ML18043A458
| ML18043A458 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 02/02/1979 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| TASK-05-04, TASK-5-4, TASK-RR NUDOCS 7902060251 | |
| Download: ML18043A458 (4) | |
Text
consumers Power company General Offices: !21!2 West Michigan Avenue, Jackson, Michigan 49!201
- Area Code 517 788-0550 February 2, 1979
- Director, Nuclear Reactor Regulation Att Mr Dennis L Ziemann, Chief Operating Reactors Branch No 2 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - VIBRATORY LOADS IN CHARGING PUMPS
©rPW Consumers Power Company's response to your re~uest for additional informa-tion dated December 14, 1978 is as follows:
Item 1 Your response dated August 3, 1978 states that "Excessive vibration was observed with the original mechanical dampers, but has been reduced to accept-able levels by addition of the accumulators and appropriate pipe restraints."
Submit the basis for determining acceptable levels of vibration along with any data measurements on both the suction and discharge piping to substantiate your conclusions that vibration has been reduced to acceptable levels.
Response
The basis for determining "acceptable levels" in 1972 was established primarily through visual inspections and the elimination of discharge line failures.
Pump discharge lines were failing due to excessive vibration and corresponding fatigue.
Corrective action taken to reduce these vibrations consisted of adding pulsation dampeners, long radius elbows in the pump discharge piping, and more pipe restraints.
This action reduced the vibration levels to less than 3 mils and eliminated discharge piping fatigue failures.
Thus, it was concluded by both Consumers Power Company and Bechtel Corporation engineers that the excessive vibration problem had been solved and that acceptable levels of vibration had been obtained.
A limited number of IRD measurements were taken before and after the corrective action (Enclosure 1).
The largest vibrations were reduced by a factor of fifty or more.
7902060 :2.5*(
2 Item 2 Furnish the percentage of the discharge pressure pulsations removed by the pulsation dampeners.
Response
Consumers Power Company has not been able to retrieve any discharge pressure pulsation data from its files or from the files of the architect-engineer who performed the worK-.-,However;-it is believed that this data was taken and used in making the engineering judgment concerning the adequacy of the
.fix.
A limited number of vibration measurements were taken with an IRD.
This data shows the average vibration level to have been reduced by a factor of over 25, with the larger vibrations being reduced by a factor of 50 or more.
The largest vibration, 43 mils, was reduced to 0.3 mils - a reduction factor of 143.
David P Hoffman (Signed)
David P Hoffman Assistant Nuclear Licensing Administrator CC JGKeppler, USNRC
ENCLOSURE 1 MAX VIBRATION IN MILS Before After Modifications Modifications Point 8-27-71 7-27-72 8-3-72 Pumps Running A
. 05 0.6- -----P55A B
0.1 0.5 P55A c
0.1 o.4 P55A D
0.2 0.7 P55A E
0.3 o.8 P55A F
0.3 P55A G
0.3 P55A H
0.2 P55A J
0.7 P55A & P55B K
1.1 P55A & P55B L
1.2 P55A & P55B
-M 1.3 P55A & P55B N
2.5 P55A & P55B p
0.3 P55A & P55B Q
0.7 All R
- 1. 0 All s
1.0 All T
0.5 All u
0.3 All v
43 0.3 P55A & "All, 11 Respectively w
18 P55A y
3,1 P55A 1 of 2
v I\\)
0 HJ I\\)
PALISADES CHARGING PUMP DISCHARGE PIPING p
y Check Valve H
w
~ i G
I
.x Isolation Valve F
Puls et ion Rel;::f (
Damper Val6.
D B {j~
f I
~
(')
t"i 0
rJl
~
I-'