ML19208B095
| ML19208B095 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/26/1979 |
| From: | Bensel R, Marquette Rogers Metropolitan Edison Co, NRC Office of Inspection & Enforcement (IE Region I) |
| To: | |
| References | |
| TASK-TF, TASK-TMR NUDOCS 7909190049 | |
| Download: ML19208B095 (34) | |
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UNITED STATES OF AMERICA NUCLEAR REGUI.ATORY COMMISSION In. the Matter of:
2!
IE TMI INVESTIGATICH INTERVIEW 21 of Richard William Bensel Engineer III, Nuclear 4:
i Si 6i 7!
at Trailer #203 9!
NRC Investigation Site TMI Nuclear Power Plant 10!
Middletcwn, Pennsylvania 11!
July 5, 1979 12:
(Gate of Intarview) 13t July 25, 1979 (Date Transcript Typea) 14i 328 15l (Tape Numcer(s))
16i 17i 18i 19i 20!
21,
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NRC PERSONNEL:
22' Mike Rogers James Creswell 23l Timothy Martin Anthony M. Fasano 24, 25:
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ROGERS:
I'm an investigator with the United States Nuclear Regulatory 2
Commission, Region I Office.
The time is 9:12, the date July 5, 1979.
The 3j location is trailer 203 at Three Mile Island.
Also present with me in the 4j room are: James Creswell and Timothy Martin, also of the NRC. And Mr.
gl Richard William Bensel. We're here for the purpose of interviewing Mr.
t Gj Bensel and prior to beginning the interview, I'd like to direct Mr. Sensel's
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7j attention to the two page statement that he signed prior to the beginning i
8l of the intarview. Mr. Bensel, I'll ask you, are you familiar with the contents of this statement?
g 101 BENSEL:
Yes, I am.
u:
ROGERS:
The statement outlines the authority of the NRC to start the 14!
investigation.
There were three questions which you checked off on the statement, I'm going to ask you them verbally.
First of all, do you under-stand the statement as it was given?
171 BENSEL:
Yes, I do.
19!
ROGERS:
Do we have your permission to tape this interview?
21:
BENSEL:
Yes, you do.
22t 23 ROGERS:
Would you want a copy of this interview, a tape of the interview.
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BENSEL:
Yes, I would.
2!.
ROGERS:
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Alright, one other question I would like to ask you is, you do 4;
understand that you could have a company representative or anybody you 3
chose present with while you're being interviewed.
Si BENSEL: Yes.
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ROGERS: What's your feeling on that?
g 10!
BENSEL:
I don't think that's necessary.
12!
ROGERS:
Okay. At this point I'de like to turn the interview over to Mr.
Martin of the NRC.
14 15 MARTIN:
Dick, one of the first thin ('s I want to get confirmed was the approximate time you were called on the morning of the event, and when you arrived, and your license status.
191 BENSEL:
I was called at approximately six a.m. in the morning, and I 201 arrived on-site between 6:45 and 7:00, I don't rememoer the exact time.
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And I am presently not licensed.
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231 MARTIN:
Dick, I know you've been researching for some electrical problems 24l in the plant.
I would like to pursue some of those now to get them on 25!
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d record.
The first one I'de like to talk about is the findings you've had l
relative to automatic manual switch, in the condensate booster pump and 2
3 condensate pump trip circuits.
41 Sj BENSEL:
I actually did not perform that investigation, that was performed l
by George Leeman of GPU Service Corporation.
But, the results of their 5
investigation were that the trip circuit, for the A condensate pump, the gj auto-manual switches in auto and booster pump trips and low suction pressure, it will trip the condensate pump also.
However, during the incident, or g,
10 pri r to the incident, the auto manual switch is in manual and this interlock j
would not have been there.
For the elementary so the A condensate cump should not have tripped, but their investigation showed that rather than
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the auto-manual contact was not wired into the trip circuit for the A N
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condensate pump so that the booster pump trip and low suction pressure that j.
l 15i came back and tripped the condensate pump, even though the switch was in
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D manual.
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- 4 MARTIN:
18I Dick, is this wiring error peculiar to the A pump pair only?
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,s BENSEL:
To the best of my knowledge, yes.
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4 21 N
MARTIN:
I understand there was a report that one of the condensate pumps 22 was damaged during this event.
Was this the pump that was left running 23I after the initial transcient?
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y BENSEL: Yes, it was the 8 pump. We have no record that that pump automa-gj tically tripped.
i 31 MARTIN: What was the nature of the damage to that pump?
4l Si BENSEL:
6 Damage to the lower bearing on the motor, is the initial damage that we saw.
7i Subsequent, the pump itself was also damaged due to cafitation, 8{
but I don't know what that was related to.
91 N:
Has s damage been related to the event?
101 i
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BENSEL:
I don't know if that was ever really confirmed.
It's possible that it could have been.
24[
f MARTIN:
In reviewing the elementaries for the condensate booster pumo and the feed pump trip circuit, I note that there is a contact or should have been a contact in the circuit when the condensate booster pump trips, it 171 would automatically trip the feed pump.
191 BENSEL:
Yes, there is a contact there to do that, but that contact will 20!
only function wnen the auto-manual switch is in auto.
21i 22l MARTIN:
Is this another case of where the contact was miswired as we found 23{
l in the A pump pair?
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BENSEL:
No, that's actually per design.
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MARTIN:
Dick, I would like to pursue another area of your investigation, 4i that being related to the diesel.
In reviewing the computer printout, we 5
have noted four computer points that printout indicating diesel or labe-oil 6j status.
The indicators.<e got would suggest that the ccmputer points are 7
not properly labeled.
Could you expand on what you found in researching this problem?
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BENSEL:
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Frem our investigation, we found that computer point 3156 is DFX1B g
fault, computer point 3157 is DFX1B low lube-oil pressure, computer point f
3158 is DFX1A fault, and computer point 3159 is DFX1A low lube-cil pressure.
This is contrary to what the actual point designaters on the computer print out.
15!
MARTIN:
Is this not also contrary to what the elementaries would require?
, 6, 1
171 l
BENSEL:
Yes, it is.
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19f CRESWELL: Alright Ofck, I'de like to pursue now, how did you conduct this investigation? Did you go down and check the wiring to the input of the computer?
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BENSEL:
What we did, we exercised the contacts that bring in the ccmputer 2 41 points.
In other words, diesel generator fault ccmputer input is from 25i
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contact from the 5 E relay so, in order to get that computer point to print 2
out, we manually activated the 5 E relay and the computer points for low I
3j lube-il pressure, we actually did those by using jumpers and opening links ff the actual relay contacts that pick up the computer point.
4 51 CRESWELL:
Dick, during pre-operational testing, were these computer Gi points verified?
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BENSEL:
They were supposed to have been verified in turnove" documentation g
should show that they were verfied.
11:
CRESWELL:
Did you go back and look at that?
131 BENSEL:
No, I did not.
15i MARTIN:
Dick, one other area I would like to explore that you may have been involved in is related to the make-up pump circuitry, start circuitry 17!
in the trip circuitry.
During the event, we had multiple trips of the one 18l A pump, we had multiple times where the one A pump did not sta c on the 191 manual attempt. We had one attempt where the one C pump did not start 20!
during the ES apparently during a manual start attempt.
Are you aware of 21!
any investigation into the causes of these trips and have you been involved 22!
or do you know of anyone who is involved in that investigation?
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BENSEL:
Quincey Bellings, a GPU Service Corporation, went through all 1;
2l computer printouts for the makeup pumps during the incident.
And,'ack i
3j Laughton and myself spent a lot of time explaining to him what the computer printout means and helped him in his determination of what was going on at 4
the make up pumps. There are a couple of computer points there that were g;
wr ng achards, a 3,000 series points where ne A and C make up pump 6
j were reading trip when they should have been reading normal, and those those points are picked up by a relay designator that's a 30 T relay which 81 means that the pump if it says trip means that the pump had to automatically tripped.
11:
CRESWELL: Was that the 30 T as in Tom?
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BENSEL:
Yes.
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151 MARTIN:
Have we looked into why the operators had trouble in starting these pumps?
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i 18f BENSEL:
I don't, I'm not sure if they really had that much trouble starting 191 the pumps from what I've been able to ascertain. Initially, after the 20) event, it appears that they started the A pump probably got the red light 21}
and then immediately tripped.
Why it did that I don't know.
Several, less 22!
than a minute after that, they restarted the pump and it appeared that they 23!
really did not have that many problems with that pump subsequent to that.
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I lj HARTIN:
Later in the afternoon, the operators were attempting to start the l
2:
A. pump.
And, had such a problem with it that they finally pulled it to 3
lock and left it that way.
This has been confirmed also in the interviews.
4 Has this been referred to you or to anyone else to investigate why the A Sj pump didn't start?
6i BENSEL:
No, it was not.
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CRESWELL:
Do you have any knowledge that any breakers were tripped off, g
10i any fuses connected w m the pump?
11!
BENSEL:
No, I do not.
One likely cause why the pump wouldn't start, it y
would probably be that cooling water flow interlock.
i 14I MARTIN:
In reviewing the computer print outs and I've also talked to Mr.
Quincey Billingsley, he and I both have come to the tentative conclusion, U:
that late in the evening, when we attempted to start the one C pump, imme-i dic,tely following the jogging of the reactor coolant pump.
Pressure dropped very rapidly and the operator apparently seeing this attempted to terminate the drop by manually starting the 1C pump.
During the start sequence, pressure had finally dropped to the point where it initiated ES and ES 21:
i switch would bypass this hose cooling water flow switch, yet the pump still 22l tripped and did not, the 52 contact, the breaker, did not move.
In investi-23i gation of this we have isolated in on possible culprits or things that 24l could have prevented the start.
Among them, is the start switch which I 25i i\\u 7
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d understand is an SPM switch which you had a construction deficiency report i
2j on.
Is this switch one that was replaced as a result of the CDR that was issued back in 1977?
3 4l BENSEL: All switches with safety related components were supposed to have 3
Si been replaced and there should be a QC documentation to that effect.
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8 has been asked to look into it.
Do you know for a fact thought that this g
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vintage?
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BENSEL:
I do not know for a fact.
131 14; MARTIN:
Do you plan or do you know of anyone else who plans to look into why these makeup pumps appeared not to be as reliable as we would like them to be?
17l i
ISt BENSEL:
Possibly long term, but not immediately.
19:
20i MRTIN:
Dick, the next area I'de like to pursue is what electrical things 21:
you were involved in during the first 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of the event.
If you would, 22!
l please give us a quick overview of those things you were involved in and 23l i
then we will pursue questions in each area.
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-1l CRESWELL:
Could I kinda set the stafe for that it is my understanding gj whenever you came on-site that essentially immediately you were involved in 3
the implementation of the emergency plan, that is, you were involved in l
4, making notifications that you kapt an open lines, I believe to the NRC.
Is 3j that correct?
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BENSEL:
,7 I was either in the open line witn the NRC or with the Department of Radiclogical Health, possibly both.
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During de period of time that you were keeping the open line 101 did anybcdy breck in and ask your 3dvise on say the interlock reactor coolant pumps anac. hat jumpers should ba installed in r? actor coolant cumps?
11:
-a 14 BENSI1:
Ivan Porter primarily did that, I vaguely rem;mber some discussion whare there was one rel.?v the: ve bad to get picked,;o which is X3 relay.
K3 relay really constitutes, consitts of the cooling wate'r interlocxs to 5 171 x
the pump, seri infectio~n flow and all the oil interlocks for the mon.
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Did you get a crawing, cat,. :nd icok at it curing the course of r
this particular action?
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'dENSEL:
I don't remember doing that.
T ' cow Ivan, myself and other 231 l
reople that were in the contrcl rocm at the time knew that in order to 2W start the rear _t;r coolant puaa, the K3 reJ!y had to be picked up.
In that
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l lj point in time, the best way to do that was to just go down in the switch 2
gear and manually pick up the relay, wnich is, if I remember correctly, 31 what Ivan eventually did 41 gl CRE5WELL: Oksy, how would you characterize your particular involvement in that evolution.
That is, the jumpering of the interlocks on the reactor 6
p coolant pump.
I 8!
BENSEL:
The initial jumpering is very minimal.
I was primerily involved g
with the phone calls.
101 lli CRESWELL: Were there any other electrical areas that you were involved in that day, the day of the 28th?
1.1, 14:
BENSEL:
Diesel generators they started on the initial safety infection actuation and the only way that they could be tripped was by tripping tr.e fuel reactor which the operators did, at what point in time, I'm not actually sure.
That can be picked off the alarm typewritter printout.
l They tripped the diesels and they initially did not reset the fuel racks.
191 I know the morning of the 28th prior to noon, the shift foreman and myself 20f discussed getting the diesels reset. And they did reset tne fuel racks and then due to where the plant was, shift foreman and I discussed and decided 22 that to flip the diesels and maintenance excercise so there was another ES 231 actuation it would not automatically start.
And, the reason we did that is 24:
cause if they did automatically start a require sending personnel out 2Si to the diesels to trip them again and reset them.
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lj CRESWELL: Why would that be necessary?
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BENSEL:
Because, by the design, the diesel starts in the safety injection 3
4 signal.
You can not trip the diesel or shut it down from the control room.
5j It has to be manual actioned at the diesel.
And, in a situation of plant 6
diesels were not needed and it had ran for a period of time under no load 7
and it's very detrimental to the engine itself to run under no load condition.
Si CRESWELL: When did you have this discussion with the shift foreman and who g
was the shift foreman you had the discussion with?
n.:
i BENSEL:
The shift foreman was Adam Miller and probably the discussion took l
place between 10 and 11.
131 141 MARTIN:
Dick, in review in the computer printout, we do see the indications with the clarification on the computer points, the diesel starting shortly after the initial ES. We see again with the clarification of the computer points that the diesel EFX1A and 18, SE relays were picked up at approximately 18f 30 ainutes into the event.
We don't see another indication on those relays until 9:30 in the morning, and we don't see any further indication in -he 20:
rest of the day.
Now, correct me if I'm wrong, but this sequence would 21!
imply to me that they started on the initial ES, the operators manually 22l tripped the, since they would be started, since they were started by the 23!
ES, they could only be shutdown locally.
That we see both SE relays picked 2 41 up, essentially simultaneously, within 30 seconds of each other.
30 minutes 25!
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into the event that that was indicative o the operators tripping the fuel 2l racks and that because we don't see any further indication until 9:30, that f
would mean they were not reset until that time.
The fact that we didn't 3
4l see any further indication of them starting or being shutdown for the rest gj of the day, although we had one, two, three, four additional ES's would 6
indicate that at least to that period of time they were in this maintenance 7j position.
Is that history correct, is that scenario seem to be correct?
81 BENSEL:
Yes, it does.
g 10!
j MARTIN: Where is this book, first of all, we talk about a maintenance position, maintenance excercise position.
Is that a device which prevents the diesel from rolling so that the guy who working on the diesel doesn't get hurt?
141 15:
BENSEL:
It's a selector :: witch on the control room panels for the diesel.
In maintenance excercise the diesel can be started frcm the control room 17!
and locally by tne pressing push buttons.
181 191 MARTIN:
In this position, does it prevent an ES from starting these?
21!
BENSEL:
Yes.
23 CRESWELL:
Upon loss of off-site power, would the diesel start?
24!
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BENSEL:
In this case, no.
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3l CRESWELL:
How would the diesels be started then?
4j gj BENSEL:
Operator action.
Si MARTIN:
7 In further confirmation of the fact that the diesels didn't I
gj start, these diesels are air started, is that Correct?
l 91 10l 11t MARTIN:
In the initial ES, we see the air compressors energized. Are they l
not energized on low pressure?
131 14!
SENSEL: They start on low pressure in the air receivers, yes.
16i MARTIN:
The fact that they never start again in fact they shut down 17i shortly after the ES, after we assumed they'de pumped it up.
The fact that 18f they never start again is that also indicative of the fact that diesels 19I were never again operated.
201 21 BENSEL:
Yes.
22l l
23l MARTIN:
In light of the times that we've now discussed do you believe this 2 41 discussion occured prior to resetting the fuel racks or sometime after they i
25i were reset at around 9:30?
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!lj BENSEL:
The discussion occured prior to resetting the fuel racks.
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3 But put it earlier than what I initially said.
4; MARTIN:
I understand that in light of all the things that were occuring, Si 6
no one seems to have a good grasp of time, so I can understand that.
One 7
of the things that I would like to explore was, do you know why the fuel racks were immediately reset?
8 91 BENSEL:
No, I did not and I was somewhat upset when I saw that they 10; weren't. When I finally had a change to look at the panels in the control rcom.
13!
MARTIN:
Are they not required to be reset and operable in that plant conditien?
16i l
BENSEL:
Yes.
17 18i CRESWELL:
Did you tell Mr. Miller that the switch position ought to be manged?
20f f
21!
BENSEL: Well, my discussions with Mr. Miller were to get the fuel racks 22!
reset so that the diesels would be available if needed and I agreed that 23l where we were at, we'de be better off having diesels in maintenance exercise 24!
rather than emergency standby. In the event that the diesels could be, we 2Si l
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1 were, the plant was at the point where they would automatically start 2j again.
They weren t required cause off-site power was available.
In order i
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to go out and trip the diesels and put them back to standby again you'd
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43 have to go through the auxiliary building which is high radiation levels in 5
the building at the time.
Or go through security decrs and security guards i
Si were not readily available and also through the doors between the basement p
fuel handling building, the basement of diesel buildings, nobody's really 8
sure what the radiation levels were in the diesel generator buildings either.
It was my judgement that the best position for the diesels would g,
be maintenance exCerCise and if off~ site power Was lost, the operator in a timely manner could manually start the diesel from the control room.
12!
I CRESWELL:
How was the, how was this excercise completed which you've 131 g
suggested that the fuel racks would be reset?
15 BENSEL:
Well, it was just discussion that, said better get the fuel racks reset, and get the diesels back in the operat operable status and he agreed and set an auxiliary operator out to reset the fuel racks.
19!
MARTIN:
Then in effect, what we did was place the plant in a safer cr.ndition 20!
by enabling a control room start.
By sending the auxiliary operator out 21i 22!_
and resetting the fuel racks, you then regain the capability of starting i
them rapidly from the control room.
23!
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BENSEL: Yes.
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MARTIN:
Let me pursue again, I know we've already talked about it but, in 3
4 putting the diesel in this maintenance exercise condition are we still not gl violating the tech specs that would require...
61 l
BENSEL:
At that point in time, I was more concerned about keeping the 7
diesel generators operable than I was violating a tech spec. Diesel starts 8
and runs for a long period of time and you're asking for a fire.
Ofesels g
nn ng un er n a.
a a a ea y appene e
ese s and I 10l didn't want to see it happen again and I'd rather avoid having fuel, lube-y oil, fuel oil accumulate in the exhause system than if they started and weren't really needed.
I didn't want, I wanted to minimi;:e the possibility of having a fire started in the diesel.
141 15i CRESWELL: Was a guideline developed on hcw long the diesel should be allowed to run in a no load condition?
17!
i 18f BENSEL:
Vendor manuals themselves say that that is supposed to avoid doing 191 that in any way possible.
201 l
21:
CRESWELL:Was that incorporated in your proceduree?
22 23!
BENSEL:
It is in the procedure as a limit precaution, if I remember 241 properly.
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CRESWELL:
How much time is there, exactly, do you recall?
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3j BENSEL: Well, no.
I don't even know if it's a time limit on that.
4l Si MARTIN:
The understanding is well aware of the fact that diesels aren't 6
designed to sit unloaded and the fact we've had one diesel blowup as a 7j result of such operation.
So, the precaution to prevent them from running g
for long periods of time, in an unloaded condition is recognized.
I'd like to pursue another area with you Dick.
We have a sheet in front of us which 10l weeds that existed as of April 8,1979.
I'd like to ask you a couple of questions about certain jumpers which are on here and your knowledge of I
when they were installed and the purpose for them.
The first one is number 131 three on the list and it is related to RCV-2, job control.
Could you 14 expand on that?
15i 16 i
BENSEL:
RCV-2 job control was desired for vent path from the reactor 17i coolant system... for loss of off-site power.
Controlable event path.
So 181 that to maintain high pressure injection flow and then through the pressurizer 191 through RCV-2.
In other words, have electromatic relief valve open and 20:
then control the flow through it with the block valve.
21!
MARTIN:
For clarification, an RCV-2 is the EMOV lock valve?
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19 lj BENSEL:
Yes, it is.
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3j MARTIN: When was this jumper installed?
4l BENSEL:
Actually, it wasn't a jumper, it was lifted the leads to the g
6i ceiling contact were in the pushbutton station.
However,' when the electri-7 cians did that, they lifted, instead of lifting the leads to the ceiling contact, they lifted the leads for the local pushbutton stations so job 81 control for RCV-2 actually is not sucessfully implemented at that time.
g u sequen a, an was wrmen to install job control for p2 U 10!
i it was desired, but that was never implemented.
12l MARTIN: The next item is number 5 that I'm interested in.
And is related 13l to the RCPK3 relay interlock. Would you expand on that one 141 15; BENSEL:
Okay, jumpers wetacted by representatives of Metropolitan Edison since you resigned?
175 ISt MARTIN:
Does this mean that it was incumbent upon the operator to verify 19!
conditions existed that would allow the pump to operate without damage in 20!
that the electrical automatic verification of those conditions was removed?
21i 22l r
BENSEL:
Yes.
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j 20 Ig CRESWELL: Can the. operator do that from the control room? Verify that all 2
the interlocks that are being fed into the K3 relay are satisfied?
3i BENSEL:
I know he can verify fuel injections low and he can verify that 4
5 the cooling water flow that would serve as closed pumps are operating that flow is established to the reactor building.
I'm not sure if cooling water 6
J flow alarms or not.
I just don't remember.
/!
8k CRESWELL: What about lube-oil flow?
10!
BENSEL:
I don't think that is, if that's alarmed it would be in the computer and I don't remember that either. But we were at the point where if we had to start a reactor coolant pump, that we were desperate, not so 131 sure that the operator would spent too much time really trying to verify 14!
that he'd met all the initial conditions or not.
15:
16; MARTIN: At approximately 7:00 on th'= 28th, we finally established pressure to start reactor coolant pump.
Initial attempts were apparently unsucessful 1St because we had some electri al buses that had been possed earlier during 191 the day. Were you involved at all when deciding what interlocks had to be 20!
bypassed so that the reactor coolant pump 1A could be started?
21!
22!
j BENSEL: Are you talking 7 p.m. or 7 a.m.
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l lj MARTIN:
7 p.m.
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3l BENSEL:
I don't remember doing that.
41 h
MARTIN: Were you involved with, at any time during the day, the loss of 9
6i certain 480 volt busses, that is is the pressurizer heaters or at any other time?
,f I
i 81 BENSEL:
g; Pressurizer heater busses were not, were not lost that I remember.
Two 4 A volt busses that were lost would have been 232 A and 242 A which i
are non-safety reactor coolant system valves and equipment such as that.
i 11:
And I think the oil pumps reactor coolant pumps were also off of there.
12!
I 131 MARTIN:
Since we've brought up the subject of the pressurizer heaters, I'de like to pursue that for a moment.
The pressurizer heaters ait divided into groups.
The indication in the control room which I've been able to find is associated with large numbers of these groups and I think is labeled 17l 1 through 5.
I have been told in interviews that the operators can't tell 18i when subgroups trip.
Is that true?
19!
20f BENSEL:
That is true.
In other words, individual heater breakers, if they 21; trip, the control rcom operator has no indication of that.
22l l
23{
MARTIN:
Does this mean that, in fact, every subgroup could trip, the light 24i could indicate that the larger group was energized and in fact they would 25l be no heaters attached?
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22 BENSEL: That would be possible.
1 l
2; MARTIN:
Is the selective tripping such that a trip would occur on the 3
4 subgroup breaker before it would occur on the master breaker?
51
~
l BENSEL:
In most car,es.
However, the master breaker for'each group has 6
l' ground fault relay on it which does that trips does have indication in the
/
Control room, and there were several instances where those ground fault relays do trip.
g 10{
MARTIN: What is the problem that we keep seeing in the pressurizer heaters 11,:
relative to their loss on some as undetermined fault at this time?
12!
(
13!
BENSEL:
Cables to the pressurizer heaters inside the 0 rings, in the reactor builoing, are asbestos jacket type cables, is our belief that asbestos absorbs moisture and grounds the cables out.
17l MARTIN:
Even prior to this accident, we apparently had a history of 18i pressurized heaters tripping out.
19f 20!
BENSEL: Okay, that was due to high temperature in the area where the motor 21!
control centers for the pressurizer heaters are located. The breakers that 22!
supply the individual heaters in all the case breakers have the thermal i
23l l
element in them that was sensitive to the ambient temperature and caused 24i the breakers to trip. We had pretty much solved that problem by assuring 25i l
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y that the spot coolers in the area were in service and by putting fans on 2
the heater, on the breakers themselves.
31 4l MARTIN:
Are you aware of the fact that those fans did trip on the date of l
gj the event, as a result of high temperatures.
I believe associated with the fire alam system?
6 7f BENS 51L:
Those fans I don't know why they would have tripped, they're just g
[l off receptacles.
I'm not sure if they did trip.
101 MARTIN:
If no one else has any questions on the pressuri::er heaters, I'd 11!
like to procede to the next lifted leader jumper indicated on this sheet.
12!
l That's number 8 l'de like to talk about.
It states MUVE 376 hot temperature interlock and they did brackets, caution tag. Would you expand on that?
141 15!
BENSEL:
That was farther into the event, it has problems establishing good 16i let down flos, so in order to develop that possibly could have happened was 17!
baron crystali::ation in the letdown line.
So, in order to get rid of the 1
18!
boron crystals, crystalization, they wanted to keep letdown temperatures 19!
up, so we defeated the interlock and closed in MUV376 so that they could 20!
possibly operate at a higher letdown temperature. ROGERS: We're going to 21' Dause at this time in the interview with Richard Bensel to flip the tape.
22 231 ROGER 1:
Continuing the interview with Richard Bensel, the time is now 24i 9:52.
It should also be noted that Mr. Anthony Fasano, Inspection Specialist 25i
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24 l
d with U.S.N.R.C. has also joined the interview.
I will now turn it back to l
2l Mr. Martin.
I 3;
4j MARTIN:
Dick, in pursuing this, in particular, MUV 376, the lifted lead or 5
jumper in defeating this interlock, did we not remove protection for the i
6i demineralizer resins that were downstream from this valve, and what was the 7{
rationale for, have we just decided to throw away those resins?
8 BENSEL:
g Well, I think due to the radiation, exposure those resin are
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At that point in time they may have been bypassing the demineralizers j
anyway, I don't rememoer.
13!
CRESWELL: Was there any change made in the letdown cooling to prompt the higher temperature in the letdown?
16i BENSEL: Yes, we also installed jog control for the cooling water inlet valves to the letdown cooler so that cooling water could be, cooling water flow to the coolers could be throttled back in order to achieve a higner 13i temperature.
201 21l MARTIN:
I'd like to move now to item number 13 on the list.
It's description 22!
l is, " Defeat Pressurizer Heater Cutout", could you expand on that?
231 241 2Si
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25 l
lj BENSEL:
If I remember correctly, that was to defeat the low pressurizer 2j level interlock.
Pressurizer heaters.
Pressurizer level goes below 85 3
inches, and pressurizer heater is automatically cut out and a point in time i
4l when that was done, you are losing pressurize-level transmitters, or we 5
may have, or the pressurizer level transmitter that that switch comes off f, may have been in the process of dying.
I know that's wny that was 6
accomplished.
7 I
8 MARTIN:
Item 21, description, "ICS Feed and Bleed Pernit", could you g
i expand on that?
101 11:
BENSEL: That was one done by I&C 02partment, but I think what they there, i
I'm talking off the top of my head so I'm not sure how accurate this will 13 be, I think that was accomplished so that they could inject baron into the 141 system without satisfying the interlocks to do that.
I could be wrong.
16i MAR TIN: 'de won't pursue that one since you don't have personal knowledge of it.
Let us go down to jumper number 23 wnich is related to DHV1/171 and 18; 2 interlock defeat.
191 20)
BENSEL:
Okay, that was one that was discussed but never installed.
21!
CHVl/171 and 2, there is an interlock such that the valves could not be 22!
open until the reacter coolant system pressure is less than 320 pounds, and 231 i
there was some discussion to defeat that interlock so that they couldn't 24l possibly open the valves under higher pressure if conditions dictated.
25!
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26 MARTIN: When was this discussion held?
1 l
2l i
3j BENSEL:
It would have been the first couple of days of the event, the actual day I don't remember.
Si MARTIN:
That's all I have right now.
I think the other two inspectors may Si l
have some additional questions.
/
l al FASANO:
I have, I'de like to get some background information on the electromatic relief valve and the electromatic lock valve. I quess that's the RCRV 2 and the RCV 2, and I understand that there was some work done en the block valve earlier either this year or just late last year. Where the motor operator was changed out, do you recall this?
131 14' BENSEL:
I don't recall changing out the motor operator on the block valve.
The only motor operator that I remember doing work on valves on 16i top of the pressurizer was RCV 1 where we had limit switch trouble.
r 17; ISI FASANO:
RC..
191 20:
BENSEL:
V 1, the spray valve.
21!
22!
I FASANO:
Okay, and the electrcmatic relief valve, I believe after March 23i 29th to April 1978 there was some work done on that.
Do you recall when 241 that was completed and retested?
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27 1!
BENSEL:
I don't remember the dates associated with that, but I do remember i
2j a problem with electromatic relief valve in that the valve would not actuate yl-and we've later determined that a contact on the valve itself was stuck 4l that it couldn't, wasn't causing that was the problem.
That was corrected 5l and that eleviated the problem with the valve.
Si FASANO:
l' As far as the modifications after April, I quess it was March 29, gl where the valve was changd.
Do you recall it being retested after that, modification?
g 10l BENSEL:
I wasn't involved with the retesting, but I'm sure something was done.
12 13!
FASANO:
Okay, in that, you don't have direct knowledge of that, let that go. On the pressurizer heater, after the belows rupture, I quess that was with January, 1979, was there any known lasting effect due to the steam, that it was released in that area and is there a major change done at that 17!
time on the SER's or the and also the heater panel?
18(
191 BENSEL:
No, there was not.
As a result of the steam damage both the 20!
transformers that supply power to the pressurizer heaters had to be...
were 21l repaired they were both faultea, and I don't remember the action number, 22}
but there were a couple SER's that were bad and a cat.ple of the printed 2 31
[
circuit boards for the control of the SER's were bad repaired.
24:
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28.
1!
CRESWELL:
SER's are still in the control rectifier?
i 2!
i 3l BENSEL: Yes. Other than that I don't know of anything else that we had a 41 problem with as a result of the steam from the bellows outage.
l 5
6l FASANO:
In the evaluation of that steam bellow ruptures, was there any 7
evaluation as to the effect on the e:'ergency feed valving in the M20 area g
as well as the adjacent room where the "B" valves were located, the "A" g
valves in the direct area where the major amount of steam came in and the m beside it, apparently, there are some holes through the wall which 10j r
allow steam to go to both rooms.
Was there any evaluation done on a poten-f tial common failure?
13l BENSEL:
Staff engineering did not perform any such evaluation. I'd have to y
go back through paper work I have to actually give you a better answer on that.
I can't answer that completely off the top of my head.
i 17!
FASANO:
Was there any damage to these motor operated valves, particularly the bypass valves, which would bypass the eleven valves and the twelve valves?
20!
21!
BENSEL:
No.
22l r
23f FASANO:
No damage 241
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did I
8
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lj BENSEL:
None.
2!
l FASANO:
Thank you, that's all I have for now.
3{
i 4l Sj CRESWELL: You mentioned that you had a discussion with Adam Miller I think we determined that this was somewhere arount 9:30 A.M. on March 28th about Si the positioning of the switches for the emergency diesel generator Did he 7
indicate at that time hew the fuel racks had been manipulated earlier in g
the day?
f I
10!
BENSEL: Well, I don't know if he per se indicated how they were manipulated 11.,
I we both knew that that's the only way to trip the diesel when it started on 12l t
an ES signal.
So we knew that an aux operator was dispatched to trip the 131 diesel by tripping the fuel racks. We actually did't discuss how it was done or why the diesels weren't reset immediately.
16 CRESWELL: Do you know who the aux operator was?
18t BENSEL:
No, I do not.
19!
201 CRESWELL: 00 you know who cispatched him to do that?
21!
22 BENSEL:
No.
23!
24!
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I 30 l
lj MARTIN:
How did you know that the diesels were, in fact, in this condition 2l with the fuel racks tripped?
i 31 BENSEL: You have a speed trip alarms running for both diesels?
4 l
51 MARTIN:
Does that mean that...?
ol 7l BENSEL: When ever the fuel racks are tripped, the over speed trip alarm 8
comes in. When the over speed trip on the diesel actually works off a g
separate governor that would over speed trips set points reached, it trips 101 the fuel rack mechanically.
11!
12!
MARTIN:
Following your discussion with Adam Miller, do you know who he 13!
dispatched to reset these fuel racks?
15i BENSEL:
No, I don't remember.
16i 17' MARTIN: Were these fuel racks reset immediately after this discussion?
18t 191 BENSEL:
I know he dispatched somebody after we finished the conversation.
20!
21 CRESWELL: Was anybody else privy to the converration that you had with Adam 22!
Miller?
23!
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BENSEL: We may have said something to George Kunder that that's the condition 1,
2j we wanted-to leave the diesels in but...
3!
CRESWELL:
To your knowledge he would be the only individual possibly to,
4 Sj hear abcut this condition.
Si 7{
BENSEL:
Yes.
I 8l gj CRESWELL:
The shift supervisor 101 BENSEL: Adam may have said something tc the shift supervisor to.
i 12!
CRESWELL:
To your knowledge he didn't.
131 14!
BENSEL:
Right.
16i FASANO:
I have one general question.
Did you have a need or do you know 17:
of any one that did have a need or did call Burns and Roe on the 28th?
181 191 BENSEL:
I know the 28th Rich Brownwell, Burns and Roe engineer assigned to 20!
this site did call control room and ask if we needed any Burns and Roe 21!
assistance.
22,i i
23!
FASANO:
Rich Brownwell, is he 8 and R?
2 41 2Sf'
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BENSEL:
Yes.
a l
2!
l 3j FASANO:
Burns and Roe?
i 4l l
BENSEL:
Yes.
g Gi CRESWELL: What was he told?
7 81 BENSEL:
He was told to stand by in the observation center.
9) 101 i
CRESWELL: With no specific request for maintenance.
11!
12l BENSEL:
No. Unless somebody else needed him, but I don't remember any.
14i FASANO:
One other question. This test that I have in front of me here, 15.
Electrical Feed Water Latch Functional Test,. have you seen the final results on that test?
171 18(
i BENSEL:
I take it these are the results.
19i 20I l
FASANO:
That's why I'm asking the question.
21i 22 BENSEL:
This is the first that I've seen them.
23 24}
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33 3j FASANO:
It appears to me that it's finalized and this note here indicates 2j that it was satisfactorily completed.
That was my conclusion, I just 3
wondered, it appeared that the engineer would not have to be called if 4;
nothing had happened.
This is usual for a test?
i Si BENSEL:
6 Jim Pauley, the engineer who performed this test, I don't 7j remember him discussing anything with me per se on the results of it.
This gj does appear that the twelve's did not close.
91 FASANO:
Yes, that's how it appeared to me, thank you very much.
11:
i 12l
-ROGERS:
I would like to ask Mr. Sensel two or three questions.
We were I
joined half way through the interview by Mr. Fasano.
I'll ask you again if 13!
this was a voluntary interview?
141 15; 8ENSEL:
Yes, this was.
1Si 17l ROGERS:
And Mr. Fasano's joining us, has this effected your choice to ISI have someone present or not to have someone present?
191 20!
i BENSEL:
No, would not.
21!
22!
ROGERS:
Ok. At this time we will conclude the interview with Mr. Rich &rd 23l l
Bensel.
Time is 10:07, July 5,1979.
Thank you, Mr. Bensel.
24l
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