ML20084J392
| ML20084J392 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 01/25/1973 |
| From: | Stephenson B COMMONWEALTH EDISON CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084J394 | List: |
| References | |
| BBS-73-13, NUDOCS 8305120583 | |
| Download: ML20084J392 (2) | |
Text
<
p__ --
C:m c;lth Edis:n s
&5 Quad-Cmes Nuclear Power Station Post Ofhce Box 216 e
+
Cordova,Ilknois 61242 Telephone 309/654-2241 f
hl h.
p;..
a
,1.'
a, lG s.
l{',
f[t'j:l' r ;dA E
t$yg?Il'73.
- 2
'- t j
- .'A S!
BBS-73-13 f
.A t r
..:.?
,.r f M
kQ January 25, 1973 Mr. A. Giambu::so Deputy Director for Reactor Projects Directorate of Licensing U. S. Atomic Energy Commission Washington, D.C. 20545
REFERENCE:
Quad-Cities Nuclear Power Station, Unit 1 Docket No. 50-254 License DPR-29,. Appendix A Sections 1.0.A.2 and 3.2.B
Dear Mr. Giambus'so:
The purpose of this letter is to inform you of the de-tails concerning the setpoint drift of a Reactor Low Pressure switch which was detected on January 18, 1973 The setpoint of the left hand switch of PS-1-263-52B was found to be at 271 psig decreasing contrary to.
Technical' Specification 3.2.B which requires that this switch close at 300 p
350 psig.
This switch performs a low pressure permissive function for the low pressure core cooling systems.
The right hand switch was found to be normal.
This abnormal occurrence was reported to you by telegram on January 19, 1973 The switch is a Barton Model #288 with two internal switches and is calibrated quarterly.
During a routine calibration. the setpoint of the lef t hand switch was 4
i found to have drif ted from a nominal setpoint of 325 psig to 271 psig.
No reason could be -found for this drift.
No previous problems have been encountered with
=i-this instrument.
j' The left hand switch is used in the LPCI mode of the RHRS and the right hand one is used in the Core Spray j
System.
Because of the reduced setpoint actuation of the "B" logic of LPCI would have been delayed slightly i
i during a blowdown, but the "A" logic would have per-i formed normally.
In addition, the Core Spray System
]
was completely operable.
i M,
j 8305120583 730125 ~
Q *
'g d.4. > -
]
PDR ADOCK 05000254 j_
pgg f
S a.
. 6. 7 8 4
Mr. A. Giambusso January 25, 1973 The setpoint of the left hand switch was recalibrated in accordance with station procedures.
Because the drif t history of this instrument has been random, i.e. not consistently increasing or decreasing, the setpoint of 325 psig has not been changed.
This switch will be calibrated at two week intervals until it has been determined that the setpoint is no longer drifting.
Sincerely,
/ ~~'
te15h} ens on/b5'hNb B.B.
Superintendent QUAD-CITIES ITUCLEAR POWER STATIO!1 BBS/lk i
4
)
a e
p.
Y.
i.
4 e
i-r n
_m