ML19351E238
| ML19351E238 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 03/20/1972 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| References | |
| NUDOCS 8011260324 | |
| Download: ML19351E238 (9) | |
Text
__ __ _ __ _ _ _ _ _. _ _ _ _ _ _ _ _ _.
8
$3pririory file Cy.
~
s..
l 6.e,a wu,.w 3.9o.-7 a i
..s.., :.-
YANKEE UUCLEAR POWER STATI0II OPERATION REPORT NO. 134 1
For the Month of February 1972 l
l f
i i
Submitted by YANKEE ATOMIC ELECTRIC COMPANY Westboro Massachusetts March 20, 1972 l
l l
g o 11 :2 6 03k
- e q This report covers the operation of the Yankee Atomic Electric
)
Company at Rowe, Massachusetts for the month of February,1972.
(N
/
s/
At the beginning of the period the plant was continuing its stretchout operation at a load of 141.3 MWe. On February 12 the plant experienced a turbine generator trip and subsequent reactor scram from a load of 136 MWe. Details of the generator trip are presented in Abnormal Occurrence No. 72-2, below. Investigation of the generator trip.
revealed the need for a prolonged shutdown in order to effect necesscry repairs.
The plant had been scheduled for its Core IX-X refueling and maintenance shutdown to commence April 1, 1972. In order to minimize the plant total down time this date was changed such that the refueling and maintenance shutdown will coincide with the turbine generator repair period.
The remaining 20 new, Core X fuel assemblies were received on site during the report period.
The total electric generation for Core IX was 1,80h,769;800 KWh.
During the Core IX operation period, reactor availability and the plant capacity factor including stretchout operation but exclusive of refueling shutdown time were 88.65% and 85.11%, respectively.
l The ninth, Core IX vapor container air leakage surveillance period was terminated coincident with reactor shutdown on February 12.
Leakage during the period was normal.
On February 15 and 16 a 60,000 gallon continuous dilution of the main coolant was performed to reduce the system tritium inventory, i
Tritium concentrations before and after the dilution were 1.08 ue/ml and 8.6h x 10-2-uc/ml respectively.
All main steam line safety valves were tested on February 17 Plant cooldown had been completed and the main coolant was borated to the refueling concentration as of February 18.
Vapor container integrity was broken at 09h5 hours on February 19 and work was commenced preparatory to removal of the reactor vessel head.
-Purging of the vapor container was commenced at this time and was continued through the duration of the report period.
Removal of reactor head closure studs was completed February 29; and the reactor head was ready for removal at the end of the period.
A vapor container evacuation drill was performed for each work shift at the onset of the refueling outace.
Plant Abnormal Occurrences (j)
Abnormal Occurrence No. 72-2, " Generator Trip From 136 MWe".
At 0657 hours0.0076 days <br />0.183 hours <br />0.00109 weeks <br />2.499885e-4 months <br /> on February 12, 1972 a fault in the main electrical
-e r
.*rs
+
' l generator initiated a turbine trip and reactor scram. The Z-126 line
/n\\ ~
vent' dead. The normal power supply from the generator to the No. 2 and No.3
)
main coolant pumps was lost. Relay operation auto closed the 2h00 volt g
1324 tie breaker allowing continuous operation of the No. 2 and tio. 3 main coolant pumps. The No. 1 main coolant pump remained in continuous operation.
Following normalization of power supplies, the plant was placed ~
in a hot standby condition.
A survey of the plant indications verified that, with the exception of the generator fault, no abnormal conditions existed.
- i l
f The absence of the turbine trip overspeed panalarm confirmed that j
the turbine'did not overspeed on the trip.
k l
l Electrical testing indicated failures in the generator stator j
l vindings. A lover than normal vinding to ground resistance reading was l
F observed on the generator rotor.
j Hydrogen was purged from the generator in preparation for a j
visual inspection. This inspection, when performed, confirmed the failure i
of several stator top coils.
Removal of the generator rotor permitted a more detailed investi-gation of the stater. the coil failure was caused by the fretting action of a broken off piece of the polyester molding used as a filler material P
in the coil area. At the end of the report period, repairs were in progress.
f Abnormal Occurrence No. 72-3, " Leakage From Test Tank No. 2".
During routine sarapling of test tank contents at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> on February 18, 1972, a chemist noticed moisture issuing from under the i
thermally insulated containment structure around the level indication pipe tap in the No. 2 test tank. Coincident with detection the leakage had reached ground level at the base or the tank.
Inaule. tion was removed and the leakage was traced to the level indicator isolation valve DW-V-721.
Closing the valve had no effect on the leakage thus indicating a failed diaphragm.
i Containment of the leakage was effected at 0915 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.481575e-4 months <br />.
I The leak rate during the 15 minute period was measured at 270 ml per minute.
The volume and radioactivity of the leakage, all of which was recovered, was 4.05 liters and 2.017 me, respectively.
Abnormal Occurrence No. 72-h, " Reactor Scram From a Hot Standby Status".
On February-13, 1972 the plant was in a hot standby status; the
[N reactor was critical; and calibration of a source range nuclear channel
(
vas in progress. At 1545 hours0.0179 days <br />0.429 hours <br />0.00255 weeks <br />5.878725e-4 months <br /> that date a reactor scram occurred.
m p
!k-
(..
- l, I-i.
l l
The scram was attributed to the erroneous connection of a ' test-I voltmeter to the power supply of an intermediate range nuclear channel, which initiated a spurious start-up rate scram signal.
Plant Load Reductions February 1 (11h5-1500):
Load reduction to 90 MWe for e tube leak check in the East water box of the main condenser.
'One tube was plugged.
February ~h (11hB-lh30):
Load reduc' tion to 90 MWe for a tube leak check in the West water box of the main condenser.
One tube was plugged.
Plant Shutdowns
~
Shutdown No. 120-10-72:
2/12/72, commenced plant shutdown for turbine generator repairs ; and for concurrent refueling and maintenance. Datage current at end of i
report period.
Core IX-X Major Work Items Work was commenced on the master list of major work items to be i
completed during the current shutdown period. At-the end of the period all i
l G
such.vork vas still in progress.
\\
Inspections
)
1.
The secondary side of the No. 2 and No. b ' steam generators was inspected.
I No abnormalities vere noted.
2.
The upper bearing in the No. 2 circulating water pump was inspected and the race was found to be cracked. A new bearing was installed.
3.
Leak tests were performed on the air ejector condenser; the gland steam condenser; and the three feed water heaters. No leaks were detected.
Instrumentation and Control
-The. following is a list of pertinent instrumentation and control maintenance items performed by the plant staff during the month of February,.
-1972.
1.
Calibration of the. following was performed:
a.
Secondary plant pressure. transmitters and gauges, j
b.
The four feedvater flow transmitters'.
I c.
'Dae four steam' flow transmitters. -
l
'd.
The pressurizer pressure channel.
The four main coolant flow channels.
L e e.
f.
The main' coolant loop fill pressure channel.
- g.. The main coolant pressure channel.
1
, I
_4_
l
,[
')
2.
A new detector was installed in thimble No. 4 for channel No. 2
(/
of the source range nuclear instrumentation.
3.
New detectors were installed in thimble No. 3 for channels Fo. 4 and No. 8 of the nuclear instrumentation intermediate range and power range, respectively.
4.
The signal cables from the detectors in thimbles No. 2, No. 4, No.5,
- and No. 7 vere replaced.
Secondary Plant Performance Feedvater heater terminal differences were as follows:
No. 1 = 3.6 F No. 2 = 6.5 F No. 3 = 5.8 F The condenser performance was as follows :
137.0 MWe; 0.90" Hg B.P.; 455 3 MWt; 36.0 F C.W. in; TTD = 28.6 F; cleanliness factor = 6h.6%.
Chemistry The main coolant ammonia concentration averaged 13.1 ppm until February 15 Dilution of the main coolant plus ion exchange removed ammonia
/s to' trace levels as of February 18.
On February 17 the main coolant system was berated to h90 p,pm for physics testing; and then further borated to shutdown concentration on February 18.
The main coolant system concentration averaged 2h31 ppm during the balance of the period.
The main coolant system pH averaged 9.18 until the system was borated.
Subsequently the pH averaged h.95 The main coolant specific r_;tivity and crud level averaged 6.37 x '0-2 uc/ml and 0.03 ppm respectively through February 11.
On February 12, approxi-mately one hour after the reactor scram, the specific activity measured 1.34 x 10-1 uc/ml and the crud level measured Ih.1 ppm. During the remainder of the period the specific activity end crud level averaged 6.29 x 10-3 ue/ml and 0.16 ppm, respectively.
A 60,000 gallon dilution of the main coolant on February 15 and 16 reduced the tritium concentration from 1.08 uc/ml to 8.6h x 10-2 uc/ml.
Prior to the reacter scram on February 12 the iodine-131 specific activity averaged 7.06 x 10-5 uc/ml and the iodine 131/133 atomic ratio averaged l'.17.
By the end of the month the iodine-131 specific activity had decreased to 2.93 x 10-5 ue/ml.
/m A crud sample for the month collected on February 4, had the
()j '
following radiochemical analyses: dpm/mg crud
I l
Cr-51 Mn-54 7
6 Fe-59 6 Co-58 7
2.10 x 10 1.52 x 10 1.39 x 10 1.59 x 10 Co-60 Ag-110Mg 5
5 Zr-95 Sb-12h 6
3.61 x 10 2.0h x 10 5.35 x 10 1.32 x 10 A main coolant gas sample, collected on February 7, had the j
follcwing radiochemical analyses: ue/cc gas 1
Xe-133 Xe-135 Ar-bl
-2
-2 l
1.49 x 10-2.6h x 10 a.6h x in j
Health and Safety 4
1 4
Waste disposal liquid releases totalled 71,958 gallons containing l
0.038 me of gross beta-gamma activity and 90.630 curies of tritium. Gaseous releases during the period totalled 0.596 curies of gross beta-gamma i
activity and 0.054 curies of tritium. Secondary plant water discharged I
totalled 291,703 gallons containing 0.031 me of gross beta-gamma activity-and 0.084 curies of tritium.
In addition to the above releases 0.h81 curies of gaseous gross l
beta-gamma activity and 1.hhh curies of tritium as a vapor were purged from the vapor container through the primary vent stack.
t Radiation exposure doses for Yankee personnel and N.E.P.S.Co.
personnel as measured by film badge, for the month of February,1972 were:
Yankee Plant Personnel:
l Average accumulated exposure dose:
97 mrem Maximum.lecumulated exposure dose: 690 mrem
}
N.E.P.S.Co. Personnel:
}
l Average accumulated exposure dose: 12h mrem f
Maximum accumulated exposure dose: 690 mrem operations u
l Attached is a summary of plant. operating statistics and a plot l
of daily average ~1oad f or the month of February,1972.
e i
s l
t l
O t
l
..-_ ___-__..__ _ _ _, _.. _ ___ __ __ - __.-_. ~ - _,_... _.,..,._ _ __. _ -.. _ _
_._,,.i
YANKEE ATOMIC ELECTRIC COMPANY - OPERATING SUWARY Febrt'.ry 1972 ELECTRICAL MONTH YEAR TO DATE' Gross Ger.iration KWH 37,376,600 L47,688,100 13,163,56h,000 Sta. Serv.ce (While Gen. Incl. Losses)
KWH 2,680,331 10,086,184 851,155,798 Net Output KWH 34,696,269 137,601,916 12,312,h08,202 Station Service 7 17 6.83 6.h7 Sta. Service (While Not Gen. Incl. Losses) KWH 1,30h,007 1,304,007 34,408,399*
Ave. Gen. For Month (696)
KW 53,702.0 Ave. Gen, Running (270 95)
KW 137,946.5 PLANT PERFORMANCE Net Plant Efficiency 5
27.3h 27.92 28.h5 Net Plant Heat Rate btu /DTH 12,501 12,232 11,974 30.39 57.04 76.69 b
Plant Capacity Factor
=
Reactor Plant Availability 61.12 81.21 85.23 MONTH CORE IX TOTAL NUCLEAR Rours Critical HRS h12.25 10,520.59 85,h8h.99 Times Scrammed 2
5 66 Burnup Core Average M4D/lGU 254.53 11,946.29 Region Average M4D/MTU A (INNER) 257.8h 11,757.84 28,961.51 B (MIDDLE) 289 97 13,9ho.87 22,682.72 C (OUTER) 218.81 9,974.66 9,974.66 D (ZIRCALOY) 1
- Error found on total to date in October 1971, corrected this month.
1 YANKEE ATOF ECTRIC COMPANY l
DAILY AVERAGE LOAD i
FOR t
February 1972 i
l 1
i l
l I
200-5 s
s l.
~
l t
2 i
2!!
~
4 l
o
[
j g
150 _
I 9
f l
~
L_J g
o 4
{
a I
ca o
- 11 i
100 _
i 1
4 i
b
~
Q a
l 50 -
?
0 8
3 4
I l
a g
i i
g g
i i
5 10 15 20 25 30 DAYS
CO F x
A B
C D
E F
G H
J K
y XX XX 3
2 NXIX X'X/
X'><
XX s
XX XX o
gX WM X a X
MM X
~
c XX XX 7
XX XX o
/ ><'X
'XXN o
f XXXX 4=-
=
e i
e
-. x X
c-FORM RE-9