ML20107C930
Text
k)
)
- ~
To:
James P. O'Reilly Directorate of Regulatory Operations Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 From:
Jersey Central. Power 6 light Company Oyster Creek Kuclear Generating Station Docket #$0 219 Forked River, New Jersey 08731
Subject:
Abnormal Occurrence Report No $0-219/74/ 12 The following is a preliminary report being submitted in compliance with the Technical specifiestions paragraph 6,6,2, Prelininary Approval:
v n a.,.,,.
kJ. T. Carroll, Jr. M Date cc:
'4r. A Gianhusso hY G
DEKOK95-258 PDR
....u.......
Report Date:
2/19/74 Occurrencer 1525
(
OYSTER CREEX NUCLEAR GENERATING STATION
' FORKED RIVER, NEW JURSEY 08731
. Abnormat Occurrance Report No. 50-219/74/J
- IDENT1PICATION Violation of the Technical Specifications, paragraph 2.3.7, OF OCCURRENCE
Low Passuro Main Steam Line Pressure Switches, RE23A and B, worc found to trip at pressures Icss than minimum nquired value of 860 psig.
'Ihis event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph 1.15A CONDITIONS PRIOR
~TO OCCURRENCE X
Steady State Power Routine Shutdown Hot Standby Operation Cold Shutdown Load Changes During Refueling Shutdown Routine Power Operation
~ Routine Startup
_ Other (Specify)
Operation The major plant paramotors at the time of the occurrence were Power:
Reactor,1904 MWt Bloctric, 670 MWe Plow:
Recire., 59.86 x 10' lb/hr Feed., 7.11 x 10' lb/hr Reactor Pressure:
1020 psig Stack Gas:
29,329 pCi/sce 1
f DESCRIPTION On Friday, February 15,1974, at 1525, while performing a sur-3 OF OCCURIENG:
vc111ance test on the four Main Steam I,ine few Pressure Switches, i
it was discovered that RE23A and B trlpped At 855 and 853 p$lf, t
respectively.
'these values are below the minimum required trip point of 860 psig which is derived by adding to the Technical Specification limit of 850 psig a 10 psig head correction factor.
l (See Attachment 1 for test results.)
f
n APPARENT CAUSE X
Design Procedure '
0F OCCURRENCE:
Manufacture
~ Unusual Service Condition
~ Installation /
Inc. Environmental Construction component Failure Operator-
_ Other (Specify)
Sensor drift is a recognized problem and work is in pmgress to formulato a ' final solution. We Attps required to achiCVc this end were delineated in Abnormal Occurrence Report No, y
H 73-30 and restated in Abnormal Occurrenco Report No. 74 9.
?
i ANA!3 SIS OF As indiented in the. bases of the Technical Specifications; "The OCCURPNCI!:
U.
' low prcGGUrc i301stion of the Main Steam Lines at 850 psig was l
L pmvided to 9,1ve protection.ap.ainst fast reactor depressurination l
I and the resultant rapid cooldown of the vessel. Advantage was taken of the scram fouture which occurs when the Main $ team Iso-lation Valves are closed to provide for reactor shutdown so thnt
.high power operation ~ at low reactor pressure does not occur, thus providing protection for the fuel ciudding integrlty safety limit. "
%e adverse consequences of reactor isolation occurring at reactor pressure approximttely 7 psig below the specified mini-l mun Value of B60 psig is limited to those effects attendant to a greater than normal reactor cooldown rate. The fuel" cladding integrity safety limit only comes into effect for power opera-i tion at reactor pressures less than 600 psig or for~ power opera.
tion greater than 354 MWt with less than 10% recirculation flow, Therefore', the consequences of a,7 psig lower than n~ormal reactor isolation.and scraa setpoint has no threatening effect whatso-S
?
.,...._..,m.
l _ __,.
l
i
- Report No,- 50 219/74/12 eagr.t-
-~-
~
i
.(3
, - +-.-
ever on the fuel cladding integrity, i
..The effects of a too rapid cooldown due to the lower isolation 1
pressure are inconsequential since.there is less than 14 dir-i ference between the saturation temperature for 860 psig and 853 paig.
CQRRECTIVE Continuing corrective actisma being taken at this time are ax ACTI0th stated in Abnormal Occurrence Report Nos. 74-9 and 74-10 and t
es restated herein:
).
Investigation is being conducted into the basis for the steam linc low pressure Aetting of 850 psig. Development of a Technical Specification change to lower the setpoint will follow if results of transient analyses indicate this possibility (see Abnormal Occurrence Report No, 73-30)..
2.
Recommendations to possibly reduce or climinate the sensor setpoint change problem have been received.
It was reported -
that General Elcetric test.s on a pulsating line to,41pulate plant conditions show that pre-cycled Barksdale switches show improvement but that the switches still do not meet it re-poatability, General Electric, therefore, recommended an Axhcroft switch as it is more accurate. 'Ihe Ashcroft entalog number is 61 S 6080 BN20-06L-1028.
As. a result tme switch of each type (pre-cycled sarksdale and Ashcroft.) are being purchased for test and evaluation e
at Oyster Creck.
x 6
9 a
h 4
.n
R:; port No, fyS-2821/FfJ/H2
~
^
^ ~
~
'~ '~'~~~~ V
(
FA11 AIRE DATA:
Ma:tufacturer date portinent to these switdies are as follims:
Heletron Corp. (subsidiary of Barksdale)
Los Angelos, California Pressure Actuated Switdt Model 372 Catalog #372-6SS4DL 295 Range 20-1400 psig Proof Psi. 1750 G I
I l
I' kh t
=
sam '
_ /
_P l'
t
t i
(i
- f
- Abnormal Occurrence l
"~
Report No. 50-210/74/12 Attachwnt - 1 i
~
'the as found switch settings were:
Test Resulis
^
Fli23A 855 p$lg RE23B 853 psig RB23C 860 psig RE23D 861 psig The pressure switches were then recalilirated and cliecked to actuate ax t'ollows:
Test Results 1&23A 860 psig RE23B 860 psig 9
e 4
4 4