ML19351E125
| ML19351E125 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 01/27/1964 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| References | |
| NUDOCS 8011250635 | |
| Download: ML19351E125 (12) | |
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' YANKEE NUCLF.1R POW 1lR STATION
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t OCRATION REPORT NO. 36 e.r, 2 9..g C _4 For the month of-j DECEMBER 1963 1
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1 SubmLtted by IANKEE ATOMIC ELECTRIC COMPANY Boston Massachusetts January 27, 196h O
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This report covers the operations of the Yankee Atomi.c Electrie-Cogany plant at Rowe, Massachusetts for the month of December 1963 1-Until December 23, the plant was operated continuously at near rated capacity of 167-168 rWe gross. On that.date the plant was shutdown to repair a main roolant leak. The leak was similar to that reported in the~ Operations Report for November 1963.being traced to a second pinhole failure in -the, wsl weld of the plug, over. shin positimi number 26, onLthe reactor vessel head. - The original leak, on the. same plug, was in an area immediately adjacent to the most recent failure. To eliminate future
-recurrences of this type failure the entire seal weld was reworked using a three pass overlay.
On De<<.vaber 25, the~ generator was phased to the line and plant electrical outy.it was raised to 167 Wo. Having received A.E.C. approval
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to operate at 600 Nt, power level was gradually increased until December 30 when a power level of 185 We was achieved.
j' Periodically throughout the month control rod exercises and movement for wear equalization were carried out as scheduled.
During the recent refueling shutdown four high. flux irradiation test specimens wore removed from the reactor vessel. In mid-December the specimens were placed in a lead cask and shipped off site for~ avn=4 nation.
Twenty-four ' Core II silver-indium-cadmium control rods have been O
loaded into a cask "and are now awaiting shipment to a burial facility.
Plant Shutdowns Shutdown No. 66-3-h 12/23/63 - 11/25/63 A h6.9 hour1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> shutdown to repair a primary system O
leak in a seal weld of a position plug on the nor vessel head.
Maintenance 4
Following is a summary of. major activitier carried out by plant l
maintenance personnel during December:
1.
A leak in the lines leading to the fuel pit ion exchange unit was. repaired.
2.
The check valves in the heating boiler feed lines were repaired.
3.
The generator hydrogen vent line heat trace was repaired.
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- h. ~ Relays were replaced on an instrument air dryer control system.
5.
No.-1 auxiliary heating boiler was cleaned and inspected by an insurance. company inspector.
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- 6..Several diaphragm valves.in the waste disposal plant were repaired.
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h 7.E A broken contact shoe on the waste disposal hoist was replaced.
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- 8. - A' broken check valve spring was repl$ced in No. 3 charging pump.
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A defective diaphragm valve:on the waste holdup tank was l
repaired.
- 10. New heat tracing was installed on the waste. disposal drumuLag line.
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- 11. New brushes were installed on the vital bus inverter.
12 ~ The ccamuttator on both battery charges was cleaned.
LLO 13.
-ti-w- r.1-ed ar-d the -isture s arators -d 4
associated' piping.
lb. A leak in the seal weld of shim rod number 26 plug was
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repaired-by complete rewelding of the' whole seal.-
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- 15. MLacellanaous valve packing was added or adjusted as required 1
L in both the primary and secondary plants.
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- 16.. A h80 v. ground was found on the PCA storage bnilding crane l
and repaired.
- 17. No.17 control rod coil stack was replaced with.a spare coil stack. Replacement was necessary due to grounds developing on four'of the five coils of the stack resulting from moisture discharge during the seal weld leak.
i Chemistry During the month a program was initiated to measure. oxygen P
buillup in the pressurizer.. Early in.the reporting period' samples of
. pressurizer liquid, gas and steam phase were analyzed for dissolved F
oxygen, gaseous oxygen and boron. Dissolved oxygen was negative in the-j main coolant prior to pressurizer level changes but increased =to 0.09 ppe inusediately following level changes.- Pressurizer water contained 0.20 ppa i
dissolved oxygen prior to the test and decreased to undetectable amounts afterwards. Pressurizer gas-sagles' were quantitatively analyzed and found to contain 95% combustible gases. No oxygen 'was detected,- however,. it should be noted that the apparatus used is incapable of detecting oxygen-
> below 0.1%.. Condertsate samples were found to contain 36 ppa boron, indicating boron volatility of approximately 11%. This verifies data 1
obtained previously from vaste' disposal: operations with boron and laboratory' experiments on boron volatility.-
Inter on in the month the pressurizer vent system _was sampled.
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- ? lashed gas concentration had increased from 770 cc/ liter-to 1050 cc/ liter..
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{ts mentioned previously, oxygen could not be detected initially in the gas, l
wwever, an' average of 0.5% was detected in this. most recent -sampia.
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'fhe dissolved oxygen.in the pressurizer drain sample also increased from L-260 ppb to 370 ppb. :An' attempt was, therefore,;made to lower the overall-L.
axygen content of the pressurizer by-establishing a continuous vent to the-f 1Iow Pressure Surge ~ Tank atia c=aillav flow rate:of h9:1bs/hr.
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After eight days of venting,the flashed gas concentration decreased from 1050 cc/ liter to 6h0 cc/ liter. The oxygen concentration decreased from 0.5% to 0.2% this being the approximate equipment detection limit. However, water samples from the pramrizer drain line indicated oxygen levels had increased from 370 ppb to 700 ppb. The cause of this increase is as yet undetermined.
Following further continuous venting,. the fla' hed gas concen-s tration and the oxygen content again decreased to 51h cc/ liter and <0.2%
respectively. Also, the dissolved oxygen in the drain line decreased to 160 ppb.
Following startup after the cold shutdown of December 23, both the gas concentration and oxygen content showed no chan2e while the dissolved oxygen in'the drain line further decreased to h0 ppb.
O At the end of the reporting period continuous venting of the pressurizer to the Iow Pressure Surge Tank was still in progress.
Until the shutdown on December 23, the average main coolant specific activity remained essentially constant'at 1.2 x 10-1 g/ml.
Following startup on December 25, the specific activity increased to 1
3.h x 10 1 pc/ml but had again returned to the pre-shutdown value of 1.2 x 10- pc/ml at the end of the reporting period.
The main coolant crud level was measured at approxtmately 0.12 ppm until the shutdown, whereupon, the loop bypass valves were opened and the level increased to 13 7 ppm.
A mahi coolant iodine analysis made at the beginning of the reporting period indicated:
OO I-133 3 1 x 10 h pc/ml 3
I-131 8.7 x 10- pc/ml I-131/I-133 atart: ratio 2.78 Following startup on December 25, there was a small increase in I-131 concentration to 2.9 x 10-3 pc/ml. A steady decre the end of the reporting period, the I-131 was h.0 x 10 gse followed and at Jtc/ml at 185 We, A typical main coolant crud analysis made during the period indicated the following:
6 2.8 x 10 ' dpm/mg Cr-51 Iti-5h 6.2 x dpm/mg Fe-59 2.9 x dpm/mg Co-58 3.h x dpm/mg Co 60 6.2 x 10 dpm/mg Mg-110m 3.3 x dpm/mg Reactor Plant Performance Operation with boron in the main coolant continued throughout the reporting period. Only slight control rod motion was experienced as reactivity losses through burning were compensated for by periodic reductions
-h-O in the main coolant boron concentration. The slight control rod motion experienced during the month was that necessary for the wear distribution prog: am.
Considerable data taken during the Core III startup test program has been analyzed and the results are tabulated below:
1.
Average boron worth at operati,rg temperatures
-0.6 x 10-5. 6 9/ ppm 2
Boron concentration required for all rods out criticality at operating temperature 1300 ppm O
3.
Boron concentration required for all rods out criticality at 2500F 1600 ppm h.
Boron concentration required for 5% shutdown in the cold condition:
1100 ppm 5
Boron concentration required for h% shutdown at operating temperatures 200 ppm
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6.
The incremental worth of all rods banked was fitted over a measured range of bank height from 18 to 70 inches as:
88 3
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Total programmed rod worth at operating temperature as determined from rod oscillation data:
Total Group Worth Group 1
.012 K-Group 5
.021 K
Group 6
.023 K
Group 8
.025 K
8.
The inconal clad Ag-In-Cd control rods are equivalent to 95% af the hafnium rod worth.
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The moderator temperature coefficient is essentially the same as that measured over previous cores.
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As part of the Core III startup program a drop test sedes for all 2h control rods was made. All control rods were tested once %the cold
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condition and five times with the reactor at operating temperature md pressure. A recently complated analyeis of this data has shown a13 drop times to be in good accord with that data obtained.previously. In he cold condition the aurage drop time recorded was 1.676 seconds while at a temperature of 51h%' Trrg, the average drop tire for all 2h rods was 1.h5h seconds. The redachion in average drop time between the coM and hot tests is as expected due to changes in water density.
During the month a plot was maintained of actual reactivity behavior versus predicted reactivity behavior to account for any unexplained reactivity variances. At the beginning of the reporting period an un-explained reactivity loss of 0.1% 6(O was measured, this figure increasing to 0.2% 6 g at the end of the month. Across the shutdown '.f December 23, Q,,
a reactivity loss of 0.2% 6(O was experienced but was mih-rwntly regained through reduced burnup at rated power in the ensuing two weeks following startup.
The following were determined by means of in-core instrumentation measurements at a power level of 5h0 Et with control rod group 2 at 72 3/8" and all other groups at 75 6/8".
3.5 F
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3.5 Iate in the reporting period a gradual approach of the plant to the most recent autborized power level of 600 Nt was made. The first stage of the power increase consisted of a slow withdrawal of boron from (Nu) the main coolant accompanied by a corresponding insertion of control rods
'o maintain Tavg. and plant output constant. At the preselected boron concentration of approximatel 50 ppm the main coolant temperature was increased by rod withdrawal,aile the generator output was held constant by closing turbine control valves. Once the main coolant temperature had stabilized, the generator output was increased until all four control valves were fully open.
This same procedure was repeated until the plant had reached its newly rated output of 185 We, corresponding to a reactor power level of 600 Mt at a main coolant average temperature of $27 F.
0 No difficulties wem encountered with the primary plant during the load increase. All auxiliary systems accepted the additional load placed on them.
Turbine Plant Performance At several points during the plant loading to 185 We miscellaneous secondary plant performance checks were made. The resultant data has (O
shown all secondary side equipment accepted the load increase smoothly.
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6-No loss of circulating water discharge vacuum occurred during the
,(s month and consequently it is still impossible to determine the complete effectiveness of the modifications inade during the refueling outage.
The results of a typical fe6dvater heater terminal difference measurement made during the period indicated:
@ 18h We 1.6 " Hg 505 psig throttle 0
No. 1 9.0 F 0
No. 2 15.3 F 0
No. 3 6.2 F As reported in previous Operation Reports, substantial modifi-cations were made to the suspension system of the main steam piping during (V
the refueling outage. Main steam line vibration had been considered D
excessive during Core I and Core II operation. A series of tests performed by an outside consulting service during Core II operation resulted in the modification mentioned previously.
During the month, test data on vibration amplitude and frequency were measured at corresponding locations to those measured during Core II.
Substantial reductions in vibration amp;itudes were recorded at most locations. A slight increase was noted in the frequency of vibration.
This most recent data has been transmitted to the construction contractor and it is expected that only minor modifications will be required to make
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the new damping system completely effective.
Instrumentation and Control During the month the followir.g maintenance items were carried out by the plant Instramentation and Control group:
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1.
Installed new flux wires in drives No.1 and 3 and investigated power supply problems to the in-core instrumentation system.
2.
Repaired the turbine centrol valve position irglicator.
3 Modified spare FN equipment to incorporate recent changes brought about by the plant load increase.
h.
Reset the level alarms on the waste disposal loop seal.
5.
Checked the resistance readings of temperature detectors in the main generator.
6.
Completed decontamination of equipment used during refueling.
7.
Cleared the filter paper drive path on the vapor container air particulate monitor.
m 8.
Checked the calibration of the We recorder.
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Performed the bi-annual check of the Civil Defense equipment.
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- 10. Calibrated the four feedwater flow channels to cherk high readings of integrated flow.
- 11. Checked oparation of the air ejector effluent detector. The pipe to the stack had frozen causing erratic counting rates.
12 Checked sluggish operation of the Low Pressure Surge Tank level channel.
- 13. Readjusted the high THNR alarms to 555 F and the automatic
" rods in" to 529er end 518 F to their respected requirements at higher poirer operation.
Ih. Repaired the iricore thermocouple recorder range change circuit board
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- 15. Readjusted the set points on the main condenser level controls.
lL Reset the boiler feed pump suction pressure switch for operation at higher power.
Health and Safety During the month of December, 120 drums of solid radioactive p
waste, containing approximately 552 me, were prepared. Included in this d
total are 2h drums containing the effluent drained from the control rod shipping cask. These 2h drums contained 370 of the 552 me total.
One hundred avd two drums of solid radioactive waste, containing as estimated quanticy 41.21 curies were shipped off-site for disposal.
i I1guid vaste containing a total activity of 0.68 me was dis-charged from the clant during December. Gaseous release from the plant contained an estimated -7 0 me due primarily to radiochemistry sampling.
At all times the concentration of waste products discharged from the site was well below the==v4 =i=_ permissible.
Radiation levels of the LPST cubicle area were 110 mr/hr at the entrance,80-130 mr/hr geraral area, 200 nr/hr contact bottom of tank south, 350 mr/hr contact bottom north, and 1 r/hr contact bottom center.
Radiation levels measured in the fuel chute lower lock valve cubicle were 15-35 mr/hr general area, 150-200 mr/he contact lock valve, and 1500 mr/hr contact drain valve.
During the month four high flux irradimbion spacimens were shipped off-site for evn=4 nation. Radiation levels and contamination levels measured on the cask prior to shipment were h0 mr/hr taav4=i=
2 contact and 300 dpa/ft respectively. The total estimated activity of the shipment was 70 curies.
- A Inte in the' month reached a==v4== of 5 x 10 f-borne activity in the vapor container Jtc/cc due to the main coolant laak.
. O seaun ~ 1eak -
sin tu vagor c-teer red-ed = +-b-activity to 1 x 10-10
/ce. Appropriate respiratory equipment was required to be worn by all personnel ettering the vapor container during the period of leakage and repairs.
Radiation levels in the shield tank cavity during seal welding of the leak were., h0-100 m/hr general area, h0 mr/hr work area outside of the control rod coi.r. stack air baffle and 50-150 mr/hr inside the baffle.
Personnel exposures for Yankee plant personnel as measured by film ba4p for the month of December 1963 were 125 mr Average for all station personnel
=
h60 mr M== individual exposure
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Plant O g ations Attached is a summary of plant operation statistics fo* the month of December 1%3 and a plot of daily average plant load for the same period.
Also attached is a revised data sheet of plant operation statis-tics for the month of November 1963. The corrected sheet is necessary due to a revised feedwater flow calibration which resulted in increased reactor power level.
Additional revlsions will be noted in the December sheet dae to applied correction factors for main coolant pump thermal input and system thermal losses. Previously these corrections were only made at the end of core life but will now be included as part of the normal monthly O
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YANKEE ATOMIC EIECTRIC COMPANY - OPERATING -SUMARY -
DECE!EER 1963 EIECTRICAL MONTH YEAR g DATE Gross Generation KWH n7,518,100 1,00h,087,900 2,705,559,900 Sta. Service (While Gen. Incl. Losses)
KWH 7,132,532 67,0m,%8 197,772,035 Net Generation KWH 110,385,568 937,072,h32 2,507,787,865
' Station Service 6.07 6.67 7 30 Sta. Service (While Not Gen. Incl. Losses)
KW 232,200 h,076,h13 17,0h5,251 Ave. Gen. For Month (7hh HRS)
W 157,9h5 Ave. Gen. Running (697 1. HRS)
KW 168,581 PLANT PERFCRMANCE
-l Net Plant Efficiency 28.88 28.51 Net Plant Heat Rate Btu /KWH n,817 n,970 y
Ibs,*,tean@ietKW
%.00 1h.31 Cit.alating Water Inlet Temp.
Maximum F
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F 36 Plant Operating Factor 92 55 69.33 6h.98i NUCIEAR MONTH
_ CORE II TO DATE Times Critical 1
15 322 Hours Critical HRS 70h.0 1138.23 22,681.3h Times Scranuned O
3 h1 Equivalent Reactor Hours @ Sho MWt HRS 707.89 1019.15 16,222.h5 Average Burnup of Core MWD /mtU 766.36 n03.36 Control Rod Position at Month End Equilibrium at 600 IWt 527 F Tavg.
Group 1 Rods out-inchea 42 h/8 Group 2 76 h/8 Group 3 76 h/8 Group h 76 h/8 Group 5 76 h/8 Group 6 76 h/8 Group 7 76 h/8 M. C. Boron Conc. 55 ppm
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YANKEE ATOMIC ELECTRIC COMPANY - OPERATING 'SUltdRY NOVEMBa 1963 (REVISED)
EIECTRICAL MONTH YEAR
'TO DATE-
'51,923,h5h
.886,569,h36 800 800-2,588,0hl,800
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Gross Generation KWH 3,3hh, 59,882 190,639,503 Sta. Service (While Gen. Incl. Losses)
KWH Not Generation KWH h8,579,3h6 826,686,,86h 2,397,h02,297 Station service 6.hh-6.75
..16,813,051 7.37 Sta. Service (While Not Gen. Incl. Losses)
KWH 1,380,900.
3,8hh,213
. Ave. Gen. For Month (720 HRS)
W 72,200 Ave. Gen. Running (338.38 HRS)
KW 153,625 PIANT PERFGtMANCE Net Plant Efficiency 28.57 28.ho J
Net Plant Heat Rate Btu /KWH 11,9h5 12,016 p
Ibs. Steas@(et KWH 1h.27 2.36 Circulating Water Inlet Temp.
Maximum F
h7 Minimum oF
. h3 Plant Operating Factor h3 7h 67.2h 6h.h0' NUCIEAR MONTH CORE III TO DATE
. Times Critical 13 1h-321 Hours Critical HRS h03 25 h3h.23 21,987.3h Times Scrasuned 3
3 h1 Equivalent Reactor Hours @ $h0 MWt HRS 31h.90 31h.90 15,518.20 Average Burmup of Core WD/mtU 3h0.90 3h0 90 Control Rod Position at Month End Equilibrium at ShO Nt 51h0F Tavg.
Group 1 Rods out-inches 75 3/8 Group 2 67 7/8 Group 3 75 3/8
' Group h 75 3/8 Group 5 75 3/8 Group 6 75 3/8 Group 7 75 3/8 1
M.'C. Boron Conc.
~ 312 ppm
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