ML19332F081
| ML19332F081 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 12/01/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-318C, NUDOCS 8912130373 | |
| Download: ML19332F081 (8) | |
Text
1 l
VIRGINIA ELECTRIC AND POWER COMPANY J
RicnMoNo, VIRGINIA 23261 December 1,1989 U.S. Nuclear Regulatory Commission Serial No.
89 3180 Attention: Document Control Desk -
PES /JRH R1 Washington, D.C. 20555 Docket No.
50 338 License No. NPF-4 i
Gentlemen:
i VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER _SIATION _UlilI_1 MODIFIED. Twn,. TEMPERATURE REDUCTION PROQRAM REVISED RELOAD INFORMATION FOR CYCLE B 1
North Anna Unit 1 has implemented the THot temperature reduction project described j
in our letter dated September 14,1989 (Serial No. 89 646) and is currently operating with a E F reduction in average Reactor Coolant System (RCS) temperature.
However, operating system interaction and responsiveness problems associated with l
the turbine-generator electro-hydraulic control system and the turbine governor valves have resulted in a reduction in core power to less than rated thermal power in order to maintain the fuli 6*F reduction in average RCS temperature it has been determined that the plant can return to and maintain rated thermal power with an average RCS temperature of 583.0*F (i.e.,3.8*F reduction from the original 586.8*F in lieu of the 6 F reduction).
c The Cycle 8 reload core has been reanalyzed for an average RCS temperature of i
583.0*F which may be implemented between the current burnup and 9000 MWD /MTU.
implementation of this modified THot temperature reduction program recuires that the N zu function for normal operation be revised. Therefoie, the Core Surve llance Report fo(r North Anna Unit 1 must be revised to reflect this new operating temperature an revised N(z) function for normal operation. This letter transmits to you a revised Core Surveillance Report containing the specific power distribution limits for Cycle 8 operation with the modified temperature reduction.
The Cycle 8 core with the modified temperature reduction was analyzed in accordance l
with the methodology documanted in approved topical report VEP FRD 42. Revision 1 A, " Reload Nuclear Design Methodology," using the NRC approved codes as referenced in the topical report. The information in the report was developed in accordance with our topical report VEP-NE 1 A, " Relaxed Power Distribution Control Methodology and Associated FO Surveillance Technical Specific &tlons."
The analyses were performed and reviewed by our technical staff. The reeults of the analyses indicated that no key analysis parameters would become more limiting j-
. during Cycle 8 operation with the modified temperature conditions than the values i
P l
I
assumed in the applicable stsiety analyses of the UFSAR and as specified in the Nodh Anna Unit 1 Technical Specifications.
The Core Surveillance Report provid9d as Attachment 1 consists of the Cycle 8 Np function and the Axial Flux Difference Limits for operation following implementation c}i the increase in average RCS temperature to 583.0'F. The limits presented in the Core Survelliance Report are based upon the current total peaking factor (Fo) limit of 2.10 and the LOCA analysis assumption of 15 percent Steam Generator tube plugging.
Technical Specification 6.9.1.7 requires that tlie Core Surveillance Report be provided to the NRC sixty days prior to the date the information provided in the report becomes effective unless otherwise approved by the NRC by letter. However, because North Anna Unit 1 is currently operating at approximately 98% rated thermal power, we prefer to take advantage of this revised Core Surveillance Report as soon as possible.
Therefore, in accordance with the allowed Technical Specification provision, we request the sixty day advance submittal requirement of Technical Specification 6.9.1.7 be waived by the NRC and allow us to implement this revised Core Surveillance Report in an expeditious manner.
' A review has been performed by the Station Nuclear Safety and Operating Committee.
It has been determined that no unreviewed safety question as defitted in 10 CFR 50.59 will exist as a result of operation at an average RCS temperature of 583.0*F.
Our assessment of the impact of th!s modified temperature reduction has determined that no core alterations nor physical changes to plant systems are necessary, in addition, no Technical Specifications changes or changes to the conclusions of any safety analysis described in the UFSAR are required for this modified THot temperature reduction program.
Very truly yours, k.
N W. L. Stewart Senior Vice President - Nuclear Attachment
(
1.
Core Surveillance Repoit for North Anna Unit 1, Cycle 8 oc:
U.S. Nuclear Regulatory Commission l
Region ll l
101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. J. L. Caldwell l
NRC Senior Res dont inspector North Anna Power Station
e Attechment 1 p
I: e, r
l s
. Core Surveillance Report for North Anna Unit 1 Cycle 8 Modified Temperature Reduction Program 1,
l l-L i
I l
4 l-E I
1.
f.i[
3, ;
'}
~
'~
7 6-i;[, g f:'.
,m-i:
NORTH ANNA UNIT l' CYCLE 8 CORE SURVEILLANCE rep 0RT~
r FOR REDUCED TEMPERATURE OPERATION s
E This Core Surveillance Report is provided ir, accordance with Section Kl,
6.9.1.7-of the North Anna Unit 1 Technical Specifications, s.
t
, 7 The bu.nup-dependent Cycle 8 N(z)' function for Technical Specification L
4.2.2.2'C is shown in Figures 'l-3.
N(z) was calculated according to the T y; procedure of VEP-NE-1-A..
3 zThe N(z) function
- will be used to confirm that:the heat flux hot channel
+
factor, FQ(z), will.be limited to the Technical Specifications values of p
l 2.19.K(z) 4 FQ(z) 5.-----------.,- P > 0.5 and P-4 FQ(z) s 4.38 K(Z),
P s 0.5.
7, The: Cycle 8 Axial Flux Difference (AFD) limits for Technical Specification 3.2.1 are.shown'in Figure 4
~These limits were calculated according to the methods of.VEP-NE-1-A and are comparable to. the previous Cycle 7 limits.
The-limits on Axial Flux Difference assure that the FQ(z) upper bounc envelope is not exceeded during either normal operation or in the event of xenon redistribution following power changes.
o
- The N(z) function, when applied to a power distr'bution measured under
- equilibr N 1 conditions, demonstrates that the init.ial conditions assumed in the LOCA~ analysis are met, along with tne ~ CS acceptance criteria of 10CFR50.46.
W
p; w
V
.[
7 L'%
l s[b 1:
g w
FIGURE 1 - WZ) FUNCTION FOR NIC8 AT-2893 MW.
b; 5
- REDUCED TEMPERATURE OPERATION f'
FROM 50G0 to 7000-MWD /MTV BURNUP iOP AND BOTTOM 15 PERCENT EXCLUDED 4-nS PER TECll SPEC 4.2.2.2.G HEIGHT N(Z)
.(FEET) a.
-10.20' 1.198 g
10.00 1.193 h
9.80 1.186 9.60 1.180 1.2E+00 9,40 1,177 J
l 9.20 1.181 N."
\\
9.00 1,188 A
8.80 1.198 i
3.60
-1.204 i
I
)
8.40
.1.208 3
4 t,
- 1. 22 + 001 -
I t
I
-l l
8.20 1.210 8.00 1.210
.=-
i 1
1 7.80 1.208 r
1
[]
7.60 1.205
=
1 7.40 1.200 g
/
I 7.20 1.199 E
I~
k t
UI1.18+00 l
\\
l 7.00 1.194 6.80 1.188
=
y
~
/
6.60 1.184
~5
/
6.40 1.179 6.20 1.172
-5 l
6.00 1.164
't 5.80 1.154 g.1.14+00 l
I 5.60
'1.142 1
'5.40 1.130 i
1 5.20 1.119 4
s l
\\
l 5.00 1.120
~
4.80 1.126 4.60 1.134 1,10+00 4.40 1.142 4.20 1.150 0.00+00 2.00400 4.00+00 6.00+00 8.00+00 1.00+01 4.00 1.158 COREHEIGHT(FEET) 3.80 1.165 3.60 1.171 3.40 1.176 3.20 1.182 N1C5/ ANN (2)FUNCTIONFOR 5000-7000 HD/NTUBURNUP 3.00 1.194 2.80 1.206 2.60 1.218 2.40 1.228 2.20 1.238 2.00 1.246 1.80 1.254
+
kl[h~h
> y nx 5
4;ic b
FIGURE '2 - N(Z). FUNCTION FOR NICS AT 2893 MW REDUCED TEMPERATURE OPERATION k.
FROM 7000 to 16000 MWD /MTU BURNUP TOP AND BOTTOM 15 PERCENT EXCLUDED cAS-PER TECH SPEC 4.2.2.2.G i
HEIGHT-N(Z)~
(FEET)-
10.20 1.200 10.00 1.196 9.80 1.190 9.60 1.184
.1;2000 9,40 1,178 9.20-1.185-9.00 1.198 i
eS 3.80 l.'213 l
l 3.60 1.225 I
i 40-1.234 1.24+001 L
i i
I I
I l
\\
l i
i 8.20 1.242 5
,b j
B.00 1.249 ac 7.80 1~.255
{
- /
7.60 1.260 7.40 1.263
--:a' 7.20 1.265-i 1;20+H 7.00 1.264 5
6.80 1.262 f
1 6.60 1.256 5
6.40 1.250 t
6.20 1.240 g.
f3 6.00 1.231
's;
-5.80 1.216 8 \\;15+00 5.60 1.202 i
{
i 5.40 1.183 i
l i
5.20 1.158 I
,\\
I 5.00 1.141
~
V 4.80 1.135 1.60 1.136 1.12t00 4.40 1.139 4.20 1.144 O.00+00 2.00+00 4.00+C0 6.00+00 3.00+00 1.00+01 4.00 1.147 COREHEIGHT(FEET) 3.80 1.150 3
3.60 1.151 3.40 1.150 3.20 1.151 i
N105/ ANN (2)FUNCTIONFOR 7000-16000 WWD/WTUSURNUP 3.00 1.154 2.80 1.161 2.60 1.168 2.40 1.175 2.20 1.182 2.00 1.187 1.80 1.193 i
Il
$ ; - fi o q, u. -.
r j;j
- 1 w
l,v p
,'~
r 1
J r
E<'
FIGURE 3 - N(Z) FUNCTION FOR NICS AT 2393 MW R'
REDUCED TEMPERATURE OPERATION '
FROM 16000 MWD /MTU BURNUP TO EOL f
TOP AND BOTTOM 15 PERCERT EXCLUDED
+
AS.PER TECH SPEC 4.2.2.2.G -
HEIGHT
.N(Z)
(FEET) 10.20 1.200 10.00 1.~196 9.80
~1.190 9.60 1.184 Tl 1.28+00 7.40-1.175~
l S
9.20 1.185 t
9.00 1.198 l
A 8.80 1.213 e
i
'/
.j i
8.60-1.225
~
3,40 1.234 1.24+001 1
- I
/
k i.I 8.20 1.242' 8.00-1.249 g
X
=
7.80 1.255-y
't
/
7.60 1.260 7.40 1.263 k
- d
?
7.20 1;265
\\
7.00 1.264 E f.20t00--
G.80 1.262 y
.p z ;;; _
6.60 1.256 6.40 1.250 f
6.20
.1.240 3
f V
6.00
'1.231 T
g_
_\\
l 5.80 1.216 E ~ 1.10t001 5.60 1.202 i
'l l
l 5.40 1.183.
i i.
5.20 1.158
,w 4
I.
i 5.00 1.141 m
\\
/
V 4.80 1.135
\\/
4.60 1.136 1.12400 4.40 1.139 4.20 1.142 i
0.00+00 2.00+00 4.00+00 6.00+00 8.00+00 1.00+01 4.00 1.142 COREHEIGHT(TEET) 3.80 1.140 3.60 1.138 3.40 1.133 3.20 1.129 4108/AN H(Z) FUNCil0N FOR 16000 WND/WTU SURNUP IO E0L 3.00 1.126 n
2.80 1.128 s
3, 2.60 1.132 2.40 1.141 2.20 1.148 l
2.00 1.157 l
1.80 1.166 l.
1 f
i k. ' s.
p.:
- r
~
9.
4,
- p.
r
^
y
'4;
]
b>
E tE.
. FIGURE AXIAL FLUX DIFFERENCE LIMITS i
m AS A FUNCTION OF RATED THERMAL POWER I
FROM 5000 MWD /MTU BURNUP TO EOLE H
"f FOR NORTH ANNA UNIT 1 CYCLE 8-u.
- REDUCED TEMPERATLRE 0PERATION
{$ '
i b
y y_
.U 1;20+02_
t 4
1.00+02
-12,'.00)
(6 100) y
\\
/
\\
E'
/
i
~
' 's.00+01'
/_
\\
- 3
/
\\ Uriacce;taole
]
\\
Opera tion 5
e
' s. 0 0 + 01,
\\
Acceptable i
y
/
U 3 erat lon
\\
g
/;
)
'e'4.00+01
( -27,5 ))-
(20,50)
O t.
5 J
2.00+01 i
i 0.00+06
-5.00+01
.-3.00401
-1.00601 1.00+01 3.00+01 5.00+01 PERCENTFLUXDIFFERENCE(DELTA-1)
)
j NIC8/ANAfDllWITSFORREDUCEDTfWPERATUREOPERATION NICS/AN Axial Flux Difference Limits l-
.i m
..