.
QUESTIONER: The reason I asked is that we were briefed by telephone with several officials'of the NRC yesterday from Bethesda relying
- presumably on information they were getting from here'and
! they were, I think it's safe to say, a little edgy if not g
nervous about some of the methods being used to bring the pressure and heat down and the rate of that. That's why I asked.
............: Well, I was involved in that sir.
j 2
Ithinkwhatyouarereferrinq to is the question several times as to why wasn't the primary .
i fuel pump energized and I think that was part of our concern too. But, the operator's have many more facts available than i
.- - .. ~ ,. . . . . -- - . -. -. .- - - - . . . . . . - .
it !
+ e we did even though communications 'between our response
& *. e (continued) center and the control room and so on was quite good.
It's difficult really to be able to integrate all the information that exists at the plant. That will take some time.
QUETTIONER: I think'thats an interesting aspect I would share with
[ l Iy{Sira you that Senator Hart is the chairman of the committee i
as he has said and I'm the ranking minority member and our principle job in that role is oversight of the NRC.
i and that's really why I'm here, to be sure that this governmental agency -is responding and you're responding together because of this critical situation. I'm very pleased I came. I came for that reason. I didn't'come to follow the T.V. cameras, especially since I don't even know where it is in Wyoming. Anyway, I appreciate it j very much.
a HERBEIN: Thank you sir.
QUESTIONER: There was a suggestion to us yesterday by an NRC official from Washington that operator error may have been involved.
F Are you at liberty to express your own opinion on that matter?
{ ....I....: I really couldn't sir.
I wasn't aware that that comment i
had been made and as you can probably appreciate, there were a number of activities going on back there at the time.
I was not ..... the response center. I was back~in my own i office with a team of individuals working on the' problem separately. So, I couldn't comment.
1 -
i QUESTIONERS: Thank you very much. Thank you. You did a very nice job.
i i
a 1
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