ML20082C092
| ML20082C092 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 04/04/1995 |
| From: | Stokes K GEORGIA POWER CO. |
| To: | |
| Shared Package | |
| ML20082B958 | List: |
| References | |
| 93-671-OLA-3, OLA-3, NUDOCS 9504060154 | |
| Download: ML20082C092 (6) | |
Text
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NUCLEAR REGULATORY COMMISSION OFFICE OF 5ECPETARY BEFORE THE ATOMIC SAFETY AND LICENSING BdQ@E11NG & i.ERVICE BRANCH In the Matter of Docket Nos. 50-424-OLA-3 GEORGIA POWER COMPANY, at al.
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 OF KENNETH STOKES ON DIESEL GENERATOR AIR QUALITY STATEMENTS r
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21' TESTIMONY OF EENNETE STOKES 2
Q:
PLEASE STATE YOUR NAME AND POSITION.
3 A:.
My name is Kenneth Stokes.
I an a senior. engineer for Georgia
'4 Power Company in the Engineering Support Department of Plant
.5 Vogtle and my office is located on-the Vogtle site.
I have 6'
held this' position since 1989.
i 7'
Q.
WHAT ARE YOUR PROFESSIONAL QUALIFICATIONS?
8 A.
A summary of my professional qualifications is attached hereto 9
as Exhibit A.
i h
10 Q.
WHAT ROLE DID YOU HAVE IN THE REVIEW OF THE DIESEL GENERATORS' 11 INSTRUMENT AIR QUALITY FOLLOWING THE MARCH 20, 1990 SITE AREA 12 EMERGENCY?
i 13 A.
I assisted the Plant Vogtle staff in addressing questions that 14 had arisen concerning the diesels' instrument air quality.
15 Q.
HAVE YOU LISTENED TO THE TAPE RECORDING (TAPE 41) MADE BY MR.
16 MOSBAUGH OF A DISCUSSION ON APRIL 11, 1990 IN WHICH YOU 17 PARTICIPATED?
18 A.
Yes I have.
A copy of the transcript of that discussion is 19 attached to Mr. Bockhold's testimony as Exhibit I (GPC Exh.
l 20 55).
I believe that transcript accurately ~ reflects the 21 discussion.
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1 Q.
WHAT OCCURRED DURING THAT APRIL'11, 1990 DISCUSSION?
2 A.
Mr. Mosbaugh had raised a concern about the quality of the
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'3 diesel generators' instrument air.
A copy of a memorandum he 4
wrote on the subject on April 10, 1990 is attached to Mr.
5 Bockhold's testimony as Exhibit H (GPC Exh. 54).
As the 6
transcript of the discussion indicates, Mr. Bockhold asked the 7
engineers on his staff who were knowledgeable about the diesel 8
generators if there was a problem with the statement that the 9
Company had made to the NRC on April 9,'1990 concerning the 10 diesel air quality.
The statement, included in an April 9 11 letter to NRC, reads:
12 GPC has reviewed air quality of the D/G air system 13 including dewpoint control and has concluded that air 14 quality is satisfactory.
Initial reports of higher than 15 expected dewpoints were later attributed to faulty 16 instrumentation.
This was confirmed by internal 17 inspection of one air receiver on April 6,1990, periodic j
18 replacement of the control air filters which showed no 19 indication of corrosion and daily air receiver blowdowns 20 with no significant water discharge.
21 Eg.g.McCoy Exhibit K (GPC Exh. 13).
22 Q.
WHAT DID YOU CONCLUDE WITH RESPECT TO THE STATEMENT?
23 A.
I concluded that the statement was accurate.
As the 24 transcript of our discussion indicates (Bockhold Exh. I; GPC 25 Exh. 55), we believed that the diesel generators' air quality 26 was acceptable for a number of reasons.
First, on April 6, 27 1990, I participated in the inspection of the 1A diesel air 28 receiver, which showed no sign of unsatisfactory air quality.
29 Second, the diesel instrument air system air filters were 1 4
i 1
inspected in March, 1990 and they looked like new, with no
-l 2
indication of an air quality problem (e.g.,
there was no I
3 evidence of corrosion products on the filters). Third, it was 4
the opinion of the diesel vendor (Cooper) representatives that 5
air quality at Vogtle was not a problem.
Fourth, the diesel 6
air receivers were blown down daily and no appreciable water 7
was discharged during those blow-downs.
- Fifth, a 30
'F 8
depression in dew point occurs in the system 'because the 9
system pressure drops from about 250 psi in the air receiver 10 to 60 psi in the air sensing lines.
11 I was aware that in the May 1988 to May 1989 time frame, 12 when one or more dryers may have been out of service, dew 13 point readings were not good.
However, I and my colleagues 14 believed, based on our collective engineering judgment, that 1
15 this did not affect our conclusion that the current state of 16 the diesel generator instrument air quality was acceptable.
17 Q.
ARE YOU AWARE OF WATER EVER BEING FOUND IN THE DIESEL 18 INSTRUMENT AIR SENSING LINES?
19 A.
No I am not.
However, it is possible that water could leak' 20 into the air sensing lines during testing of those lines 21 (referred to as " bubble testing")
performed periodically 22 during maintenance outages to determine if there are any air 1
23 leaks in the sensing lines.
I am aware of an isolated 24 instance in which water was found in a sensor, but not the 4
'. ~ -
1 sensing line.
The sensor was found in a visibly degraded 2
condition due to corrosion.
i 3
Q.
IS IT POSSIBLE THAT THE MARCH 20, 1990 FAILURE OF THE 1A 4-DIESEL IS ATTRIBUTABLE TO WATER IN EITHER THE AIR SENSING 5
LINES OR THE SENSOR ITSELF7 6
A.
In my opinion, no.
If that were the case, there would have 7
been degradation due to corrosion or corrosion products which 8
would have been obvious during our inspection and testing of 9
the diesel following the March 20 event.
We did not find 10 evidence of corrosion during our inpsection and testing.
11 Q.
WHAT DO BELIEVE TO BE THE CAUSE OF THE MARCH 20, 1990 FAILURE 12 OF THE 1A DIESEL GENERATOR?
13 A.
I believe the cause of the 1A diesel failure on March 20, 1990 14 was poor calibration techniques and debris or contaminants 15 later found in the Calcon sensor instruments, as documented in 16 the report of Wyle Laboratories, dated May 22, 1990, included 17 in Ward Exhibit E (GPC Exh. 63)..
C GPC EXillBIT 58 STOKES EX. A SU10tARY OF PROFESSIONAL QUALIFICATIONS FOR K.C. STOKE 8 Earned a BS Degree in Electrical and Computer Engineering from the University of South Carolina in 1981.
Began work at Georgia Power's Plant Vogtle on June 8, 1981.
Performed various Engineering Technical Reviews including the writing of Construction Acceptance Tests for certain plant equipment. (1981-1983)
As a System Engineer with primary responsibility for the Diesel Generators, completed a Design Review and Quality Revalidation Program on all four diesel generators.
This program involved an essential complete disassembly, inspection and reassembly of each diesel prior to installation, in consultation with other diesel experts.
(1983-1984)
Completed the installation and start-up phase on the Unit i diesels and other systems.
This included verification of proper installation of these systems by construction personnel, writing or reviewing all test procedures and conducting Component Acceptance Testing / Pre-operational Testing prior to turnover to the Operations Staff.
(1984-1986)
Served a short time as a system engineer on Unit 1 during commercial operation, then performed Unit 2
Start-up activities similar to those on Unit 1.
(1986-1989)
System Engineer in Engineering Support Department at Plant Vogtle with primary responsibility for the diesel generators.
(1989-Present) i
.