ML19351E052
| ML19351E052 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 11/25/1964 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E049 | List: |
| References | |
| NUDOCS 8011250538 | |
| Download: ML19351E052 (10) | |
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. YANKEE NUCLEAR POWER STATION l8 l
OPERATION REPORF NO. L6 '
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~ For the month of i'
I OCTOBER 196h 1
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Submitted by.
YANKEE ATOMIC ELETRIC COMPANY l
. Boston Massachusetts i
l-November 25,196h j
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This report covers the operation of the Yankee Atomic Electric Company plant at Rowe, Massachusetts for the month of October,196h.
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At the beginning of the reporting period the plant was opert cing k'~~'/
at a power level of 178 We, Output remained essentially constant at that point until October 18, when it was necessary to shutdown to investigate a vibrating noise in the main condenser. Inspection showed that a baffle plate at the condensate recirculating penetration had broken loose and dropped into the hotwell.
With the plant off the line the main condenser tubing was cleaned in an attempt to improve the cleanliness factor v
h has been abnormally low since Core IV startup.
Following completion of the maintenance items within the condenser, the generator was phased and loaded to 16h We.
On October 20, the plant load was increased to 180 We.
On October 22, an unscheduled scram from full power occurred as a result of accidental operation of the power range gain control knob on
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a main control board power level indicator. As the scram gas readily det-ermined to be of a spurious nature, preparations were made for an immediate return to power generation whereupon difficulties were encountered in restoring the left hand turbine throttle valve to its open position. Turbine roll-off was accompanied by a second reactor scram, the cause of which is discussed in the Turbine Plant Performance section of this report. Following the scram the throttle valve and servo mechanisms were disassembled and inspected. No abnormalities were noted within the mechanisms and following p}
assembly, the valve operated normally. The plant was, therefore, returned
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to line at 1656 hours0.0192 days <br />0.46 hours <br />0.00274 weeks <br />6.30108e-4 months <br /> on October 23 Plant output reached 182 We on October 25, and remained constant at that point throughout the balance of the reporting period.
During the outage a vapor contr.iner inspection was made with no abnormalities noted.
A Control rod and turbine valve exercising were carried out as C) scheduled during the month.
Plant Shutdowns Shutdown No. 75-h-h 10-18-6h A 12.17 hour1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> scheduled shutdown for main condenser maintenance.
Shutdown No. 76-h-5 10-22 -6h A 22 35 hour4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br />' shutdown resulting from a reactor scram.
Scram No.
h7-h-3 10-22-6h An automatic reactor scram from a power level of 595 We resulting from inadvertent operation of the power range
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i gain control knob on the
(_j main control board.
s Scram No, h8-h-h 10-22-6h An automatic reactor scram
'N from a power level of <1/M4t j
resulting from a turbine trip.
Plant Maintenance Following is a summary of major activities carried out by the plant maintenance staff during October.
1.
The waste disposal incinerator was cleaned.
2.
Replaced steam trap in rear of No. 1 house heating boiler.
3 Removed and repaired VD915 in PAB valve room.
h.
Footings for the primary water storage tank heat exchanger were poured.
The vapor container purge fan was inspected.
6.
New carbon rings were installed in No. 3 charging pump packing boxes.
7 The decontaminatio.i room ventilation fan was inspected.
8 8.
Exciter brushes and air filters were inspected.
9 Cleaned main condenser tubes in both water boxes during scheduled shutdown.
10.
Opened lef t hand turbine throttle valve for inspection.
11.
Repaired a leaking boiler feed pump flange.
<-(s) 12.
Inspected the exciter field air circuit breaker.
13 Repaired a failed baffle in the main condenser.
lb. Cleaned and inspected No. 2 steam heating boiler.
15 Both control air compressors were cleaned and inspected.
Chemistry Throughout the reporting period the main coolant oxygen concen-tration remained below the point of detection.
At various times during the period the ave activity was measured at 7.8 x 10-2 ;uc/ml, 7.6 x 10 gage main coolant specific suc/ml, 7 5 x 10-2,cc/ml and 7.2 x 10-2Atc/ml.
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-h-Turbine Plant Performance
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Continued poor condenser performance data coupled with the
\\d previously mentioned-condenser baffle failure led to the shutdown of October 18.. The. condenser cleanliness factor has been continuously
'below the Core III set point'since Core IV startup. :In September a' plant shutdown was made to. clean. tubes causing the cleanliness factor to
' increase from $9% to 68%. The second cleaning on October 18, resulted' inJa further increase to 75%, a net' increase overall of approximately
'12 Mde at corrected conditions. At the end of the reporting period the condenser cleanliness factor was approximately the same as that measured during Core III operation.
Following the initial scram on October 22, the turbine was returned to slow roll and speed was increased gradually until the governor took over. As the'left hand throttle controller was run down to open the valve, an unsual noise was heard and the turbine speed quickly rose to 2000 rpm.. Coincide.it manual and automatic overspeed tripped the turbine and was quickly followed by a reactor scram since the turbine trip circuit p)
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was activated with one throttle valve closed.
As memtioned previously the valve was opened and inspected. No adverse conditions were found and the valve was reassembled. Both throttle valves were tested and operated satisfactorily. Steam was again admitted to the turbine and phasing was accomplished without incident at 165h hours on October 23rd.
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- During the month vibration measurements were obtained on the main C/
steam piping at the same locations as data obtained during Core III operation.
The results indicate that.the latest measurements are essentially the same as those made during Core III.
Instrumentation and Control-The following is a list of. major activities carried out by the plant Instrumentation and Control group during October.
1.
Recalibrated the charging flow transmitter and receiver.
2.
Checked operation of tha vapor container air particulate monitor after moisture had condensed in the air lines.
3.. Checked the plateau on the primary vent stack monitor.
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Removed instrurentation from the stripper cubicle.
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Made up new coaxial jumper cables for the ion chamber thimbles to' maintain a spare cable supply adequate for complete cable
-replacement.
4 Health and Safety During the month of October, % drums of radioactive wastes con-V taining a total activity of 73h mc were prepared and shipped from the site.
This shipment consisted of 51 drums of routine waste containing h96 me, The Iodine-131 ac)ivity was measured a) 2 5 x 10-5,ue/m1, 1.3 x 10-6 c/ml, 7.9 x 10-0Ac/ml and 1.2 x 10->Ac/ml; the I-131/I-133 A
atomic ratio was 0.92, 0.68, 0 58 and 0.69 respectively.
Core burnup follow through boron concentration reduction proceeded uniformly during the month with the concentration measured at 690 ppm at the beginning of the reporting period, decreasing to $$0 ppm at month's end.
The main coolant crud concentration remained essentially below 1 ppm throughout the month except for short periods of increase to approxi-mately 2.5 ppm following control rod :xercising.
A typical main coolant gas analysis performed on October lb,196h indicated:
Xe - 133 6.2 x 10-3,uc/cc Xe - 135 1.0 x 10-',cc /cc A-h1 9.3 x 10-2,uc/cc A typical main coolant crud analyuia performed on October 23, LWh indicated:
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Cr - $1 = h.1 x 10 dpm/mg Co - 60
= 1.3 x 10 dpm/mg Ih-$h=9.7x10hdpm/mg lif - 181 = 6.0 x 103 dpdag Fe - $9 = 2.1 x 10 dpm/mg In - 116m = 7.8 x 107 dpm/mg 0
6 Co - $8 = 7.0 x 10 dpm/mg 8
were leak tected in the spent fuel pit.
Both sources that were renoved frca the core during the past refueling The results obtained are now under investigation and will be reported in a future Operations Report.
Reactor Plant Performance Core reactivity follow is maintained on a daily basis to determine composite unexplained gains or losses in reactivity.
During the month the J
Core IV data previously obtained was recalculated using a new boron worth curve that shaus changes in baron worth with changes in boron concentration.
The revised reactivity curve was found to be in excellent agreement with a predicted depletion rate of 1.12% & [ per 1000 W D/MI'U.
t Analysis of a six wire flux wire irradiation during transient Xenon at 5h0 M4g gave the following results.
0 526 F Tavg 612 ppm Boron Gp. A @ 3h 1/8" FQ 27 F i H 2.1 QDNBR h.3 Hot Channel Outlet
$87 F W
f 16 drums 'of expended ion exchange resins containing 16 me and one drum containing a low flux specimen hole plug consisting of $0 mc.
Liquid wastes containing a total activity of 0.26 me were dis-charged during October. Gaseous wastes containing a total activity of h me due primarily to radiochemistry sampling were discharged during the same period.
A radiation survey in the vapor container during the shutdown of October 18, produced the following results.
Radiation Level mr/hr Location Loop 1 Loop 2 Loop 3 M.C. Piping Th Contact Maximum 150 350 200 M.C. Piping T Contact Maximum 125 300 70 c
M.C. Stop Valve Th Contact 'iximum ho 160 200 m
M.C. Stop Valve T Contact, Aaximum 70 90 70 c
f Bypass Valve Contact Maximum 90 300 150 Bypass Valve Contact Maximum 125 350 22$
Drain Valve Contact Maximum 125 1000 200 General Cubicle Area 13-h0 15-93 Leakage from the ion exchange pit during October was measured at 117,8h9 gallons containing a total activity of 0.18 me.
During the month a local contractor utilized to analyze and evaluate
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the environmental survey program reported the presence of slight activity in the plant well water supply. Although the concentration of activity was below levels for human consumption, ac a precaution, the plant drinking water was turned off and replaced by bottled water.
Subsequent plant investigation served to confirm the contractor's findings; however, some doubt was raised as to the value of the data. The (D
normal background of the chemistry counting room is such that defining of low level isotopes in environmental samples is difficult. Additional samples were, therefore, sent to the original contractor and one other independent agency whereupon both organizations confirmed that the activity was due to natural occurring radium and radium decay product with the well water below levels for human consumption.
Personnel exposure for Yankee plant personnel as measured by film badge for the month of October, 196h werea h9 nr Average for all station personnel
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Maximum individual exposure 220 mr
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Plant Operations Attached is a summary of plant operation statistics for the month c
of October,196h, and a plot of daily average plant load for the same period.
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1-During the month an error was discovered in'the January,196h Operations Report wherein the Equivalent Reactor Hours @ 600 Wt was
. incorrectly reported. The corrected data'is presented below:
t --
-Month Core III
~To Date 3-1 January 731.17 1651.68
.15,278.81 February 662.22 2313.90-15,9hl.03 j
March 720.53-303h.h3 16,661.56
-April' 626.55 3660.98' 17,288.11 May 586.32 h2h7.30 17,87h.h3 June
$19.59 h766.89.
~18,872.80 18,39h.02 July h78.78 52h5.67
[
August 15.90-
$261'.57 18,888.70 1-j Core IV i
September
.$12.60 512.60 19,h01 30 1
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TANKEE ATOMIC ELETRIC COMPANY - OPERATINO SU) TERT RIETRICAL MEITH TEAR TO DATE Gross Generation DiH 125,1h3,h00 991,683,200 3,697,2h3,100 Sta. Service (While Gen. Incl. Iosses)
DiH 7,679,895 65,803,939 263,575,97h Net Generation EWH 117,h63,505 925,879,261 3,h33,667,126 Station Service 6.1h 6.6h.
7.13 Sta. Service (While Not Gen. Incl. Iosses)
KWH 199,100 1,753,200 20,608,651-Ave. Gen. For Month (7h5 HRS)
EW 167,977 Ave. Gen.
D==in, (709 HRS)
KW 176,506 PIANT PERFGURNCE Not Plant Efficiency 28.22 27.82 Net Plant Heat Rate Btu /DfH 12,093 12,267 Ibs. Steam / Net KWH 13 01 13.h5 4
Circulating Water Inlet Teep, i
Maximam F
65 MLntunn OF h9 Plant Operating Factor 93 11 75.78 67.6h K2iTH CORE IV
-TO DATE NUCLELR 2
19 3hh Times Critical j
Hears Critical IRS 717.$3 1365.09 29,165.58 2
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Times Scraaned R nivalent Reactor Hours @ 600 Mit HRS 693.63 1206.23 19,913 90 I
l Average Burnup of Core mfd /mtU 1
i Control Rod Position at Month 3x1 l
Equilibrium at 595 Mit 527 F Tavg REGION MONTH CORE IV l
Group A Rods out-inches 723 Group B 90 INNER 871.9 10,20).0 Group C 90 MIDDLE 1033.0 6701.9 j
Group D 90 OtTfER 636.h 1080.0 E-6 737.8 23,5h0.7 l:
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Boron 550 ppm i
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YANKEE ATOMIC ELECTRIC COMPANY t
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DAILY AVERAGE LOAD t
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(a) Shutdown No. 75-h-b j
3 (b) Shutdown No. 76-h-5 l
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10 15 20 25 30 1
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CORE IV REDION IDCATIONS OUTER REDION MIDDLE REION y
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