ML20084R122
| ML20084R122 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities, 05000000 |
| Issue date: | 10/12/1973 |
| From: | Stephenson B COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20084R054 | List: |
| References | |
| BBS-73-212, NUDOCS 8306140804 | |
| Download: ML20084R122 (2) | |
Text
-
C mm
- lth Edison p)
^ >
C Jad-C.
oclear Power Station v
i i
~~t J-Post Offic ox 216 l
M b'
Cordova. lilinois 61242 Telephone 309/654-2241 BBS-73-212 October 12, 1973 Mr. James G. Keppler Regional Director Directorate of Regulatory Operations - Region III U. S. Atomic Energy Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
SUBJECT:
Reinspection of Unit 1 Hydraulic Shock Suppressors at Quad-Cities Nuclear Power Station
Dear Mr. Keppler:
In accordance with Regulatory Operations Bulletin No. 73-4 a re-inspection was conducted recently on Unit 1 to determine the con-dition of Bergen-Patterson hydraulic shock absorbers installed in safety related systems.
Seven of the twenty-nine shock absor-bers inspected after about 46 days of operation were found in an uns atis fact ory. condition.
All of the shock absorbers were in-spected in-place following the September 22, 1973 shutdown and 24 were replaced with rebuilt units obtained from Bergen-Pat terson.
The remaining five were removed, rebuilt, and reinstalled.
The defective shock absorbers were disassembled and thoroughly in-spected during the week of October 1,1973 following the outage.
All of the shock absorbers removed from Unit 1 have been rebuilt by station maintenance personnel.
Molded polyurethane seals and ethylene propylene o-rings were utilized in the repair of these units which will be installed in Unit 2 during the forthcoming outage.
Six of the shock absorbers received from Bergen-Patterson were also rebuilt in this manner prior to installation in Unit' 1.
5his was necessary when minor oil leaks were discovered at i
the base of the accumulator piston.
It should be : emphasized that these were very small leaks and in-our opinion would not have affected the proper operation of the shock absorbers.
DESCRIPTION-OF FAILURES SNUBBER SIZE FLUID REBUILT IN l
ID. NO.
STROKE X BORE SYSTEM S' AT(fS@
AUGUST 1973 f
Rec 14m03 hh3TMOD
- 33MO 1-2 6" x 2 1/2" Le ak Yes 1-5 6" x 5" Recirc Empty No Recir61 II g Iggn68 @
1-11 6" x 5" Recire No
'-13 6" x 5" Leak No 24 6" x 2'l/2" RHR-Leak Yes 0CT 15 1 115 6" x 2 1/2" RHR g358@@y Yes 1-25 6" x 4"
- Rgcire, Empty Yes
'nb
~
\\ ?(d[ b )
8306140804~740716
~
-\\
PDR ADOCK 05000254
(
G PDR
r Mr. J ame s G. Keppler October 12, 1973 All the failures tabulated above were the result of leaks from 0-ring failures.
In those snubbers which were not repaired in
{ August 1973 the original 0-rings were found in a gummy condition.
Of tne snubbers which were previously repaired, some of the O-rings appeared to have taken a set and showed varying degrees of hardness including those where there was no evidence of fluid leakage.
Although a discoloration was observed in most of the cup seals, no indications of failures of these parts were detec-ted.
Some 0-rings also appeared to have been pinched, however, not to the extent that would have resulted in leakage.
I Just prior to the Unit 1 startup on September 29, 1973 all of the shock suppressors which were replaced during the octage were in-spected again and no leaks were observed.
A permanent program for the modification and periodic reinspection of hydraulic shock suppressors has not yet been established.
This program will be developed following the reinspections to be performed on Quad-Cities Unit 2 and at Dresden Huclear Power Station.
To establish the basis for this program the results of laboratory testing currently being performed by Commonwealth Edison, General Electric, and Bergen-Patterson must also be evaluated.
Very truly yours,,9
. - ((
ggh4dw/+C B. B. Ste'phenson Station Superintendent BBS/RAN/lk e
4