ML20236E671
| ML20236E671 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/31/1989 |
| From: | NORTHEAST NUCLEAR ENERGY CO. |
| To: | |
| Shared Package | |
| ML20236E669 | List: |
| References | |
| NUDOCS 8908070039 | |
| Download: ML20236E671 (34) | |
Text
_-__-__ - ___-
4 6
Docket No. 50-336 B13310 Millstone Nuclear Power Station, Unit No. 2 Evaluation of Hot Leg Temperatures July 1989
$$$$ $$0[{f,2g n
l pp a oa 1
l l
EVALUATION OF MILLSTONE 2 HOT LEG TEMPERATURE FLUCTUATIONS
==
Introduction:==
On or about June 1, 1989 C-E was requested by Northeast Utilities to evaluate hot leg RTD temperature data taken at Millstone Unit 2 at the beginning of cycle 10. These data exhibited unusually large fluctuations and side-to-side temperature offsets compared to similar data from earlier cycles. Northeast was aware that C-E had observed similar temperature fluctuations on other plants. This report presents the results, conclusions, and recommendations of
'3 that evaluation.
i The following information was received from Northeast Utilities, and forms the
~
basis of the evaluation:
1.
24-hour temperature traces for hot leg channels A, B, C, and D on l
loops I and 2 taken from 11:59 May 17 to 11:55 May 18, 1989.
2.
Deviations from loop average temperatures for hot and cold leg channels A, B, C, and D on loops 1 and 2 during initial startup of cycle 10.
3.
Deviations from loop average temperatures for hot and cold leg channels A, B, C, and D on loops 1 and 2 for a cycle 9 startup on June 13, 1988.
4.
1 -minute temperature traces for hot leg channels A, B, C, and D on loops 1 and 2 taken between 9:00 and 9:15 on May 15, 1989.
5.
I&C speed trace for about 19 seconds for channel A on loop 1.
6.
Six 1-hour traces for hot leg channels A, B, C, and D on loops 1 and 2 for the period 3:00 and 9:00 on June 2, 1989.
7.
735-minute traces for the following parameters between 00:59 and 13:42 June 1, 1989.
- a. wide range nuclear power
- b. loop 1 and 2 hot and cold leg temperatures
- c. in-phase control and protective channel RTD traces for loops 1 and 2 hot and cold iegs.
8.
1201-minute traces for tSe following parameters between 16:59 June 1, 1989 and 12:59 June 2, 1989.
- a. wide range nuclear power
- b. power range nuclear power for upper and lower detectors for both A and C channels,
- c. loop 1 and 2 hot and cold leg temperatures.
- d. in-phase control and protective channel RTD traces for loops 1 and 2 hot and cold legs.
y Dnllp>a
.y
- e. secondary pressure and level for steam generators 1 and 2.
- f. steam and feedwater flow for loops 1 and 2.
9.
736-minute traces for the following parameters between 00:59 and t
l 13i15 on June 5, 1989.
- a. wide range nuclear power
- b. loop 1 and 2 steam ger.erator. pressure drops.
- c. loop 1 and 2 hot and cold leg temperatures.
I
- d. in-phase control and protective channel RTD traces for loops 1 and 2 hot and cold legs.
- 10. Section from Bechtel drawing showing plan view of the RCS with locations of the A, B, C, and D RTD channels on the hot and cold legs.
1
- 11. Core radial power distribution for one octant from INCA for the-time period over which the above data was taken.
Two separate evaluations of the data were conducted.
Part I reviews the temperature traces, discusses possible causes of the temperature fluctuations and side-to-side offsets, and compares the Millstore 2~ cycle 10 behavior with hot leg temperature fluctuations and offsets that hsve been observed on other C-E plants.
Part 2 addresses the potential impact of the fluctuations and offsets on the behavior of the Thermal Margin Low Pressure Trip system.
i 1
l I
i l
N
- - = - - - _ _. _. - _., _ _ _. _ _ _. _ _ _ _. _ _
q
., y.
l l
s i
i I
1 4
PART 1 i
REVIEW OF MILLSTONE UNIT 2 HOT LEG TEMPERATURE ANOMALY DATA 1
- i to Review of Millstone Unit 2 Hot Leg Temperature Anomaly Data A.
Introduction and Summary During the start-up of Cycle 10 at Millstone Unit 2, fluctuations in the hot leg temperatures were observed.
Cycle 10, which contains Westinghouse and ANF 14x14 fuel, is the first cycle of low leakage fuel management at Millstone 2.
Traces of hot leg and cold leg temperatures, excore signals, and various steam generator signals were transmitted to C-E for review and identification of possible causes based on previous experiences at other C-E plants.
A review of the traces 1ent to C-E identified two types of correlated temperature fluctuations occurring at Mill-stone 2; a short-term fluctuation (20 -120 seconds) which is correlated among the resistance temperature detectors (RTDs) in one hot leg, and a long-term fluctuation (6 - 300 minutes) whi h is correlated between the two hot legs.
The short-term fluctuations have multiple magnitudes and,;for most RTD channels, may be positive or negative in direction, The long-term fluctuations have only two conditions which alternately occur for various lengths of time.
The short-term fluctua-tions occurred more frequently (up to 8 times a minute on Hot Leg 1) than the long-term fluctuations.
Since the steam generator plenums have incomplete mixing, the long-term
'flucutations are observed in the cold leg temperatures.
The magnitude of the cold leg fluctuations are approximately a
~
factor of ten lower than the observed hot leg changes.
No changes which correspond.to the' hot leg temperature fluctua-tions were evident on the traces of the remaining signals transmitted to C-E.
correlated temperature fluctuations within a single hot leg pipe have previously been observed'during the initial start-up at Arkansas-2 and SONGS-3 and during the start-up of.
Cycle 5 at St. Lucie 1.
Extensive analytical and experimental work during the Arkansas-2 start-up showed that the observed
temperature reversals in the hot leg were caused by changes in 1
l the flow patterns between the core exit and hot leg tempera-l ture sensor locations.
It is noted that cycle 5 at St. Lucie 1 and Cycle 10 at Millstone 2 are the first cycles in low leakage fuel management.
The low leakage fuel management profiles have very low power bundles at the core periphery, resulting in larger temperature variations at the core exit and outlet pipes.
Based on the close similarity of the char-acteristics of the short-term fluctuations at Millstone 2 with those observed at other plants, it is felt that the short-term fluctuations are probably caused by flow pattern variations similar to those at Arkansas.
The long-term fluctuations may also be caused by flow pattern changes since there are large temperature variations at the core exit.
Since only two rela-tively stable conditions are observed and because the mechanism which changes the flow pattern sffects both hot legs simultaneously, motion of an internal componant cannot be ruled out, based on the available data, as a possible source of the long-term fluctuations.
It is recommended that further data, using the internals vibration monitoring system, be obtained to investigate the possibility of core barrel motion j
during one of the long-term temperature swings.
B.
Discussion The Millstone 2 plant is arranged such that the two steam generators lie on a line running approximately east and westi Five resistance temperature detectors (RTD's) are installed on the hot leg pipes with the orientation and positions shown in Figure 1.
During the ste.rt-up of Cycle 10, fluctuations of the hot leg temperatures were observed on all channels.
To investigate the nature of the fluctuations, traces of the RTD signals were taken digitally at various sampling rates and sent to C-E for review.
These traces revealed that both
I a
short-term (20 seconds to-2 minutes).and long-term (6 minutes to 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />) fluctuations occurred (Figures 2, 3 & 4).
The short-term fluctuations vary in both direction and magnitude with the maximum observed variations given'in Table 1.
The long-term fluctuations appear to have two semi-steady conditions which alternately exist for time intervals of varying lengths.
The average temperatures, based on the traces, for the two conditions are given in Figure 5.
During a 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> period from June 1st and June 5th, Condition 1
)
occurred 55% of the time and condition 2, 45% of the time.
Additionally, on June 1st and 2nd, Channel A on Hot Leg 2
)
appeared to drift from 602.5'F to 605'F then drop back to l
602.5'F.
During this time, no changes were observed on the other RTD channels, so this temperature drift may not be related to the remaining observed fluctuations.
Traces of cold leg temperature, excore nuclear power, and steam generator Delta P, pressure, level,. steam and feedwater
)
flow signals were also taken to investigate whether corresponding fluctuations occurred on-these channels.
Based on a visual inspection of these traces, corresponding long-term fluctuations are' observed on-the cold leg. temperature signals, Figure 6 & 7, but not on the remaining signals.- It is not possible to visually detect a. cold leg temperature change which corresponds to the short-term temperature fluctuations on the hot legs.
As expected, the cold legs on
)
the north side of the reactor have temperture changes'which agree, in direction, with the observed changes on the north l
side of the hot leg pipes, indicating incomplete mixing in the l
steam generator plenums.
The magnitude of the cold leg temperature changes are approximately a factor of ten lower I
than the hot leg temperature changes.
In the past, hot leg temperature fluctuations have been observed at three other C-E plants, Arkansas 2 and SONGS 3 l
during initial start-up and St. Lucie 1 during the start-up of l
Cycle 5.
The observed characteristics for each plant are given in Section C.
During the start-up of Arkansas 2, l
i f
}'
1
______:__- - -- - ---- Q
4 extensive analytical and experimental work was performed to evaluate the cause of the hot leg temperature reversals and it was concluded that the phenomenon was caused by changes in the flow pattern between the core exit and hot leg RTD locations, and thus had no direct effect on the safety of the reactor.
A comparison of the hot leg temperature fluctuations on the four C-E plants was made to determine the similarities and dissimi-larities of the characteristics observed at Millstone 2 with those observed at the remaining plants.
Based on this comparison, it was observed that:
o The duration of the short-term fluctuations at i
Millstone are on the same order of magnitude as those observed at the remaining plants.
o The temperature fluctuations in the two hot legs were not correlated at both Arkansas and SONGS.
There is an indication that fluctuations occurred simultaneously in both hot legs at St. Lucie 1; however, the magnitudes were less than 1.0* and persisted for only 180 seconds.
The fluctuations also occurred at a less frequent rate than that observed at Millstone.
As a historical note, the thermal shie.d at St. Lucie 1 was removed prior to the start-up of Cycle 6.
However, there is no evidence that the simultaneous hot leg fluctuations and the damage to the thermal shield are related.
The short-term fluctuations at Millstone 2 do not appear to be correlated between hot legs.
o The cold leg temperature fluctuations observed at Millstone are very similar to those observed at Arkansas.
At Arkansas, the transit time between observed hot leg and cold leg fluctuations was measured to be six seconds, the fluid travel time through the steam generators.
1 J
3
.It is noted that Cycle 5 at St. Lucie 1 was the first cycle with low leakage fuel management, as Cycle 10 is the first low leakage cycle at Millstone 2.
The low leakage fuel management profiles have very low power bundles at the l
periphery of the core resulting in larger temperature variations at the core exit and in the hot legs. 'The computer code DELTSTRAT was used with the Millstone 2 relative power j
density map, Figure 8, to predict the hot leg temperature
.(
distribution at the RTD positions assuming no swirl of the j
flow, Figure 9.
The measured temperatures were also input to j
determine the optimum swirl angles to provide the best match j
~
d between predicted and measured temperatures.
.For the two conditions identified in Figure 5, the optimum swirl angles were computed to be:
Condition 1 Condition 2 Rotation Hot Leg 1
-20'
-56'
-36' l
]
Hot Leg 2
+56'
+38'
-18' 1
The angles, with zero degrees at the top of the pipe, are baserf on a view looking downstream toward the steam genera-tors, Figure 3.
The measured temperatures seem to indicate better mixing between the core exit and hot leg RTD positions q
than predicted, but a simultaneous rotation or change of the-flow patterns could cause the observed temperature fluctua-tions.
Based on the close similarity of the characteristics of l
the short-term fluctuations at Millstone 2 with those observed ~
l at other plants, it is felt that the'short-term fluctuations are probably caused by flow pattern variations in the region i
between the core exit and hot leg RTD positions.
These patterns change slightly on a continuous basis with the patterns in one hot leg independent of the patterns in the second hot leg.
Since only two relatively stable conditions are observed for the long-term fluctuations and because the mechanism which changes the flow patterns affects both hot legs simultaneously, motion of an' internal component cannot be ruled out as a possible cause for the long-term fluctuation.
i
s.
^
1 It is recommended that the Internals Vibration Monitoring System.(IVM) at Connecticut Yankee be used with the excore neutron flux detector signals to monitor for core barrel' motion.
It is possible that other mechanisms exist since there'is a larger temperature variation at the core exit due to the present low leakage fuel power distribution.
C. Hot Leg Temperature Fluctuation Characteristics 3
1 on C-E Plants Arkansas 2 - Cycle 1 o
Fluctuation magnitude: Approximately 6*F on top half (high temperature lowered, lov temperature raised) see Figure 10.
Approximately 3.5 - 4.0'F on bottom half (high temperature lowered, low temperature raised).
o Frequency:
6 - 8 per hour on Hot Leg 1 (A_ loop) and j
2 - 3 per day on Hot Leg 2;(B loop) o Duration of fluctuation:
20 - 100 see i
o Typical Pk to Pk noise outside of fluctuations: -10.5'F o
No correlation between_ fluctuations on the-two hot legs-l o
Fluctuations observed on cold legs (east cold: leg'RTD went in same direction as RTD on east side of hot leg).
Magnitude of cold leg fluctuation approximately 1/10th of l
hot leg fluctuation.
j o
pressure measurements with taps on hot legshad-pressure fluctuations which correlated with temperature l
fluctuations.
o No fluctuations observed on core exit thermocouple, i
incore and'excore instrumentation indicated normal core behavior.
o surface thermocouple indicated symmetric temperature profile at outlet nozzle which changed in near' linear-fashion to non-symmetric profile observed at RTD station.
I 1
j
-)
- o. Fo] lowing internals inspection, frequency changed to 1-2 per hour on Hot Leg 1 and fluctuations very infrequent on Hot Leg 2,. indicating a possible relationship between L
UGS-core support barrel alignment and frequency of temperature fluctuations.
j ST. Lucie 1 - Cycle 5 o
Fluctuation:
-0.8*F (high temperature lowered, low temperature raised) See Figure 10.
o Frequency:
Once per 1 to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> o-Duration of fluctuations on chart - 60 see to 600 sec-
~ Typical Pk to Pk noise outside of fluctuations:
o t0.5 to 0.9'F
- o. Most fluctuations observed on Hot Leg 2 o
Some observed on both hot legs - Magnitude on Hot Leg 1 generally had fluctuations.of less than 0.5'F - so difficult to identify (not all channels monitored).
FP&L reported drop of 1.-2*F on all channels for period o
of hours, then return to original value - not observed on strip charts.
o First cycle of low leakage fuel-management.
SONGS 3 - Cycle 1 o
For Hot Leg 1, Fluctuations are: Chn. A
+1.l'F See Figure 10
~Chn. B
+1.5'F Chn. C-
+0.5'F Chn. D'
-2.3*F
~
i o
For Hot Leg 2, Fluctuations are: Chn. A'
-l.0 to +1.5'F
'Chn. B
-1. 0
- F.
Chn. C
+1.0 to'-1.5'F l
Chn. D:
+1.5'to -1.0'F o
Frequency: ~2/ minute on Hot Leg _1, 1/4 minutes on Hot Leg 2 i
I j
r, o
Duration of Fluctuations on chart 100 sec o
Typical Pk to Pk noise.outside of. fluctuations: -
0.7
- F.
o No indication of simultaneous fluctuations on the two hot-legs Millstone 2'- Cycle 10 o
Based on data sent to C-E, two types of fluctuations are observed.
A)
Short-term Fluctuations - magnitudes vary -imaximum values given in Table 1 - see Figures l'and 5.
B)
Long-term Fluctuations - see' Figure 5'for average temperature'for the two observed conditions.
No intermediate long-term positions between those two-
' conditions observed.
o Frequency:
A)
Short-term Fluctuations - up to 8/ minute cn1 Hot Leg 1, only 1/4 minutes in Hot Leg 2.
B)
Long-term Fluctuations - average of 1/90 minutes one both hot legs.
o Duration of Fluctuations on Chart:
A)
Short-term Fluctuations 120 seconds..
B)
Tang-term Fluctuations- - 6 minutes - 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.
o Typical' Pk to Pk Noise Outside of-F.luctuation:
Outside of long-term fluctuations -
0.7'F'to i 2.0*F.
Difficult to evaluate outside of short-term fluctuations, o
Short-term fluctuations on the;two hot legs do not appear.
to be correlated.
Long-term fluctuations on the two hot legs ~are definitely correlated.
v.
o Long-term fluctuations observed on cold legs (north cold leg RTD went in same direction as RTD on north side of hot leg).
Magnitude of cold leg fluctuation approximate-ly 1/10th of hot leg fluctuation.
o Nc corresponding fluctuations visible on traces of nuclear pcwer, steam generator delta P, pressure, level, steam and feedwater flows.
)
l i.
(--.
j i
i TABLE 1
l MILLSTONE UNIT 2 i
MAXIMUM SHORT-TERM HOT LEG TEMPERATURE VARIATIONS (Based On Data From 6/2/89) l I
Long-Term Condition 1 (See Figure 5)
_ Hot Leg i Hot Leg 2 Channel A
+1.3,
-1.8 Channel A
+0.6,
-0.8 B
+0.9,
-1.4 3
+0.7,
-1.0 C
+1.6,
-1.8 C
+1.5,
-1.0 j
D
+1.0,
-1.5 D
+1.7,
-2.2 j
i l
Long-Term condition 2 (See Figure 5)
Hot Leg 1 Hot Leg 2 Channel A
+1.3,
-1.6 Channel A
+1.0,
-1.3 B
+1.0,
-1.4 B
+0.6,
-1.1 C
+1.1,
-1.4 C
+1.3.-
-1.0 D
+1.4,
-1.1' D
+1.8,
-1.5
l
)
l l
. {
l l
i 1
- i4 l
l 2
PART 2 NON-LOCA TRANSIENT ANALYSIS AND TM/LP TRIP CONSIDERATIONS
'i
]
4 j
i l
l i
1 s
i
___________w
~
NON-LOCA TRANSIENT ANALYSIS AND TM/LP TRIP CONSIDERATIONS A.
INTRODUCTION AND
SUMMARY
Since the TM/LP trip is' intended to protect the core from exceeding the DNBR SAFDL, it must be shown analy'tically that.it performs the function during all A00's. When necessary, the TM/LP trip setpoint is altered through the alpha, beta, gamma, A-0NE and.Q-R ONE constants.
Because the dynamic response to the A00's can change from cycle to cycle due t'o changes in core loading or changes in plant equipment or equipment performance, the adequacy of the'TM/LP trip setpoints is typically evaluated each cycle in some manner from engineering judgement up to and including a. full analysis.
The analysis that is performed to generate the TM/LP trip setpoints includes uncertainties in the process variable input to the RPS channel (i.e.
temperature and power).
This is also true of the transient analysis of the limiting A00's that are used as input to the TM/LP trip setpoint analysis.
However, what is not typically accounted for in the modelling is large fluctuations of process' variables that are input to each TM/LP channel.
- Also, not modelled is large fluctuations of procest variables between TM/LP channels. The discussion that follows addresses the impact of fluctuations.
seen at Millstone II in the hot and cold leg temperatures.
B.
DISCUSSION The impact of fluctuating hot and cold leg temperatures on the Reactor Protection System and margin to trip is manifested through the TM/LP (Thermal Margin / Low Pressure) trip circuitry. This trip (referred to as.the Pvar '
in the Technical Specifications) is functionalized on Tin, core power'and axial shape index. The core power that is supplied to the TM/LP-trip is the auctioneered higher of delta-T. power and excore detector power.
The delta-T power is determined by the delta-T power calculator-which functionlizes delta-t power on the temperature rise across the core (delta-t) and core inlet temperature.
Delta-T as defined by the delta-T power-1 calculator for each RPS channel is the difference between the maximum of two opposite cold leg temperatures and the average of two hot leg temperatures.
,,.4 o,
s Based on these hot and cold leg temperatures and appropriate coefficients,'the calculators predict delta-T power as the sum of a static term and a dynamic term.
The coefficients of the dynamic term of delta-T power are choosen such that the sum of the static and dynamic. terms yields a calculated delta-T power that is equal to, or conservative with respect to, the core average heat flux during those transients requiring delta-T power input to the RPS.
The static term of delta-T power is calorimetrically calibrated periodically during steady state full power operation to ensure accuracy of this portion of the delta-T power calculation.
During certain transients, changes in core inlet temperatures and/or.CEA position can decalibrate the excore detectors.
This decalibration can result in non-conservative NI power being supplied to the TM/LP trip function of each RPS channel'.
For those transients which do produce a non-conservative decalibration of the excore detectors, the del --T power calculators must be set (through the dynamic term coefficients) so as to produce the required conservative signal.
This is accomplished during the off-line analysis of the limiting transients that decalibrate the excore detectors.
If the coefficients of the dynamic term are set too aggressively, then it is possible'for the delta-T power calculators to predict large. increases in core power from a small change in actual delta-T. This can lead to frequent needless pre-trip alarms or actual trips.
To avoid this problem, CE has recommended to its reload customers with analog protection systems to "zero out" the dynamic term of the delta-T power calculators. However, since you don't get something_for nothing, the margin lost by eliminating the dynamic term must be recovered by some other'means.
...s,.
This is typically done by either setting aside additional initial steady state margin through the Technical Specification LCO's (Limiting Conditions for Operation) or by modifying the coefficients of the TM/LP function.
Both cases require re-analysis of the appropriate limiting transients and possibly l
re-categorizing certain A00 events from RPS protected to sufficient initial margin.
l Based on a review of the data shown in Figures 1 through 4, the following
)
conclusions have been drawn:
l l
Using the maximum peaks of the temperature swings for each channel,
)
delta-T of each channel could change approximately as much as follows (from
)
high to low):
J Channel A
3.6%
B 4.0%
C 5.9%
D 5.7%
Since delta-T is directly proportional to delta-T power then these values are also approximate values of the delta-T power s'etings of each channel.
Typically, the TM/LP trio is approximately 5 to 6% power away from a trip'at steady state full power operation.
Consequently, it would not be surprising if pre-trip alarms are occurring.
The largest difference between any two channels (lowest delta-T to highest delta-T) could be approximately 18.5%.
Since the delta-T power calculators are calibrated periodically, the values of delta-T at the time of calibration are not very important.
- However,
1
' '$hf,
- from that moment on, delta-T power and ultimately Pvar will "see" changes in power' based on the swings _in hot and cold leg temperatures even if these swings are not the result of actual core power changes.
C.
' CONCLUSION From the data above it_seems possible that after the given moment when j
.the delta-T power for'each channel is calibrated, the delta-T'powerLcould
'l change by as much as the values quoted above.
This implies'that iffdelta-T.
j decreases (as "seen" by a channel) then that channel 1TM/LP trip function will 1
incorrectly "see" a gain in margin'to trip due to'the apparent reduction in
. hether or, power. This could result in a non-conservative trip actuation.
W not the results for any given transient could actually be non-conservative is q
dependent on the amount of demonstrable conservatism that exists in the analytical methods employed in the licensing analysis and~the amount of conservatism in the Pvar and delta-T power equation coefficients relative to-the analytical results for that event.
i l
i i
-l ARD-T51/2 l
i i
l l
l l
1
1 p.
I i
l
.(
1 i
1 o
m b
k[.
l C.f7 6 4 3 s T 1 C -J 2 #2 H 5 4 i L O[
N
's
- e J
V V
N G
ro a
v; 9
S S
O tR CPO
'8 G
'3 S
O O
G M
a a
.a m
m u
ut,i
--A a
o s
m in s
~~-
1
'J
- 5 J l
I I
I I
VI I
l g {U h
v#
^
^
a
-C'E 1
m
-4 v e
s
}b ^$7 9
i
>- 4--
l
=
-4*
~
\\
9",
x5 m
)
~.,
g
-E, j
?
A G
G i.;-
my
?
~~-
4 N
d d*
s t
J
-t; m
b
\\
.i Q
N-e.
R N
f m
(D
- 4.,f E
W i
's.y.
?-
-b I
n y
1.
s
?
2 o
n-y
.= - A - - -,
t-r
<s n
.a 4
-4
<5 3
A
.i' Z
- r.?.
a Z_
a Z
j t-.
_>C d
g 4
- ::65-W q
1 A.
- )-
2;,~
.ar "'
z.
3
, = - = z(
"1 y. : - - -=7 c
,v a*=c-Q v
a.,
s n_
\\4,s.
g o!
K A_,,
y m
Or q
r 4
g o
J.c 4.
k s
y}
p>.
7 1
J S
5 5
)
O 7
,e m
L 3
3 A
m m-5*
O N
N d.
h
~
' <g p
2.- 2
{
,a.
5;, :
x g
i i
I I
I I __ > 1%C la v",
n e
~e J
5 re a
e 4
nv o ~;
a,- e ca a
a e
a e
a o
ya Ja a j s
'a e
m a
4 4
e a
u s
t w i vH s e t.t c s i er w s s s _L
,,6
.e.ege e
emD -
- ___._.__..m_.
l e
..<p.
=.
l s
L o
f f,e,.-
hv ** '
l E
C -J bHE5TL C.-J 3 rI H 3 E T.L M*
5 n
a m
.a v
v n
a m
s' O
G W
G
- 1 G8 4
S S
S G
G G.
=g==="
J M
,s
.s a_
m m
o y
.a
.o a
e in I
l' e I
I I
I Ji I
I re U
).b a
p-s
\\
v
_5
<L,,
e
- -2 t
-a}
{
o a
W s.> 'l i
o g(-
1.
s w-2 N
L' 4
sn 0
m
-8 a
~&
n
<;C
~"
~
'k W
l 3
a 9
n o
4-g g
a
, k~,
"2 5
?
s 5
o
_3 6
i N
is C
O I
c u
s.
g yQ
'i
\\
g %r-*-
b; k
h.
s'%
H
,e d
~l 1 s
n-
~
\\
m m
in es 4
s a
s:=--
h 4
e-r.
~>" '
a e-N3 g
3
.y
- . *?).
F
~ ~ < -
ca-
_p.
F g
E 1
4 F
I g
am g
I I
-I I
I8 a
e e
n e
e1 4
v v
n e
e a
v r
- s..
e a
e a
a ej e
a e_
a a
y.
ea ad e,.s';a m
,*;c a
, 4 4
.s e
e
_ c d2 ww w.s v.a.
.. _ A..,... t ea m w a v v a.. - -
_mm.____._m__.__
T7T 3
1 H
. 6 45
)
60 7
/S 3
N~
5 7
4 E~
- 5 C
S 3
A 9
[G E
4 8
4 C
5 8g v
W
/A
^
^
0 o
0 3mR f
0 o-4 r
1
/ n-5 f -
^
o
?
6i 7
t 0i
'c Y
ai
, 4 a
2 ve O
h].
f "6
3 D
P e-5
/
c o
r g
0 u
b Ut 1
4^
5 j
T m i
4' 9
e r
2 Rp
~
s 1
5 m-Ae Q
T
=
n T
^_
8
^
0 p
Se
^
o
=
^_
0 a
^
3 L
2S p
2 5
C PR n
p 7
f*,,
1 M
U k
7 84 r
33 1
5 4
3 3
1 5
5 4
3 2
1 O
1 2
3 5 4 v egnI
,y
}
3 0
/g
, 8 4
5 8
_r N
8 o
6 t
4 S
N 5
G x
S 3
m._,
3 A
6 8
e 4
M S
8g T
v 1
a
/ A 5
(
P 7
3 m_
0 o
4 1
r 5
f n-1
/
7 o
u7 5
6i m
3 ta 0i P
v t,
4 l}
e n
3 o
m.-
,)0 D
5 Pr e.
y Utu. L 3
ry a-5 T
r
.1 9
e 3
2 G
Rp D
Ae
.r 5
m T
T 3
So 8
p
.v o
0 3
L T
5 2S
.w C
PR m
0 E
M J.
J t 1
eA 7
oc 8
S 4
80 1
- 5 4
0 1
1 5
S 4 5
4 3
2 1
0 2
3 4
~
C IF 1!
C D
A 8
H H
2 2
r 2
2 n
o p
2 E
2 S n
)
m mt m
1 1
u aa 2 u
P er P
E E
t e #
T e
G B
B
+
\\
i w
f e
i V
(
t
+
A B
n 7 B B
H H
e 1
m
+
+
2 2
e 8
2 2
g 8
1 1
na 3-N E
E r
T T
r
.J A
me ts r
y o
S w
t e
c
" N t
i a
n V
e a
R lo n
o a
C l
P 2
A B
t s
H H
i
+
n 2
2 U
l 1
7 I
1 e
1 n
E E
o 8
T t
2 A A
t T
s 1
1 y+,.
1 i
A l
f A
t w
e i
i
('
V r
B o
A C
D mt I
1 I
H aa 1
I N
p er p
2 2
m t e #
m l
l u
S n u
I l
P e
P G
E E
T T
l
O:y m
s m
A[W WWl r
e h
d A
1 jhEtN J
S 4
f P
f
[
3, M
/;
AmWj E
\\
T W t M
l D
T a
v R
iN JwM hT C
A E
k op M
L
\\
jANAtGNi T
b p
GH A
y d
P l d 1
v k
fD3 O
I i
W
[a k
O y
YiyWj-L t6
/
/
6 5
4 3
2 7
6 5
4
'~"5 0
0 0
0 0
9 9
9 9
6 6
6 6
6 5
5 5
g" t
02 d' %v
- 8 y
5 s
y 8
b
. 0 3
h L
,v q
. 0 v4 l
0 0
eI Jy i
5 b
. 8 I
r S
i 4
k r-
. 0 P
4 i
Ir m
4 M
T 0
E t
L
r 1
/
w' gy
. 4 h
i v
T aa 8
Y
. 0 v
n s
D
/
h1 A u
]
i'l 0
T hY v
T 2:
a i}
3 R
b k
3 I
s A[
NV!
.,5 y
A' 0
g C
a' 9
iu N
. 0 2
8 E
l
/
Y D
a' l'
L k
n l
. 0
/
3
,V l
y 5
6 g
2
- bgh, T
t'
. 8 i
r I
. 0 O
N E A H
L J
i f,
. 4 q'
/
u 0
f lV VA I '
6 l
2
}V
)
l P
.V DV 1
L
. 0 8
Y
/
J A'
dU O
A[
M nylaf
. 0 O
. 2
)
L i
A M
V f
8
. 0 M.f n'
V
.p A(i
,y
. 8
[
.. 0 i
.[
N I
]-
u YLV ig ni J
. 0
. 0
. 0 i
l il 0
- 8 6
3 2
1 0
8 0
6 5
4 0
0 E
0 0
8 5
9 9
9 6
6 6
6 5
5 5
5 5
oy
!Z C
^,
3 E
gA] n[35 kE o
n l
f'
)
Y E
s s
a 2
G 6
Y g
a l
Q e
a G
G Q
x bg g
6 l
5 h
5 s s
6 h
S bW*
5 x
3 2
4 7
7 1
Q N
C r
a Y'
- h. -
/
len s
G e
r:
f ma
/
%}4 ah s
SC d
G t s AA
+
g o
asn a
(-
I e
2 l o
@d a
Sei s l\\
4 nt S
ni w
t as 5
f ho 1
CP f
l r 3
oa Y
rl 1
f, )pQ t u
=
ng on E
CA W'
M 2
2 I
4 4
2 1
I T
4 4
N m
G G
gd D
E E
e
%y L
L N
z e
E s
T T
l 4
0 c
0 f
t u
i I
E 0
p M
S s.
?,
I A,v 5
1 T
4 4
Q Q
o I
/
4
$ v' 2
2 6
%uk 4^
0 2
4 y d
[v 0
5 b
V. m e
7 7
J i
I 4
4 G
)%h 1
1 g
=
i E
f 1
t 1
I N
hQ T
k w
T
&w T
? $
A..
h J
f.
Y f,~
8 G
J a
6 a
l s
6 4
2 Q
s 0
a l
a 0
a G
G 2
6 e
l s
6 s
s_
is 5
O 3
jl
i l
FIGURE 5 MILLSTONE UNIT 2 AVERAGE TEMPERATURES AT CBSERVED LONG-TERM CCFOlT!ONS l
I CONDITION 1
4 i
HOT LEG 1 HOT LEG 2 600.2
, 600.2 602.5 598.5 A
C C
A l
i 0
6 s
a E 98.2 598.7 599.5 596.2 CONDITION 2 HOT LEG 1 HOT LEG 2 598.9 s 601.0 602.0 600.0 A
C C
A i
O b
b D
A
/
597.6 599.3 599.1 597.2
~
nwOEm m o
3,aaw+cO5 ca #
t 9,o.
m* Heate2 E nm*
e t8e M
~
r C
ntaoo jep NIL u Q O N 4, 4b 2
a a
s a
2 G
8 6
4 2
a A
S 4
4 4
4 a
s 4
a a
4 D
6 S
5 5
s s
s s
s s
s s
3 2
N W-7 7
Q R
^-
/
s G
/
W b
O 9
e M
s I
8 eI 2
n 5
s o
4 i
=
t 5
a u
1 t
N~"
c
=
u 3
e l
M F
1
=
m r
E e
M M
T 2
2 I
W 4
4I g
1 T
n 4
4 o s C
L g
b D
e w
N f
o L X
T M
^
E t
dr o
C
~
o H p
T s
s e E
Q
%C e h r T M
R
/
r I
e.
o n T
s O
4 4
0 2
oI s
1
/
W n
2 2
o b
i G
t
~
M.
i so 3
w P
2
~
4 d
e
~
e l
e G
m c
e r
s i
C 7
7 o
M
^
0 1
4 4I J
M 1
1
=
f_
E 1
N t
I N"
~-
T T
s a
wr
+
R.
q_ -
4 T
e 1
a 0
a n
4 2
0 5
6-4 2
0 5
4 a
4 4
5 4
4 4
4 4
5 s
s 5
s 5
5 5
5 s
3 nit" (u 3 a p nILaAUNqteh
,i l'
rllllll
{\\j il:l4l1iii lI m
-- 4 r.OEm N e.-
3*av+rO5 C3a o
m
- 5 t
m o
,a rm* 4oas@ E+rC3m t
rO0 t
t m
m 2
=-
7
'- i " 0 U U " f
'IL"QogNdI t
a a
6 G
a 6
4 2
0 A
s a
4 d
d E
4 4
4 4
4 s
s s
k h
5 5
5 5
5 5
3 3
~
~ ~ v.
6 7
7
"- m-Q
- W
' w a
w S
=
/
S c
Q
=
fs f.
/
h m
c W
Q Q
=-
- r S
8l I
2
- ~4 n
S 5
o 4
i t
M>
a 5
u 1
tc
- " a_
e u
3 l
x 1
F m
wT
" w
=
n s
n E
m e
M 2
2 I
m
~-
4 4]
g I
~x L
r n
4 4
~.
o
^
s D
=
s D
g b
"~ w.
N o e I
~m d
T L E
u M
m t
C p
E
w n lo o
f 2
s e 1
m 3
e h b
r T I
^
/
r m
T G'
~_
5 m
o n 4
4 C O 0
x Q
0I I
/
s 2
2 "w
n 6
o 0
i wd t
^
~~ e 2
is x
o P
4
" v-
^-
e w.
l 0
5 c
' m, r
i 7
7 n
C Q
4 4I l
+
Q 1
1
=
A_
E
~-
% e, 1
t I
T 4
n
=
~.
T
~
==;
~.
R.
~
E T
J G
0 8
s a
0 8
6
^
2 0
5 d
4 a
5 4
4 4
4 5
S g
s g
s 9
5 5
5 5
nL kgo,,4
, i [ g,u H " F t
l1l lll!l
- ,
- l'
- e, FIGURE 8 1
Millstone Unit 2 Rel;tive Power Density Map l
Cycle 10 l
f l
l
- o. *A G t
- 0. 2. S G I
i 1.1 o 3 1.oo l
- o. (,s s o.74 3 o.34a i
- 1. g12.
1 272 1 112.
l.143
- 1. co E o.37.3 i
- 1. I B G lAoS j.241 1.357 c.373 0.904 g, 39,3 1.1 o I l.07 J.l83 1.t o r,
). iso o.27S i.co a.
- o. 34 a 1 016 1113
- 1. l l o 1.24 E I.2 0 G i.s s *T i. i t,3 c.743 l.301
- 1. l os I.237
- 1. t i o 3.lg3 3,g4 i 3,g ig.
e, g g o.23G l.318 0 273 1.10 5
- 1. 18 3 1071 1.108 1 2'72 n.oo I o.3si g
k' l'318 1.S o l 1, 0 4 (,
3,t o t g. 3 8 (a 1.2 2 2.
l.109 2
i i
E
e FIGURE 9 e%
O b
^
=>=.
.t
-r"
- =4 m
A a si -,=
n.
MM'-
n
-%t i
,p
- 11(
.--e t1.T1 hs1s m_i
.s "N
T 1
--. 1.
^
ssX' s
1sA M
N s i 2r M
omt 1s w
Y v
0 m
'i, m.
w J
spm O
L t
r a
b n
-u am um O
gam (
g ea 1
L C
W
=
- t. a 3
0 I
4 e
a Ch N
M E
,a g
g, s:t 4 -DM v
0 m
r2-sr c
o e.
n.
b b
e C
3 3
r-a Pa=
A m
wmc-naf D
and
./
O Cn C
c o
O
.h.
o O
e.J J
m
'1 C
C 0
p m*
h N
"fi-"'-'-
s D
L
- =>
a O
3 J'
-fy T
E d
38 rT L;
+s
[4 U
13
+-
'u _ -
~4 Y
,y C
3 M
y s
o b
,9 4
-* ~~~p-
"d Q
f2 I,"
m-
'itt w
Q -4 y,
- -- g "w C:=
4 m M 1.-
'd
@b a..
,r'^
2"'
w
- a
.,11,,'
'n '
~
N V. --.C
+--
%,4 4
W
?
O
,' +-
4....
-j y
l
.q.... 0
+
4..
~.....
-- ;j
-p..-,
..-3.
. _~.4 e
[
t g
g e=.--.+
.-.. 9 -.....-e
_qa "i*",,'
i
_, 7,*" [*- ~
^
y
+. _ _.. _
- ,+
. - _. ~.
_ n. -.
- - -. -.. +. __
.k
.. - ~,... _. _
rn p.g m
.-.._An-....
.?. ' ~..
N
~~
q
~
a*.-+-5+=-
I T
W 4.
g-.Ed.-+.'...=.*.--UE..**.=-E='.-....-.h-
- a t,~
. =..
g
~.
. [
..4...._w
,.........,9.--.
. %.3
,s...-,.-.--. - -
p
...g......
9 9
..-.4
.p.
y e
.....~.g...
4 i.e-+...--.
{..-...
g.
e 4
l....
6 u
i %
_%_..l,....,.$
....-4---.. %
4
..a.
.a s
+.
,.-+-.,*g.'."%W -*** U..
O_
hh *
]*.. hh
_. _~~,.-**._... _
g p...
4 e.%.....g.,....-
4...
.. - - =.-4.-.....4 4..,.
(
4 g.
. 4 6
..-4,e, n.% -
0 1
6 1
6 A) 2 O
GE L
1 T
O E
H C
o+\\
LC 1
8 e
Y 0
s C
6 06 S
E 4
L 5
S 3
1 1
FI 3
1 J
2 1
'd 0
7 1
4) 9 4
S 6
O 6
l 9
0 G
R 0
6 6
3, N
D O
P B
1 2,
4 E
G 1
OS G
E E
R R
L L
U O
T 3,
T T
T O
0 O
2, A
A H
4 H
A s
5
\\'
1 R
R 7'.
E l
0 6
2 E
E 2
O P
B i
1' 0
6 9
1 L
7 C
C 6
4 4
6 0
4 M
6 0
Y E
M 6
C T
AE T
G S
2 4
t EL D
S 4
R 1
0 o
3 A
8 A
2 4,
ti.
8 8
S T
W N
6 1
4 4
0 6
i O
O A
B
)
6 H
T A
5, 4
K 5
- u K
D, 1
2, B
G R
G 1
G E
N A
E T
I L
E L
A O
T T
O O
3, Ti C,
2 1
4 E
O A
S L
H 2,
L H
/8 Y
6 5
4 C
[lX 1
5 Y
3 0
D 0
3 g
0 C
9 b
A A
4 6
6 5
ET 1
S E
4 I
7 C
8 U
5 l
L
)
A E
o 0,
T 1
S 3
1 G
L c,
T O
A H
~
l'-
9 9
8 5
1 l