ML20210T470
| ML20210T470 | |
| Person / Time | |
|---|---|
| Site: | Millstone, 05000000 |
| Issue date: | 10/25/1976 |
| From: | Ferland E NORTHEAST NUCLEAR ENERGY CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20210T454 | List: |
| References | |
| FOIA-86-236 MP-2-213, NUDOCS 8605300463 | |
| Download: ML20210T470 (15) | |
Text
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HANTFORD CONNECT: CUT CG'C1 NORTHEAST NUCLEAR ENERGY COMPANY MM" A NORTHEAST UTILITIES COMPANY October 25, 1976 MP-2-213 Mr. James P. O'Reilly Director, Region I Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19402
Reference:
1.
Facility Operating License No. DPR-65, Docket No. 50-336 2.
Millstone Unit 2 Startup Test Report - F. W. Hartley to Mr. James P. O'Reilly, dated 8/25/76
Dear Sir:
In Millstone Unit 2's Startup Report (Reference 2), it was stated that analysis of the ejected CEA test would be submitted at a later time.
That analysis is attached; it has been page numbered for inclusion in the original report.
Two (2) additional copies are also enclosed.
Very truly yours,
.Q j
~"
E. J. Ferland Plant Superintendent Northeast Nuclear Energy Company EJF/jj Enclosures cc:
Director, Office of Inspection and Enforcement, U. S. Nuclear Regulatory Coninission, Washington, D.C.
(25)
Director, Office of Management Information and Program Control, Washington, D.C.
(2) i koj53 mufg3860521
~
128 5.4 Misaligned CEA Tests 5.4.1 Ejected CEA Test Discussion The static Ejected CEA Test was performed to determine the NSSS response associated with a CEA being ejected from a group located at the 100% Power Dependent Insertion Limit (PDIL). The experimental data acquired from this test was utilized to affirm the adequacy of the calculational models and methods used to determine the peaking factor changes associated with CEA ejection configurations.
The test was conducted in three sections while maintaining the reactor at 50% power.
Initially the reactor was at equilibrium conditions with all the Group 7 Control Element Assemblies (CEAs) at 97 steps withdrawal, which corresponds to the "100% PDIL".
CEA Groups 1 through 6 were. located at the full-out position.
The first section of the test involved borating CEA #1 of Group 7 (refer to Figure 5.4.1-1 for exact CEA core location) to its full-out position. The remaining eight Group 7 CEAs (38, 39, 40, 41, 59, 62, 65, and 68) were maintained at their original position of 97 steps withdrawal.
CEA position was recorded every five minutes during withdrawal which took approximately 18 minutes.
This elabled accurate modeling of the transient.
The second section of the test encompassed a " control rod swap" of CEA 7-1 with 7-59.
During the swap, CEA 7-1 was inserted to i.ts original Group 7 position whi.le simultaneously withdrawing CEA 59 of Group 7 (refer to Figure 5.4.1-1 fcr exact CEA core location) to its full-out position.
RCS dilution was required to return CEA 7-1 to its original position. Again, CEA position was recorded every five minutes.
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~*
129 8
The third section of the test involved diluting CEA 7-59 back to its original Group 7 position, recording its position every five minutes.
Background and sensitivity corrected signals from each of four axial levels of each operable in-core detector string were obtained immediately before "boration" of CEA 7-1, and immediately after completion of the "boration" and " rod swap" (refer to Figure 5.4.1-2 for in-core detector locations).
In addition,. four detector strings (01, 06,19, and 38) were trended every 60 seconds throughout the test to ascertain that' the core was being maintained within the allowable linear heat rate limits.,
Results The objectives of the Ejected CEA Tests were to verify the following:
1.
The peak linear heat rate as monitored by the In-core Alarms did not exceed 15.3 Kw/ft.
2.
The Ejected CEA calculational mcdel conservatively predicts the resultant power distribution following an ejected CEA.
The first objective was fulfilled during the test since there were no N
In-core Alams, which were set at 15.3 Kw/ft., received during perfomance of the test.
In addition, trending four detector strinas (01, 06,19 and 38) during the test indicated that the core was maintained within the allowable linear heat rate limit.
The second objective of the test was fulfilled through an off-site analysis of background and sensitivity corrected in-core detector signals.
Signals from each of four axial levels of each operable in-core detector string were recorded at the starting equilibrium condition, imediately after rod 7-1 reached the full-out position, i
1 m. - - - _ - - - _ - -. _ _ - - - - _ - - - - _ - - - _ _ _ _ _ - _ - - - - _,. - -. _ - - _ _ _ _ _ _. _ -_-
129A and following the " rod swap" of rod 7-1 with rod 7-59.
Level 3 signals, which includes the axial region from 54% to 66% of active fuel length from the core bottom, were chosen as the bases for comparison between experiment and calculation because the temperatures and power density at this axial level best represent the conditions in the 2-D PDQ calculations of box power changes.
The method used to analyze this test involved the following steps:
a.
Calculation of the af ter-to-before in-core signal ratios for the ejection of rdd 7-1 at a time when rod 7-1 reached the fully with-
~
~
drawn position.
b.
Calculation of the after-to-before in-core signal ratios for the ejection of rod 7-59 at a time when rod 7-59 reached the fully withdrawn position.
c.
Calculation of the after-to-before in-core signal ratios for the swapping of rod 7-1 with rod 7-59.
d.
Comparison of the measured Millstone II signal ratios with the analogous measured ratios for the Calvert Cliffs-1 ejected rod test.
Evaluation of the comparison of step d. for any differences between e.
the two tests to determine the implied conservatism in the calculational model.
Table 5.4.1-1 compares significant ejected CEA test conditions between Millstone II and Calvert Cliffs-1.
The power level difference resulted in the Millstone II, core experiencing less Doppler feedback than Calvert Cliffs-1. The time intervals between first and last ejected rods differ, primarily, because the Calvert Cliffs-1 test involved the ejection of an additional rod not tested at Millstone II, which
1298 suggests that the test result comparisons for Millstone II rod 5-59 and Calvert Cliffs-1 rod 5-58 would vary slightly due to different xenon distributions.
Figures 5.4.1-3, 5.4.1-4 and 5.4.1-5 show the comparisons of measured ratios of after-to-before in-core signals with calculated ratios of after-to-before box powers for the ejection of rod 5-1, the ejection of rod 5-58 and the swap of 5-1 with 5-58 respectively as taken from the Calvert Cliffs-1 ejected rod test analysis. To facilitate the comparisons, the Calvert Cliffs-1 data in Figures 5.4.1-6, 5.4.1-7 and 5.4.1-8 has been rotated 90* counter-clockwise to bring the rod and in-core detector locations into coincidence with corresoonding rods and detectors for flillstone II.
The data shown on these figures re.oresent the ratios:
Calvert Cliffs-1 PDQ-2D calculated assembly-to-core averace power density after rod motion comoleted Ci
=
Calvert Cliffs-1 PDQ-20 calculated assembly-to-core average power density before rod motion initiated Millstone II measured level 3 in-core detector signal after rod motion comoleted Mi
=
Millstone II measured level 3 in-core detector signal before rod motion initiated Calvert Cliffs-1 measured level 3 in-core detector sional after rod motion completed Bi
=
Calvert Cliffs-l measured level 3 in-core detector signal before rod motion initiated i
Figure 5.4.1-6 compares Hillstone II measured signal ratios for the ejection of rod 7-1 with Calvert Cliffs-1 measured signal ratios for the ejection of the equivalent rod, 5-1.
The results shown on Figure 5.4.1-6 are very similar.
Figure 5.4.1-3 shows that the Calvert Cliffs
i 129C calculational model gives a conservative estimate of local power peaking changes, therefore, Figure 5.4.1-6 indicates that the ilillstone II PDQ model also provides conservative input to the safety analysis.
Figure 5.4.1-7 compares Millstone II measured signal ratios for the ejection of rod 7-59 with Calvert Cliffs-1 measured signal ratios for the ejection of the equivalent rod, 5-58.
These results are also in good agreement, with Millstone II box power increases slightly larger than Calvert Cliffs-1.
Differences can be attributed mainly to the different xenon distributions between the two cores (due to the additional rod maneuvering performed during the Calvert Cliffs-1 test) and because there is less Doppler feedback in the Millstone II core (see Table -
5.4.1-1).
Figure 5.4.1-8 comhares liillstone II measured signal ratios for the swapping of rod 7-1 with 7-59 with Calvert Cliffs-1 measured signal ratios for the equivalent swap.
The agreement seen here naturally follows from Figures 5.4.1-6 and 5.4.1-7, and the arguments previously discussed remain valid.
The results of the ejected CEA tests are similar. The Calvert Cliffs-1 ejected rod test analysis demonstrated that the Calvert Cliffs-1 calculational model conservatively predicts the measured local power increases. The Millstone II core is very similar to Calvert Cliffs-1 as are the corresponding calculational models.
It is therefore indicated that the Millstone II calculational model conservatively predicts the measured local power increases for the ejected rod test.
Since the same calculational model is used to calculate peaking factor J
1290 input to the safety analysis of the ejected rod transient, and since the predicted radial peaking factor increases for these transients are similar (22% increase for Millstone II and a 27% increase for Calvert Cliffs-1), the safety input data is also indicated to be conservative.
Therefore, the acceptance criteria for the test has been met.
4 i
=_
]
129E Table 5.4.1-1 l
)
Canparison of Ejected Rod Test Conditions Between i
Calvert Cliffs-1 and Millstone II Item CC-1 Millstone II 1.
Core conditions just before the test I
a.
Burnup 500 MWD /T 630 MWD /T j
b.
Power 20% full power 50% full power c.
Lead bank rod 46%
46%
]
insertion 4
j d.
Xenon Equilibrium Equilibrium e.
Power Coef. at
-1.34 x 10-4 AK/K
.98 x 10~4 aK/K
]
stated power l
2.
Ejected Rods l
l a.
Sequence of 5-1 7-1 i
ejection 5-37 7-59 i
5-58 i
b.
Center rod worth
.030% ap
.025% ap j
c.
Time between data 90 minutes 50 minutes I
taken for first and i
last ejection j
4 4
i I
l
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l l
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_y l
NORTH A
B C
D-E F
GHJKLMNPR S
T V
W X
Y 1
2 i
3-63 3 64 3
^45 4 53 7-40 4-54 A48 j
N e
s 4
e 7-62 A45 1-29 1 30 A-46 7-65
,I 5
A 44 P-35 2-21 P-12 2-22 P-36 A 47 1
s 6
A44 6-15 6-16 A47 i
7-4-52 2-20 B-7 5-4 B-8 2-23 4-55 L
.8-s 9-3-61 1 28 B7 B8 1 31 3 66 1
10 -
2.1-7 39 P-11 5-3 71 55 P-13 7-41
..2-13 -
3 60 1 27 B-6 B-9 1-32 3 67 14 -
s 15 -
4 51 2 19 B6 52 B-9 2-24 4-56 16 A43 6-14 6-17 A48
/
/
g 17 A43 P-34 2 18 P-10 2-25 P 37 A-48 1
10 7-59 f42 1-26 1 33 Ay 7 68 19 s
A-42 4-50 7-38 4 57 A49 20 3-58 3-69 l
21-c i
I i
Millstone CONTROL ELEMENT ASSEMBLIES GROUP Figure
""['"g'['i" AND NUMBER DESIGNATION 5.4.1-1 e
f i
i
- 'D" WlDE "D"
RANGE SAFETY I
i A
B C
D E
F GHJKLMNPR S
T V
W X
Y b
2 O
0 0
0 i
i 3
- 42 43 29 l
4 O
O O
7" CONTROL 27 28 45 CHANNEL U
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41 25 U
O O
O 6
26 08 09 30 "C"
AFE O
O O
O 40 24 07 31 8-9-
0 0
- C" U
10 -
R NGE k 12 -
01 10 12 32 0
13 -
22 14 _
O D
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o O
33 j CONTROL 21 02 13 i CHANNEL O
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20 04 03 14 15 d
17 0
a 16 34 1
18 0
0 0
38 18 17
- B" SAFETY 19 0
0
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19 35 O
"B" WIDE RANGE -
O 37 36 g
i 2i c>
O 4 RHODIUM DETECTORS
^ " '
^
1 VANADIUM DETECTOR "A" SAFETY j
1 THERMOCOUPLE O 4 R!iODIUM DETECTORS 1 BACKGROUND BUILDING
{
1 THERMOCOUPLE NORTH j
EXCORE DETECTOR RADIAL LOCATIONS NOT TO SCALE
\\
INCo$E ANb EXCORE DETECTOR CORE LOCATIONS Floure Nuclear v er Station Unit No. 2
- AND DESIGNATIONS 5.4.1-2 1
L.
t 1.02 0.93 0.98*
0.92 0.93 0.94 1.01 1.00 1.02 0.97 0.96 0.93 0.98*
1.00 1.00 0.94 0.93 0.94 0.96 0.96 1.0G 1.0%
0.98 1.08 1.03 0.94 0.95 1.00 1.11 0.98 0.93 0.96 1.15 0.93 1.11 1.03 0.98 1.15 0.92 1.01 1.07 Failed 1.07 1.01 0.97 g
0.97 1.08 1.44 1.08 0.97 0.93 0.99 0.94 1.00 0.98 1.12 1.00 0.92 0.93 1.15 0.96 0.99 1.05 1.07 1.01 0.94 1.06 1.08 0.97 0.09 1.03 1.00 0.98 j
0.96 1.01 0.96 0.93 1.04 1.01 1.01 0.93 0.96 0.97 0.99 0.99 g
0.94 0.93 j
1.04 0.93
- VALUE REVISED FROM ORIGINAL CALVERT CLIFFS 1 REPORT LOCATION OF EJECTED ROD G1 0;
AFTER/DEFORE RATIO OF IN CORE DETECTOR SIGNALS (MEAS.)
Ci AFTER/BEFORE RATIO OF ASSEMBLY POWER (CALC.)
Millstone tk.cicar rower sioi;on EJECTED ROD 5 - 1
D" unii ta. 2 5.4.1-3
i 0.96*
0.98 1.28*
1.09' 1.67 1.30 0.99 0.97 1.00 g
't F 1.07 1.00 0.94 1.11*
1.18 1.11 0.95 1.39 1.48 1.35 0.95 0.97 0.96 0.95 1.04 0.93 0.92 1.00 1.CG
- 0.98 0.95 1.19 1.19 l
1.05 0.91 0.98 0.94 1.00 1.05 0.92 1.10 0.99 0.97 Failed 0.96 0.94 0.92
'.90 0.89 1.03 1.03 0.94 0.92 O
0.98 1.03 0.93 0.98 0.95 0.94 0.88 1.01 0.91 0.59 0.96 0.94 0.95 0.93 0.98 0.92 0.91 0.88 0.96 0.94 0.94 0.93 0.94 0.89 0.89 0.83 1.00
'0.95 0.95 0.95 0.90 0.89 O.93 0.95 0.87 0.87 1.00 0.90 4
- VALUE REVISED FROM ORIGINAL t
cal. VERT CLIFFS 1 REPORT
/
LOCATION'OF EJECTED ROD 5-58 Bi AFTER/BEFORE RATIO OF IN. CORE DETECTO,R SIGNALS (MEAS.)
Ci AFTER/BEFORE RATIO OF ASSEMBLY POWER (CALC.)
Millstone p;0ure Nuclect Power Srbtion EJECTED R0D 5 - 58 Unit No. 2 5.4.1-4
e.
0.98 1.06 1.30 1.09 1.82 1.39 0
0.98 0.96 0.98 1.10 1.04 1.01 1.13 1.18 1.11 0.95 1.50 1.56 1.41 0.99 0.91 0.92 0.96 0.96 0.94 0.98 1.05 1.03 0.88 0.96 1.28 1.24 0.91 0.98 0.88 0.91 1.02 0.91 0.91 1.20 3
0.91 Failed 0.86 0.93 0.96 1.09 0.96 0.66 0.85 0.93 0.97 0.99 1.09
_0.93 0.99 0.85 0.94 0.96 1.09 0.79 0.92 0.97 0.89 0.89 0.93 1.05 0.86 0.84 0.91 0.96 0.91 0.94 0.96 0.98 0.88 0.92 0.95 0.97 0.94 0.94 1.02 0.94 0.91 0.95 0.96 0.93 0.94 0.96 0.98 LOCATION OF EJECTED ROD 5-58 g
LOCATION OF ROD 5-1 WHICH HAS BEEN RE-INSERTED Bi AFTER/BEFORE RATIO OF IN CORE DETECTOR SIGNALS (MEAS.)
Ci AFTER/BEFORE RATIO OF ASSEMBLY POWER (CALC.)
Millstone Figure Nuclear Power Station SWAPPED R0D 5 - 1 WITH ROD 5 - 58 Unit No. 2 5.4.1-5
CC-1 h
NORTH 3.00 MILLSTONE 2 1
0.23 1.00 1.01 l
1.02 0.98 1.02 1.01 '
1.00 1.01 1.00 0.99 1.00 1.02 l
1.07 1.1J0 '
1.07 0.99 1.02 1.00
+,
1.03 1.03 1.02 1.07 1.06 1.02 1.01 1.06 1.07 1.01 I
I g
I l
1.01 i
l 1.01 1.01 1.07 0.92 127 1.00
' 'M 1.00 1.01 1.02' 0.98 f.00 1.01 i
1.00 1
1.04 1.00 0.98 l
LOCATION CF EJECTED RODS
,Mi M-2 MILLSTONE 2 Bi CC-1 CALVERT' CLIFFS 1 Millstone COMPARISON OF MILLSTONE 2 & CC-1 INCORE Figure Fluclear Power 9ation SIGNAL RATIOS (AFTER/BEFORE) EJECTION OF Unit No. 2 RODS 7-1 (M-2) & 5-1 (CC-1) 5.4.1-6
CALVERT CLIFFS 1 J
^
d NORTH 6.97 MILLSTONE 2 0.93 0.98 0.98 1.00 0.95 0.97 0.98 0.97 0.04 0.9 %
0.95 1.00 1.00
' O.99 0.97 0.96 0.93 1.01 0.97 0.98 0.94 1,05 1.03 0.99 0.97
~
0.09 0.97 0.95 0.95 0.93 0.95 1.18 1.03 1.09 0.97 0.98 1.00 1.49 1.10 1.04 1.28 1.03 0.99 0.99 1.00 1.24 1.11 LOCATION OF EJECTED ROD Mi M-2
' MILLSTONE 2 g
CC 1 CALVERT CLIFFS 1 Minstonc COMPARISON OF MILLSTONE 2 & CC-1 INCORE Figure Nuclear Power Station SIGNAL RATIOS (AFTERIBEFORE) EJECTION OF Unit No. 2 RODS 7-59 (M-2) & 5-58 (CC-1) 5.4.1-7
. 1:
CC-1 h
NORTH 0.97 M-2 0.96 0.99 0.97 0.98 0.96 0.96 0.97 0.97 0.93 0.04 0.96 0.98 0.98 0.92 0.97 0.86 0.95 0.99 0.96 0.95 0.91 1.02 0.97 67.h 0.93 0.95 0.98 0.91 (5-g 0.89 0.94 0.97 0.94 1.18 0.96 1.09 0.91 0.98 0.96 1.49 6.59 1.09 1.02 1.30 Q58) 1.03 0.98 0.99 0.97 1.24 1.13 DENOTES ROD LOCATIONS Mi M-2 MILLSTONE 2 8;
_ CC-1 CALVERT CLIFFS 1 Millstone COMPARISON OF MILLSTONE 2 & CC-1 DETECTOR Figure Nuclear Power Slotion SIGNAL RATIOS AFTER/BEFORE SWAP OF RODS uni, no. 2 7-1 7-59 (M-2) & 5-1 5-58 (CC-1) 5.4.1-8
.