ML20046C611
| ML20046C611 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/04/1993 |
| From: | Baker E Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-M86911, NUDOCS 9308110225 | |
| Download: ML20046C611 (16) | |
Text
.
gusg j
Q 3
E UNITED STATES i
"I NUCLEAR REGULATORY COMMISSION
,/
WASHINGTON, D.C. 2055MD01
- ++
August 4, 1993 Docket No. 50-458 LICENSEE: Gulf States Utilities FACILITY: River Bend Station
SUBJECT:
SUMMARY
OF MEETING REGARDING REACTOR VESSEL LEVEL INSTRUMENTATION MODIFICATIONS (TAC NO. M86911)
On May 13, 1993, the staff met with representatives of Gulf States Utilities (GSU) to discuss the status of the licensee's efforts to implement modifications to the reactor vessel level instrumentation. The licensee made a presentation on their approach, status, and schedule for completion. The topics discussed appear on the enclosed copy of the agenda.
The licensee proposed that they would implement two modifications to resolve the degassing issue. The fuel zone level instrumentation would be modified to create a core range monitor that will measure level from -11 inches to -310 inches from instrument zero. The licensee's position is that the core range monitor addresses the concern of rapid depressurization because it would not i
be susceptable to degassing and provides an appropriate range of level indication. The licensee also intends to install a system to provide backfill flow to the reference legs. However, the licensee proposes to backfill on an intermittent basis rather than on a continuous basis. With the core range monitor addressing rapid depressurization, the only concern is slow depressurization during shutdowns. The licensee would backfill the reference legs prior to going below 450 pounds to remove non-condensable gases.
The completion of the engineering and procurement for the backfill modification is currently scheduled for the end of October 1993. The licensee proposed that they would install the core range monitor during the next cold shutdown scheduled to exceed 15 days and would delay the installation of the backfill modification until the next refueling outage, presently scheduled for March / April 1994. The licensee also stated that the written response to Bulletin 93-02 would document the presentation made during the meeting.
\\
93081'3225 930804 PDR
,6DCK G5000458 P
ppyy
()\\
1 a! *
\\;
~ August 4, 1993 The staff stated that they would review the licensee's proposals upon receipt of the written submittal.
At the end of the meeting the licensee stated that the plant is currently in cold shutdown and startup may not occur until July 31 or August 1.
The licensee then asked if the NRC would require them to remain shutdown and install the backfill modification if startup was delayed until after July 30, 1993. After consultation with the Director, Division of Systems Safety and Analysis, the licensee was informed that if startup was delayed until after July 30, 1993, the NRC would not require that the plant remain in cold shutdown until the modification was installed.
Original Signed By Edward T. Baker, Senior Project Manager Project Directorate IV-2 Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation l
Enclosures:
DISTRIBUTION 1.
Agenda Docket File 2.
List of Attendees NRC PDR i
Local PDR i
cc w/ enclosure:
PDIV-2 R/F See next page TMurley FMiraglia JPartlow JRoe EAdensam EBaker EPeyton 0GC EJordan NRC Participants ACRS (10)
JMitchell JGagliardo, RGN-IV 0FFICE PDIV-2/LA PDIV-2/PM PDIV_2/D EP$y'ifn#
EIaNrhe SBlh N
DATE 8/'i/93 8/Y/93 8/N/93
/ /
/ /
COPY ES NO
'YES/NO YES/fl0)
YES/NO YES/NO
^
OFFICIAL RECORD COPY
~~
FILENAME: B:\\MTG7-27.RB
- August 4, 1993 cc:
Winston & Strawn Ms. H. Anne Plettinger ATTN: Mark J. Wetterhahn, Esq.
3456 Villa Rose Drive -
1400 L Street, N.W.
Baton Rouge, Louisiana ' 70806 Washington, D.C. 20005-3502 Gulf States Utilities Mr. Les England ATTN: Mr. Philip D. Graham Director - Nuclear Licensing Vice President (RBNG)
Gulf States Utilities Company Post Office Box 220 St. Francisville, Louisiana 70775 St. Francisville, Louisiana 70775 Mr. Philip G. Harris Cajun Electric Power Coop, Inc.
10719 Airline Highway P. O. Box 15540 Baton Rouge, Louisiana 70895 Senior Resident Inspector P. O. Box 1051 St. Francisville, Louisiana 70775 President of West Feliciana Police Jury P. O. Boy. 1921 St. Francisville, Louisiana 70775 Regior,al Administrator, Region IV U.S. Nuclear Regulctory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Mr. J. David McNeill, III William G. Davis, Esq.
Department of Justice Attorney General's Office P. O. Box 94095 Baton Rouge, Louisiana 70804-9095 Administrator Louisiana Radiation Protection Division P. O. Box 82135 Baton Rouge, Louisiana 70884-2135
2.
RIVER BEND STATION REACTOR WATER LEVEL INSTRUMENTATION PRFSENTATION TO NRC JULY 27,1993 i
INTRODUCTION AND PURPOSE JIM BOOKER RECOMMENDED PLAN AND SCIIEDULE JOIIN IIAMILTON ACTIONS IMPLEMENTED TO DATE JIM MORGAN IIARDWARE MODIFICATION OITIONS RICII BUELL BACKFILL (CONTINUOUS / INTERMITTENT)
CORE RANGE MONITOR COMBINATIONS PSA EVALUATIONS JOE BURTON BASELINE (NO MODS)
CONTINUOUS BACKFILL CORE RANGE MONITOR WITII MANUAL BACKFILL BOTII MODS. WITII ONLY INTERMFITENT USE OF BACKFILL PROBABILITIES FOR JULY 30,1993 VS. REFUEL 5 DISCUSSION ALL
~
RECOMMENDED PLAN AND SCIIEDULE PREFERRED APPROACII AS SUPPORTED BY PSA 1.
INSTALL CORE RANGE MONITOR AT NEXT COLD SIIUTDOWN OF SUFFICIENT DURATION (> 15 DAYS) 2.
CONTINUE ENIIANCED MONITORING AND MANUAL BACKFILL PROCEDURES TO SUPPORT SIIUTDOWNS 3.
RECEIVE ALL PARTS FOR BACKFILL MOD. AND COMPLETE DESIGN PACKAGE AS SOON AS POSSIBLE 4.
DESIGN, INSTALL, AND TEST TEMP. MOD. FORTRANSMFITER SENSITIVITY. RESOLVE ANY IDENTIFIED UNACCElrrABLE PERTURBATIONS WITII DESIGN ENIIANCEMENTS.
5.
WIIEN TESTING IS COMPLETED AND ALL OTIIER SAFETY CONCERNS ARE ANSWERED COMPLETE INSTALLATION DURING RF 5.
Y t
i D
t Q
t r
tR uo-5 C
L T
RA T
s P
r 1J
=
2 q
1C EM S
y n i11ifli'_
- A g
c E
g TF OI N
A
/
o 3
1 It I IIIllIi III!
- ii 1 i Ily
/
D S
9
/
Y S
c A
L 5
D D
N w
E P
O 1>
S C
N O
S U
O T Y R
W i
R Tl i
t t
j A
v t
N P i 6
t l
G A IiII t /
C -
i Q
B F
T I
IL 9
t R
x R
C I
N A
O A B
A N V E A P
C P
L 1
t O
L
[
3/
v l
8 t
Q D
O M
t f
,'8II o,1Iiil{
LW
~
R R
3 O
i
~
'i3Ill
,II S iI I I!
- Il1II!
- ,teet'
/
F s
W SY S
L E
T A
R N
1
\\
Y O
A R
T Y
t P
E y
P D
D M
t U
A R
it q
S C
O s
L t
4 N
D O
I 5
~
3 s
y P
U T
t D
C N
O n
N E
l W
i TI S,
O L
t u
T W
r U
C U
(
l O
R t
D I
i s
R r
M l
O t
J P
s E
C M
R E
P R
A t
F e
t U
O M
l C
F A
U C
C i
M A
T C
B w
P P
L 0
S A
R N
t t
R N
O G
N t
M t
F I
N v
S t
r E
I O
t, G
D t
S R
tO
~
O/
pc
~
7
~
7
~
t s
C s
S t
N t.
L E
a N
E G
t S
I N
S s
!t E
t, L
x Y
D c
D s -
A ti R
N T
Y A
A N
U W
u G
R R
R G
N I
O A
4 S
N M
G h
V ft O
O' l
t E
f n
u o
N A
m C
it r
I r
C f
T C
P S
t
/
S e
GO R
r O
O O
On
]
~
ACTIONS TAKEN TO DATE VERIFIED STEAM INLET AND REFERENCE LEG 9/92 INSTALLATION AND INSULATION PERFORMED COST ESTIMATE FOR POSITIVE VENT MOD 10/92 CONDUCTED OPERATOR TRAINING ON NON-CONDENSIHLE 12/92 GAS ISSUES & BWROG LTRS92-096 & 92-125 CONDUCTED TRAINING ON VIDEO TAPE FOR RAPID 1/93-2/93 DEPRESS. ONE POINT CALIBRATION (GE/ BWROG EPC)
MONITORED FOR NOTCIIING DURING SIIUTDOWN - NONE FOUND 4/I7/93 PERFORMED ASME PIPE ROUTING WALKDQ.WN 4/19-4/23/93 (FOR POSITIVE VENT MOD.)
CONDUCTED INTENSIVE LICENSED OPERATOR TRAINING 6/5-6/12/93 ON NON-CONDENSIBLE GAS LSSUE, WNP-2 EVENT, RIIR INVENTORY LOSS SCENARIOS, SAITTY ASSESSMENTS, ENIIANCED MONITORING, PROCEDURE CIIANGES DEVELOPED AND INSTALLED MODIFICATION TO 6/10/93-PROVIDE FOUR NARROW RANGE LEVEL CIIANNELS WITII BETI'ER RESOLIII' ION IN TIIE CONTROL ROOM
ACTIONS TAKEN TO DATE REVISED SIIUTDOWN PROCEDURE TO REQUIRE BACKFILL OF 6/12/93 REFERENCE LEGS PRIOR TO DEPRESSURIZING BELOW 450 PSIG, INCREASE LEVEL MONITORING USING FOUR CIIANNEL CRT DISPLAY AT 600 PSIG, CAUTION ABOUT NOTCIIING AND DEGASSING EVENTS DURING DEPRESSURIZATION, BACKFILL A CIIANNEL TIIAT EXIIIBITS NOTCIIING.
REVISED RIIR SOP CAUTIONING ABOUT NOTCIIING AND 6/12/93 DEGASSING DURING SIIUTDOWN.
WALKED DOWN POTENTIAL ROUTING OF TUBING 6/29/93 FOR BACKFILL SYS. AND TEMP. MOD. ON 5" POT FOR SENSITIVITY TEST PRELIMINARY SYSTEM DESIGN COMPLETED 7/2/93 AND SENSITIVITY TEST MOD. DESIGN COMPLETED BEGAN SEARCII AND SELECTION OF MAJOR COMPONENTS 7/5/93 FOR BACKFILL SYSTEM (METERING VALVES, FLOW METERS, ASME VALVES,ETC.)
MONITORED FOR NOTCIIING DURING SIIUTDOWN 7/13/93'
- NONE FOUND
ACTIONS TAKEN TO DATE INITIATED DESIGN OF tulle ROUTING, 7/19/93 SELECTION OF EXISTING SUPIVRTS &
NEW SUPPORTS, UPDATING OF ASSOCIATED DRAWINGS, AND COORD. SUPPORTS LOAD ANALYSIS W/ ENGR.
k
IIARDWARE MODIFICATION OITIONS PREFERRED PASSIVE MOD. SUCII AS POSITIVE VENT TO MAIN STEAM LINE ONLY VIABLE FIX IN REASONABLE TIME FRAME IS BACKFILL MOD CORE RANGE MONITOR WILL IIANDLE RAPID DEPRESSURIZATION SCENARIO CONCERNS INTERMITTENT BACKFILL AND CORE RANGE TOGETIIER COVER ALL SCENARIOS AND REDUCE CORE DAMAGE FREQUENCY (PER PSA)
I s
I f
-w,,;
w e-
--cww
, e w-
-w m,-i-e,+
-,, - +.
.v.
---e vor.---
-+-,,-+,--S+-,,sm
-,,.<-tv
-rw
-w
-,-r 3-
+
--v'-
w v--
~--.-,,*--r
- =*.
<w-1 s -we
~.
LIARDWARE MODIFICATION Ol'rIONS PLAN t
DEPRESS. RATE INTERIM OPERATIONS FINAL CONDITION RAPID AWARENESS, TRAINING, CORE RANGE MONITOR POST ACCIDENT ONE (FIRST COLD S/D AFFER 7/30/93.0F POINT CALIBRATION PER
> 15 DAYS)
VIDEO SLOW MANUAL BACKFILL PRIOR BACKFILL MOD. WTI"lI TO 450 PSIG, ENIIANCED INTERMrlTENT/ PERIODIC MONITORING, TRAINING, OPERATION AWARENESS (INSTALL DURING REFUEL 5) l l
l l
. - ~.. ~. -.
~ ~..
m.
_ v.
i E
{i t,5 'I 1.T
- 1
-n i, I
i i.
.r.i 1
1 Ml 9
i i ij
~ =
4 i
4 h.
t 5
t-t~.--
f I
t I
1 I
T I
l i-ci
.:, i, t 1,l i.
=
v ' l, g
t-c- - -~-
a I
- s I
i lI.
i>
dI a
n
~
j
- Ni' 1
1, ii
, s..
e
~
,1
~J
---]
-++-]
,-+ -]
14.
sp;
/
/
sgs.
- "-3 3
3 3
,l, l
II!!
" -]
]
]
I.;>y l;>y i;>I
~
_9
_9
~ _
8, 8
4._
I, 1
1, 1,
I i.x i
I V
y y
g I'
M 1
g
}k; 4
s 5 6 g
i
-(= *
~
- L,
+
1 1
a s
W
6 9
I l
I A
1 1
A 1
- "),
e M
B:
=,l}
i I
F i
i l
i
\\\\
l l
t n
[II(
)
e
j 1
7 i
I l
I j
i IMPACT OF Mf7UENCE LEO OPTIONS ON CDF l
i r
1.76E OS 1.76E46 l
1.80E-05 --
{
l l
1.66E46 l
1.66E46 1.60E-05 --
1.40E-05 --
T N dI N M U:,
.;kt) l i
1.20E -
l 1.00E -
l l
8.00E -
6.00E 06 -
4.00E -
l l
2.00E 0.00E + 00 -
IPE BASELINE NO BACKFILL CONT. BACKFILL MANUAL BACKFILL l
5 soO O inANs.
E tose O T iNouCEo toCA l
l
SAFETY IMPACT OF REFERENCE LEG OPTIONS y
IPE BASELINE 1.55E-5/YR PHENOMENON WAS NOT MODELED NO BACKFILL 1.76E-5/YR 13% INCREASE IN CDF OVER IPE (TRANSIENT ACCIDENT SEQUENCES) 100" LEVEL ERROR IMPACTS OPERATOR RECOVERY OF LONG TERM CORE COOLING CONTINUOUS 1.76E-5/YR RESOLVES TRANSIENT BACKFILL PROBLEM, BUT INTRODUCES NEW FAILURE ' MECHANISM (CHECK VALVE LEAKAGE)
DURING LOSP ACCIDENT SEQUENCES MANUAL 1.55E-5/YR CORE RANGE MONITOR BACKFILL ELIMINATES TRANSIENT (PLUS CORE ACCIDENT SEQUENCES.
RANGE MONITOR)
MANUAL BACKFILL IS NOT AS SUSCEPTIBLE TO CHECK VALVE LEAKAGE
^
s
t i
ENCLOSURE 2 1
MEETING ATTENDEES July 27, 1993 GSU 1 NRC HAME AFFILIATION Edward Baker NRC/NRR/PD IV-2 I
-Elinor Adensam NRC/NRR/DRPW/AD45 l
Dave Trimble
'NRC/NRR/PD II-4 Joe Williams NRC/NRR/PD II-4 Jim Clifford NRC/NRR/PD V t
Suzie Wittenberg-NRC/NRR/PD IV-2 Robert Jones NRC/NRR/DSSA/RXSB Jerry Carter NRC/NRR/ DORS /0EAB Tomoho Yamada
""C/NRR/ DORS /0EAB
-l Jim Booker GSU John Hamilton GSU Lesley England GSU Joe Burton GSU:
Richard Buell GSU-David Lorfing GSU' Jim Morgan GSU-Charles Williams NUS
- -