ML17058B581
| ML17058B581 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/26/1991 |
| From: | NRC - INCIDENT INVESTIGATION TEAM |
| To: | |
| Shared Package | |
| ML17056C371 | List:
|
| References | |
| CON-IIT07-161A-91, CON-IIT07-161B-91, CON-IIT7-161A-91, CON-IIT7-161B-91 NUREG-1455, NUDOCS 9305070030 | |
| Download: ML17058B581 (92) | |
Text
ORlGlNAL OFFICIALT1VDSCRIPI'F PROCEEDINGS Agency:
Title:
Nuclear Regulatory Commission Incident Investigation Team Nine Mile Point Nuclear Power Plant Interview of:
NIKE COLOMB Docket No.
IQChTIOH:
- Scriba, New York DhTE:
- Monday, August 26, 1991 PRES:
1 19 AI'&RILEY&ASSOCIATES, LTD.
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<<0 UNITED STATES NUCLEAR REGULATORY CQMMISSlON REGION I 415 ALLENOQLEROAb KING OF PRUSSIA, P/NNSYLVAfhIA@lI05
'September, 27, 1991 HEHOBMDUH FOR:
Hartin J.
McCormick, Plant Manager, Nine Mile Point Unit 2 FROM:
SUBJECT:
Hayne L. Schmidt, Senior Resident Inspector, Nine Mile Point Review of IIT Interview Transcripts The IIT has sent the transcripts of interviews conducted with the personnel listed below to the resident inspector s office.
If any of the listed individuals wish to review the transcripts they should do so at the resident inspector s office by October 4, 1991.
Guidelines for the review of transcripts are provided in the enclosure.
If an individual does not review his transcript by that date we will assume that he did not wish to do so and that the statement is correct to the best of his knowledge.
Alan DeGarcia, Bee
- Doty, Dave Barre
, Jerry Helker Jim,Burr, Bob~rand Robe
- rown, A l Julka, Perry
- rtsch, James Spadafore, Joe
- Savoca, ike Co omb, ames Kinsl Marty McCormick, Chris Kolod, Irin~errer, e, Anthony etrelli, Jim Reid, Fred Hhite, Rick Slade, Bruce Hennigan, and Tom Tomlinson.
Thank you for your help. If there are any questions please contact me.
9J CL~t Hayne L. Schmidt Senior Resident Inspector Nine Mile Point
ERRATA, SHEET
~Pa e Line ADDENDUM Correction and Reason for Correction Date Signature
~ sr
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION INCIDENT INVESTIGATION TEAM 6
Interview of 7
MIKE COLOMB 8
(Closed)'0 12 13 14 15 16 17 18 Conference Room B
Administration Building Nine Mile Point Nuclear Power Plant, Unit Two Lake Road
- Scriba, New York 13093
- Monday, August 26, 1991 19 20 21 The interview commenced, pursuant to notice, at 4:00 p.m.
22 23 24 25 PRESENT FOR THE IIT:
Walton Jensen, NRC William Vatter, INPO
P R 0 C
E E
D I N G
S
[4:00 p.m.]
MR.
VATTER: It's August 26.
We'e in the Nine 5
Mile Point P building, and this is an interview in 6
conjunction with the incident investigation of an event that 7
occurred at Nine Mile Point Unit Two on August 13.
I m Bill 8
Vatter.
10 MR. JENSEN:
Walt Jensen, NRC.
MR.
COLOMB:
My name is Michael Colomb.
I work 11 for Niagara Mohawk Power Corporation. I am the operations 12 manager at Unit Two.
13 MR. VATTER:
Okay.
Mike, could you give us a
14 brief outline of your background?
15 MR.
COLOMB:
Sure.
I came with Niagara Mohawk--
16 do you want me to go all the way back to the start with 17 Niagara Mohawk?
I had a very short duration with non-18 nuclear--
19 MR. VATTER:
What you think is pertinent to your 20 present job.
21 22 MR.
COLOMB:
Okay.
I spent several years as an auxiliary non-licensed 23 operator at Nine Mile Point Unit One and James A.
24 FitzPatrick nuclear power plants.
I obtained a reactor 25 operator license at the James A. FitzPatrick nuclear power
3 1
plant approximately 15 years ago.
I operated as an in-plant 2
licensed operator and as a control room licensed operator at 3
James A. FitzPatrick nuclear power plant during the startup 4
phase.
I obtained an SRO license at Nine Mile Point Unit 5
One after leaving FitzPatrick.
That was approximately 6
1981.
Several years later I obtained a senior reactor 8
operator license at Nine Mile Point Unit Two, became a
9 station shift supervisor at Nine Mile Point Unit Two, spent 10 several years as a station shift supervisor at Nine Mile ll Point Unit Two, was promoted to an assistant operations 12 superintendent at Nine Mile Point Unit Two, and spent about 13 a year, I guess, as an assistant operations superintendent.
14 Then I went to a position called director of nuclear 15 regulatory compliance, which reported to what was then out 16 site superintendent.
I was in that position for 17 approximately a year and then came back to operations at 18 Nine Mile Point Unit Two as operations superintendent.
19 About six months after I came back, we reorganized, and I 20 became operations manager.
21 MR.
VATTER:
- Thanks, Mike.
Your background is 22 impressive.
23 24 MR.
COLOMB:
Long, right?
MR. VATTER:
I wanted to ask first if you could 25 just outline your role during the event.
What were you
1 involved in?
MR.
COLOMB:
I was actually not involved in the 3
event.
I was supposed to be on vacation when this happened.
4 I came into the scene the morning after the event.
I talked 5
to Jerry Helker the evening of the event, just after we had 6
come out of the site area emergency.
We discussed some of 7
the getting-into-the-outage requirements.
MR.
VATTER:
When did you find out about the 9
event?
10 MR.
COLOMB:
I found out about the event on 11
- Tuesday, through the news media, actually, and,.again, I
12 talked to the plant that night.
13 14 MR.
VATTER:
Okay.
I'e got a couple of technical questions that I'e 15 been looking for the answer to.
Do you know what the 16 setpoint is for the turbine bypass valves?
How much is that 17 biased above the throttle setpoint?
18 MR.
COLOMB:
The pressure set is a single pressure 19 set that controls both the opening of the control and bypass 20 valves; it just depends on whether or not the turbine is 21 tripped.
Do you understand what I'm saying?
22 MR.
VATTER:
Yes, I do.
So the bypass valves will 23 open to control pressure 24 MR.
COLOMB:
-- after a turbine trip at the same 25 pressure setting as the turbine control system was set.
MR.
VATTER:
Thanks.
I think I remember that now.
MR.
COLOMB:
Okay.
MR.
VATTER:
Do you know which safety relief 4
valves opened?
MR.
COLOMB:
By number I do not.
I believe it was 6
the two with the lowest setpoint, 1076, but I don't remember 7
by number which two that is.
MR.
VATTER:
Okay.
I wanted to ask you about the feed pump suction 10
- valves, which are MOV-84-A, B, and C.
12 MR.
COLOMB:
Right.
MR. VATTER:
Our understanding is that the 13 procedure that was being used to operate the condensate 14 booster pumps requires the suction valve to be closed before 15 you start the booster pump.
16 17 18 MR.
COLOMB:
That's correct.
MR.
VATTER:
Why is that?
MR.
COLOMB:
I guess I'm remember back a long 19 ways, to when we inserted that in the procedure.
I believe 20 we did that to reduce the possibility of having a water 21 hammer on the piping downstream of the valves and, if I 22 remember correctly -- and I'd really have to look back at 23 the history here -- it was that we had experienced some 24 lifting of suction reliefs when we started boosters
- pumps, 25 so we inserted that step in there to shut those valves,
1 start the booster
- pumps, equalize around them to get 2
pressure up in the piping downstream slowly, then open the 3
valves.
I believe that is the reason, but, again, this is a
4 few years ago.
MR. VATTER:
In order to keep moving through this, 6
our understanding is that there may have been some problem 7
with voids in that piping that would contribute to water 8
hammer.
My question is, has that been a longstanding 9
problem?
Has it been corrected by design change or other 10 method?
MR.
COLOMB:
I guess I don't remember voids in the 12 problem.
I do remember us having the problem with the 13 suction release, and it did correct that problem.
We ended 14 up making some changes to the suction relief valves, also.
15 We changed the design of the suction relief valves to make 16 them more resistant, I guess, to that type of problem.
17 Honestly I don't remember having a problem with voids in 18 that piping.
19 MR.
VATTER:
Do you close the discharge valve for 20 the feed pump before you close the suction valve?
h 21 MR.
COLOMB:
I'd have to look at the procedure.
I 22 don't remember that step in there, but I'd have to look at 23 the procedure to be sure.
24 MR.
VATTER:
Do you think your operators try to 25 close discharge valves before they close suction valves?
Is
1 that one of your expectations?
MR.
COLOMB: I would say standard operating 3
practice would be to make sure a discharge valve is shut 4
before you shut a suction valve.
As a matter of fact, 5
standard practice would be to make sure that the pump 6
breaker is racked out or the pump switch is open before you 7
shut a suction valve.
MR. VATTER:
Our understanding of this event is 9
that it didn t happen like that at this time.
I was 10 wondering whether you thought that was a problem or not.
MR.
COLOMB:
I believe that's in accordance with 12 the procedure.
I will say that the feed pumps do not have 13 auto starts.
This is a manual startup of the feedwater 14 system; it's not intended to operate that way for the long 15 term.
The intention is that you would shut those valves, 16 equalize across
- them, open them up, and then go to the next 17 step in the procedure.
18 I guess I don't see a problem in that procedure, 19 and I think that's what the procedure reads.
I don't think 20 the procedure has you racking out the breaker for the feed 21 pump before you do this.
I'm sure it doesn'.
22 23 MR.
VATTER:
Okay.
Our understanding is that the MOV-84 is supposed 24 to be able to open against a large DP, but that's not 25 generally done that way because it's better to bypass and
equalize pressure.
Is our understanding correct?
MR.
COLOMB:
That would be my understanding, also.
That's correct.
MR.
VATTER:
So it's a problem that the valve 5
would not open over that DP.
MR.
COLOMB: I would consider that a problem if it 7
would not open at that DP.
I would consider that different 8
than what I understand that valve design to do.
MR. VATTER:
Okay.
10 12 13 14 15 Do you have questions about the MOV-84, Walt?
MR.
JENSEN:
No, I don'.
MR.
VATTER:
I wanted to ask you next about I
radiation alarms in the turbine building.
Our understanding is that there were,
- perhaps, some continuous air monitors and/or area radiation monitors that were alarming and that 16 that caused the supervisor to evacuate personnel from the 17 turbine building and that that precluded bypassing MOV-84.
18 Do you know why those alarms came in?
19 20 MR.
COLOMB:
I guess I can't say I know why those alarms came in right now.
No, I can't -- although I know we 21 lost a lot of power to the DRMS system.
I would expect it 22 probably was related to the power loss, but I can'0 say that 23 I'e looked at why those alarms came in.
24 MR. VATTER:, Okay.
So probably related to the 25 power loss, but not sure.
I g+
0
10 1
MR.
COLOMB:
When I think about 18 minutes, that '
2 a long time.
However, it's relative.
If there's a 'lot 3
going on, it's not that long a time to decide, We'l use the 4
137 instead of trying to get somebody in the turbine 5
building.
MR. VATTER:
The operators put the hoggers on 7
service at about 7:30, and our understanding is that there 8
was no condenser air removal in service for about an hour 9
and a half, then, from the initiating event until when the 10 hogger was put on.
12 MR.
COLOMB:
Okay.
MR. VATTER:
I was wondering whether that seemed 13 like a long time to be able to hold a vacuum without an air-14 ejecting method.
15 16 time?
MR.
COLOMB:
Would you repeat the time?
How much 17 MR. VATTER:
Well, the event occurred at 5:48, at 18 which time we supposed that the normal air ejectors isolated 19 due to loss of the rad monitor.
Then they put the hogger on 20 at 7:30, which was more than an hour and a half.
21 22 time.
MR.
COLOMB:
That does seem like quite a bit of 23 MR. VATTER:
When they put the hogger on, our 24 understanding is that the normal air ejector radiation 25 monitor was not able to monitor that release point.
I'm
1 MR.
COLOMB:
Right.
MR.
VATTER:
In the log we saw that the operators 3
had trouble opening MOV-84-A, B, and C at 6:40 in the 4
morning.
At 6:58 they began to feed the vessel through the 5
startup bypass valve, LCV-137, and that it was about 18 6
minutes from when they were unable to open the valve in 7
their preferred flow path to when they started feeding on 8
the bypass.
I wanted to know if you thought that was a long 9
period of time, 18 minutes, for them to find another path, 10 or whether that's what you would expect them to take in that 11 situation.
12 MR.
COLOMB:
I guess it's very hard for me, 13 without being in that situation, to make a judgement like 14 this.
Eighteen minutes -- I guess when I listen to that 15 much time, it sounds like a lot of time.
However, I'm sure 16 that a lot of discussion went on about what vessel level was 17 doing and what the best way was to recover it.
Again, it' 18 hard to me to make that kind of a judgement without being 19 in that situation.
I know they were faced with a lot 20
- problems, and I'm sure a lot of discussion took place about 21 what was happening with level and what was the best way to 22 take care of the level problem.
23 24 question.
I don't want to sound like I'm evading the 25 MR. VATTER:
No, I don't think so at all.
11 1
interesting in knowing whether you'e aware of what 2
radiation monitoring of that release was accomplished.
MR.
COLOMB:
I guess I can't say that I know at 4
that point what they were using for release rate monitoring.
5 No, I do not know that.
MR.
VATTER:
Are you confident that that was a
7 monitored release?
MR.
COLOMB:
I wouldn't make that statement 9
without going back and talking to the operators again.
10 MR. VATTER:
Okay.
So to your knowledge that 11 hasn't been question to where somebody asked and it was 12 resolved?
13 MR.
COLOMB:
I guess I can say that, if it was 14 questioned, I haven't heard the answer, although I did hear 15 in an interview somebody make a statement about a skid 16 working, but I'd have to go back and look at who said that 17 and what was 18 19 MR.
VATTER:
A skid working?
MR.
COLOMB:
Somebody was a skid working before 20 they -- I'd have to go back and look.
I'd hate to make 21 that statement without going back.
22 23 MR. VATTER:
Okay.
In the log, they started a second condensate pump 24 at 7:38, noting that the operating condensate
- pump, which 25 was the A pump -- was that P1A?
12 MR.
COLOMB:
Yes.
MR.
VATTER:
And then PlB was the second one.
I was wondering if you had any feel for why that, 4
might have been a problem, that they had to have two 5
condensate pumps.
What I think might have happened is that the 7
condensate reject valve to the condenser opened with the 8
loss of control power to the condensate system and that the 9
valve was not reclosed at a later time when power was 10 restored and that there was a rather large amount of 11 condensate flow as being diverted back to the condenser.
12 MR.
COLOMB:
My understanding of that is we saw 13 they saw a high standard temperature on the one pump.
I 14 believe they recognized the fact that it was a due to a high 15 flow condition and started the second condensate pump.
16 MR. VATTER: I wondered whether they should have 17 been reducing the amount of flow on that running pump?
18 MR.
COLOMB:
What I can't say is what was 19 happening with the min flow valve.
You mentioned that you 20 thought a valve had failed opened and not been reclosed, 21 that valve normally acts automatically, or rather it should 22 have been acting automatically if the power was restored.
23 MR. VATTER:
So if the pump had a high flow 24 condition, we don',
know exactly where all that flow was 25 going?
13 1
MR.
COLOMB:
I can't say -- I can'0 say where all 2
that flow was going.
MR.
VATTER:
I can't either, I guess.
I'm just 4
trying to guess a little bit and try to figure that out.
MR.
COLOMB:
I know that they saw a high standard 6
temperature on it.
I believe it was related to high flow 7
when they started the second pump to provide the additional 8
flow.
MR.
VATTER:
We also noted in the log that the 10 stack GEMS, that gaseous effluent monitoring system was 11 inoperable at 8:05, but apparently that had been inoperable 12 for a long period of time or from the start of the event.
13 MR.
COLOMB:
I know it was inoperable, I know we 14 were tracking why that was a problem.
We'e looking into 15 why that was a problem.
I can't say it was inoperable 16 before the event without looking back, I guess.
17 MR. VATTER: I didn't mean to imply that I thought 18 it was.
My perception was that it became inoperable at the 19 start of the event?
20 21 MR.
COLOMB:
Yes, I believe that's true.
MR.
VATTER:
And that they recognized that it was 22 inoperable at 8:05 and declared it such?
23 24 MR.
COLOMB:
Right.
That sounds correct.
MR.
VATTER:
Now, I'm not sure what all different 25 ways you have of monitoring a release path from the
14 1
condenser, but if the condenser air rejecter is not 2
available, if that rad monitor is not available and the 3
stack GEMS is not available, is there some other radiation 4
monitor in that release path that we'd be able to see?
MR.
COLOMB:
No. I don't believe there is.
I 6
think that if the GEMS is inoperable, then the next method 7
is grab samples.
MR.
VATTER:
Okay.
So possibly there was an 9
unmonitored release at 7:30 when they put the hoggers on 10 service?
I don't know how important that is, but we'e 11 trying to understand that.
12 MR.
COLOMB:
Um hm.
I understand.
13 MR.
VATTER:
Who do you think I ought to talk to 14 to get a more clear perception of that release path and how 15 it might have been monitored?
16 MR.
COLOMB:
Do you what to know specifics about 18 technically how the release path is monitored?
MR. VATTER: I would like to know how it was 19 17 what somebody saw in the event or do you want to just know 20 monitored during the event because we don't -- or I don' 21 see right now a way that it was monitored.
I would like to 22 know that it was being monitored.
23 MR.
COLOMB:
Yeah.
- Well, we probably have to look 24 back to the sequence and just verify the monitors.
I would 25 have to say if the GEMS -- if the GEMS was inoperable and
15 1
the mechanical vacuum pumps were started that that was 2
probably an unmonitored release.
MR.
VATTER:
Okay.
We'l need to research that a
4 little bit more.
MR.
COLOMB:
Okay.
MR. VATTER:
Mike, those are all the questions 7
that I had for you.
Is there anything that -- do you have 8
something, Walt?
MR.
JENSEN:
Yeah.
I might as well ask a few.
10 Let's see, we know that at the first of the event that there 11 were two RHR trains out of service and wondering what your 12 policy was with regard in having two trains of safety 13 equipment out of service and how long they had been out of 14 service?
15 MR.
COLOMB:
We typically do work and preventative 16 maintenance and systems by division. It is not -- it's the 17 exception we have two out at once, but we would only do that 18
-- in other words we separate it so that if we'e working on 19 division two, everything in division one and division three 20 is operable.
That's how we schedule and perform our 21 maintenance and preventative maintenance and surveill'ance 22 activities.
23 MR.
JENSEN:
Do you have any effort not to have 24 to have no more than one out of service or is this an 25 unusual circumstance to have two trains out of service at
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the same time?
MR.
COLOMB:
I guess I would have to go back and 3
look at our history.
I can say that we typically -- we 4
typically work on just one train at a time, but I can' 5
that's it's unusual that we would be working on one MOV and 6
you know if the work was scheduled, to be working on both 7
trains in a division.
We don't have any policy that says don't work on 9
both trains at once.
We go by division and we wouldn' 10 unnecessarily schedule a train out unless we had something 11 to do on it.
12 MR. JENSEN:
Okay.
There was a water hammer 13 reported in the RHR system when the valve going to the rad 14 waste system was opened, I believe that was a result of 15 perhaps opening the valve too fast, done locally, has that 16 been a problem in the past?
Have you had trouble with that 17 particular valve in the past?
18 MR.
COLOMB:
To my knowledge that has not been a
19 problem in the past.
20 MR.
JENSEN:
Okay.
Have you had water hammers in 21 the RHR system in the past that you'e aware of?
22 23 MR.
COLOMB:
Not that I'm aware of, no.
MR.
JENSEN:
There was difficulty, I believe, in 24 initiating the water cleanup system that is tripped of when 25 it's first started up and I believe that was laid to a
0
17 1
confusing procedure.
Have you had trouble initiating water 2
cleanup before?
MR.
COLOMB:
We have had -- we have had problems 4
with our cleanup system, specifically the delta flows in the cleanup system that were very sensitive to system 6
We have had many problems with those.
I can' 7
-- I'd have to look back to say that we have had this 10 12 13 specific condition.
I don't think we'e had this specific condition before, but we have had many problems with those delta flows during system configuration changes, if you will; starting up, shutting down, going from one load to another.
MR.
JENSEN:
And have you had trouble with water 14 hammer in the cleanup system before?
15 MR.
COLOMB:
I don't remember having a problem 16 with the water hammer before.
17 MR.
JENSEN:
Let's see, there was difficulty noted 18 with controlling the RCIC system and automatic control.
Has 19 this been a long standing problem and what. efforts have been 20 made to fix the automatic RCIC control?
21 MR.
COLOMB:
I believe we have had problems with 22 it in the past and typically what we do is on a restart 23 after any RCIC maintenance, we will run the turbine which is 24 a tech spec surveillance and tune the controller while RCIC 25 is running.
18 1
MR. JENSEN:
Okay.
There was indeterminate valve 2
position indication on the RCIC injection valves, valve 3
number 156 and
- 157, has this been a problem in the past?
MR.
COLOMB:
We have had problems with indications 5
and testable checks in the past, yes.
RCIC -- including 6
RCIC.
We have had problems with that.
MR. JENSEN:
And this is something that occurred 8
and has been corrected as it occurred?
MR.
COLOMB:
Yes.
Correct.
It's had corrective 10 maintenance and modifications to the limits switch 11 configurations, both.
To some of them, I can't say 12 specifically which ones.
13 MR. JENSEN:
Okay.
There were a couple of safety 14 valves that were leaking at the start of the event, do you 15 know how long these have been leaking and was there a
16 corrective action plan to fix the leak?
17 MR.
COLOMB:
They had been leaking -- if I said 18 how long it. would be a guess, but they'e been leaking for 19 quite a while, and yes, there are corrective -- there' 20 corrective action paperwork to fix those in refuel outage, 21 take those out and replace them in the refuel outage.
22 MR.
JENSEN:
What is your refueling outage 23 scheduled to be?
24 MR.
COLOMB:
I believe it's scheduled to start the 25 end of February of 1992.
19
[Pause.]
MR. JENSEN:
I think that's all I have, Bill.
MR. VATTER:
Mike, is there anything that you 4
think that we haven'0 gotten about the event that we ought 5
to know about?
MR.
COLOMB:
I guess I presume that all the 7
information we'e gotten in our RAP-6 we'e shared with you, 8
so I have to say, no, that I think you probably have all 9
that.
10 MR. VATTER:
What was that acronym?
MR.
COLOMB:
We have a reactor analysis procedure 12 that does an evaluation of a scram.
And I know we developed 13 a sequence of events and I'm pretty confident that we'e 14 shared that with you, so I assume that 16 events?
MR.
VATTER:
I assume you mean the sequence of 17 MR.
COLOMB:
Then I think you know everything that 18 we know about it.
19 20 MR.
VATTER:
Okay.
[Whereupon, at 4:30 p.m. the taking of the 21 interview was concluded.]
22 23 24 25
~ i;l
REPORTER'S CERTIFICATE This is to certify that the attached proceedings before the United States Nuclear Regulatory Commission In the Matter of:
NAME OF PROCEEDING:
Interview of Mike Colomb DOCKET NUMBER:
(Not applicable)
PLACE OF PROCEEDING:
- Scriba, New York were held as herein appears, and that this is the original transcript thereof for the file of the United States Nuclear Regulatory Commission taken by me and thereafter reduced to typewriting by me or under the direction of the court reporting
- company, and that the transcript is a true and accurate record of the foregoing proceedings.
Mark Handy Official Reporter Ann Riley
& Associates, Ltd.
l; fg
/
>1- ~cl 6-~1 OFFICIALT1VDSCRIFI'F PROCEEDINGS Agency:
Title:
Nuclear Regulatory Commission Incident Investigation Team Nine Mile Point Nuclear Power Plant Interview of:
Docket No.
- Scriba, New York DATE:
- Monday, August 26, 1991 PAtJES: '1 19 ized& RILEY&ASSOCIATES, LTD.
1612 KR, N.W.; Suite 300
%hshinyon, D.C 20006 (zoz) z93-39So.
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UNITED STATES NUCLEAR REGULATORY t;IMMISSION REGION I 475 ALLENOQLE ROAD KlNG OF PRUSSIA, P)NNSYLVAhlIA8%%
r
'September 27, 1991 MEMORANDUM FOR:
FROM:
SUBJECT:
Martin J.
McCormick, Plant Manager, Nine Mile Point Unit 2 Wayne L. Schmidt, Senior Resident Inspector, Nine Mile Point Review of IIT Interview Transcripts The IIT has sent the transcripts of interviews conducted with the personnel listed below to the resident inspector s office.
If any of the listed individuals wish to review the transcripts they should do so at the resident inspector s office by October 4, 1991.
Guidelines for the review of transcripts are provided in the enclosure.
If an individual does not review his transcript by that date we will assume that he did not wish to do so and that the statement is correct to the best of his knowledge t
Alan DeGarcia, Bte
- Doty, Dave Barre
, Jerry Helker, Jim Burr Bo.b ~rwanda Ro
- rown, A
1 Julka, Perry
- rtsch, James Spadafore, Joe
- Savoca, Make
- Colomb, James Kinsl Marty McCormick, Chris Kolod, Irin~<errer, r
i.
- one, Anthony etrelli, Jim Reid, Fred White, Rick Slade, Bruce Hennigan, and Tom Tomlinson.
Thank you for your help. If there are any questions please
- contact, me.
MCB.~ L.5~~~~~
Wayne L. Schmidt Senior Resident Inspector Nine Mile Point
I
ERRATA, SHEET
~Pa e Line ADDENDUM Correction and Reason for Correction Date
'ignature
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'I
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION INCIDENT INVESTIGATION TEAM 6
Interview of 7
MIKE COLOMB 8
(Closed) 10 12 13 14 15 17 18 Conference Room B
Administration Building Nine Mile Point Nuclear Power Plant, Unit Two Lake Road
- Scriba, New York 13093 Monday, August 26, 1991 19 The interview commenced, pursuant to notice, 20 at 4:00 p.m.
21 22 23 24 25 PRESENT FOR THE IIT:
Walton Jensen, NRC William Vatter, INPO
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P R 0 C
E E
D I N
G S
[4:00 p.m.]
MR.
VATTER: It's August 26.
We'e in the Nine 5
Mile Point P building, and this is an interview in 6
conjunction with the incident investigation of an event that 7
occurred at Nine Mile Point Unit Two on August 13.
I'm Bill 8
Vatter.
10 MR. JENSEN:
Walt Jensen, NRC.
MR.
COLOMB:
My name is Michael Colomb.
I work ll for Niagara Mohawk Power Corporation. I am the operations 12 manager at Unit Two.
13 MR.
VATTER:
Okay.
Mike, could you give us a
14 brief outline of your background?
15 MR.
COLOMB:
Sure.
I came with Niagara Mohawk--
16 do you want me to go all the way back to the start with 17 Niagara Mohawk?
I had a very short duration with non-18 nuclear--
19 MR. VATTER:
What you think is pertinent to your 20 present.
job.
21 22 MR.
COLOMB:
Okay.
I spent several years as an auxiliary non-licensed 23 operator at Nine Mile Point Unit One and James A.
24 FitzPatrick nuclear power plants.
I obtained a reactor 25 operator license at the James A. FitzPatrick nuclear power k
I o
o o
3 1
plant approximately 15 years ago.
I operated as an in-plant 2
licensed operator and as a control room licensed operator at 3
James A. FitzPatrick nuclear power plant during the startup 4
phase.
I obtained an SRO license at Nine Mile Point Unit 5
One after leaving FitzPatrick.
That was approximately 6
1981.
Several years later I obtained a senior reactor 8
operator license at Nine Mile Point Unit Two, became a
9 station shift supervisor at, Nine Mile Point Unit Two, spent 10 several years as a station shift supervisor at Nine Mile 11 Point Unit Two, was promoted to an assistant operations 12 superintendent at Nine Mile Point Unit Two, and spent about 13 a year, I guess, as an assistant operations superintendent.
14 Then I went to a position called director of nuclear 15 regulatory compliance, which reported to what was then out 16 site superintendent.
I was in that position for 17 approximately a year and then came back to operations at 18 Nine Mile Point Unit Two as operations superintendent.
19 About six months after I came back, we reorganized, and I 20 became operations manager.
21 MR.
VATTER:
- Thanks, Mike.
Your background is 22 impressive.
23 24 MR.
COLOMB:
Long, right?
MR. VATTER: I wanted to ask first if you could 25 just outline your role during the event.
What were you
0
1 involved in?
MR.
COLOMB:
I was actually not involved in the 3
event.
I was supposed to be on vacation when this happened.
4 I came into the scene the morning after the event.
I talked 5
to Jerry Helker the evening of the event, just after we had 6
come out of the site area emergency.
We discussed some of 7
the getting-into-the-outage requirements.
9 event?
MR.
VATTER:
When did you find out about the 10 MR.
COLOMB:
I found out about the event on 11
- Tuesday, through the news media, actually,
- and, again, I 12 talked to the plant that night.
13 MR. VATTER:
Okay.
14 I'e got a couple of technical questions that I'e 15 been looking for the answer to.
Do you know what the 16 setpoint is for the turbine bypass valves?
How much is that 17 biased above the throttle setpoint?
18 MR.
COLOMB:
The pressure set is a single pressure 19 set that controls both the opening of the control and bypass 20 valves; it, just depends on whether or not the turbine is 21 tripped.
Do you understand what, I'm saying?
22 MR. VATTER:
Yes, I do.
So the bypass valves will 23 open to control pressure 24 MR.
COLOMB:
-- after a turbine trip at the same 25 pressure setting as the turbine control system was set.
MR.
VATTER:
Thanks.
I think I remember that now.
MR.
COLOMB:
Okay.
MR.
VATTER:
Do you know which safety relief 4
valves opened?
MR.
COLOMB:
By number I do not.
I believe it was 6
the two with the lowest setpoint, 1076, but I don't remember 7
by number which two that is.
MR. VATTER:
Okay.
I wanted to ask you about the feed pump suction 10
- valves, which are MOV-84-A, B, and C.
12 MRS COLOMB:
Right.
MR. VATTER:
Our understanding is that the 13 procedure that was being used to operate the condensate 14 booster pumps requires the suction valve to be closed before 15 you start the booster pump.
16 17 18 MR.
COLOMB:
That's correct.
MR.
VATTER:
Why is that?
MR.
COLOMB:
I guess I'm remember back a long 19 ways, to when we inserted that in the procedure.
I believe 20 we did that to reduce the possibility of having a water 21 hammer on the piping downstream of the valves and, if I 22 remember correctly -- and I'd really have to look back at 23 the history here -- it was that we had experienced some 24 lifting of suction reliefs when we started boosters pumpsg 25 so we inserted that step in there to shut those valves,
Cl 0
1 start the booster
- pumps, equalize around them to get 2
pressure up in the piping downstream slowly, then open the 3
valves.
I believe that is the reason, but, again, this is a
4 few years ago.
MR.
VATTER:
In order to keep moving through this, 6
our understanding is that there may have been some problem 7
with voids in that, piping that would contribute to water 8
hammer.
My question is, has'hat been a longstanding 9
problem?
. Has it been corrected by design change or other 10 method?
MR.
COLOMB:
I guess I don't remember voids in the 12 problem.
I do remember us having the problem with the 13 suction release, and it did correct that problem.
We ended 14 up making some changes to the suction relief valves, also.
15 We changed the design of the suction relief valves to make 16 them more resistant, I guess, to that type of problem.
17 Honestly I don't remember having a problem with voids in 18 that piping.
19 MR. VATTER:
Do you close the discharge valve for 20 the feed pump before you close the suction valve?
21 MR.
COLOMB: I'd have to look at the procedure.
I 22 don't remember that step in there, but I'd have to look at 23 the procedure to be sure.
24 MR. VATTER:
Do you think your operators try to 25 close discharge valves before they close suction valves?
Is
Cl
MR.
COLOMB: I would say standard operating 3
practice would be to make sure a discharge valve is shut 4
before you shut a suction valve.
As a matter of fact, 5
standard practice would be to make sure that the pump 6
breaker is racked out or the pump switch is open before you 7
shut a suction valve.
MR.
VATTER:
Our understanding of this event is 9
that it didn t happen like that at this time.
I was 10 wondering whether you thought that was a problem or not.
MR.
COLOMB:
I believe that's in accordance with 12 the procedure.
I will say that the feed pumps do not have 13 auto starts.
This is a manual startup of the feedwater 14 system; it's not intended to operate that way for the long 15 term.
The intention is that you would shut those valves, 16 equalize across
- them, open them up, and then go to the next 17 step in the procedure.
18 I guess I don't see a problem in that procedure, 19 and I think that's what the procedure reads.
I don't think 20 the procedure has you racking out the breaker for the feed 21 pump before you do this.
I'm sure it doesn'.
22 23 MR. VATTER:
Okay.
Our understanding is that the MOV-84 is supposed 24 to be able to open against a large DP, but that's not 25 generally done that way because it's better to bypass and
Qi
1 equalize pressure.
Is our understanding correct?
MR.
COLOMB:
That would be my understanding, also.
3 That's correct.
MR.
VATTER:
So it's a problem that the valve 5
would not open over that DP.
MR.
COLOMB:
I would consider that a problem if it 7
would not open at that DP.
I would consider that different 8
than what I understand that valve design to do.
10 12 MR.
VATTER:
Okay.
Do you have questions about the MOV 84'alt?
MR. JENSEN:
No, I don'.
MR. VATTER: I wanted to ask you next about 13 radiation alarms in the turbine building.
Our understanding 14 is that there were,
- perhaps, some continuous air monitors 15 and/or area radiation monitors that were alarming and that 16 that caused the supervisor to evacuate personnel from the 17 turbine building and that that precluded bypassing MOV-84.
18 19 Do you know why those alarms came in?
MR.
COLOMB: I guess I can't say I know why those 20 alarms came in right now.
No, I can't -- although I know we 21 lost a lot of power to the DRMS system.
I would expect. it 22 probably was related to the power loss, but I can'0 say that 23 I'e looked at why those alarms came in.
24 MR.
VATTER:
Okay.
So probably related to the 25 power loss, but not sure.
0
MR.
COLOMB:
Right.
MR.
VATTER:
In the log we saw that the operators 3
had trouble opening MOV-84-A, B, and C at 6:40 in the 4
morning.
At 6:58 they began to feed the vessel through the 5
startup bypass valve, LCV-137, and that it was about 18 6
minutes from when they were unable to open the valve in 7
their preferred flow path to when they started feeding on 8
the bypass.
I wanted to know if you thought that was a long 9
period of time, 18 minutes, for them to find another path, 10 or whether that's what you would expect them to take in that 11 situation.
12 MR.
COLOMB:
I guess it's very hard for me, 13 without being in that situation, to make a judgement like 14 this.
Eighteen minutes -- I guess when I listen to that 15 much time, it sounds like a lot of time.
However, I'm sure 16 that a lot of discussion went on about what vessel level was 17 doing and what the best way was to recover it.
Again, it' 18 hard to me to make that kind of a judgement without being 19 in that situation.
I know they were faced with a lot 20
- problems, and I'm sure a lot of discussion took place about 21 what was happening with level and what was the best way to 22 take care of the level problem.
23 24 question.
I don't want to sound like I'm evading the 25 MR. VATTER:
No, I don't think so at all.
10 1
MR.
COLOMB:
When I think about 18 minutes, that' 2
a long time.
However, it's relative.
If there's a lot 3
going on, it's not that long a time to decide, We'l use the 4
137 instead of trying to get somebody in the turbine 5
building.
MR. VATTER:
The operators put the hoggers on 7
service at about 7:30, and our understanding is that there 8
was no condenser air removal in service for about, an hour 9
and a half, then, from the initiating event until when the 10 hogger was put on.
12 MR.
COLOMB:
Okay.
MR. VATTER: I was wondering whether that seemed 13 like a long time to be able to hold a vacuum without an air-14 ejecting method.
15 16 time?
MR.
COLOMB:
Would you repeat the time?
How much 17 MR. VATTER:
Well, the event occurred at 5:48, at 18 which time we supposed that, the normal air ejectors isolated 19 due to loss of the rad monitor.
Then they put the hogger on 20 at 7:30, which was more than an hour and a 'half.
21 22 time.
MR.
COLOMB:
That does seem like quite a bit of 23 MR.
VATTER:
When they put the hogger on, our 24 understanding is that the normal air ejector radiation 25 monitor was not able to monitor that release point.
I'm
tf ~
E P
I 4,
f
11 1
interesting in knowing whether you'e aware of what 2
radiation monitoring of that release was accomplished.
MR.
COLOMB:
I guess I can't say that I know at 4
that point what they were using for release rate monitoring.
5 No, I do not know that.
MR.
VATTER:
Are you confident that that was a
7 monitored release?
MR.
COLOMB:
I wouldn't make that statement 9
without going back and talking to the operators again.
10 MR. VATTER:
Okay.
So to your knowledge that 11 hasn't been question to where somebody asked and it was 12 resolved?
13 MR.
COLOMB:
I guess I can say that, if it was 14 questioned, I haven't heard the answer, although I did hear 15 in an interview somebody make a statement about a skid 16 working, but I'd have to go back and look at who said that 17 and what was 18 19 MR. VATTER:
A skid working?
MR.
COLOMB:
Somebody was a skid working before 20 they -- I'd have to go back and look.
I'd hate to make 21 that statement without going back.
22 23 MR.
VATTER:
Okay.
In the log, they started a second condensate pump 24 at 7:38, noting that the operating condensate
- pump, which 25 was the A pump -- was that P1A?
12 MR.
COLOMB:
Yes .
MR.
VATTER:
And then P1B was the second one.
I was wondering if you had any feel for why that 4
might have been a problem, that they had to have two 5
condensate pumps.
What I think might have happened is that the 7
condensate reject valve to the condenser opened with the 8
loss of control power to the condensate system and that the 9
valve was not reclosed at a later time when power was 10 restored and that there was a rather large amount of 11 condensate flow as being diverted back to the condenser.
12 MR.
COLOMB:
My understanding of that is we saw--
13 they saw a high standard temperature on the one pump.
I 14 believe they recognized the fact that it was a due to a high 15 flow condition and started the second condensate pump.
16 MR. VATTER:
I wondered whether they should have 17 been reducing the amount of flow on that running pump?
18 MR.
COLOMB:
What I can't say is what was 19 happening with the min flow valve.
You mentioned that you 20 thought a valve had failed opened and not been reclosed, 21 that valve normally acts automatically, or rather it should 22 have been acting automatically if the power was restored.
23 MR.
VATTER:
So if the pump had a high flow 24 condition, we don't know exactly where all that flow was 25 going?
0 Cl 0
13 MR.
COLOMB:
I can't say -- I can't say where all 2
that flow was going.
MR.
VATTER:
I can't either, I guess.
I'm just 4
trying to guess a little bit and try to figure that out.
MR.
COLOMB:
I know that they saw a high standard 6
temperature on it.
I believe it was related to high flow 7
when they started the second pump to provide the additional 8
flow.
MR. VATTER:
We also noted in the log that the 10 stack GEMS, that gaseous effluent monitoring system was 11 inoperable at 8:05, but apparently that had been inoperable 12 for a long period of time or from the start of the event.
13 MR.
COLOMB:
I know it was inoperable, I know we 14 were tracking why that was a problem.
We'e looking into 15 why that was a problem.
I can't say it was inoperable 16 before the event, without looking back, I guess.
17 MR. VATTER:
I didn't mean to imply that I thought 18 it was.
My perception was that it became inoperable at the 19 start of the event?
20 21 MR.
COLOMB:
Yes, I believe that's true.
MR.
VATTER:
And that they recognized that it was 22 inoperable at 8:05 and declared it such?
23 24 MR.
COLOMB:
Right.
That sounds correct.
MR. VATTER:
Now, I'm not sure what all different 25 ways you have of monitoring a release path from the
S 0
14 2
available, if that rad monitor is not available and the 3
stack GEMS is not available, is there some other radiation 4
monitor in that, release path that we'd be able to see?
MR.
COLOMB:
No. I don't believe there is.
I 6
think that if the GEMS is inoperable, then the next method 7
is grab samples.
MR.
VATTER:
Okay.
So possibly there was an 9
unmonitored release at 7:30 when they put the hoggers on 10 service?
I don't know how important that is, but we'e 11 trying to understand that.
12 MR.
COLOMB:
Um hm.
I understand.
13 MR. VATTER:
Who do you think I ought to talk to 14 to get a more clear perception of that release path and how 15 it might have been monitored?
16 MR.
COLOMB:
Do you what to know specifics about 17 what somebody saw in the event or do you want to just know 18 technically how the release path is monitored?
19 MR. VATTER: I would like to know how it was 20 monitored during the event because we don't -- or I don' 21 see right now a way that it was monitored.
I would like to 22 know that it was being monitored.
23 MR.
COLOMB:
Yeah.
- Well, we probably have to look 24 back to the sequence and just verify the monitors.
I would 25 have to say if the GEMS -- if the GEMS was inoperable and
0
15 2
probably an unmonitored release.
MR.
VATTER:
Okay.
We'l need to research that a
4 little bit more.
MR.
COLOMB:
Okay.
MR.
VATTER:
Mike, those are all the questions 7
that I had for you.
Is there anything that -- do you have 8
something, Walt?
MR.
JENSEN:
Yeah.
I might as well ask a few.
10 Let's see, we know that at, the first of the event that there 11 were two RHR trains out of service and wondering what your 12 policy was with regard in having two trains of safety 13 equipment out of service and how long they had been out of 14 service?
15 MR.
COLOMB:
We typically do work and preventative 16 maintenance and systems by division. It is not -- it's the 17 exception we have two out at once, but we would only do that 18
-- in other words we separate it so that if we'e working on 19 division two, everything in division one and division three 20 is operable.
That's how we schedule and perform our 21 maintenance and preventative maintenance and surveillance 22 activities.
23 MR. JENSEN:
Do you have any effort not to have 24 to have no more than one out of service or is this an 25 unusual circumstance to have two trains out of service at
8
16 1
the same time?
MR.
COLOMB:
I guess I would have to go back and 3
look at our history.
I can say that we typically -- we 4 'ypically work on just one train at a time, but I can' 5
that's it's unusual that we would be working on one MOV and 6
you know if the work was scheduled, to be working on both 7
trains in a division.
We don't have any policy that says don't work on 9
both trains at once.
We go by division and we wouldn' 10 unnecessarily schedule a train out unless we had something 11 to do on it.
12 MR.
JENSEN:
Okay.
There was a water hammer 13 reported in the RHR system when the valve going to the rad 14 waste system was opened, I believe that was a result of 15 perhaps opening the valve too fast, done locally, has that 16 been a problem in the past?
Have you had trouble with that 17 particular valve in the past?
18 MR.
COLOMB:
To my knowledge that has not been a
19 problem in the past.
20 MR. JENSEN:
Okay.
Have you had water hammers in 21 the RHR system in the past that you'e aware of?
22 23 MR.
COLOMB:
Not that. I '
aware of, no.
MR.
JENSEN:
There was difficulty, I believe, in 24 initiating the water cleanup system that is tripped of when 25 it's first, started up and I believe that was laid to a
8 0
17 1
confusing procedure.
Have you had trouble initiating water 2
cleanup before?
MR.
COLOMB:
We have had -- we have had problems 4
with our cleanup system, specifically the delta flows in the 5
cleanup system that were very sensitive to system 6
We have had many problems with those.
I can' 7
-- I'd have to look back to say that we have had this 8
specific condition.
I don't think we've'had this specific 9
condition before, but we have had many problems with those 10 delta flows during system configuration changes, if you 11 will; starting up, shutting down, going from one load to 12 another.
13 MR. JENSEN:
14 hammer in the cleanup And have you had trouble with water system before?
15 MR.
COLOMB:
I don't remember having a problem 16 with the water hammer before.
17 MR. JENSEN:
Let's see, there was difficulty noted 18 with controlling the RCIC system and automatic control.
Has 19 this been a long standing problem and what efforts have been 20 made to fix the automatic RCIC control?
21 MR.
COLOMB:
I believe we have had problems with 22 it in the past and typically what we do is on a restart 23 after any RCIC maintenance, we will run the turbine which is 24 a tech spec surveillance and tune the controller while RCIC 25 is running.
0
18 1
MR.
JENSEN:
Okay.
There was indeterminate valve 2
position indication on the RCIC injection valves, valve 3
number 156 and
- 157, has this been a problem in the past?
MR.
COLOMB:
We have had problems with indications 5
and testable checks in the past, yes.
RCIC -- including 6
RCIC.
We have had problems with that.
MR. JENSEN:
And this is something that occurred 8
and has been corrected as it occurred?
MR.
COLOMB:
Yes.
Correct.
It's had corrective 10 maintenance and modifications to the limits switch 11 configurations, both.
To some of them, I can't say 12 specifically which ones.
13 MR.
JENSEN:
Okay.
There were a couple of safety 14 valves that were leaking at the start of the event, do you 15 know how long these have been leaking and was there a
16 corrective action plan to fix the leak?
17 MR.
COLOMB:
They had been leaking -- if I said 18 how long it would be a guess, but they'e been leaking for 19 quite a while, and yes, there are corrective -- there' 20 corrective action paperwork to fix those in refuel outage, 21 take those out and replace them in the refuel outage.
22 MR.
JENSEN:
What is your refueling outage 23 scheduled to be?
MR.
COLOMB:
I believe it's scheduled to start the 25 end of February of 1992.
8
19
[Pause.]
MR. JENSEN:
I think that's all I have, Bill.
MR. VATTER:
Mike, is there anything that you 4
think that we haven't gotten about the event that we ought 5
to know about?
MR.
COLOMB: I guess I presume that all the 7
information we'e gotten in our RAP-6 we'e shared with you, 8
so I have to say, no, that I think you probably have all 9
that.
10 MR.
VATTER:
What was that acronym?
MR.
COLOMB:
We have a reactor analysis procedure 12 that does an evaluation of a scram.
And I know we developed 13 a sequence of events and I'm pretty confident that we'e 14 shared that with you, so I assume that 15 16 events?
MR. VATTER: I assume you mean the sequence of 17 MR.
COLOMB:
Then I think you know everything that 18 we know about it.
19 20 MR. VATTER:
Okay.
[Whereupon, at 4:30 p.m. the taking of the 21 interview was concluded.]
22 23 24 25
'L 0
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REPORTER'S CERTIFICATE This is to certify that the attached proceedings before the United States Nuclear Regulatory Commission In the Matter of:
NAME OF PROCEEDING:
Interview of Mike Colomb DOCKET NUMBER:
(Not applicable)
PLACE OF PROCEEDING:
- Scriba, New York were held as herein appears, and that this is the original transcript thereof for the file of the United States Nuclear Regulatory Commission taken by me and thereafter reduced to typewriting by me or under the direction of the court reporting
- company, and that the transcript is a true and accurate record of the foregoing proceedings.
Mark Handy Official Reporter Ann Riley
& Associates, Ltd.
J