ML20086H617
| ML20086H617 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 07/25/1975 |
| From: | Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Anthony Giambusso Office of Nuclear Reactor Regulation |
| References | |
| AO-75-42, NUDOCS 8401180173 | |
| Download: ML20086H617 (2) | |
Text
,
O O
PHILADELPHIA ELECTRIC COMPANY
- /
2301 MARKET STREET PHILADELPHIA PA.19101 O
'3
[...
1215l 8414000 July 25, 1975
't-Mr. A. Giambusso Director Division of Reactor Licensing Of fice of Nuclear Reactor Regulations i
United States Nuclear Regulatory Co:miission Washington, DC 20555 Ocar Mr. Giambusso:
Subject:
Abnormal Occurrence The following occurrence was reported to Mr. Walt Baunack, Region 1, Of fice of Inspection and Enforcement, United States Nuclear Regulatory Commission on July 17, 1975 Written notification was made to Mr. James P. O'Reilly, Region 1, Of fice of Inspection and Enforcement, United States Nucicar Regulatory Commission on July 17, 1975 In accordance with Section 6 7 2.A of the Technical Speci f i ca t i ons,
Appendix A nf DPR-56 for Unit 3 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Reactor Licensing as an Abnormal Occurrence.
Reference:
License Number DPR-56 Technical Specification
Reference:
4 7.D Report No.:
50-278-75-42 Repor i Date:
July 25, 1975 Occurrence Date:
July 16, 1975 Facility:
Peach Bottom Atomic Power Station R.D. 1, Delta, Pennsylvania l
Identification of Occurrance:
l l
Failure of the "C" TIP machine ball valve to close.
l Conditions Prior to Occurrence:
Unit 3 at 50% power.
f3 Q Description of Gecurrence:
hd f';
O l
[
During routino operation of the TIP machines, the "C" detector
[
failed to stop at the shield limit and close the ball valve as it was being withdrawn to the shield chamber.
i P
81.d u l
84011801'73 750725 PDR ADOCK OJOOO278 s
N
(
COPY cilfXf RIMION dm
r s
s...
O o
g 50-278-75-42 l
Mr. A. Giambusso July 25, 1975
]'
Page 2
/
Designation of Apparent Cause of Occurrence:
The shield limit switch, which controls detector. travel and ball valve operation, failed to operate when the detector reachcd the
.~
This allowed the detector to continue its with-
~
"in-shield" position.
drawat until it was manually stopped.
4 Analysis of Occurrence _:
The failure of the limit switch to halt the withdrawal and
,l close the ball valve was immediately observed and corrected by switching 7,'
It to the manual mode of operation and stopping the machine. The ability to close the ball valve by turning the machine off (de-en'crgize to close)
]
.i Therefore, there "
was verified and would have been available if required.
i are no safety implications to this occurrence.
/
s, Corrective Action:
The detector was returned to its in-shield position. The
,/'
l machine was de-energized, and the ball valve was verified to be closed.
., 7 9
[
The shield limit switch mechanism was dismantled, inspected, and found to be clean and free of binding; reassembled, and readjusted for more The switch was then successfully tested f
f positive switch operation.
f) several times.
'4 i
Failure Data:
2
'l Previous failures of this type reported as 50-278-75-31 and 50-278-75-34.
l 1
e s
Very truly yours, M
i M.
Cooney Ass't Gen'l Superintendent l
Generation Division cc: Mr. J. P. O' Rei l l y Director, Region i Office of Inspection and Enforcement United States Nuclear Regulatory Comnission 631 Park Avenue J'
King.of Prussia, PA.
19406 x
e l
--,,--.,_..~.,,,.,,__,,,,_,v-
_