ML19351E180
| ML19351E180 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 04/20/1967 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E179 | List: |
| References | |
| NUDOCS 8011250723 | |
| Download: ML19351E180 (9) | |
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9 YANKEE NUCIZAR POWER STATION OPERATION REPORT NO. 75 For the month of MARCH 1967 1
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l Sub.-d.tted by YANKEE ATOMIC ELECTRIC COMPANY Boston Massachusetts April 20,1967
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+, W This report covers the operation of the Yankee Atomic Electric Co=pany plant at Rove, Massachusetts, for the month of March 1967.
At the beginning of the period the plant was operating at i
approximately 139 MWe, At 2100 hours0.0243 days <br />0.583 hours <br />0.00347 weeks <br />7.9905e-4 months <br /> on March 8 the plant was taken off j
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the line for the planned leak repair of No. 3 and No. L steam generators.
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By 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, March 9, the reactor was suberitical and borated to shut-I down concentrations and initial vapor ecntainer entry was in progress.
Radiation surveys conducted around Ho. h steam generator prepar-l atory to starting work indicated that the radiation levels were lover than previously anticipated.
Subsequent internal surveys showed levels of 5 to 6 r/hr approximately one foot from surface of the tube sheet. On this basis and in consideration of the time involved, it was decided to effect repairs on No. L steam generator without prior loop chemical decontamination. By March 11, both inlet and outlet sides of the steam i
generator had been opened and the leaking tube identified, near the t
center f the tube sheet. The vertical location of the leak was ascer-tained at the juncture of the tube and the uppe-surface of the tube
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sheet on the outlet side.
By 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />, March 14, velded plug repairs V
in No. L generator had been completed and hydrostatic tests successfully concluded.
Final close out of the primary and secondary sides was made on March 16.
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No. 3 steam generator was initially opened on March 12.
Internal radiation levels in excess of 16 r/hr approximately one foot frce the tube sheet surface were significantly greater than that encoun-I j
tered in No. b stean generator.
Eovever, as a result of the success and refinements to the repair techniques repair of No. 3 was also initiated
'V without prior loop decontamination.
By 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br />, March lb, the tube shcving the greatest amount of leakage had been identified on the inlet side of the waterbox and a smaller one on the outlet side. As in No. b steam generator, both tubes were located near the center of the tube sheet.
Hydrostatic pressurization of the secondary side and tube inter-nal plug traverses similarly revealed the vertical leak location to be g3 at the upper surface of the tube sheet.
Following repair of these tubes j
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hydrostatic tests indicated the presence of several weepers, of such t
small magnitude that vertical leak locations could not be ascertained.
After two additional tubes were plugged and welded a repetition of the hydrostatic test to approximately 950 psig identified five additional j
veepers. This identificaticn was accomplished only by maintaining the secondary side pressurized for approximately one hour and observing the j
damp areas on the surface of the tube sheet.
Leakage at these tubes was en the order of one drop every four or five minutes. Final repairs and close out of No. 3 steam generator was accceplished by 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, March 18.
Concurrent with the steam generator work effort No. 2 and
- 50. k main coolant pumps were removed from the primary system for maintenance.
No. 2 pump was removed from the loop immediately after it was drained en March 10.
Disassembly was completed the following day in the clean area established in the turbine hall.
Inspection revealed the errosion failure of the nickel, thermal barrier gasket as the cause of the slowly increasing pump lower bearing temperature experienced during the past two months.
By March 14, the thermal barrier gasket flange surfaces were lapped, the gasket replaced, the pump
. re-assembled and the pump and volute flange surfaces lapped. On March 16 G
the pump was reinstalled in the loop and power and cooling water connections were made.
No. h main coolant pump was removed from the loop on March 11 for the purpose of lapping the main pump flange surfaces and replacement of the leaking main flange gasket. On March 17 all work had been completed and the pump reinstalled in the loop.
By 1745 hours0.0202 days <br />0.485 hours <br />0.00289 weeks <br />6.639725e-4 months <br />, March lu, all primary loops had been filled, j
vapor container integrity had been established and plant heat up was in progress.
Criticality was achieved at 1533 hours0.0177 days <br />0.426 hours <br />0.00253 weeks <br />5.833065e-4 months <br /> March 20.
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1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br /> plant load of 150 MWe was attained. Approximately twenty-l four hours later the load was increased to 186 MWe.
On March 13 the fuel shipping cask was loaded with nit.e fuel assemblies and transferred to the decontamination pad.
However, failure
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of the head to fully seat when the bolts were taken up necessitated the j
transfer of the cask back to the spent fuel pit, unloading of the fuel assemblies an1 replacement of an 0 ring which had slipped out of its i
grmeve.
By March 15 the cask had been reloaded.and placed on the rail car.
Shortly thereafter, cne of the car cooling water diesel en61nes failed due to loss of oil.
The engine was. removed and shipped to i
Springfield by truck for overhaul.
On March 27, the overhauled engine
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was returned to the site and reinstalled on the railcar. The loaded cask left the site " arch 23 following satisfactory completicn of engine aperational tests.
This shipment is the twentieth in the series of spent fuel shipments, bringing the number of elements shipped in the ten element cask to 192 and the total number of elements shipped to date to 208.
The third Core VI, air charge to the vapor container, initiated upon establishment of vapor container integrity prior to startup, was terminated on March 30 when the weight of dry air in the vapor container O
was approximately 65,900 lbs.
The vapor container air leakage rate was normal throughout the reporting period.
Plant Shutdowns Shutdown No. 88-6-3 3-8-67 Scheduled shutdown for steam to gener*_ tor leak repairs.
3-20 67 Total outage time:
285 hours0.0033 days <br />0.0792 hours <br />4.712302e-4 weeks <br />1.084425e-4 months <br /> i
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i Plant Maintenance The following is a list of the major plant maintenance i. ems performed by the plant staff during the r.cnth of March,1967:
1.
New high pressure gland seal steam regulator andalump control valves were installed and calibrated.
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Ninc leaking tubes were plugged in No. 2 feedwater heater.
3.
The vapor container polar crane block and cable were replaced subsequent to the parting of the cable and dropping of the unloaded hook.
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No. 1 purification pump was replaced.
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5 No. 1 and 2 component cocling pump shafts and discharge i
check valves were inspected. All were found to be in a good condition.
6.
The right-hand turbine throttle valve was disassembled, inspected and cleaned. Both valves were exercised.
7 During the plant shutdown numerous primary system valves were inspected and repacked.
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Inst _rumen_tation and Control The following is a list of the major instrumentation and control maintenance items performed by the plant staff during the month of March, 1967:
1.
A new nuclear instrumentation cable was pulled to thimble No. 1 and the EF chamber in that thimble was replaced.
3 2.
No. 3 and No h steam generater narrow range level trans-mitters were repaired and recalibrated.
3.
The vapor container air particulate monitor vacuum pump was replaced.
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The charging pump discharge flow transmitter was repaired O
and recalibrated.
S.
The condenser hotwell level controller was disassembled, cleaned and recalibrated.
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6.
Main coolant pressure, pressurizer pressure and loop flow instrument channels were calibrated as were various temperature channels.
Reactor Plant Performance Core reactivity depletion prior to shutdown continued at approximately 0.68% a K/K per 1000 MWtD/MTU.
Plant performance sub-sequent to the shutdown and at 600 MWt appeared normal. A sufficient number of data points had not been accumulated by the end of the period to adequately predict reactivity follow at this power level, t
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-h-Secondary Plant Performan_ce Feedwater heater terminal differences at 182 K4e, 1.70" Hg backpressure and 52L.9 Tavg:
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- 1 - 5.6 F f 2 - 17.7 F
- 3 - 8.5 F i
Condenser terminal difference:
34.7 F Chemistry The primary to secondary leak rate in No. 3 steam generator increased from approximately LOh gpd at the beginning of the period to 600 gpd at the time of plant shutdown. At the end of the reporting period equilibrium primary and secondary water chemistry conditions had not yet been attained.
However, steam generator leakage is estimated to be less than 10 gpd.
The main coolant boron concentration decreased from llL6 ppm to 1138 ppm prior to shutdown. The shutdown concentration was 1961 ppm.
At startup the boron concentration was decreased to lL05 ppm.
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Further dilutions during the following three days decreased the concen-tration to 923 ppm.
The concentration at the end of the period was 907 ppm.
A main coo 3ar+ crud sample collected on March 8 had the following radiochemical analyses:
dpm/cg crud:
Cr-51 110-131 Mn--S h Fe-59 Co-%
Co-60 6
h 6
(
6 6
L. U') x 10 10 2.u3 x 10 1.69 x 10>
3.66 x 10
- 1. '(2 x 10 Ag-110 M: none detected A main coolant gas cample collected on March 27 had the following radiochemical analyses:
ue/cc gas:
-3
^3
-1 Xe-133 - k.75 x 10 Xe-135 - 9.46 x 10 Ar L1 - 7.60 x 10 Health and Safety One shipment of radioactive waste was made during the period.
The shipment consisted of Sh drums containing a total activity of 181 me.
One shipment of spent fuel was made during the period consisting of nine assemblies with a t otal activity of 15.3 megacuries.
Gamma radiation levels on contac; with the cask were generally 2-7 mr/hr with a maximum of 10 mr/hr at the valve box.
Neutron radiation levels at one meter were approximately 0.8 trad/hr fast and 0.022 erad/hr slow.
Beta-gamma contamination levels showed a maximum of 1 x 10-10 curies 2
per 100 cm. There was no detectable alpha contamination.
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1 During March the waste disposal lf. quid releases totaled 197,000 gallons containing 11.36 me of gresa bet a-gamma activity and 53.167 curies of tritium.
Gaseous waste releases during the same period totaled 901.71 me of gross beta-gn-ma activity and 4.98 curies of tritium.
A total of 3.987 curies of tritium '.s a vapor was purged from the vapor container l
during the plant shutdown.
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In addition to the above l< quid waste releases a total of j
159,C00 gallons of wa er were dischcrged from the secondary plant. The i
total gross beta-gamme and tritium activities released from the secondary l
plant were 32 uc and 9.855 curies, respectively.
Radiation e>posure doses for Yankee plant personnel and NEPSCo.
personnel, as measured by film badge, for the month of March, 1967 were:
Plant personnel Average accumulated exposure dose 461 mrem Maximum accumulated exposure dose 1145 mrem Service Company personnel I
l Average accumulated exposure dose 861 mrem f
Max'_ mum accumulated exposure dose 1b21 mrem oterations
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Attached is a summary of plant operating statistics and a plot
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of daily average load for the month of March, 1967 1
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J YANKEE ATOMIC ELEDTRIC COMPANY -- OPERATING EUMMARY MARCH 1967 EIETRICAT ENTH YEAR TO DATE Gross Generation WH Th,924,h00 272,269,h00 6,63h,729,900 Sta. Service (While Gen. Incl. Losses)
WH 4,491,493 16,180,122 hh6,202,944 Net Output WH 70,h32,907 256,089,278 6,188,526,956 Station Service 5.99 5.9h 6.73 Sta. Service (While Not Gen. Incl. Losses)
WH 307,215 387,215 24,182,682 Ave. Gen. For Month (Thh Hours)
W 100,705 Ave. Gen. Running (459 Hours)
W 163,234 PIANT PERFORMANCE Net Plant Efficiency 5
28.89 29.12 28.49 Net Plant Heat Rate Bru/WH 11,813 11,720 11,979 Plant Operating Factor 54.62 67.86 71.h8 Reactor Plant Availability 62.09 86.94 82.42 NUCLEAR ENTH C0FZ VI TOTAL Hours Crltical HRg h61.95 3,219.2h h6,9hh.92 Timics Scrammed 0
2 54 Bulw p Core Average WD/MrU h89.02 3,2hh.h3 Region Average WD/MTU A (INNER) 477.946 3,264.882 20,037.39 B (MIDDLE) 581.258 3,882.590 11,557.878 C (OUTER) 398.12h 2,603.5h7 2,603.54
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