ML20084D219
| ML20084D219 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 05/01/1974 |
| From: | Ross D JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-50-219-74-28, NUDOCS 8304110006 | |
| Download: ML20084D219 (3) | |
Text
-
4 O.
O n.A,s e>>
Jersey Centra Power & Lig1t Company V9I WJ MADISON AVENUE AT PUNCH BOWL ROAD
- MORRISTOWN, N.J. 07900
- 201-539-6111 me.
a na,
), Public Utilities Corporation _
General I
I en r..
May 1, 1974 m
.s
/
4, (
3 i
Mr. A. Giambusso
$4
~
I b' Y(d Deputy Director for Reactor Projects d8 -
e.N@Q%IN Directorate of Licensing United States Atomic Energy Commission j.
Washington, D. C. 20545 W
9 N
Q,
Dear Mr. Gianbusso:
/3
Subject:
Oyster Creek Station Docket No. 50-219 Abnormal Occurrence Report No. S0-219/74/29 The purpose of this letter is to forward to you the attached Abn'ormal Occurrence Report in compliance with paragraph 6.6.2.a of the Technical Specifications.
i Enclosed are forty copies of this submittal.
I Very truly yours, y_-') ;9 g, dLt
/G dI Gf' ~ 9%/
t Donald A. Ross
\\
l Manager, Nucicar Generating Stations es Enclosures cc:
Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region I t
\\
f i
' L./
y}j ' r.a t j
,t f
COPY SENT REGION _ M 7,d I
8304110006 740501 DR ADOCK 05000219 U
PDR t
,.s
.y,,.---,-,--,,,---y e,
,,-m-,-.--,-,- -. - ~ -,,
e' v'
O.
O
/
OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 08731 Abnormal Occurrence Report No. S0-219/74/28 Report Date May 1, 1974 Occurrence Date April 23, 1974 Identification of Occurrence Violation of the Technical Specifications, paragraph 2.3.4, Electromatic Relief Valve Pressure Switches,1A83B and 1A83D, were found to trip at pressures in excess of the maximum allowable value of 1070 psig.
This event is considered to be an abnormal occurrence as defined in the Technical Specifications, paragraph 1.15A.
Conditions Prior to Occurrence The plant was shut down for refueling.
The reactor mode switch was in the REFUEL position with reactor coolant temperature approximately 100*F.
Description of Occurrence On Tuesday, April 23, 1974, while performing surveillance on the five Electromatic Relief Valve Pressure Switches, it was found that 1A83B and 1A83D tripped at 1090, psig and 1096 psig, respectively. These values are in excess of the maximum allowable trip points of 1084 psig and 1082 psig, respectively, which are derived by adding appropriate head correction factors to the Technical Specification limit of 1070 psig. Switches 1A83B and 1A83D are associated with valves NR108B and NR108D, respectively.
The "as found" and "as left" switch settings were:
Associated
" Desired" "As Found" "As Left" Switch Valve Setting Setting Setting t
1 1A83A NR108A 1079 psig 1079 psig 1079 psig l
1A83B NR108B 1084 psig 1090 psig 1084 psig 1A83C NR108C 1077 psig 1077 psig 1077 psig 1A83D NR108D 1082 psig 1096 psig 1082 psig 1A83E NR108E 1082 psig 1082 psig 1082 psig i
~
O.
O Abnormal Occurrence No. 50-219/74/29 Page 2 Apparent Cause of Occurrence Set point repeatability has been tentatively identified as the cause of this occurrence.
Analysis of Occurrence The relief valves are provided to remove sufficient energy from the primary system to prevent the safety valves from lifting during a transient.
The limiting pressure transient is that which is produced upon a turbine trip from rated design power with a failure of the bypass system to function.
Under these conditions, the five (5) relief valves are required to operate in order to prevent the pressure excursion from reaching the lowest set point of the primary system safety valves.
It should be noted that a 25 psi margin exists between the resulting peak pressure and the lowest safety valve set point as added assurance that the safety valves will not lift during this transient. With valves NR108B and NR108D actuating at 6 psig and 14 psig, respectively, above the maximum allowable trip point of 1070 psig, and assuming the most limiting pressure transient had occurred, the lowest set point safety valve or valves may have been required to actuate in order to limit the pressure transient. Since the safety valve capacity is based upon providing sufficient vessel over-pressure protection upon failure of all pressure relieving devices, in addition to a failure of the reactor to scram, over-pressur-ization of the vessel would not have occurred.
Corrective Action The involved pressure switches,1A83B and 1A83D, were immediately reset to trip at allowable pressure levels. Until the problem of set point repeatability is solved, the Electromatic Relief Valve Pressure Switches will be surveilled each time the reactor is shut down and the reactor coolant temperature is reduced to
<212*F.
Discussions with the Nuclear Steam Supply System vendor into the possibility of employing set points with instrument accuracy deviations taken into account for Technical Specification surveillances will continue. The successful termination of these discussions lies in the ability of the vendor to supply transient analysis information and to determine precisely the conservatisms utilized in those analyses that are relevant to the instrument set point analysis.
Failure Data This is the first abnormal occurrence report of the failure of these switches to trip at their preset trip point.
Manufacturer data pertinent to these switches are as follows:
Manufacturer:
Dresser Type:
1539VX Serial Nos.:
BK3339 (1A83B)
BK3338 (1A83D)
r Initin!'Jelephone Date of Report Date:
4/25/74 Occurrence:
4/23/74
'Init i al h*rit ten Ti ne of Itepoi t Date:
4/26/74 Occurrence:
1720 OYSTER CREEK NUCLliA!t GENERATING STATION l'ORKED !!!VI:R, NEW JI!CSliY 08731 Abnornal Occurrence Report No. 50-219/74/29 IDENTIFICATION Violation of the Technical Specifications, paragraph 2.3.4, OF OCCURRENCE:
!!1cctromatic Relief Valve Pressure Switches, l AS3B and 1A83D, were found to trip at pressures in excess of the naxi-iaun allowabic value of 1070 psig.
This event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph 1.1SA.
CONDITIONS PRIOR Steady State Power Routine Shutdown TO O'JCU!?PMNCE :
!!ot St::':dby Operation rni,1 % t,in..n 1,g3 cu n.,,,a n...,.,
X Refueling Shutdown.
Routine Power Operation Routine Start up Other (Specify)
Operation The reactor node suitch was in the REFUEL position with reactor coolant terperature approximately 100 F.
DESChlPT10N On Tuesday, April 23, 1974, while performing surveillance OF OCCURRl!NCE-on the five Electronatic Relief Valve Pressure Switches, it was found that 1AS3B and 1 A83D tripped at 1090 psig and 1096 psig, respectively.
These values are in excess of the maxinun allowabic trip points of 1084 psig and 1082 psig, respectively, which are derived by adding appropriate head correction factors to the Technical Specification limit of 1070 psig.
It is noted here that switches 1A83B and 1A83D are associated with valves NRIOSB and NR1080, respectively, tr
/
e
,~ --
R i
Abnormal Occurrence lieport No. 50-219/74/29 Page 2 I
i The "as fotuid" and "as Icft" switch settings were:
Associ ated
" As Found" "As Left" l
Swi t ch Valve Setting Setting _
1A83A Nit 103A 1079 psig 1079 psig d
1A83D NR10SD 1090 psig 1084 psig 1A83C NR108C 1077 psig 1077 psig 1AS3D NI108D 1096 psig 1082 psig 4
1AS311 NRIOSE 1082 psig 1082 psig API'ARENT CAUS!!
X Design Procedure
[
j OF OCCURRENG :
Manufacture Unusual Service Condition Installation /
Inc. Envi ronmental
~~
Const ru ct ion Component Failure
_ Operator other (Specify) j b
Inst rument drift has been tentatively identified as the cause of this occurrence.
1 AN/U M 1b Ui-
'the relict valves are provided to remove sut ti cient energy OCCURRf.NCE :
from the priuary system to prevent the safety valves from lif ting during a transient.
The limiting pressure transient is that which is produced upon a turbine trip from rated i
t design pcuer with a failure of the bypass systcu to function.
Under these conditions, the five (5) relief valves are re-quired to operate in order to prevent reaching the lowest set point of the primary systen safety valves.
It should be noted that a 25 psi margin exists between the resulting peak pressure and the lowest safety valve set point as added assurance that the safety valves will not lift during i
this transient.
liith valves NR108B and NR108D actuating at 6 psig and 14 psig, respectively, above the maximum allow-able trip point of 1070 psig, anil assuming the most limiting b
/
a
- _ _ _ _ = =
Abnormal Occurrence Reijort lio. 50-219/74/29 page 3 pressure transient had occurred, the lo,eest set point safety valve or valves may have been required to actuate in order to limit the pressure transient.
Since the safety valve capacity is based upon providing sufficient vessel over-prescure pro-tection upon failure of all pressure release devices, in addition to a failure of the reactor to scran, uver-pressuriza-tion of the vessel would not have occurred.
CORRiiCTIVE The involved pressure switches,1A83B and 1 A83D, were inned-ACTION:
intcly reset to trip at allowable pressure icvels.
Additional items of corrective action wil' he determined following re-view of this occurrence by the Plant Operations Review Co: aittee.
uninou o vn.
u.i...fn c r i, vnv,1 it n p,,rtin nt to these switches are as follo.is:
f.lanufacturer - Dresser Type - 1539VX Scrial Nos. - BK3339 (I AS3B)
BK3338 (I AS3D)
I l
.,g abc refaIe
)[
]y.,
_3 I
x l
x i
~
50 219
!q
,f
_,/
Q
~
\\) ~" -
i
((~
'fl.f.
de I
g
.. 4Y. i I.
- -\\
3.S?d,.
\\
Us.,,']j t..y, ' ""Q kSC C::,
t3 To:
James P. O'Iteilly L,-
7:. ',.. t f i)i rect orate of itegulatory Operations
\\ ' 'i3:$
llegion I
[
631 Park Avenue
- ~
Uk.
King of Prussia, Pennsylvania 19406 j
From:
Jersey Central Power G 1.i ght Company Oyster Creek Suclear Generating Station, Docket I'50-219 l
Forked lliver, New Jersey 08731 l
Subj e ct :
Abnorraal Occurrence Report No. 50-219/74/29 l
i The following is a preliminary report being submitted in compliance with the Technical Specifications,
paragraph 6.6. 2.
Pre 1iminary Approval:
/
. ~[ L ' /7 /.', '
h[.
- 1'. Carroll,.h r.
4/26/74 Datc 1
cc:
!!r A. Gianhusso f
.h..[ '/\\
i(
5
(
e t
j con sswr REGION _M'
--_- --