Information Notice 1993-96, Improper Reset Causes Emergency Diesel Generator Failures
K>
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
December 14, 1993
IMPROPER RESET CAUSES EMERGENCY DIESEL
GENERATOR FAILURES
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
-
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to the potential for an emergency diesel generator
(EDG) to fail to start on demand or to trip during operation due to improper
execution of the reset operation at the conclusion of the previous run. It is
expected that recipients will review the information for applicability to
their facilities and consider actions as appropriate to avoid similar
problems. However, suggestions contained in this information notice are not
NRC requirements; therefore, no specific action or written response is
required.
Description of Circumstances
H.B. Robinson
In August of 1987 at the H.B. Robinson plant, startup trips occurred on the
KA" EDG. With the assistance of a vendor representative, several steps were
taken in an effort to preclude such trips, including replacement of the
governor, replacement of the governor oil, replacement of sticky fuel
injection pumps, checking of injection pump timing, and rebalancing fuel rack
settings. In February of 1988, startup trips were again experienced. It was
concluded, after detailed inspection of the latch mechanism parts, that there
was a possibility of wear on the tip of the latch, which may have been a
contributing factor to the trips. These parts were replaced with new parts.
On June 3, 1992, during the performance of a test activity, the TAw EDG
tripped on mechanical overspeed after the engine had been operating
approximately one half hour. After detailed consideration of possible
scenarios for the trips and considering prior actions taken, it was determined
that the most probable cause was a failure to properly reset the trip
mechanism after the previous run. It was concluded that operations personnel
apparently were unaware of the importance of moving the reset lever through
its full travel. In addition, resettirg was difficult for shorter individuals
due to the location of the reset lever, which is positioned over the exhaust
9312080261 PbR
ZtE
N
o
q
cq;
1s (tat
RoII
<-N 93-96 December 14, 1993 manifold. Operations personnel were subsequently trained on the proper method
for actuating the reset lever. Also, a step was provided to permit easier
access to the lever.
Duane Arnold
On June 11,
1993, while the Duane Arnold plant was operating at 85 percent of
full power, the 'A" EDG tripped approximately 3 seconds after the initial
start signal during an operability surveillance test. An evaluation was
conducted by the licensee of possible EDG trip causes, including occurrence of
an actual overspeed condition, failure of the overspeed mechanism, actuation
of the emergency stop pushbutton, failure of the emergency stop pushbutton, latch assembly not fully latched, latch assembly failure, mechanical trip
mechanism failure, and annunciator circuit or trip lever microswitch failure.
It was concluded that the most probable cause of the trip was that the latch
--assembly was not fully engaged from the previous reset operation and engine
startup vibration unlatched the trip mechanism. Less than complete engagement
of the latch assembly could be caused by an inadequate reset operation.
Corrective actions adopted by the licensee included procedure revisions to
ensure a more positive latching operation, improved physical access to the
reset lever, and operator training.
The procedure revision directs operators to perform the reset operation a
second time following the initial resetting of the trip. The second reset is
somewhat easier to perform and should ensure that the latch is fully engaged
in the event that the initial latching sequence resulted in a partially
latched condition. Verification that the latch is fully seated is
accomplished by checking that the reset lever subsequently moves freely.
Discussion
In response to experience with previous trips during fast starts, the diesel
manufacturer for both plants, (Coltec/Fairbanks Morse Engine Division), had
previously issued a service information letter (SIL, Volume A, Issue 25, dated
August 1, 1991) addressing a revised overspeed trip adjustment. The SIL
recommended that the overspeed trip setting be raised from the range of 112 to
115 percent to the range of 115 to 117 percent. In light of events that
occurred at H.B. Robinson and Duane Arnold, the manufacturer has now advised
these licensees that proper resetting of the trip mechanism would be enhanced
by slowly moving the reset lever fully to the reset position and back, twice.
The inadvertent partial reset latching operations described above may also
occur on other units having similar mechanical trip mechanisms.
- IN 93-96 December 14, 1993 This notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Larry
(404)
Garner, RII
331-4663 Chris
(319)
G. Miller,
851-5111 RIII
Walter P. Haass, NRR
(301) 504-3219 Attachment:
List of Recently Issued NRC Information Notices
Att'achment
December 14, 1993 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
93-93
93-92
91-21, Supp. 1
89-77, Supp. 1
93-91 Storm-Related Loss of
Offsite Power Events
due to Salt Buildup
on Switchyard Insulators
Unauthorized Forced
Entry into the Pro- tected Area at Three
Mile Island Unit 1 on
February 7, 1993
Inadequate Control of
Conditions During Shutdown
Plant Improvements to
Mitigate Common Depend- encies in Component
Cooling Water Systems
Inadequate Quality
Assurance Program of
Vendor Supplying
Safety-Related Equipment
Debris in Containment
Emergency Sumps and
Incorrect Screen
Configurations
Misadjustment Between
General Electric 4.16-KV
Circuit Breakers and Their
Associated Cubicles
12/13/93
12/09/93
12/08/93
12/07/93
12/07/93
12/03/93
12/03/93
All holders of OLs or CPs
for nuclear power reactors
located close to a large
body of salt water.
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors
and all recipients of
NUREG-0040, license Con- tractor and Vendor Inspec- tion Status Report' (White
Book).
All holders of OLs or CPs
for nuclear power reactors.
All holders of OLs or CPs
for nuclear power reactors.
. OL = Operating License
CP - Construction Permit
IN 93-96 December 14, 1993 This notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Larry
(404)
Garner, RII
331-4663 Chris
(319)
G. Miller,
851-5111 RIII
Walter P. Haass, NRR
(301) 504-3219 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL*
l REGION III*
REGION II*
VIB/DRIL*
VIB/DRIL*
NAME
WHaass
CHiller
LGarner
UPotapovs
LNorrholm
DATE
09/09/93
09/09/93
08/30/93
09/10/93
09/15/93 TECH ED*
DRIL/NRR*
EEKB/NRR*
OGCB/DORS* 1 C:OGCB/DORS*
D:
N
DGable
CERossi
CBerlinger
PCWen
GHMarcus l
09/14/93- 09/20/93
10/21/93
11/10/93
11/16/93
12/7/93 OFIICIAL ---
U~
KJUL4
4NL
s~~r
I
OFFICIAL RECORD COPY
WULUMMNT NAME: VJ-V0.1N
IN 93-XX
December xx, 1993
This notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Larry Garner, RII
(404) 331-4663 Chris
(319)
G. Miller, RIII
851-5111
Walter P. Haass, NRR
(301) 504-3219 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL*
REGION III*
REGION II*
VIB/DRIL*
l VIB/DRIL*
NAME
WHaass
CMiller
LGarner I
UPotapovs
LNorrholm
DATE
09/09/93
09/09/93
08/30/93
09/10/93
09/15/93 TECH ED*
DRIL/NRR* FEEKB/NRR*
OGCB/DORS*
C:OGCB DORS* lD:DORS/NRR
DGable
CERossi
CBerlinger
PCWen
GHMarcus
BKGrimes
09/14/93
09/20/93
10/21/93
11/10/93
11/16/93
12/ /93 UIIILIRL nrLLUrU Luryv
UULrIs~r~II slaver.
1NrrubrT.wen..._
MtLUAL KtLUKU LUFT
00CUMEN1 NAME:
Mtubbl.wen
IN 93-XX
November xx, 1993
This notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Larry Garner, RII
(404) 331-4663 Chris
(319)
G. Miller, RIII
851-5111 Walter P. Haass,
(301) 504-3219 NRR
Attachment:
List of Recently Issued NRC Information Notices
r III
.1,
- SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL*
REGION I*
REGION II*
VIB/DRIL*
VIB/DRIL*
NAME
WHaass
CMiller
LGarner
UPotapovs
LNorrholm
DATE
09/09/93
109/09/93
08/30/93
09/10/93
9/15/93 TECH ED*
DRIL/NRR*
EEKB/NRR*
OGCB/DORS*
C:OGCB/DORS
D:DORS/NRR
DGable
CERossi
CBerlinger
PCWen
GHMarcu l r- BKGrimes t
09/14/93
09/20/93
10/21/93
11/10/93
11/16/93
11/ /93
%rrTrTAI
TA
pretinn FAnu
r%^Opalkdr-af,-
,IAar
T.
urr ll.1lL KKORD^
COPY
UUUUMLN I NAME:
INEDGi3 I.wen
IN 93-XX
October xx, 1993 This notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Larry Garner, R11
(404) 331-4663
Chris G. Miller, RIII
(319) 851-5111
Walter P. Haass, NRR
(301) 504-3219 Attachment:
1. List of Recently Issued Information Notices
- SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL*
REGIONX*
REGION II* VIB/DRIL*
VIB/DRIL*
NAME
WHaass
CMiller
LGarner
UPotapovs
LNorrholm
DATE
09/09/93
09/09/93
08/30/93
09/10/93
09/15/93 TECH ED*
DRIL/NRR* l EEKB/NRR*
lOGCB/DORS
C:OGCB/DORS
D:DORS/NRR
DGable
CERossi
CBerlinger
PCWen10l GHMarcus
BKGrimes
09/14/93
09/20/93
10/21/93 1
11/10/93
11/
/93
11/ /93
OFFICIAL RECORD COPY
DOCUMENT NAME:
INEDGST.wen
J re I'
P:1 4. 14"3 r
0
'S'0
Cf;'
c
m.1&4,rt )
e
Ads L44 (^ MosP;
f"JA )
WtA,. bftVgJz
wltu
coca
d
e4
4
- Sa
'
She ver1s! COMal
A
4aC,
kry04;tr- peIIo
IN 93-XX
October xx, 1993 This notice requires no specific action or written response. If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Larry Garner, RII
(404) 331-4663
Chris G. Miller, RIII
(319) 851-5111
Walter P. Haass, NRR
(301) 504-3219 Attachment:
1. List of Recently Issued Information Notices
- SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL*
REGION I*
REGION II*
VIB/DRIL*
VIB/DRIL*
NAME
WHaass
CMiller
LGarner
UPotapovs
LNorrholm
DATE
09/09/93
09/09/93
08/30/93
1 09/10/93
09/15/93 TECH ED*
DRIL/NRR* J
EEKB/NROM OGCB/DORS
C:OGCB/DORS
D:DORS/NRR
DGable
CERossi
CBerlinger
PCWen
GHMarcus
BKGrimes
09/14/93
09/20/93
10/13/93
10/
/93
10/
/93
10/ /93
OFFICIAL RECORD COPY
DOCUMENT NAME:
INEDGST.wen
IN 93-XX
October xx, 1993 Discussion
The staff is continuing its review of the above events with the manufacturer
of the diesel engines, Coltec/Fairbanks Morse Engine Division, to arrive at a
more detailed and consistent set of procedures to assure a positive latching
operation.
In addition, it should be noted that other diesel engine
manufacturers may have similar mechanical trip mechanisms, and licensees
should be aware that potential inadvertent partial reset latching operations
may also occur on those units.
This notice requires no specific action or written response.
If you have any
questions about the information in this notice, please contact one of the
technical contacts listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Chris G. Miller, RI at Duane Arnold
(319) 851-5111
Larry Garner, R11
(404) 331-4663
Walter P. Haass, NRR
(301) 504-3219 Attachment:
1. List of Recently Issued Information Notices
- SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL
REGION I
REGION II
VIB/DRIL
VI5/YOL
NAME
WHaass
CMiller
LGarner
UPotapovs
1; R
holm
DATE
9 / 9/93*
9/9/93*
8/30/93*
9/10/93*
l
C//) /93 COPY
YES
NO
YES
NO
YES
NO
YES
NO
6 NO
DOC
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_ _
_ _ _ _
_ _ _
_ _ _
_ _ _ _ -
r-
1II
OFFICF I TFCH FDTTOR
DRTI /NRR
OGCE/NRR
EELB/NRR
DORS/NRR
-o
-vo
.
- v.--f""---
---
-
I------
-li~~
-i -~~ -I~ ~-
--
-- -
NAME
C
AiiI7%iiiI
GMarcus
CBerlinger
BGrimes
DATE
) p
/93
1 61A/93
/ /93
/
/93
/ /93 COPY
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
D
O C
_
_
_
_
_
_
_ _ __
__
_
__
_._ 1 1 _ _ _ _ _ .
_ _ _ _ _
~~~~~~~~~~I........
% - ..-
-
I
-
P -
T hu rni-FT
UttLLIAL KtLUKU LUFY
UOCUMenll Namie: U\\lnCUva1
IN 93-XX
October xx, 1993
Page.4 of 3 Attachment:
1. List of Recently Issued Information Notices
SEE PREVIOUS CONCURRENCE
OFFICE
VIB/DRIL
REGION I
REGION II
VIB/DRIL
VIB/DRIL
NAME
WHaass
CMiller
LGarner
UPotapovs
LNorrholm
DATE
9 / 9/93*
9/9/93*
8/30/93*
9/10/93*
/
/93 COPY
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
DOC
OFFICE
TECH EDITOR
DRIL/NRR
OGCB/NRR
EELB/NRR
DORS/NRR
NAME
a 44, CERossi
GMarcus
CBerlinger
BGrimes
DATE
7 /
9
/
/93
/
/93
/
/93
/
/93 COPY
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
DOC
U-II
IEODCP
DouetNm:G\\NDS
OFFICIAL RECORD COPY
Document Name: G:\\INEDGST
IN 93-XX
October xx, 1993 Discussion
The staff is continuing its review of the above events with the manufacturer
of the diesel engines, Coltec/Fairbanks Morse Engine Division, to arrive at a
more detailed and consistent set of procedures to assure a positive latching
operation.
In addition, it should be noted that other diesel engine
manufacturers may have similar mechanical trip mechanisms, and licensees
should be aware that potential inadvertent partial reset latching operations
may also occur on those units.
This information notice requires no specific action or written response.
If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Chris G. Miller, RI at Duane Arnold
(319) 851-5111
Larry Garner, RII
(404) 331-4663
Walter P. Haass, NRR
(301) 504-3219 a.?
Attachment:
1. List of Recently Issued Information Notices
' CL
1-e
OFFICE
VIBDRIL
E
VIBD
VIB/DRIL
NAME
WHaass
amfil
F 4It
_f arne r A
UPot
V
LNorrholm
DATE
9/ 9/93
?9//93
93
/
/93
93/
/93 COPY
Y
NO
E
NO
Y
NO
YE
NO
YES
NO
D o c_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_ _
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
OFFICE
DRIL/NRR
OGCB/NRR
EELB/NRR
DORS/NRR
NAME
CERossi
GMarcus
CBerlinger
BGrimes
DATE
I /93 I /93 I
/93 I /93 COPY
YES
NO
YES
NO
YES
NO
YES
NO
DO
.J__ __ _ _ _ _ _ _ _ ___
.,
__
__
__
_
_
.
___________A
_
_
i_ __
_
_
_
_
_
DO-CIA
EODCP
ouetNm:G\\NDS
MFICIAL RECORD COPY
Document Name: 6:\\INEUGST