ML20132C359
| ML20132C359 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 09/20/1985 |
| From: | Jens W DETROIT EDISON CO. |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| RC-LG-85-0048, RC-LG-85-48, NUDOCS 8509270020 | |
| Download: ML20132C359 (12) | |
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September 20, 1985 operssons RC-LC-85-0048 Director of Nuclear Reactor Regulation Mr.
B.
J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U.
S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Youngblood:
Reference:
(1)
Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43 (2)
Detroit Edison to NRC, " Clarification of Diesel Generator Commitments", NE-85-0459, dated March 14, 1985
Subject:
Diesel Generator Lubrication Annivnin Program In Reference (2), Detroit Edison committed to develop a-program to sample, analyze and trend lubricating oil in the four Fermi 2 diesel generators.
This program is presented in the attachment to this letter.
The attachment also
~
provides information concerning the Detroit Edison / Colt Industries design review of the air boost prelubrication system which is ongoing, and a discussion of the-diesel generator slow start design modification that will be
~ implemented during the October, 1985 outage.
This submittal is in compliance with License Condition 10 to the Fermi 2 Operating License.
If you should have any questions, please contact Mr. Robert L.
Woolley at (313) 586-4211.
8509270020 850920 PDR ADOCK 05000341 Sincerely, P
PDR cc:
(all with attachment)
M Mr. P.
M.
Byron 6
Mr..M.
David Lynch Mr.~A.
R.
Ungaro Mr.
G.
C.
Wright (Region III) cp\\
USNRC Document Contrel Desk Washington, D.C.
20555 l
t \\
~ Attachment to RC-LC-85-0048 Page 1 of 5 The following d iscus s ion p r~ ovid es information in accordance with Detroit Edison commitments in Reference 1.
The information below is intended to complement information previously transmitted to the NRC in References 2, 3 and 4 (see pg. 5).
A.
EDC Lubrication Analvais-Program Reference 1 committed to sample and analyze the EDG lubrication oil stating:
" Detroit Edison will establish a program to evaluate and trend the data for use in prediction and detection of bearing failure.
The program. if possible, will establish limiting criteria to initiate action if the criteria are exceeded.
Until this program is established, the results of these analyses will be reviewed by cognizant Edison engineering personnel and by a contracted analysis laboratory.
Detroit Edison commits'to provide its proposed program for use of this data and any preliminary results six months after receipt of the Operating License."
Since the January 1985 failures of EDGs 11 & 12, changes have been accomplished in the methods by which lubrication-related data is obtained and analyzed.
The following discussion summarizes the current data gathering and review methodology, and presents the data and observations made.
Consistency in lube oil sampling has been greatly improved.
Samples of the oil entering the filter are drawn after oil temperature has stabilized during the monthly start and load test, to ensure that a representative sample is obtained.. The sample.is divided and sent to the following three laboratories for the referenced analysis:
1)
The Detroit Edison Fermi 2 site lab performs both pentane insolubles and' kinematic viscosity analyses.
These prov'ide quick, gross indications of. oil quality and associated engine-wear.
2)
The Detroit Edison Engineering Research Physical and Analytical Chemistry (ER-PAC) lab performs pentane insolubles and insoluble metals analyses.
These provide the concentrations of specific metals suspended in -the circulating oil, which may indicate wear of a particular engine component.
1
Attachment to a
~ RC-LG-85-0048 Page 2 of 5 3)
The Cleveland Technical Center (CTC) lab performs suspended metals analyses and six other tests that provide:
a) specific ~ metal concentrations in the circulating' oil, possibly indicating engine component wear; b) indications of fuel oil, water, and dirt intrusion to the lube oil system; and c) ind ic a tion s of specific oil qualities (e.g.,
oxidation resistance and anti-wear additive quantities).
Test data from oil samples taken to date on the four diesel engines is provided in Table 1.
Due to the limited quantity of-data available, final conclusions on the effectiveness of the revised surveillance program cannot be developed.
However, a review of the data in Table 1 indicates the following.
1)
The oil quality is comparable to new oil, in that the neutralization number for all sixteen data values is an average of 8.5.
[0il degradation for each engine will be slow due to infrequent engine operation (approximately 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br /> per year per engine).]
2)
The amount of insoluble material is low in all four engines, generally indicating little wear of engine components.
The nineteen data points for pentane insolubles' identified by the Edison ER-PAC lab reflect values at or slightly above the level of detection.
These low values are significantly below the upper limit defined by the ZR-PAC lab for diesel engine operation-in similar applications at other facilities.
3) of all the wear metals measured, iron and aluminum have been detected in the largest concentrations.
(The piston rings are made of iron and the main bearings of aluminum.)
As indicated in the table, though, these values are still below the proposed acceptance criteria limits.
Table 1 also reflects a proposed' criteria-that will be used by Detroit Edison to evaluate and quantify engine
-wear of the four diesel generators.
The proposed criteria identified in Table I was developed by Detroit Edison using both past experience with the utility's peaker units and the engineering' judgement of both Edison and CTC personnel.
If the proposed acceptance criteria is exceeded for a given parameter in two consecutive months, a bearing clearance check will-be
Attachment to RC-LG-85-0048-Page 3 of 5 performed.
.As additional test and operating data becomes available, and the significance of the various parameters examined is determined, the proposed acceptance criteria may be revised.
The data in Table 1 also confirms that consistent results=are provided by the different testing' methods used at the Detroit Edison ER-PAC lab and the CTC.
In add'ition to the enhanced oil sampling and analysis program discussed above, Detroit Edison has revised the frequency of lube oil filter changes and inspections.
As committed to in Reference 3, the frequency of filter changes has been increased from yearly to quarterly, in order to avoid possible excessive deposition and. dif ferential pres sure buildup.
Furthermore, the frequent filter changes ensure that any foreign material that entered the lube oil system during the January / February corrective maintenance inspections would be' removed.
The filter elements are visually inspected for metallic fragments larger than 1/16".
If more than an average of one such fragment per filter disc is seen, the clearance between the upper crankline bearing and bearing cap is checked.
Six filter changes have been accomplished since the January / February corrective maintenance; two each on EDGs 11 and 12 and - one each on EDGs 13 and 14.
On EDGs 11 and-12, the second s e t'.o f filters had much less metal deposited than on the first set of filters, but enough to trigger the bearing clearance check in the case of EDG 11.
The subsequent bearing check on EDG 11 confirmed that the clearance was within the acceptance criteria.
The filters from EDGs 13 and 14 reflected less than one fragment per disc.
The replaced filters are examined by removing.that portion of the filter'with the heaviest deposits and having it ashed at 1000 F.
The metals left behind are suspended in oil and analyzed by emission s p e c t r o s c o p y... The resulting values indicate relative amounts of each metal measured.
The total amounts are compared with an estimation of oil volume through the filter vessel and are listed in Table 2.
Three sets'of filters have been analyzed to date those from the first changes on EDGs 11, 12 and 13.
Due to the limited data available, no comprehensive assessment of the data in Table 2 has been made as
.yet.
The data is being provided consistent with Detroit Edison commitments to the NRC.
i
Attachment to RC-LG-85-0048 Page 4 of 5 Simi1~arly, in response to a Region III inspector's request during a recent inspection (Item 3(h)(2) in Reference 5), Detroit Edison has sent a sample of new lube oil to CTC for analysis.
The results of this analysis.have not been received to date.
The data from this sample can be used to evaluate the proposed acceptance criteria and test results.
B.
Air Banat Prelubriention Svatam In Reference 1, Detroit Edison committed to perform a review-of the lube oil' booster / accumulator system j
with the diesel generator vendor (Colt Industries) and provide the results of.that review to the NRC..
This review presently is ongoing; an interim report is provided below.
Detroit Edison requested an engineering evaluation
[
of the lube oil booster / accumulator design by Colt
)
Industries.
The evaluation is to' include a review of available test data collected during the development of the booster system for fast-start engines.
A model has been developed by Colt Industries and reflects booster system parameters, e.g.,
flow rates, booster volume and oil distribution.
'k The analytical model of the existing system consists of,a multiple branched piping system and booster tank.
This model is. augmented with features from the existing engine-such as pumps, j
skid piping and engine piping.
The computer program is intended to analyze time development of l
pressures and flows in the system model.
The model provides the requested data relative to booster volume, distribution of oil and time required to i
deliver oil.
Preliminary results of the study have been-discussed with' Colt Industries.
Results from the rodel of the booster syst'em have been reviewed and i
isvorably compared with-measured data.from a six cylinder engine..These' preliminary results show that approximately one cup of oil.is deliveredsto each' bearing and the booster is emptied in one second.
Pressure is not developed at the bearing from the oil discharged from the booster.
As indicated in Reference 3, the lube-oil
-booster / accumulator system provides some' oil to all bearings during an EDG-start, but is not.an adequate replacement for the manual prelubrication
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Attachment to RC-LG-0048
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Page 5 of 5 system.
Colt Industries is continuing their.
analysis for a 12 cylinder model and will provide a final-report to. Detroit Edison.. Detroit. Edison will review and submit the report to the NRC upon.
completion of the study.
In'accordance with Reference 3, all planned starts of the EDG are being prelubricated to ensure adequate lubrication.
C.
Slow Start Design Modification In Reference 3. Detroit Edison indicated.that a design modification to permit. slow starts of the Emergency' Diesel Generators (EDGs) would be developed.
The design change for slow start.of the.
EDG will be implemented during the forthcoming October, 1985 outage.
The slow start design modification was initially discussed with both the NRC and Colt Industries in January, 1985 following the EDG fil bearing.
failure.
A slow start is an air start of the EDGs using the mechanical governor to achieve low speed engine operation (300-400 RPM) followed by a gradual increase of the engine speed to 900 RPM.
4 To accomplish low speed engine operation the i
exciter circuitry must be bypassed to avoid l-
~possible component damage and false alarms / trips.
Bypassing of the EDG circuitry will be achieved by installing an~ exciter bypass switch with contacts in both.the exciter reset / shutdown circuits and the-time delay for the field failure trip circuit.
Subsequent to implementation of this design modification ~the monthly operation of'the diesel-generators required lor Technical Specifications will be conducted with slow' starts, whenever possible, while fast starts (EDC attains 900 RPM in less than 10 seconds). will be conducted once per 184 days in accordance with the Fermi 2 Technical Specifications.
2 I.
f
References 1.
Detroit-Edison-letter to NRC, " Clarification,of Diesel Generator Commitments", NE-85-0459, dated March 14, 1985
'2.
Detroit Edison letter to NRC, " Final Report on 10CFR50.55(e) Item-146 Failure.of Emergency Diesel Cenerator Nos. 11 and.12", EF2-70382, dated February-12, 1985 3.
Detroit Edison letter to NRC, " Additional Information on Diesel Cenerators", NE-85-0345, dated March 6, 1985 i
4.
Detroit Edison letter to ~NRC, " Transmittal of Additionel l
Information Relative to Diesel Generator Commitments".
NE-85-0462, dated March 15, 1985 5.
NRC Inspection Report 50-341/85006, dated September.10, 1985 h
1 4
v i
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TABLE 1: Data from'EDG Lube Oil Samples EDG fil Proposed Parameter Lab Units Criteria Sample Date (1985) 4/10 5/17 6/3 6/28* 7/29 8/26 K. Visc.
Site cst @40C 181 179 175 189 184 175 170-200 P. Insolubles Site vol. %
<0.1 ~
<1 0.2
<1 0.3
<0.' 1 3 max.
P. Insolubles ER-PAC wt. %
.02
.01
.02
.03
.04 P
3 max.
Iron ER-PAC wt. ppm 5.3 3.4 2.4 11.0 6.6 P
25 max.
Aluminum ER-PAC wt. ppm 1.5 1.5 0.8
<0.5 0.9 P.
2.5 max.
i Tin ER-PAC wt. ppm
<0.5
<0.5
<0.5 <0.5
<0.5 P
1.5. max.
Zinc.
ER-PAC wt. ppm 1.5 0.4 0.4 6.0
. 0.6 P
2.5 max.
- 1 6
6 11 9
5-P-
50 max.-
Iron CTC wt. ppm _
Aluminum CTC wt. ppm 0
0 0
2 0
P 15 max.
Tin' CTC' wt.-ppa 2
- 2' 2
5 4
P
- 10. max.
Zine CTC wt. ppa 2-3 3
3.
7 P
15 max.
Nsut. No.
CTC mg KOH/gm 9.3 8.3
- 8.2 8.8 8.8 P
2 min.
P - Performing analysis.at stated lab. Awaiting results.
- - Anomalous sample - contamination of sample postulated.
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r TABLE 1.- cont'd EDG #12 Proposed Parameter Lab Units Criteria Sample Date (1985) 4/22 5/17 6/17 7/15 8/12 K. Visc.
Site cst @40C 173 179 178 171 170 170-200 P. Insolubles Site vol. %
0.4
<1
<1
<1
<0.1 3 max.
P. Insolubles ER-PAC wt. %
.01
.05
.04 D
.01 3 max.
Iron ER-PAC wt. ppm 0.4 3.4 7.5 D
1.4 25 max.
j Aluminum ER-PAC wt.. ppm 1.7 0.8
<0.5 D
0.8 2.5 max.
Tin ER-PAC wt. ppm
<0.5
<0.5
<0.5 D
<0.5 1.5 max.
Zine ER-PAC wt. ppm 0.4 0.8 0.9 D
0.3 2.5 max.
Iron CTC wt. ppm 6
12-7 D
7 50 max.
Aluminum CTC wt. ppm 0
0 0
.D 0
15 max.
Tin CTC wt. ppm 0
1 5
D-1
'10 max.
Zine CTC wt. ppm 0
1 2
D 2
-15 max.
Naut. No..
CTC mg KOH/gm 8.0 8.8-9.1 D
8.6 2 min.
D - Sample damaged in shipment - results not available.
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TABLE 1 - cont'd EDC #13 4
Proposed Parameter Lab' Units Criteria Sample Date (1985) 4/4 4/27 5/16 6/12 7/10 7/12 8/6 K. Visc.
Site cst @40C 190 188 188 186 188 187 184 170-200 P.1Insolubles Site vol.'%
.<1 0.5
<1 0.4 0.7
<1
<1 3 max.
P..Insolubles ER-PAC wt. %
.02
.04
.04
.06
.04 P
P 3 max.
Iron ER-PAC wt. ppm 0.9 2.5 1.7 6.7 6.3 1P P
25 max.
Aluminum ER-PAC wt. ppm 1.0 0.7 1.0
<0.5
<0.5 P
P 2.5 max.
Tin ER-PAC wt. ppe
<.5
<.5
<.5
<.5
<.5 P
P 1.5 max.
'Zine ER-PAC wt. ppe 0.5 0.6 0.7 0.9 0.9 P
P 2.5 max.
Iron CTC wt. ppm 4
9 7
10 9
17 P
50 max.
Aluminum CTC wt. ppe 0
O.
0 0
0 0
P 15 max.
Tin CTC wt. ppa 0
4 2
0 5
5 P
10 max.
Zine CTC wt. ppm 3
5 4
8 7
8 F
15 max.
4 Naut. No.
CTC mg KOH/gm 8.5 8.1 7.8 8.9 8.7 8.8 P
2 min.
i i-j P - Performing analysis at stated lab. Awaiting results t
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TABLE 1 - cont'd
'EDG #14 Proposed Parameter Lab Units Criteria Sample Date (1985) 4/5 5/27* 6/24 7/22 7/25 8/19 K.'Visc.
Site cst @40C ~174 173 NA 198 173 174 170-200 P. Insolubles Site vol. %
<1 0.7 NA 0.5
<0.1
<0.1 3 max.
P. Insolubles ER-PAC wt. %
.03
.14
.06
.04
.14 P
3' max.
~ER-PAC wt. ppm 42 110 6.7 5.4 1.9 P
25 max.
Aluminum ER-PAC wt. ppm 0.4 1.0
<0.5 0.8 2.1 P
2.5 max.
Tin ER-PAC' wt. ppm
<0.5 0.5
<0.5
<0.5
<0.5 P.
1.5 max.
Zinc ER-PAC wt. ppm 0.5 31 0.9 0.5 2
P 2.5 max.
8 P
50 max.
Aluminum CTC wt. ppm 0
0 3
0 0
P 15 max.
Tin CTC wt. ppm 0
1 5
3 4
P 10 max.
.CTC wt. ppm 5
4 4
1 2
P 15 max.
Neut. No.
CTC
.mg.KOH/gm_8.6 8.1 8.8 8.3 8. 2_-
P 1 2 min.
P - Performing analysis at stated lab. Awaiting results.
- - Anomalous sample - contamination of sample postulated.
NA - Data not available i.
4 4 of 4 l
Table 2: Data from EDG Lube Oil Filter Changes EDG Removal Service Volume Deposited Metals from Duration Throughput Service (est.)
( e's t. )
Al Fe Cr Sn Cu Zn Date Days 106 Gallons (For comparison only) 11 5/7/85 69 1.2 59 19 0 0
2 5
12 5/8/85 64 1.1 71 18 2 4
3 2
13 6/7/85 118 2.0 109 17 4 1
2 1
1 of 1