ML20129B907
| ML20129B907 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/10/1985 |
| From: | NRC COMMISSION (OCM) |
| To: | |
| References | |
| NUDOCS 8507290293 | |
| Download: ML20129B907 (31) | |
Text
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o UNITED STATES NUCLEAR REGULATORY COMMISSION IN THE MATTER OF:
DOCKET NO:
DAVIS BESSE IflCIDEitT (INTERVIEll a f1EETIl1G)
(CLOSED)
MEETING BETWEEN T!!E NRC FACT-FINDING TEAM AND TOLEDO EDISON f)
ON SEQUENCE OF EVENTS LOCATION:
VAK HARBOR, OH PAGES: 1 through 24 DATE:
JULY 10, 1985 ACE-FEDERAL REPORTERS, INC.
OfficialReporters 444 North Capitol Street 1
8507290293 050710 Washington. D.C. 20001 ADOCK0500g6 (202)347-3700 PDR NATIONWICE COVERACE
1
.. +a-Sim~1-1 1
UNITED STATES OF AMERICA 2
NUCLEAR REGULATORY COMMISSION 3
4 WEDNESDAY, JULY 10, 1985 5
i 6
MEETING BETWEEN THE NRC FACT-FINDING TEAM AND TOLEDO EDISON 7
i ON 8
9 SEQUENCY OF EVENTS 4
10 1
11 l
NRC FACT-FINDING MEMBERS PRESENT:
12 ERNEST ROSSI i:
13 J. T.-BEARD
- j4 LARRY BELL OTHER NRC MEMBERS PRESENT:
-15 16 W. ROGERS N. JACKIW 17 TOLEDO EDISON MEMBERS PRESENT:
18
.j9 V.
MacDONALD J. MARLEY 20 J
LINGENFELTER 2I J. WOOD 22 23 24 AceF.deral Reporters, Inc.
25 i
I1
.E-.
2 Sim
-2 PROCEEDINGS
)
(1:12 p.m.)
2 3
MR. ROSSI:
Why don't we go ahead and start then.
4 What we are going to do now is talk about the 5
sequence of events and additional information that the 6
licensee has that may warrant corrections to a couple of the 7
items in the team's sequence of events that was dated 8
June 24th, 1985.
9 You have given us a couple of pieces of paper 10 here.
11 MR. BEARD: - They will be' entered as exhibits to 12 this meeting.
1 13 MR.-ROSSI: ~ Both of them have been?
14 MR. BEARD:
Yes.
15 MR.'ROSSI: 'Okay, fine.
16 MR. BEARD:
There is'the memo from Mr. Jain, and 17 then there'is a one-page hSndwritten document.
18 (The documents referred to were marked 19 Exhibit No. l and were submitted.for the 20 record.)
21 MR. ROSSI:
Okay.
Why don't.you go ahead and-22 explain what the changes are.
23 MR. LINGENFELTER:
Okay.. We will do the simple 24 item first, the one(handwritten page.
This'was just a typo.
Ac.-F.d.cos n.po,$.ri, inc.
25 on the times for_when low suction pressure was developed:
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3 i
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-on the No. 1 aux feed pump.
The original sequence of 2
events read.1:57:33, and we feel that should be changed o'l:57:53 to go along with what was in the alarm printout,
~
3 t-4 which is a minor item.
5 MR.' BEARD:
So actually, if I understand it, there 6
are two changes.- One is in the time that the entry should 7
be entered, and the time should be 1:57:53 instead of 33 ---
8 MR. LINGENFELTER:
Right.
9
-MR. BEARD:
And the corresponding changes, the 10 duration was 34 seconds instead of 54 seconds.
11 MR. LINGENFELTERi-Correct.
12 MR.. BEARD:
Questions?
13 MR., BELL:
Yes.- This low suction pressure 14 condition did result in a shift of. suction from the CST 15
'to'the' surface. water system though,'right?
16
.MR..LINGENFELTER:
That is correct.
It was just 17 in the time that we thought it was a-typo there.
18 MR. ROSSI:
Later on it talksJabout the shift in 19 the suction and I' assume that that time is correct.
20 MR. LINGENFELTER:
That is the 1:58:40 entry.
21 MR. BEARD: -Let me'back~up.
There is an entry 22 in. the sequence of events wherein we believe that the 23 suction actually did transfer, okay, and that was later, 24 and-it.was returned manually by the operator.
But;now this u+r.a a ng=*m, lac.
~
25 entry:that you brought up here-was intended to say that,
4
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o 01" ' 01" 4 A'l according to the information that we had, there had really 2
been a.true low suction condition like a minute before that 3
lasted for some number of seconds and then it cleared prior to the' actual transfer.
5 MR. BELL:
But wasn't suction pressure restored 6
to normal when.the service water supply valve. opened?
'7 Wouldn't that raise the~ suction pressure back to this 8
normal value?:
~9 MR..MARLEY:; The : point which I'sa's.trying.
10 to make on the clarification on this sheet.wasithat it II appeared to my mind that'there might have:been a typo-12 graphical' error made just in the item that was referenced, 13
<being the item at 1:57:33 appeared like it correlated to 14 the item on~the alarm which was shown-Ito'be'l':57:53, and 15
.that was the alarm point P006 for aux feed pump suction-16 pressure' low.
It-did return to normal at'1:58:27.
The I7 only clarification I.was trying to make atithat point was 18 that it appeared.that the wrong time was referenced for 19 that change in state.
20 MR.: BEARD: -What wa's the data point on that one 21 again?.
MR. MARLEY:
The point number was P006.
MR. LINGENFELTER:
Then the actual transfer-24 occurred later.
. AceFederal Reporters, Inc.
~
~5 MR. MARLEY: !Later, that:is correct.
(~
5 Sim 4A-5 1
MR. BEARD:
I think that it is a typo type of 2
mistake, but'we will look into it and if we are convinced, 3
then we will make the correction.
I think you are right.
?
4 MR. LINGENFELTER:
The second document, the 5
memo from Susmil Jain to John Wood in regards to the aux 6
feed pump turbine cont'rols is discussing a little more 7
detailed understanding of what the operators were doing 8
with respect to aux feed pump No.
2.
9 And the suggested changes in here, and there 10 are specifically two of.them, one at 1:53:22, the sequence II of events currently makes reference'to the fact that the 12 pump could not be controlled from the^ control room.
13 Our feeling now is that indeed the pump could have I4 been controlled-from 'the control r'oom' at this. time had -
15 he attempted.to do it.
16 MR. BEARD:
Is this a change in the information 17 that we have been previously given?
In.other words, is 18 someone's memory now different?
I am_trying to understand 19 whether we misunderstood what someone said in~one of our 20 interviews or something, or whether they now remember 21 differently.
22 MR. LINGENFELTER:
I think we are-just getting 23 down to.more details'of what happened.
We have'had a 24 better chance to talk to-the operators and find out what
. Ace-Federal Reporkrs Inc.
25 they:wcre doing'and getting'all the details of the data I
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6 "Y&.
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understood,-and it now appears as though ---
j MR. ROSSI:
Well, you know, one of the things 2
that I think there has always been a question on how we 3
had our sequence of events worded here compared to what 4
we have been told.
This we have discussed in a couple 5
ficarlier meetings, as I recall..
6 MR. BEARD:
That entry has been discussed many 7
times.
8 MR. ROSSI:
Yes.
And I think that Wayne is 9
preparing a write-up on the sequence of; events that is 10 ji
' based primarily on the various transcripts.
So he is l
king at what we can tell from the transcripts compared
~
12 to what you h, ave given us here compared to what you can 13 34
- get from the sequence of events printouts-and so forth.
15
.There.may be some of these things where Tee are f-16 just not going to ever know for sure.
I don't know.
If j7 it is totally dependent on what somebody remembers from 18 the event and it is different in the transcripts compared 19 to-what is in-here, or if the equipment operators say 20 something that is a little different than the control 21 room operators, we may just not be able to resolve it.
I don't know whether this is one of those or not.
22
~
123 MR.lBEARD:. That is what I;was trying to 24
-understand..
Ace-Federal Repor%rs, Inc.
25 MR. LINGENFELTERr:
I think that there is t
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Sim 4A-7
~1 evidence for this, and let me go back and explain to you 2
what I can tell you about what I recall.
3 I told you before what I understood about control
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l 4
of the No. 2 aux feed pump around this time.
As I recall, 5
and I-did not go back to the previous transcript, but as 6
I recall,'my understanding previously had been that the 7
operator locally was attempting to control aux feed pump 8
No. 2'to bring the-pump up to speed, and indeed at this 9
time ~;he had established" steam flow to the turbine.
10 My understanding previously was that he had 11 difficulty getting the trip throttle valve all the way 12 open, and in fact the pump was coming up to speed with the 13 trip throttle valve not fully opened.~
14 If that had been the case, then control from the control room woul'd have been' difficult since the 16 majority of the differential pressure drop, and the 17 pressure drop was across the trip throttle valve.
18 After looking'at all of the data closer, the-19 alarm printout shows something'I had missed before, that 20 the trip throttle valve showed that it was fully opened' 21 at this time, and in fact'the flow-wasl coming up and.the 22 control room operator,;I guess as:I' understand it now, t
basically left local control..In other words, he told the 24 guy down in the aux feed pump room'to try to bring the Ac.-Federal teporten, Inc.
7 25 1:
pump back, and he then closed'the trip throttle valve.
=
=
2
8 He was.trying to maintain control locally.
4_
j Had the control room operator attempted to use or 2
taken enough time to use the aux feed pump control in the 3
.l control-room, he would have succeeded, but he did not do that.
4 It is a relatively minor point, but'the fact is
'S that'we feel now that he could have controlled the pump at 6
7 that time, for what that is worth.
8 MR. BEARD:
So it is somewhat different and more recent information than we have previously been given.
9 10 MR. BELL:
How does this significantly affect the 11 event?
12
'MR. LINGENFELTER:
'I' don't think'it does.
'It is 13
'only a' matter'of trying to clarify whether or not we indeed 14
-had any kind.of real big problems with the controls-themselves i
~
15 at that' point.
I mean you obviously had some troubles with 16 the things going out at a' lower speed and you had'some
[17 trouble getting the trip throttle valves reset, but we 18 originally had thought.that if something was wrong with the
.19 circuitry up there, and we don't think that is the case-end Sim 20
.now.
Sue fois 21
'22 23
-24
' Ace-Federal Reporters, Inc.
25
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9
, ;#5-1-SueWalsh MR. BEARD:
I think that that's one change that t
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L 2
you are proposing in this area.
And I believe there is a-i second change that says:
In an area where we may not have 3
4 indicated there was a control problem there now seems to p
5 be there was.
6 In other words, as I read this memo that you have 7
given us, the third paragraph indicates that later there 8
'was a control problem.
.So, as I understand the essence of 9
the change-that you are proposing is to the place where we 4
j 10 indicated there may,have~been_a control problem, you are i
11 saying:
Well, no, that's not really the. case as wo under-I'
'12 stand it now.
But there is a case later where there is a i
13 control problem..
j 14 That's the way I read the bottom line.
15 MR. LINGENFELTER:
Okay.
Now, you are referring 16 now to this third paragraph where it says he later had l-17 difficulty assuming manual control of aux feed pump 2.
i
, And this you are saying here, as I L
18 MR. ROSSI:
19 read this, because the throttle valve wasn't --
l l
20
',MR.4 LINGENFELTER:
Wasn ' t all :the 'way open.
t 21 MR. ROSSI:
Because he had been locally controlling i
22 it for some period of ' time and just didn't have it all 'the 23 way open.
i 24 MR. BELL:
But even if the. throttle valve wasn't~
j Ac.-F.d.r.: n.por,.ri. Inc.
25 all' the way open, 'shouldn't the operator have been able to l
l 5
.. ~
10
- 5-2-SueWalshi decrease turbine speed from the control room?
2 MR. LINGENFELTER:
He should have.
1 3
MR. BELL:
But was he able to decrease speed?
4 MR. LINGENFELTER:
I don't think he tried up 4
5 front, at least not at the time we are. making this initial 6
change.
l f 7
MR. BELL:
We are talking about the 201 --
8 MR. BEARD:
Yes.
L
{
9 MR. BELL:
Let's break it up into the later part, 4
10
.the 201 time frame because it says that steam generator 11 j
-levels were about seventy-five and eighty inches.
And that 12 would be closer like where you would like to hold level 13 constant.
14 MR. BEARD:
I think it also says, Jack, the 15 sentence in'the middle of that paragraph, it says:
- Further, i
16 according to him even th'c auto essential level control --
1.-
j 17 and gives the times -
did.not'show,any. response for steam 18 generator Number 2 level.
1 i
19 So, I-read that as later on there was apparently
- 20
~ some problem.
And then I hink in your fourth paragraph you
- 21 go into more 'of 'an explanation as.ito what ' the conditions 27 were that made this problem seem to appear.
l 23 (Mr. Lingenfelter is looking at a document.)
i 24 MR. LINGENFELTER: At.1:52:.53 the alarm printout'
' Ace Federal Reporters, Inc.
25 shows that the trip throttle valve; was t il the way open.
2
p-11
- 5-3-SueWalshj MR. BEARD:
Repeat that.
2 MR.'LINGENFELTER:
At 1:52:53 shows that the trip 3
. throttle valve was all the-way open.
That's.Z002.
4 And then at 1:53:51 the trip throttle valve is 5
n longer all'the way open.
6 MR.~ BEARD:
1:53 what?
7 MR. LINGENFELTER:
51.
8 MR. BEARD:
So about a' minute later,'it's no 9
longer open?
10 MR. LINGENFELTER:
Right.
j)
MR. WOOD:
No longer full open.
12 MR. LINGENFELTER:
Right.
No longer full open.
13 And quite frankly, I wish Sushil were-here. 'Ile was the-one 14 that has been doing all the talking.
But, as I understand it,-
15 my understanding was th,at the operator locally started crank-16 ing back'on the valve'at that' point.
17 I guess my point is.that with that valve not fully 18 OPen, you can't guarantee whether you are going to have any 19 good control of the governor..
20 MR. BELL:
But my point is that if -- even with the 21 trip throttle valve.only. partially open'you should be able to 22 f ully. close the governor and slow the speed of that turbine
- 23 down, which apparently the operator wasn't able to do.
24 MR. LINGENFELTER:
It depends on how'long he gave Acer.d.ror m. porters, Inc.
25 it a chance to work.
. -- --...-...---.----A- --..-----.-.
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12
- 5-4-SueWalsh)
MR. BELL:
Yeah.
2 MR. LINGENFELTER:
You know, sixty seconds --
3 MR. BELL:
But my only point is, based on -- I 4 don't think that we can honestly say that there was no problem 5 with manual control from the control room based on this letter.
6 That's my only point.
7 MR. LINGENFELTER:
Okay.
8 MR. BELL:
Do you agree or disagree?
9 MR. LINGENFELTER:
I don't think that I can adequately 10 explain it to you.
11 MR. ROSSI:
Well,at 2:01 their change says that the 12 control room operator experienced difficulty in manual control 13 of the pump, and the pump was initially locally controlled.
14 That's what it says.
15 MR. BEARD:
That's the 2:01 time?
16 MR. ROSSI:
Yes.
That's the 2:01 time.
17 MR. BEARD:
Yeah.
But I guess what I'm trying to 18 understand is that the third paragraph of the letter says that 19 he tried to go into auto essential about 2:01'and~got what he 20aaid did not show any response.
21 So, at 2:01 I read that thing as saying that the 22 automatic. controls appeared not to be working.
23
.MR. LINGENFELTER:
If you use the word " appeared" I 24 don't have any trouble with that.
From what we have seen, Ac r.deral Reporters, lac.
25 there is no way to tell whether there was an actual circuitry
13 f
- 5-5~-SueWalshi problem or not.
The real question is whether or not the 2
operator gave the automatic controls enough time to respond.
3
'There is reason to believe'that with the governor, 4
. with the trip throttle valve rather closed ' to some degree 5
that it's going to.take a lot longer for the thing to work 4
6 than it would otherwise.
I 7
MR. ROSSI:
Well, is there another possibility 8
that if the guy that's controlling the trip throttle valve 1
j 9
locally.is moving that valve in one direction and the opera-10 tor in the control room or the auto essential control is i
11 trying to move the governor in the opposite direction, it 12 would appear to the guy.in the control room that it's not 13 controlling properly?
14 Is that a possibility?
15 MR. LINGENFELTER:
It's possible.
But I again i
16 don't know exactly what he was seeing at the time he saw --
17.
he made that statement.
4 l
18 MR. ROSSI: ' Yeah.
I -- that's directed to you 4-
- .s 19 Larry and J.T. also.
l 20 MR. DEARD:
Yeah.-
I think it's clearly a pos-21 sibility because,' you know, this was a high stress situation.
f:
22 People were trying to.get aux feed working.
The situation 4
23 in the pump _ room-was,,I'm sure, noisy.
Communications were
[
.24 at optimum.
- A.Fawdagenws,bc.
I 25 And I could envision.a clear possibility of one l
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14
- 5-6-SueWalshi guy going up and the other guy going down.
But, you know 2
it's still in the possibility range.
We don't really know.
3 Okay.
4 But I do have a question, Jack, in this 2:01 type 5
of time frame.
As I read your third paragraph here again, 6
that I keep coming back to, what I get out of it was it 7
appeared that the auto wasn' t performing to him.
Okay.
And 8
I can understand that based on what you are telling us about 9
the time and how long he allowed it to try before he decided 10 it wasn't working, et cetera.
11 What I'm trying to correlate now is, you are 12 proposing a change that we add to 2:01 that said:
The control 13 room operator experienced difficulty in the manual control.
14 And I'm trying to relate those two together.
And 15 I don't -- I get a disconnect.
16 MR. LINGENFELTER:
Between manual control and 17 automatic control?
18 MR. BEARD:
I read the third paragraph saying he 19 had problems in auto-essential.
I don't see anything in the 20 third paragraph that said he had troubles beyond that.
21 MR. ROSSI:
Well, the third paragraph also has 22 this thing in there that says that the DADS data showed that 23 the auto control function was working properly betwoon 2:01:04 24 and 2:01:19.
AcNederal Reporters, Inc.
25 MR. BEARD:
Where are you reading now, Ernie?
o 15
- 5-7-SueWalshi MR. ROSSI:
That's the sentence right after the one 2
that you read.
"...the DADS data showed that this auto-control 3
did function correctly... " that is since the auxiliary feed-4 water pump turbine speed was indeed decreasing because the 5
steam generator level was significantly higher than the level 6
control setpoint.
7 MR. BEARD:
And that could have been the auto con-8 trol; it could have been the manual control; or, it could have 9
been the local operator.
We don't know that.
10 All they are doing is making a judgment that level 11 was g61ng in the right direction.
12 MR. ROSSI:
Can you tell from the printouts when 13 he was in auto-essential level control?
14 MR. LINGENFELTER:
You can tell when he switched 15 back and forth between.
16 MR. ROSSI:
So that you can tell that between 17 2:01:11 and 2:01:24 in some printout that he was indeed in 18 auto-essential level control, I assume?
19 (Mr. Lingenfelter is looking at a document.)
20 MR. LINGENFELTER:
Okay.
Yeah, during -- between 21 2:01:11'and 2:01:24 the switch was'in the auto-essential 22 position.
23 MR. ROSSI:
So you know now that between those 24 times the switch was in auto-essential and the next sentence Ace-Federal Reporters, Inc.
25 is saying that the data shows that the pump speed was decreasing,
16
- 5-8-SueWalsll which is what you would have expected for that steam generator 2
level?
3 MR. LINGENFELTER:
Yes.
4 MR. ROSSI:
Does that clarify anything or not?
5 MR. BELL:
We are at a disadvantage because-we don't 6
have the printouts nor the plots to look at to agree or dis-7 agree with this gentleman.
8 If I might make a suggestion, I would like to take 9
the time for the Team to look at those plots.
10 MR. ROSSI:
Okay.
Why don't we go off the record Il for a few minutes.
I2 MR. BEARD:
Well, let me make an alternate suggestion.
13 MR. BELL:
I wasn't finished.
I4 MR. ROSSI:
Well, let Larry finish first.
15 MR. BELL:
Toledo Edison is going to troublechoot 16 the governor of the aux feed pump turbine through some action 17 plan because of the over-speed t' rip.
If there are any problems 18 in the circuitry, will your action plan discover those problems 19 regardless of this letter from Mr. Jain?
20 MR. LINGENFELTER:
I hope so.
2I MR. BEARD:
My understanding is quite different 22 from that.
23 MR. BELL:
If the action plan will reveal a control 24 circuitry problem within the control room either in manual or Ac> Federal Reporters, Inc.
25 automatic-essential, then my concern goes away.
17
- 5-9-SueWalsh9 MR. BEARD:
Well, let me tell you what my 2
understanding is.
Maybe you guys can set it straight.
3 I don' t have in f ront of me, but my memory from 4
reading this action plan'is that the lead responsibility is 5
proposing that the plan be closed on the basis that the 6
reason there were control problems apparent in the control 7
room was purely because the trip throttle and associated 8
equipment downstairs wasn't in the proper position.
There-9 fore, it was an apparent problem and not a real problem.
10 And the resolution of the action plan is to II consider it not a real problem.
The re fo re, I don't see a 12 great deal of troubleshooting on the governor coming out 13 of that action plan.
I4 MR. WOOD:
Okay.
That is a correct assessment 15 of the Plan 1-C.
Plan 1-A and 1-B, which is the turbine over-10 speed action plan and does troubleshoot the governor.
- Also, 17 in the testing it will, by necessity, have to use the manual 18 and the auto-essential control features.
I9 So that the -- I don't recall offhand whether 20 1-C actually dees bring to light that during the testing 2I of the aux feed pump turbine those controls would be further 22 invalidated.
That perhaps is in there.
I don't recall of f-23 hand that it'is.
24 But you are correct in saying that the action plan Ace Federal Reporters, Inc.
25 1-C is being at this time generated to say that the apparent
18 35-10-SueWalsN problem was auto-essential or manual control from the control 2
room was in fact an apparent problem and not a real problem.
3 MR. BEARD:
I would like to make a couple of 4
suggestions, Ernie, and then you can go from there.
One is 5
a very general thing, that as I see it the Licensee is bring-
'6 ing us new information and proposing that we -- or, asking 7
us to consider it'and make appropriate changes to our sequence 8
of events.
9 And I think that we will do'that; We will con-10 sider them and if we find them validated we will make changes.
11 And like Ernio said earlier, if we find that it's not resolv-12 able we may have to indicato it that way.
j 13 But we certainly want to havo our sequence of 14 events as accurate as we believe.we can~get it.
And --
15 MR. ROSSI:
I believe --
16 MR. DEARD:- -- a second point is that in this 17 question about the control re aux feedwater. pump, it seems 18 to me that the number of times that we have discussed this 19 in meetings,. the fact that' there has been a memo written on 20 it, and the fact of this, that and the other, ~it seems to me
~
21 that even without reading the memos, one could say: _'I need 22 to' look. and see -. I need' to have an action p1'an to investi-23 gate the controls that. wore available during that period of 24
= time after this thing'was; latched,zrelatched, rather than Ac r.d. n.po,., lac.
'25 close it out.
N
r 19 9'i-ll-SueWall
. And I would -- I'm just saying the fact that we 2
have-had this much. discussion should suggest that you might 3
want to reconsider closing that other plan out.
END.f5' 4
JosWaleh f1ws 5
6 7
8 9
10 11 12 13 14 15 16 17 18
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1 MR. ROSSI:
It would appear to me that 2
you have to do a thorough test, both the auto essential
=3 control and manual control on these pumps to demonstrate l
4 j
4 that they are working properly before you close out the i
5 action plan.-
6 That is what it would appear to me.
Before 7
- you conclude what the. root cause of the problem is, and f
8
.your' conclusion apparently~may be that there wasn't a a
9 problem, that.you do a thorough enough test to demonstrate i
10 that there isn't a problem.
11 MR. WOOD:
I think tlie purpose for us coming 12 forward with this information is a follow-on to the meeting i
13 that we had in Bethesda, where Action Plan 1-C was bringing
)
14 information that potentially was conflicting with the i
15 sequence of events.
16 We wanted to make sure that we brought to the i
i 17
. Fact Finding Team as much information as what we understood 18 at this point in time, and granted, it may change at some 19 later time, but as it stands right now, this is the best j
20 information we feel we have on this subject.
l 21 MR. BELL:
I think it is good,'and I appreciato 22 the fact that you are bringing this information, j
23 MR. ROSSI:
Walt, do you have anything to
+
I 24 add to this?
Ace-Fedecol Reporters, Inc.
25 MR. ROGERS:
I guess one comment on page 11 of I
l m.
m
6-2-JobWal 21
-1 22~, 14104, when Actuation Channel 1 actuated, I believe 2
it isolated main feedwater to both steam generators at that 3
time, and that is not mentioned in the sequence of events.
4 MR. ROSSI:
You ' are looking at the LER S
cequence'of~ events.
6 MR. ROGERS:
-Yes.
7 MR. BEARD:
We are on a different document.
8 MR. ROSSI:
Yeah, we were talking about 9
possible corrections to the HRC sequence of events, but 10 11
'MR.
ROGERS:
Oh.
j 12 t1R. BELL:
May we have time to look at this?
f.
j-13 MR. ROSSI. There are a couple of questions; i
14 we can look at it and then come back and ask more questions 15 about it if we need to, or we can take all the information l
16 that we have, which is apparently everything that exists.
j 17 We have got.all the printouts.
We have them
(
j 18 all.
We don't have them here right now.
Wo.got all the
{
19 DADS data on pump speeds, icvels, and all that.
20 We got the interviews with all the poopic, I
I 21 and we got this additional information that they gave us.
22 We got the transcript of what they told us, and we can.
23 decido how we word the sequence of events.
l 24 MR. LINGENFELTER:
That is fine.-
l Ac> federal Reporters, Inc.
j 25 MR. WOOD:
Again, the purpose of this was.not 1
'T,t 16-3-Joe.Wal J
22
- 1 to tell you what it should 132, but only -- here is.some 2
recommended changes for your consideration.
3 MR. LINGENFELTER:
What time is Sushil coming 4
in?
5 MR. BEARD:
lie has been here all day.
6 MR. LINGENFELTER:
Ile is coming back to talk 7
to you.
I'was going to suggest that perhaps you might want 8
to let him address this.- IIe wrote the thing, did the 9
research, and he probably could certainly justify it better 10 than I'can.
11 MR. ROSSI:
Well, the only significance to 12 this, as I 'see it, is that you. don' t.want to. decide for a 13 wrong reason that you don't have a problem with the control.
14 That is the significance.
And, you know, if there is any 15 question at all that can' t be resolved, then what you 16 obviously ought to do is make sure that your ' control systems, 17 both manual and auto essential, are thoroughly checked out 18 and tested before you declare that they are operable.
19 And that is the real key.
20 MR. BEARD:
That is what I was trying to say.
21 MR. WOOD:
There is additional information 22 in Action Plan 1-C beyond this, including -testing that was 23 done immediately af ter the event, so that there is more 24 basis to saying that apparently there is a problem.
Actually Ac p.d.I sei, lac.
25 may have been
-- but your point is well taken an to finally t
e 6-4-Joa Wal 23 1
putting the root cause to rest.
And whether further 2
testing beyond what we have addressed in Action Plan 1-C 3
is appropriate, we will take that under consideration.
4 I am not certain right now that that is, in 5
fact, not a part of 1-C.
It may even be some of that in 6
1-C as it stands right now.
7 MR. BEARD:
In there anything more that wo need 8
to discuss at this meeting?
9 MR. LINGENFELTER:
(Mods head negatively.)
10 MR. ROSSI:
What we will do then -- go ahead, 11 Larry.
12 MR. BELL:
For clarification, in the cequence 13 cycnta in your LER 85-013 your latest sequence of oventn?
14 MR. LINGENFELTER:
Yon.
15 MR. ROSSI:
I went through that thin morning 16 fairly quickly, and it lookn like it in in agrooment almont 17 down to the word with ourn, except in a few canon.
18 Some of them were things like we are talkJ ng 19 about here.
They have nald things dif ferently than what 20 is in our naquence of oventn, but mont of the information 21 appearn to be the namo.
22 They even know how to apell, 'acountical,'
23 correctly, compared to the team'n apolling.
24 MR. IlEARD :
I guono that shown that even the w.d.,.in.po,,.,
i=.
25 government can mako mintakon.
6-5-Joe Wal 24 1
I suggest that we adjourn, Dr. Rossi.
2 MR. BELL:
No, si r.
3 MR. ROSSI:
Okay.
We will adjourn.
4 (Whereupon, at 1:45 p.m.,
the meeting 5
concluded.)
6 7
8 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 A. N.r.1 s.p.<e
=.
25
{
s CERTIFICATE OF OFFICIAL REPORTER This is to certify that the attached proceedings before the UNITED STATES NUCLEAR REGULATORY COMMISSION in the mattor of:
I NAME OF PROCEEDING:
DAVIS DESSE INCIDENT (IntervioW I. Mocting)
(CLOSED) l MEETING BETWEEN Tile NRC FACT-FINDING TEAM AND TOLEDO EDISON ON SEQUENCE OF EVENTS DOCKET NO.:
t 4
PLACE:
OAK IIARBOR, Oil i
DATE:
WEDNESDAY, JULY 10, 1985 woro hold as heroin appears, and that this in the original transcript thoroof for the filo of the United States Nucioar Rogulatory commission.
Intnt) fjf f.
b
).
(TYPED) CARitETT
. WALUll, JR MYRTLE II. WALSil Official Roporter Aco rodoral Roportorn official Roporter Reportor's Affiliation Jf Aco redoral Itoportorn
_f69_ _
{J+td %,
MARY EV. SIMONU Official Hoporter Aco redoral Hoportorn r
gf F ACILITY ENGirlEFRihl Ltm A, L l.'d ' ' " '
uan g,3 i TR C:MPANY MEMORANDUM
C July 8, 1985 ittC MECH J. K. Wood CHIM Covet n.s sus. set Auxiliary Feed Pump Turbine Control Problem During June 9, 1985 Trap (Actton Plan IC) attlam DUE-FILE On July 3,1985 at about 2:45 p.m. I discussed with Brian Young (Equipment Operator during the June 9,1985 reactor trip) the apparent discrepancy between the NRC segunce of events, the alarm typer printout and correla-tion of NRC sequence with the DADS data. The NRC sequence identifies difficulty in control room control of AFPT-2 at 1:53:22.
Note that this difficulty has to rn1ste to manual mode and not the auto-essential mode since the alarm typer printout does not indicate control room attempts at the auto-essential mode.
Through discussions, Brian and I suassarized that at 1:53:22 manual control of AFPT-2 was ng a problem.
In fact, at that time the turbine speed was smoothly increasing once the trip throttle valve was completely opened.
Note that this is supported by the alarm typer printout and the DADS data.
Therefore, it appears that the NRC sequence of events is incorrect in that r
I manual control of AFPT-2 was not a problem at 1:53:22.
Brian further noted that control of ATPT-2 was a problem later in the transient once significant level had been established in steam generator 2.
}{e indicated that he had dif ficulty assuming manual control of ATPT-2 when the indicated level in steam generator 2 was increasing beyond approximately 75 80".
Through a review of the DADS data, we determined this to be at 2:00 - 2:01 time f rame. Further, according to him even the auto-essential level control of ATPT-2 (2:01:11 to 2:01:24) did not show any response in steam generator 2 level. However, the DADS data showed that this auto-control did function correctly (see 2:01:04 to 2:01:19) since the AFPT speed was indeed decreasing because the steam generator level was significantly higher than the level control setpoint. Note that this response may have been somewhat dif ficult to observe on the control room speed indicator.
It is noted that the above dif ficulty in manual control of AFI'T 2 (2:00 -
2:01 time f rame) is again attributed to the AFPT 2 trip throttle valve not being fully open. Per the alarm typer printout this valve was not fully open until 2:01:58 (2:01:52 DADS time).
It is emphasized that while the trip throttle valve was not open enough to enable manual control room control during the 2:00 = 2:01 time frame, it was open enough at 2:01 -
2:02 time frame to enable auto-essential control from the control room.
This is based on the fact that slight movements of the governor valve will be ineffective if the trip throttle valve is not open beyond a certain position. Once the trip throttle valve is open beyond this position, motions of the governor valve will be effective and more limiting in controlling the ATPT. Note that if the control roon " raise-lower" switch FACill1Y ENGINEERING Jw "K
O C e t" 8 V F ri
2-was left in the ' lower' position for a longer duration, the governor valve would have closed further enough to make its position more limiting than the trip throttle valve in controlling the AFPT speed.
The following conclusions and recommendations are drawn f rom the above discussions 1.
The NRC sequence of events (pages 4 and $)'should be revised as f
attached.
6 2.
Action plan 1C should be supplemented with the information contained in this meno regarding auto-essential and manual control of AFPT-2.
Upon your concurrence, I will take steps to revise / supplement Action Plan IC.
Should you have any questions, please do not hesitate to call, se a/10 cci
- 5. R. Beyer
- 5. N. Batch R. J. Gradomski
- 5. G. Wideman B. Young e.
' )
SEOUEtiCE OF EVEliTS 01:50:13 OTSG fl Atmos. Vent Yalve opened, i
01:51:*.7 OTSG SG #1 level falls below eight inches.
j!
t
'01:51:18 P:r. PORV opens (third time) at 2435 psig; did not close.
01:51:33 Obtained flow from startup feed pump to OTSG fl.
01:51: ~2 Operator started to close Pzt. PORY blot # valve at 2140 psig.
.01:51:42 RCS Loop fl reaches a minimum pressure of 2081 psig.
Loop fl T-hot = SBB.6*F; Teve = 587.5*F.
49 Accoustic monitor indicates less than 20". flow through PORV/ block 01:51:
valve.
f 01:52:33 Pzt.-$ pray valIe closed.
01:53:00 RCS loop fl T-hot reaches peak value of 593.5'F.
01:53:22 AN f2 has significant flow, with control locally via the trio throttle valve.)The pump could not be controlled from the control)
,DF,L_11M l
01:52:25 RCS Tave reaches peak ~value of 592.3*F.
01:53:35 OTSG f2 returns to above 960 psig.
01:53 :56 PORY Block Valve, eopened by operator.
01:54:45 OTSG f1 return to above 960 psig.
01:54:46 AW (1 has significant flow, with control locally via the trip i
throttle valve.-
01:56:58 OTSG !2 Atmos. vent open; SG f 2 below 960 psig and decreasing.
01:57:05 SG (1 below 960 psig and decreasing.
Low suction pressure developed on AFW (1; 54 seconds later, suction c01:57:33
,, pressure was recovered.
The cooldown'had 01:53,, Tave restored to normal post-trip temperature. Operators manually started 1
lowered RCS pressure to about 1720 psig.
the HPI pump f1 in the piggyback mode (LPI pump 1 supplying the
- suction to the HP1 pump 1).
A slight amount of water (about 50 gallons) was injecte.
g RCS loop #1 reaches a minimum pressure of 1716 psig.
01:58:08 j
' Loop fl T-hot = 546.6*F; Tave = 546.2'F.
J e
SEOUENCE OF EVENTS 01:58:28 OTSG fl Atmos. vent closed.
c01:58:40 AFP'il suction automatically transferred from the condensate l
storage tank (CST) to the service water system. The operator realigned to CST.
' hen AFP 2 was returned to service, the control room operator controlled the pump in manual rather than returning it to Automatic. (Mio MAT 16 cepitoL lbR.lEFU/ ATTEMP TED FPoM 1: 01
- l1 To 4
Q:o t : 14) l 02:01:13 AFW f2 flow reduced.
i 02:02:27 SG f1 returns to above 950 psig.
1 02:02:30 SG !2 returns to above 950 psig.
j 02:04 Plant conditions essentially stable.
"_M_ ditional Comelications
.)Uhen vacuum was restored and the MSIYs opene
, m:in turbine bypass valves.
t.am The Adequate subcooled margin was available throughout the transient.The Quench
, 1.
Reactor Coolant Pumps..r,gmained in operation.
the discharges from the'PORV.
There is a question on the operability of S/U control valve SP-7A, which
- o
!c 2.
would be used to provide S/U feed pump flow to OTSG #2.
There is a question regarding the operation from the control room of the 3.
atmospheric vent valves.
i The above sequence of events is based upon combining infomation obtained Due to time 4.
from plant computer printouts and operator interviews.
responses of instruments providing input to plant computer systems and.
the inability to obtain the precise time of events from the operator interviews, there is some potential ambiguity in the exact times; however, such ambiguity is not considered to be significant in-understanding the event.
couTRet emon cecsAToR. 6VfERIE.De@ !#FicuLTy W
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Pg 'l z rcm Vo i:s 7:33 tow svar,,u enesaw.r seicias ou>ar<a*s 645Ecakh I.rY4R, Soc 6:u ppun wc R ec0Jre a c
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34 f.>Ermjb3 C.#rge Gu:.7,ow 9/2t, sus W As Rtcovgrt'CA,
SAotSt "T/iG c. TAM AL Aum TYPER PNiN70u r iNDCMrs 4k low Soction Petssues ALAsom Peola lut.S Rtettvtb AT o / 5 7 53 g cLsAnct A7 c/562 7.
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