ML20082B987
| ML20082B987 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 04/04/1995 |
| From: | Stringfellow N External (Affiliation Not Assigned), GEORGIA POWER CO. |
| To: | |
| Shared Package | |
| ML20082B919 | List: |
| References | |
| 93-671-OLA-3, OLA-3, NUDOCS 9504060113 | |
| Download: ML20082B987 (30) | |
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M!1 ARD CORRESPONDENCE USNRC UNITED-STATES OF-AMERICA
'95 llPR -4 All:12 NUCLEAR REGULATORY COMMISSION OFFICi Of SEC3FIARY BEFORE THE ATOMIC SAFETY AND LICENSINd TdhRdl>
" E ICI u R (.% H s
In the Matter of Docket Nos. 50-424-OLA-3 GEORGIA POWER COMPANY, 31 31 50-425-OLA-3 Re: License Amendment (Vogtle Electric Generating Plant, :
(Transfer to Units 1 and 2)
Southern Nuclear)
ASLBP NO. 93-671-OLA-3 PREFILED TESTIMONY i
OF NORMAN JACKSON STRINGFELLOW ON DIESEL GENERATOR REPORTING ISSUES 9504060113 950404
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1 TESTINONY OF NORNAN JACKSON STRINGFELLOW i
2 Q:
PLEASE STATE YOUR NAME FOR THE RECORD.
3 A:
My name is' Norman Jackson (" Jack") Stringfellow.
4 Q:
WHAT POSITION-DID YOU HOLD IN 1990?
5 A:
In 1990, I was employed by' Georgia Power Company as a project i
6 licensing engineer in the Vogtle Project licensing group, 7-working in the Birmingham corporate offices.
My immediate 8
supervisor was Mr. James Bailey, the Licensing Manager for the -
9 Vogtle Project.
10 Q:
WHAT ARE YOUR PROFESSIONAL QUALIFICATIONS?
11 A:
A summary of my professional qualifications is attached hereto 12 as Exhibit A.
13 Q:
DID YOU PARTICIPATE IN THE PREPARATION OF LICENSEE EVENT 14 REPORT ("LER")90-006, WHICH WAS SUBMITTED TO THE NRC ON APRIL 15 19, 1990?
16 A:
Yes I did.
A' copy of that LER is attached to Mr. McCoy's 17 prefiled testimony as Exhibit L (GPC Exh. 14).
l 18 Q:
PLEASE DESCRIBE YOUR INVOLVEMENT IN THE PREPARATION OF LER 90-l 19 006.
20 A:
Working from the corporate office, I interfaced with Mr. Tom f
31 Webb at the Vogtle site, who was the principal draftsman of 22 the LER.
By April 18, 1990, I had received from Tom Webb, the
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- PRB-approved comments on the draft LER.
I had the draft LER 2
retyped, incorporating those comments, and circulated it for 3
review in the corporate office.-
At.that time the draft LER 4
contained the following statement:
5-Numerous sensor calibrations '(including jacket water
)
6 temperatures),
special pneumatic leak
- testing, and 7
multiple engine starts and runs were performed under
.8 various conditions.
Since 3-20-90, DG 1A and DG 1B have 9
been started several times (more than twenty times each) 10 and no failures or problems have occurred during any of 11 these starts. In addition, an undervoltage start test 12 without air roll was conducted on 4-6-90 and DG1A started i
13 and loaded properly.'
14 On April 19, at about 6:30 a.m.
Central' Time, I sent a 15 facsimile.to the site of that same draft LER with comments I 16 had collected from corporate office personnel and had hand-
)
i 17 written on the draft LER.
A copy of that facsimile -is 18 attached hereto as Exhibit B.
The comments I wrote on the 19 draft LER included one from Mr.
Hairston to' " verify >20 20 starts," which meant that site personnel were to verify that 21 the number of diesel starts identified in the language quoted 22 above was in fact greater than 20.
23 Q:
ARE YOU AWARE OF AN APRIL 18, 1990 TELEPHONE CONVERSATION THAT 24 MR. SHIPMAN HAD WITH ALLEN MOSBAUGH CONCERNING DIESEL STARTS 25 INFORMATION?
26 A:
Yes.
Mr. Mosbaugh taped a telephone conversation he had with 27 Mr. Shipman on April 18, 1990 (Tape No. 53).
A transcript of 3
28 The actual PRB-approved language read: "Since 3-20-90, DG 1A 29 and DG 1B have been started more than 20 times each and no failures 30 or problems have occurred during any of these starts." t
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'that conversation is attached hereto as Exhibit C.
'I have 2;
listened to that tape and I believe that transcript accurately ~
? 3' reflects the conversation, which was.about diesel generator 4
'information to be included in the draft LER 90-006.
Mr.
5 Shipman asked Mr. Mosbaugh to assist the. corporate office in 6.
obtaining diesel start information in order' to meet NRC 7
reporting requirements.
I needed diesel starts information i
8 for the period after March 13, 1990 to include in the LER.
9
- However, diesel starts after March 13 had not-yet been 10 incorporated into the plant Diesel Start Log maintained by Mr.
11 Ken Stokes in the Engineering Support Department.
Mr.
12 Mosbaugh said he didn't see a problem with getting the data up 13 through March 20, but that getting it up through April 18 1
14 might be a problem.
15 Q:
HAVE YOU REVIEWED THE TRANSCRIPT OF THE TAPES CONTAINING 16 CONVERSATIONS OCCURRING ON APRIL 19, 1990 (I.E., TAPE NOS. 57 17 AND 58)?
4 18 A:
Yes I have.
Those transcripts are identified as GPC Exhibits 19 1 and 2, respectively.
i 20 Q:
PLEASE EXPLAIN MR. SHIPMAN'S STATEMENT, RECORDED ON TAPE 57 BY l
21 MR. MOSBAUGH ON APRIL 19, 1990, THAT THE DIESEL START LOG ONLY 22 WENT THROUGH APRIL 13.
23 A:
After reviewing the transcript of Tape 57 (GPC Exh. 1), at pp.
24 58-62, and listening to the conversation between Mr. Shipman l
a 1
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'4 1
and Mr.
Mosbaugh on ' April 18 (Tape 53),
I believe the 2
conversation Mr. Shipman was referring to at p. 61, 1.
23 of 3
the transcript of Tape 57, was the one recorded on Tape 53 4
from April 18 and discussed above.
I believe Mr. Shipman i.
5 mispoke in his conversation with Mr. Mosbaugh on April 19.
He 6
should have said, consistent with the conversation on April 7
18, that the Diesel Start Log had not been updated since March j
i 8
13, rather than April 13.
He simply stated the wrong month.
9 In fact, had the Start Log been updated to April 13, then the 10 data necessary to count starts through April 9 would have been 11 available in the Start Log; the conversations on April 19 12 indicate that such data was not available in that log.
13 Q:
DO YOU HAVE ANY INDEPENDENT OR REFRESHED RECOLLECTION TO ADD 14 TO THE INFORMATION CONTAINED IN THE TRANSCRIPTS OF TAPE NOS.
i 15 57 AND 58?
16 A:
For the most part, no.
Mostly all I know now is what is 17 contained in those transcripts.
I do recall the group 18 telephone conference which appears at pp.
7-19 of the 19 transcript of Tape 58 (GPC Exh. 2).
My recollection is that 20 the telephone conference took place in Mr. Shipman's office on 21 the 4th floor of the corporate office.
I believe that Mr.
22 McCoy was at the site or on another phone.
I also remember 23 that Mr. Hairston walked into the conversation after it was 24 already in progress and left before it was over.
Further, I 25 know that the corporate office was dependent on site personnel
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I 1-to verify-thel diesel' start count information.
The corporate.
2:
office did not have diesel start count data and we reasonably 3.
' relied-'on site personnel to gather and. interpret the data.
i 4-Q:
WHAT DID YOU Do WHEN MESSRS. MOSBAUGH AND AUFDENKAMPE INFORMED 5
YOU ON ' APRIL 19,.1990. THAT THERE WERE FAILURES OF THE.1B-
-6 DIESEL AFTER MARCH 20?
7' A:
As the transcript 'of Tape 57 (GPC.Exb,1) reflects,.at pp. 44-i 8
46, 50, I was informed that there had been failures of the 1B 9
diesel after. March 20 and that, in the opinion of Messrs.
'10 Mosbaugh and Aufdenkampe, the draft LER language quoted above 11 constituted a material false statement.
Also, 'I concluded that because the April 9 letter contained a similar statement 13 to the draft LER, it too was inaccurate.
While I do not have 14 a specific recollection of my actions after this call, I 15 believe I
would have passed along to Mr.
Shipman my 16 understanding at the time that the statements.in the draft LER 17 and April 9 letter were inaccurate because of'the fact.that l
18 there were failures of the 1B diesel which occurred after 19 March 20.
20 Q:
WHAT WAS YOUR UNDERSTANDING OF THE ACCURACY OF THE NUMBERS OF 21 DIESEL STARTS THAT WERE SPECIFIED IN THE DRAFT LER?
22 A:
As the transcript of Tape 57 (GPC Exh. 1) states, at pp. 50-23 51, I understood that Messrs. Mosbaugh and Aufdenkampe had 24 assigned Messrs. Odom and Webb to count diesel starts from the,
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.1 Control Log and that their work was not complete at that point 2'
in time.
Therefore, it had not been determined that the 3
numbers of starts were inaccurate.
4 Q:
WHAT ELSE TRANSPIRED DURING THE DISCUSSION BETWEEN MESSRS.
5 MOSBAUGH AND SHIPMAN IN WHICH YOU PARTICIPATED ON APRIL 19 AND 6
WHICH APPEARS ON THE TAPE 57 TRANSCRIPT AT PP.58-627 7
A:
Although I do not recall that discussion specifically, I know 8
from the transcript that I did participate in at least some 9
portion of it (agg GPC Exh.
1, Tr. 60-62).
The transcript 10 indicates to me that Mr. Shipman and I were attempting to get 11 help from Mr.
Mosbaugh and his staff, on whom we were 12 dependent, to ensure that only correct information was 13 included in LER 90-006.
We were troubled by what had 14 transpired because we knew that the PRB approved the draft LER 15 the day before.
Even though Mr. Mosbaugh was a voting member 16 in that PRB meeting, he said he wasn't sure the diesel starts 17 statement was in the drafts of the LER reviewed by the PRB.
18 Mr. Mosbaugh proceeded to tell us that he had a tabulation of 19 diesel starts prepared by a
Plant Vogtle engineering 20 supervisor, Paul Kocnery, which was also provided to the NRC 21 Incident Investigation Team. While I do not believe that this 22 list was provided to the corporate office on April 19, 1990, 23 the list that was prepared by Mr. Kochery and provided to the 24 IIT on April 6, 1990 is attached to Mr. McCoy's testimony as 25 Exhibit F (GPC Exh. 8).
The starting point (March 13) and 8:
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ending point '(March 23) of that list fits Mr..Mosbaugh's' 2
description ~on Tape 57_of the information'.
Because theLlist.
.3 only went through March' 23, it'was not sufficient to determine 4
the ' accuracy of.the numbers of - diesel starts that were-
-l 5 reported in the April 9 letter or in the' draft LER.
- However,
.6 the list did-include information concerning two failures of 7
- the1B diesel which Mr. Mosbaugh had identified to me and Mr.
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8 Shipman.
Towards the end of the conversation, Mr. Mosbaugh j
9 agreed to go off and verify the data with Paul Kochery.
10 Q:
HAVE'YOU LISTENED TO PORTIONS OF TAPE 58?
11
.A:
Yes.
I have listened to.the portion of that tape which.
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12 appears-at p.
11 (1. 20) to p.
14 (1. 27) of the transcript.
13 (GPC Exh. 2).
While I have listened to it a number of times, f
14 I cannot understand, and do not recall, precisely what was L15 said.
l l
16 Q:
DO YOU AGREE WITH THE INTERVENOR'S VERSION' OF THIS 17 CONVERSATION WHICH IS IDENTIFIED AT P.
14, LL. 7-27 OF THE j
18 TAPE 58 TRANSCRIPT?
j 19 A:
No.
Based on what I have read in the transcript leading up to 20 that conversation, I
believe the participants to the l
21 conversation had agreed that the revised language inserted 22 into LER 90-006, which appears on p. 6 of the final signed LER.
23 (McCoy Exh. L; GPC Exh.14), was accurate, based on assurances i
24 we received from Mr. Bockhold.
That is, we believed there 7-i i
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'were no failures subsequent to the comprehensive. test program 2
and that the numbers of starts were accurate.. Of-course, we j
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were' aware that there had been-some' failures of the 1B diesel f
4
'early on and believed that the'NRC was also aware of those
-5 failures.
Of the three versions of that conversation which-6 appear in the transcript, I believe that Georgia ' Power's -
7 version (GPC Exh. 2, p. 11, 1. 23 to p. 13, l. 11).is the most
'8 accurate.. It is clear on the t' ape that Mr.~Hairston asked "We 9
got the starts,.so we didn't have no didn't have no 10 trips?"
Mr. Shipman can then be heard to say "No, not 11 not...."
I do not know whether he was responding to Mr.
- i 12 Hairston or reacting to other statements which can be heard on 13 the tape but which cannot be understood.
I do.not hear Mr.
14-McCoy say "I'll testify to that'. "
I also do not hear Mr.
15 Shipman say." disavow" or "just disavow;" that is not the sort 16 of thing that he would typically say.
Moreover, whatever Mr.
l 17 Shipman said would have been. consistent with other statements l
18 that he.made on that tape which indicate his desire to ensure 19 that the statements in the LER are accurate and that the NRC 20 was not mislead.
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21 Q:
WHAT WAS YOUR UNDERSTANDING OF THE COMPLETION OF THE 22 COMPREHENSIVE TEST PROGRAM DESCRIBED IN LER 90-006?
i 23 A:
As reflected in the transcript of Tape 58 (GPC Exh. 2), at p.
l 24 22-27, based on statements made by George Bockhold earlier r
25 that day, I heard statements of the basis for the 18'and 19 t
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1 numbers which were referenced in the April 9 letter (McCoy 2
Exh. K; GPC Exh. 13).
That is, the transcript reflects that 3
I was present during a discussion that there was a string of 4
18 and 19 successful starts without failures on the 1A and IB 5
diesels, respectively, which occurred after what was described 6
as the completion of the cocprehensive test program of the 7
control systems of the diesel generators.
Based on the 8
discussions which appear at pp. 22-26 of the transcript of 9
Tape 58 (GPC Exh. 2) among Messrs. Shipman, Mosbaugh and 10 Aufdenkampe, to which I listened from Mr. Shipman's office 11 that day, I heard that the string of successful diesel starts 12 occurred after the problems had been worked out of the diesels 13 (i.e.,
after the last failure).
This string of successful 14 starts was also described in that discussion as occurring 15 after the final calibrations of the Calcon sensors.
As the 16 transcript also reflects (GPC Exh.
2, pp.
26-27),
I was 17 informed by Messrs. Aufdenkampe and Mosbaugh that they had 18 data, which I did not see, that they said did not call into 19 question the above-described information.
In summary, based 20 on the input I received on April 19, 1990 from site personnel, al on which I relied, I believed the final signed LER was 22 accurate.
23 Q:
WHY DIDN'T LER 90-006 EXPLAIN WHAT WAS MEANT BY THE 24 COMPREHENSIVE TEST PROGRAM AS YOU UNDERSTOOD IT?
25 A:
The transcript of Tape 58 (GPC Exh. 2), at p. 28-29, indicates 1
that it'was Mr. Shipman's understanding at the time that Mr.
2 McCoy had spoken with the NRC's Mr.
Brockman about "the 3
[ diesel start) numbers and what the basis of the numbers was
.4-e,s George Bockhold described it."
It was, therefore, my 5
understanding that the NRC understood what was meant by the 6
reference to the comprehensive test program and no explanation 9
7 of that was necessary in the LER.
8 Q:
WHY WASN'T THE INACCUF?.CY IN THE DIESEL STARTS STATEMENT OF 9
THE APRIL 9 LETTER CORRECTED WHEN IT WAS DISCOVERED ON APRIL 10 19, 1990?
11 A:
As discussed above, I believed that the April 9 letter was 12 inaccurate because there were failures of the 1B diesel which 13 had occurred after March 20, 1990.
It was my understanding 14 that the final signed LER corrected the statement in the April 15 9 letter and that no further action was necessary.
That is, 16 the LER statement made clear that the 18 diesel starts 17 occurred after all of the bugs had been worked out of the 18 diesels.
Further, based on the discussions appearing in the 19 transcript of Tape 58 (GPC Exh. 2), at pp. 28-29, it is'my 20 understanding that Mr.
McCoy discussed the diesel start 21 information with Mr. Brockman on April 19, 1990 so that there 22 was no misunderstanding concerning the statement in the April 23 9 letter.,
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-1 Q:
- WHEN.WERE YOU ADVISED THAT THE FINAL SIGNED LER 90-006 WAS' i
- 2 INACCURATE AND NEEDED TO'BE REVISED?
s 3<
A:
- I received a telephone call from Mr. Tom Webb within a week' or.
j 4-two after April 19, 1990.
.He advised me that the number of 5
diesel starts. reported in LER 90-006 may be inaccurate-and-6 that. site personnel lwere in the process of determining thel 7
correct-numbers.
1 8
Q:
WHY DIDN'T YOU-TAKE IMMEDIATE ACTION TO ENSURE THAT THE NRC 9
WAS AWARE OF'THE INACCURATE DIESEL' START INFORMATION IN LER 10 90-006?
i 11 A:
At the time, I didn't view it as something that required
[
12 immediate notification to the NRC.
I viewed it as a revision 13 to an LER which did not involve significant public health and 14 safety issues and did not have a specific deadline.
Because 15 I had a lot of other work that did have~ specific deadlines,.
16 the LER revision was a lower priority to me.
As a result of
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17' this proceeding and the related enforcement action, I am more.
18 sensitive to potential issues involving 10 C.F.R.
S 50.9..
19 Today, I believe I would ask more questions (although I don't 20 recall what questions I may have asked in 1990) to ensure that 21 there wasn't a violation of Section 50.9.
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Q:
WERE YOU INVOLVED IN THE PREPARATION OF GEORGIA POWER'S AUGUST 2
30, 1990 LETTER TO NRC (McCOY EXH. P; GPC EXH. 18)?
3 A:
Yes.
Principally, I relied on information that I received 4
from Messrs. Mark Ajluni, Georgie Frederick, Paul Rushton and l
l 5
Ken McCoy.
However, I also used the June 29, 1990 QA audit 6-report (McCoy Exh. M; GPC Exh. 15) to prepare an initial list 7
of diesel starts.
Ultimately, the tables included in the 8
August 30 letter were prepared by Mr. Mike Horton at the 9
Vogtle site.
f l - _ _ _ - _ _ _ _ _ - _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
GPC EXHIBIT 24 STRINGFELLOW EX. A
SUMMARY
OF PROFESSIONAL QUALIFICATIONS NORMAN JACKSON (JACK) STRINGFELLOW Formal Education:
09/77 - 12/78 Auburn University -- Master of Engineering, Mechanical Engineering 09/72 - 08/77 Auburn University - Bachelor of Engineering, Mechanical Engineering Work History:
10/88 - Present Project Licensing Engineer. Vogtle Project - Licensing Responsible for processing general correspondence with the NRC (e.g., Licensee Event Reports (LERs), proposed amendments to the operating licenses, replies to Notices of Violation, Special Reports, etc.) and other communications with NRC's Office of Nuclear Reactor Regulation.
07/84 - 09/88 Senior Licensing Engineer Southern Company Services, Inc.
Responsible for development of Vogtle Electric Generating Plant (VEGP) Unit 1 Technical Specifications (TS); day-to-day licensing activities relative to obtaining the VEGP Unit 1 operating license; safety evaluation review and preparation and development of proposed amendments for the Farley Nuclear Plant.
07/82 - 06/84 Licensing Engineer I Southern Company Services, Inc.
Responsible for development of VEGP Unit 1 TS; attended VEGP Operating Training Course at VEGP site; preparation of Hatch Unit I and Unit 2 initial Final Safety Analysis Report (FSAR) updates.
06/80 - 06/82 Licensing Engineer II Southern Company Services, Inc.
Responsible for preparation of initial Hatch Unit I and Unit 2 FSAR updates.
10/78 - 06/80 Southern Research Institute Responsible for obtaining thermal and mechanical properties of materials.
GPC EXHIBIT 25 STRINGFELLOW EX. B l
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On 3-20-90, Unit I was in a refueling outage and Unit 2 was operating at 100%
power. At 0820 C ET, the driver of a fuel truck in the switchyard backed into a support for the phase "C" insulator for the Unit 1 Reserve Auxiliary Transformer (RAT) 1A. The insulator and line fell causing a phase to ground fault. Both Unit 1 RAT 1A and Unit 2 RAT 28 High Side and Low Side breakers tripped, causing i loss of offsite power condition (LOSp). Unit 1 Diesel Generator (DG) 1A and Unit 2 DG2B started, but DGIA tripped, causing a loss of residual heat rem> val (RHR) to the reactor core since the Unit 1 Train B RAT and DG were out of se1vice for maintenance. A Site Area Emergency (SAE) was declared and the lite Emergency Plan was implemented. The core heated up to 136 degrees F from go degree F before the DG was emergency started at 0856 CST and RHR was restored.1 At 0915 CST, the SAE was downgraded to an Alert after onsite power was restored.
2 The direct cause of this series of events was a cognitive personnel error. The truck driver failed to use proper backing procedures and hit a support, causing the phase to ground fault and LOSP. The most probable cause of the DGIA trip was the intermittent actuation of the DG jacket water temperature switches.
Corrective actions include str thening policies for control of vehicles, extensive testing of the DG, epla:ementofsuspectDGtemperatureswitches[
O&inpn#1eds in Mr EAW dt*1 -
92 PRCMECT c57934 y-
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A.
REQUIREMENT FOR REPORT i
. 1 This event is reportable per: a) 10 CFR 50.73 (a)(2)(tv), because an unplanned Engineered Safety Feature (ESF) actuation occurred when the ESF Actuation System Sequencer started, and b) Technical Specification 4.8.1.1.3, because a valid diesel generator failure occurred. Additionally, this report serves as a summary of the Site Area Emergency event.
i B.
UNIT STATUS AT TIME OF EVENT Unit I was in. Mode 6 (Refueling) at 05 rated thermal power. The reactor had been shut down since 2-23-90 for a 45 day scheduled refueling outage..The reactor core reload had been completed, the initial tensioning of the reactor vessel head studs was complete, and the outage team was awaiting permission from the control room to begin the final tensioning. Reactor Coolant System (RCS) level was being maintained at mid-loop with the Train A i
Residual Heat Removal (RHR) pump in service for decay heat removal. The temperature of the RCS was being maintained at approximately 90 degrees F.
Due to the refueling outage maintenance activities in progress, some equipment was out of service and several systems were in abnonnal configurations. The Train B Diesel Generator (DG1B) was out of service for a required 36 month maintenance inspection. The Train B Reserve Auxiliary Transformer (RAT 18) had been removed from service for an oil change.
~i The Train B Class IE 4160 Volt switchgear, IBA03, was being powered from the Train A RAT 1A through its alternate supply breaker. All non-lE switchgear was being powered from the Unit Auxiliary Transformers (UAT) by backfeeding from the switchyard. All Steam Generator (S/G) nozzle dans had been removed, but only S/G's 1 and 4 had their primary manways secured.
Maintenance personnel were in the process of restoring the primary manways on S/G's 2 and 3.
RCS level was being maintained at mid-loop for valve repairs and the S/G manway restorations. In addition, the pressurizer aanway was removed to provide an RCS vent path.
C.
DESCRIPTION OF EVENT on March 20, 1990, at approximately 0817 CST, a truck driver with a security escort entered the protected area in a fuel truck. Although not a member of the plant operating staff, the driver was a Georgia Power Company employee belonging to a service group used to perform various plant services. The driver checked the welding machine that was in the area and found that it did not need fuel. He returned to the fuel truck and was in the process of i
backing out of the area when he hit a support holding the phase "C" insulator for RAT 1A. The insulator and line fell causing a phase to ground fault, and the transformer tripped.
92 PRGIECT os7p35
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At 0820 CST, both Unit 1 RAT 1A and the Unit 2 RAT 28 High Side and Low Side breakers tripped causing a loss of offsite power condition (LOSP) to the Unit 1 Train A Class IE 4160 volt Bus IAA02, the Unit 2 Train 8 Class IE Bus 28A03, and the 480 volt busses supplied by 1AA02 and 2BA03. The Unit 1 Train B Class IE 4160 volt bus 18A03 also lost power since RAT 1A was feeding both Trains of Class IE 4160 volt busses. The loss of power caused the associated ESF Actuation System Sequencers to send a start signal to one Unit I and one Unit 2 Diesel Generators. DGIA and DG2B started and sequenced the loads to their respective busses. Further description of the Unit 2 response to this event is provided in LER 50-425/1990-002.
~
One minute and twenty seconds after DGIA started and sequenced the loads to the Class IE bus, the enqine tripped. This again caused an undervoltage (UV) condition to class LE bus IAA02. The UV signal is a maintained signal at the sequencer. However, since DGIA was coasting down from the trip, the shutdown logic did not allow the DG fuel racks or starting air solenoids to open and start the engine. This properly caused the engine starting logic to lock up, a condition that existed until the UV signal was reset. For this reason, DGIA did not automatically re-start after it tripped.
After the trip, operators were dispatched to the engine control panel to investigate the cause of the trip.
According to the operator, several 4.y annunciators were lit. Without fully evaluating the condition, the
)andaPlantEquipmentOperator(PEO)wenttothesequencerpaneltoDuring this time, operator reset the annunciators.
determine if any problems were present on the 1A sequencer. The SS pushed the UV reset button, then reset the sequencer by doenergizing and energizing the power supply to the sequencer. This caused the DG air start solenoid to energize for another 5 seconds which caused the engine to start. This happened lg minutes after the DG tripped the first time. The engine started and the sequencer sequenced the available loads as designed. After 1 minute and 10 seconds, the breaker and the engine tripped a second time. It did not automatically re-start due to the starting logic being blocked.as described above. By this time, operators, a maintenance foreman and the diesel generator vendor representative were in the DG room. The initial report was that the jacket water pressure trip was the cause of the, trip.
The maintenance foreman and vendor representative observed that the jacket water pressure at the gauge was about 12-13 PSIG. The trip setpoint is 6 PSIG and the alarm setpoint is 8 PSIG. Also, the control room observed a lube oil sensor malfunction alarm.
32 PfKMECT c57934
e At 0820 CST, both Unit 1 RAT 1A and the Unit 2 RAT 28 High Side and Low Side breakers tripped causing a loss of offsite power condition (LOSP) to the Unit 1 Train A Class IE 4160 volt Bus 1AA02, the Unit 2 Train 8 Class 1E Bus 28A03, and the 480 volt busses supplied by 1AA02 and 28A03. The Unit 1 Train 8 Class IE 4160 volt bus 18A03 also lost power since RAT 1A was feeding both Trains of Class IE 4160 volt busses. The loss of power caused the associated ESF Actuation @ tee Sequencers to send a start signal to one Unit I and one Unit 2. Diesel Generators. DG1A and DG28 started and sequenced the loads to their respective busses. Further description of the Unit 2 response to this event is provided in LER 50-425/1990-002.
One minute and twenty seconds after DG1A started and sequenced the loads to the Class 1E bus, the engine tripped. This again caused an undervoltage (UV) condition to class IE bus 1AA02. The UV signal is a maintained signal at the sequencer. However, since DGIA was coasting down from the trip, the shutdown logic did not allow the DG fuel racks or starting air solenoids to open and start the engine. This properly caused the engine starting logic to lock up, a condition that existed untti the UV signal was reset. For this reason, DGIA did not automatically re-start after it tripped.
After th p, operators were dispatched to the emine control panel to investd he cause of the trip.
According to t3e operator, several j
Mgcg annun at re lit. Without full evaluating the condition, the p4N g opera o et the annunciators.
ring this time, a Shift Supervisor M
1 (SS) nd a lant Equipment Operator (PE0) went to the sequencer panel to
[ #
date if any problems were present on the 1A sequencer. The SS pushed i
the UV reset button, then reset the sequencer by deenergizing and energizing l
the power supply to the sequencer. This caused the DG air start solenoid to energize for another 5 seconds which caused the engine to start. This happened 19 minutes after the DG tripped the first time. The engine started
.i and the sequencer sequenced the available loads as designed. After 1 minute and 10 seconds, the breaker and the engine tripped a second time. It did not automatically re-start due to the starting logic being blocked as described above. By this time, operators, a maintenance foreman and the diesel generator vendor representative were in the DG roce. The initial report was that the jacket water pressure trip was the cause of the trip.
The maintenance foreman and vendor representativo observed that the jacket water pressure at the gauge was about 12-13 PSIG. The trip setpoint is 6 i
PSIG and the alarm setpoint is 8 PSIG. Also, the control room observed a lube oil sensor malfunction alarm.
92 PRCMECT c57937
)
F 1
Fifteen minutes after the second DGIA trip, DGIA was started from the engine control panel using the enerpency start breakglass button. The engine.
started and loads were manua ly loaded. When the DG is started in the emergency mode, all the trips except four are bypassed. However, all alarms will be annunciated. During the emergency run, no trip alarms were noticed by the personnel either at the contro' room or at the engine control panel.
1 The only alarms noted by the control room operator assigned for DG operation were lube oil pressure sensor malfunction and fuel oil level high/ low alarm.
At 1040 CST, RAT 18 was energized to supply power.to 4160 volt bus 18A03.
DGIA supplied power to 4160 volt bus IAA02 until 1157 CST, at which time bus
)
1AA02 was tied to RAT IB.
j A Site Area Emergency was declared at 0840 CST, due to a loss of all offsite and onsite AC power for more than 15 minutes. The Emergency g'
- 4 Director signed the notification form used to inform offsite government agencies of the emergency at 0848 CST and notifications began at 0857 CST. y7e Due to the loss of power, which rendered the primary Emergency Notification <.pi',
.w g,-j Network (ENN) inoperable, and some mis-communication, the initial M
\\r notification was not received by all agencies until 0935 CST.
The Emergency Director instructed personnel to complete various tasks for restoring containment and RCS integrity. A11' work was accomplished and maintenance personnel exited containment by 1050 CST.
The SAE was downgraded to an Alert Emergency at 0g15 CST after restoration of core cooling and one train of electrical power. By 1200 CST, plant M conditions had stabilized withActh trains of electrical power being suppited fromeoffsite source ( (RAT 18).
After discussions with the NRC and local government agencies, the emergency was terminated at 1247 CST and all agencies were notified by 1256 CST.
j D.
CAUSE OF EVENT 92 PRCMECT c5793e Di act Cause:
1.
The direct cause of the loss of offsite Class IE AC power was the fuel truck hitting a pole supporting a 230kV line for RAT 1A. This was a cognitive personnel error on the part of the truck driver. There were no unusual characteristics of the work location that directly contributed to this personnel error.
2.
The direct cause of the loss of onsite Class 1E AC power was the failure of the operable DG, DGIA, to start and load the LOSP loads on buss IAA02.
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92 PRCUECT 057939
1 Fifteen minutes after the second DGIA trip, DGIA was started from the engine control panel using the enerpency start breakglass button. The engine started and loads were manua ly loaded. When the DG is started in the j
emergency mode, all the trips except four are bypassed. However, all alarms will be annunciated. During the emergency run, no trip alarms were noticed by the personnel either at the control room or at the engine control panel.
The only alams noted by the control room operator assigned for DG operation were lube oil pressure sensor malfunction and fuel oil level high/ low alam.
At 1040 CST, RAT IB was energized to supply power to 4160 volt bus IBA03.
DGIA supplied power to 4160 volt bus 1AA02 until 1157 CST, at which time bus 1AA02 was tied to RAT 18.
~
A Site Area Emergency was declared at 0840 CST, due to a loss of all offsite and onsite AC power for more than 15 minutes. The Emergency Director signed the notification form used to inform offsite government agencies of the emergency at 0848 CST and notifications began at 0857 CST.
Due to the loss of power, which rendered the primary Emergency Notification Network (ENN) inoperable, and some mis-communication, the initial notification was not received by all agencies untti 0935 CST. -::ix;;rt
-neMBeeMene-were-eedowMheeH f fi.,.
The Emergency Director instructed personnel to complete various tasks for restoring containment and RCS integrity. All work was accomplished and maintenance personnel exited containment by 1050 CST.
The SAE was downgraded to an Alert Emergency at 0915 CST after restoration of core cooling and one train of electrical power. By 1200 CST, plant conditions had stabilized with both trains of electrical power being supplied from offsite sources (RAT 18).
After discussions with the NRC and local government agencies, the emergency was terminated at 1247 CST and all j
agencies were notified by 1256 CST.
D.
CAUSE OF EVENT Direct Cause:
1.
The direct cause of the loss of offsite Class 1E AC power was the fuel truck hitting a pole supporting a 230kV line for RAT 1A. This was a cognitive personnel error on the part of the truck driver. There were no unusual characteristics of the work location that directly contributed to this personnel error.
2.
The direct cause of the loss of onsite Class IE AC power was the failure of the operable DG, DGIA, to start and load the LOSP loads on buss 1AA02.
92 PRCMECT 05794o
.I M
$*Y' Y Y*
fW d4fss
\\
Root Cause:
I 1.
The truck driver met all current site training and qualification requirements, including holding a Class 2 Georgia driver's license.
p' A[However, site safety rules, which require a flagman for backing vehicles when viewing is impaired, were violated.
,A 2.
The root cause for the failure of DGIA has not been conclusively determined. There is no record of the trips that were annunciated after the first trip because the annunciators were reset before the condition was fully evaluated. Therefore, the cause of the first trip can only be postulated, but it was most likely the same as that which caused the second trip. The second trip occurred at the end of the timed sequence of the group 2 block logic. This logic allows the DG to achieve operating conditions before the trips become active. The block logic timed out and the trip occurred at about 70 seconds. The annunciators observed at the second trip included jacket water high temperature along with other active trips. In conducting an investigation, the tria conditions that were observed on the second DG trip on 3-20-90 could be duplicated by venting 2 out of 3 jacket water temperature sensors, simulating a tripped condition. The simulation duplicated both the annunciators and the 70 sec. trip time. The most likely cause of the DG trips was intemittent actuation of the jacket water temperture switches.
Following the 3-20-90 event, all three jacket water temperature switches, which all have a design setpoint of 2000F, were bench tested.
Switch TS-19110 was found to have a setpoint of 197 degrees F, which was approximately 6 degrees below its previous setting. Switch 15-19111 was found to have a setpoint of 199 degrees F, which was approximately the same as the original setting. Switch TS-19112 was found to have a setpoint of 186 degrees F, which was approximately 17 degrees F below the previous setting and was re-adjusted. Switch TS-19112 also had a small leak which was judged to be acceptable to support diagnostic engine tests and was reinstalled. The switches were recalibrated with the manufacturer's assistance to ensure a consistent calibration technique.
During the subsequent test run of the DG on 3-30-90, one of the switches (TS-19111) tripped and would not reset. This appeared to be an intermittent failure because it subsequently mechanically reset.
This switch and the leaking switch (TS-19112) were replaced with new switches. All subsequent testing was conducted with no additional problems.
4 92 PRCUECT 057941
,--.n.
4.
i A test of the jacket water system temperature transient during engine starts was conducted. The purpose of this test was to determine the actual jacket water temperature at the switch locations with the engine in a normal standby lineup, and then folloud by a series of starts without air rolling the engine to repli,cate the starts of 3-20-90. The test showed that jacket water temperature at the switch location decreased from a standby temperature of 163 degrees F to approximately i
156 degrees F and remained steady.
Numerous sensor calibrations (including jacket water temperatures),
special pneumatic leak testing, and multiple engine starts and runs were performed under various conditions. Since 3-20-90 DGIA and DGlB 20M have been started several times (more than twenty times each) and no 7
failures or problems have occurred during any of these starts. In addition, an undervoltage start test wit 3out air roll was conducted on 4-6-90 and DGIA started and loaded properly.
Based on the above facts, it is concluded that the jacket water high temperature switches were the most probable cause of both trips on 3-20-90.
E.
ANALYSIS OF EVENT The loss of offsite power to Class IE bus IBA03 and the failure of DGIA to start and operate successfully, coupled with DG1B and RAT 1B being out of service for maintenance, resulted in Unit 1 being without AC
>ower to both Class IE busies. With both Class IE busses deenergized, the RHR System could not perfom its required safety function. Based on a noted rate of rise in the RCS temperature of 46 degrees F in 36 minutues, the RCS water would not have been expected to begin boiling untti approximately I hour and 36 minutes after the beginning of the event.
Restoration of RHR and closure of the containment equipment hatch were completed well within the estimated I hour and 36 minutes for the projected i
onset of boiling in the RCS. A review of infomation obtained from the Process and Effluent Radiation Monitoring System (PERNS) and grab sample analysis indicated all normal values. As a result of this event, no increase in radioactive releases to either the containment or the environment occurred.
e2PguECT W
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1 Additional systems were either available or could have been made available to ensure the continued safe operation of the plant:
1.
The maintenance on RAT IB was completed and the RAT was returned to service approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> into the event.
i 2.
Offsite power was available to non-1E equipment through the generator step-up transformers which were being used to "back-feed
- the Unit and supply the non-1E busses. Provided Auxiliary Transformers (UAT)lt was cleared, Class 1E busses IAA02 and that the phase to ground fau 1BA03 could have been powered by feeding through non-1E bus INA01.
3.
The Refueling Water Storage Tank could have been used to manually j
establish gravity feed to the RCS to maintain a supply of cooling water i
to the reactor.
Consequently, neither plant safety nor the health and safety of the public i
was adversely affected by this event. A more detailed assessment of this event and an assessmen the event had it occurred under more severe circumstances will be rformed and included in a supplemental LER.
F.
CORRECTIVE ACTIONS 1.
A management policy on control and operation of vehicles has been established.
2.
Temporary barricades have been erected with signs which direct authorization for control of switchyard traffic to the SS.
3.
The Loss of Offsite Power (LOSP) diesel start and trip logic has been modified on Unit I so that an automatic " emergency" start will occur upon LOSP. Therefore, non-essential diesel engine trips are blocked upon LOSP. The Unit 2 DG's will be modified by 4-30-90.
4.
The DG1A test frequency was increased to three times per week until 4-20-90 when the test frequency will be changed to once every 7 days in accordance with Technical Specification Table 4.8-1.
This frequency E
will be continued until 7 consecutive valid tests are completed with no 1
more than one valid failure in the last 20 valid tests. Including the t
two valid failures of this event, there have been a total of four valid u
failures in 69 valid tests of DGIA as of 1157 CST on 3-20-90.
g The defective DG temperature switc
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6.
A back-up ENN system powered from the AT&T system,'which previously existed and was operational for South Carolina agencies, has been added to Georgia local and' state agencies. Shift personnel have been instructed concerning emergency communications systems and their power supplies.
7.
Further corrective actions will be addressed in a supplemental LER.
I G.
ADDITIONAL INFORMATION 1.
Failed Components:
Jacket Water High Temperature Switches manufactured by California Controls Company, Model #A-3500-W3 2.
Previous Similar Events:
None i
3.
Energy Industry Identification System Code:
Reactor CoolaK System - AB Residual Heat Renoval System - 8
' Diesel Generator Lube 011 System - LA Diesel Generator Starting Air System - LC Diesel Generator Cooling Water System - LB Diesel Generator Power Supply System - EK Safety Injection System - BQ 13.8 kV Power System - EA 1460 volt non-1E power system - EA 1460 volt Class-1E power system - EB Chemical and Volume Control System - CB Containment Building - NH 480 volt Class 1E Power System - ED Engineered Safety Features Actuation System - JE Radiation Monitoring Systes - IL 9
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~
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& M4 m,y ff, Further corrective actions will be addressed in a supplemental LER.
G.
ADDITIONAL INFORMATION 1.
Failed Components:
Jacket Water High Temperature Switches manufactured by California
)
Controls Company.
Model fA-3500-W3 2.
Previous Similar Events:
None T
3.
Energy Industry Identification System Code:
Reactor Coolant System - A8 Residual Heat Removal System - 8 Diesel Generator Lube 011 System - LA Diesel Generator Starting Air Systew - LC t
Diesel Generator Cooling Water System - L8 Diesel Generator Power Supply Systes - EK Safety Injection System - 84 l
13.8 kV Power System - EA 1460 volt non-lE power system - EA 1460 volt Class IE power system - E8 Cheetcal and Volume Control System - C8 Containment Building - NH 480 volt Class IE Power System - ED Engineered Safety Features Actuation Systes - JE Radiation. Monitoring System - IL 92 PROJECT 057945
e, GPC EXHIBIT 26 STRINGFELLOW EX. C
\\
)
1 1
l 2
1 3
l 4
5 6.
7 8
9 10 Transcript of audiotape No. 53, 11 transcribed by Judy J. Bragg, Certified Court 12 Reporter and Notary Public.
1 13 14 15 16 17 18 19 20 i
21 22 23 BROWN REPORTING, INC.
24 1100 SPRING STREET, SUITE 750 ATLANTA, GEORGIA 30309 25 (404) 876-8979
~
7 (APPROXIMATELY 70% THROUGH SIDE B) 1 MOSBAUGH:
Bill, what can I do for you?
2 SHIPMAN:
We are trying to, as you know, 3
to get these two LER's out (inaudible) the LER on the event.
I understand 4
from Jack that we are using an LER as a report of a 5
valid diesel generator failure as well as LER.
6 MOSBAUGH:
That's right, the LER on the 7
50.73 reportability requirements.
8 SHIPMAN:
Right.
To do that, the report 9
requires us to submit the number of diesel generator 10 tests, valid tests in the last 100 tests.
11 MOSBAUGH:
Right.
There is a statement 12 to that effect in the Corrective Action section.
13 SHIPMAN:
The problem that Jack (Stringfellow) has is 14 that we don't have any records in the diesel 15 generator log of the tests that were conducted after 16 the 13th of March.
17 MOSBAUGH:
'I think there were so many 18 starts and tests and all that that I know the one log 19 that we track that with down here has not had time 20 to catch up yet, but there are records of all the 21 starts and they're tabulated in a couple of different 22 places.
23 SHIPMAN:
But they are not included in 24 this LER.
25 MOSBAUGH:
I think that's true, but I
8 1
think they were going to get a look at that, or when the 2
PRB reviewed that, that was a PRB comment.
3 SHIPMAN:
The information Jack has got 4
was that we can't get that, you know, we are not 5
going to have that, and I don't really see how we 6
are going to meet our reporting requirement unless 7
we have that information in this LER, do you?
8 MOSBAUGH:
Well, thi only issue would be, 9
it obviously needs to be contained in the LER.
But 10 the only question would be up to what date and 1:
effective what date.
12 SHIPMAN:
But we are reporting a failure 13 on the 20th.
So --
14 MOSBAUGH:
Right.
It certainly needs to 15 be up through then.
16 SHIPMAN:
All right.
I think if we can 17 just say through the 20th --
18 MOSBAUGH:
Through the 20th, that's no 19 problem at all.
20 SHIPMAN:
Apparently it is from somebody, 21 and that's why I called you for some help.
22 MOSBAUGH:
I don't think that's a problem 23 at all.
Let me find out why that's a problem for 24 anybody.
I think it becomes more difficult to make 25 statements, you know, up to today.
4.
e i
9 1
SHIPMAN:
Right.
I understand.
What we 2
can do, you know, on the LER is, we can say through 3
the 20th.
4 NOSBAUGH:
I see where that should be no 5
difficulty at all.
SHIPMAN:
Would you see.
MOSBAUGHz I will get that fixed, and I 6
will have Aufdenkampe call information or 7
confirmation back to Stringfellow.
8 SHIPMAN:
Great.
I appreciate it Allen.
i 9
MOSBAUGH:
Okay.
10 SHIPMAN:
Bye.
i 11 NOSBAUGH:
Bye.
12 j
13 (End of Tape No. 53, Side B).
14 15 16 l
17 l
18 19 20 21 22 23 24 25
...