ML19351E079
| ML19351E079 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 07/24/1964 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E076 | List: |
| References | |
| NUDOCS 8011250571 | |
| Download: ML19351E079 (9) | |
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l YMiKEE NUCLEAR POWER STATION OPERATION REPOIE NO. h2 For the month of JUNE 196h i
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.i YANKEE ATOMIC EIECTRIC COMPANY Boston Massachusetts i
July 2h,196h
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[O This report covers the operation of the Yankee Atomic Electric (v,/
Company plant at Rowe, Massachusetta for the month of June,196h.
At the beginning of the reporting period plant electrical output was 128 Wo.
For the balance of the month plant operations were normal and routine. The core life extension program remained in effect as gradual reductions in plant electrical output followed burnup.
The gross drop in capability recorded over the period was approximately lh We (128 We to 11h We).
During the month, transferring of spent fuel within the fuel pit was in progress when assembly A37 decoupled from No. 2 manipulator boom and fell into an empty fuel assembly channel in the storage rack.
At the time of the drop the bottem of the assembly was approximately one foot above the top plate of the storage rack. Following the incident it was elected to visually inspect the assembly for gross damage. Although several attempts were required to latch the manipulator tool boom to the p
assembly, a successful latch was eventually made. A complete visual
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examination with binoculars revealed no apparent damage and the assembly was therefore returned to the storage rack. A further boroscope examination is planned. No specific evidence has been found as to the cause of the incident since operational aspects of the manipulator tool boom were normal.
During the month it was noted that the leakage rate from the ion exchange pit had increased. Although the specific activity of the pit water
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was below the allowable MPC (both unidentified and identified) and could
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therefore be discharged directly without dilution, filtration of the pit id water was initiated. Due to the radiation levels of some ion exchange capsules within the pit, dewatering for repair is not passible. Attempts at underwater detection of areas of leakage and repair are in progress.
Throughout the month control rod exercising and movement for wear distribution were carried out as scheduled.
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A vapor container inspection was made on June 8, and no abnormal conditions were noted.
At the end of the reporting period plant electrical output had decreased to llh No.
No reactor scrams or plant shutdowns occurred during June.
Plant Maintenance Following is a summary of major activities carried out by the plant maintenance staff during June.
1.
Periodic inspections of the station batteries and exciter were made during the month.
2.
An oil leak on the low oil level cutout switch on No. 1 p) control air compressor was repaired.
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New connectors were installed on the spare indicating coil stack.
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-(v) 15. A failed shaft was replaced in No. 1 gravity drain tank pump.
5 Piping to the sulphuric acid pump suction was renewed.
6.
Following the incident reported in the Operations section of this report, the manipulator boom and its tool were removed from the spent fuel pit for inspection. The top edge of the lead in surface of. the outer circumference was fcund rolled up heavi.ty at one point and lightly at two others.
The tool fingers were found to be free and operating properly.
7.
The concrete foundations of two vapor container columns were repaired. Surface spalling of the concrete had occurred over a period of time.
8.
Fabrication of-two guide tube disposal casks and lifting fixtures was in progress during the month.
9 The hydrazine pump was repacked.
10.
An enclosure over No. 2 decontamination pad was completed during the month.
- 11. Modifications to the purification system were completed, heat O
traced, and insulated. A complete description of the mod-(
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ifications can be found in the Design Changes section of the VM report.
Chemistry Operations with ammonia adjusted high pH continued throughout the reporting period. The ammonia cor.cintration varied between 8 and 9 ppm.
Following the completion of potassium controlled high pH operation in April it was noted and subsequently reported, that a small amount of potassium had been retained in the main coolant system and could not be removed by normal purification methods. An intensified chemistry follow program was therefore initiated and up to the present all results have been essentially negative. However, in June, traces of potassium were found in the main coolant crud. The crud contain approximately 15,00 ppm potassium (1.5%). A more detailed report on adjusted pH operation is now being compiled.
Throughout the reporting period the main co lant exygen concentra-tion remained below the point of detectior.
The average main coolant 4
specific activity was measured at 3.2 x 10 pc/ml. The main coolant crud level varied between 0.25 and 1.8 ppm. - The main coolant iodine-131/I-133 atomic ratio was 3.9.
A comparison of crud specific activities for borated unadjusted pH
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and high pH during Core III operation is as follows:
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Borated High pH l
Unadjusted pH (NH )
3 Cr - 51 h.8 x 10 dpm/mg 17.0 x 1 dpm/mg Mn'- Sh 0.8 x 10 dpm/mg 3.2 x dpm/mg Fe - 59 3.6 x 1 dpm/mg 8.6 x 1 dpm/mg Co - 58 8.1 x 10 dpm/mg 17 0 x 1 dpm/mg Co - 60 17x dpm/mg-1.6 x-1 dpm/mg Ag - llom 0.1 x 10 dpm/mg 0.5 x 1 dpm/mg specific activity of 3 0 x 10 gn Exchange Pit water resulted in a gross An analysis of the I 8Ac/ml A sample of this water was filtered and the filtrate activity was 8 x 10 bjic/ml. An analysis of the crud portion indicated that over 90% of the crud activity was Ag-llOm.
As reported in the Operations Report for May, 196h, fuel assembly pd A8 which.had seen service in both Cores I and II was loaded into a spent fuel shipping container for leak testing. Gas samples collected on June 5 and June 22 were analyzed and no detectable fission gasses were found.
Cask water soluble and insoluble activity was due to Co-58, Co-60, Mn-5h and Ag-llom radionuclides. Within the limits of the test it has been concluded that no significant cladding defects exist in this assembly.
A typical main coolant gas analysis made during the period indicated:
A - 41 5.6 x 10-2 Ac/cc gas Ie - 135 5.3 x 10- Ac/cc gas Ie - 133 h.7 x 10-lyc/cc gas Reactor Plant Performance
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Throughout the reporting period the core reactivity depletion rate remained essentially uniform and constant at 1.5 x 10-h O F/ day.
E mbers of the Reactor Plant Performance group were present and monitored all transferring of fuel in the spent fuel pit from the existing storage racks to the recently installed poison rock.
Routine plant calorimetric data was measured and tabulated throughout the reporting period.
The following were determined by means of in-core instrumentation measurements at a power level of h30 IWt with all rods banked at 88 7/8 inches.
F Fq 2.3 FdH 2*3 QDNBR 5.0 p) 5hh.3 F-g
, Hot Channel Outlet
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Turbine Plant Performance Operating data was obtained-on the feedwater heater drain pumps in an attempt to determine the causes for changes in plant output and. condenser b
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backpressure when changing operation from one pump to the other. Following tabulation of the data the trouble was traced to leaking recirculation valves that dump direct to the condenser.
Feedwater heater terminal difference measurements made during the period indicated.
123 Mle 2.55" Hg.
356 psig throttle No. 1 7.2 F No. 2 11 9 F Uo. 3 5 3*F Instrumenta'lon and Control The following is a list of major activities carried out by the plant Instrumentation and Control group during June.
1.
Installed a differential pressure indicator to measure ion exchange differential building.
2.
Checked operation of the primary vent stack radiation monitoring channel.
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3 Prepazed a power supply for the No. 1 manipulator crane tool
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boom telescoping alarm.
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Performed preventive maintenance and calibration checks of -
all area radiation monitors.
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Recalibrated the T NR main coolant temperature channels as-c l
required during the month to follow changes in the raage of main coolant temperatures.
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Tested the response of the relative hund.tity and vapor container temperature indicators to variations in line voltage. No effect could be seen.
Health and Safety During. the month of June 196h, 3 drums of routine radioactive wastes containing a total activity.of 7.6-me were prepared. Thirty-nine~ drums containing a total activity of lh5.3 me were shipped from the site during the same period.
9 Iiquid wastes containing a total activity. of 0.02 mc were discharged during June. Gaseous wastes containing a total activity of 88 me due to radiochemistry sampling were discharged during the same period.
.n A general survey of the plant " Clean Area" showed a maximum radga-
_ (v) tion level of 0.03 mr/hr, and contamination levels of less than 50 dpm/ft.
A radiation survey of the FCA tank farm showed the following levels:
. Waste holdup tank cubicle 200-300 mr/hr general area, and h r/hr murimum contact tank bottom;. activity dilution decay tank cubicle 200-300 mr/hr
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general area and 6 R/hr maximum contact tank bottom; gas surge drum cubicle
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k-O.5 mr/hr general area and 1 mr/hr maximum contact; safety injection tank h mr/hr maximum contact bottom.
The incinerator particulate filter was renewed. Radiation and contamination levels of the replaced filter bed were 1 mr/hr contact, and 2
200-700 dpm/ft,
During installation of three purification line check valves in the pipe enase adjacent to the ion exchange pit radiation levels were measured as h0-50 mr/hr general area, and 100 to 150 mr/hr contact with piping.
The ion exchange pit water was circulated through a filtering system containing nine 50 micron filter cart;-idges. After four hours operation, the filters were removed. Radiation levels measured on the bag were approximately 90 mr/hr. It was estimated that approximately 6 millicuries of activity (Ag-110m) were removed from the pit water.
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Personnelexposure for Yankee plant personnel as measured by film badge for the month of June 196h were:
89 mr Average for all station personnel
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$60 mr Maximum individual exposure
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Design Changes 7
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4d As reported in the Operations Report for November 1963, inadvertent backwashing of an ion exchange column caused the release of a small quantity of resin fines into the main coolant system. To prevent a similar recurrance check valves have now been installed in the inlet lines to the purification ion exchangers.
Plant Operations p
V Attached is a summary of plant operation statistics for the month of Junc 196h, and a plot of daily average plant load for the same period.
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TANKEE ATOMIC ELECTRIC
- OPERATING
SUMMARY
a June 196h ELECTRICAL WJNTH YEAR TO DATE Gross Generation KWH 86,78h,000 693,382'700 3,398,9h2,600 Sta. Service (While Gen. Incl. Iosses)
EWH 7,002,051 hh,812,56h 2h2,58h,599 Met Generation KWH 79,781,9h9 6h8,470,136 3,156,358,001 Station Service 8.07 6.h6 7.3 Sta. Service (While Not Gen. Incl. Iosses)
KWH 0
230,000 18,275,251 Ave. Gen. For Month (720 HRS)
KW 120,533 Ave. Gen. kanni ng (720 HRS)
KW 120,533f PIANT PERFORMuiCE Not Plant Efficiency 5
25 59 28.h7 Not Plant Heat Rate Btu /ERH 13,336 11,987 Ibs. Steam / Net KWH 15 6h u.35 Circulating Water Inlet Temp.
"F 65 " 4 3
Mari m Mininum F
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Plant Operating Factor 72.17 88.08 68.71 NUCIJER IONTH CORE III TO DATE Times Critical 0
19 326 Hours Critical HRS 720
$h83.30 27.0:'6.h1 Times Scransmed 0
6 hh Bpaivalent Reactor Hours @ 600 IWt HRS 519.59 bl65.0 17,662.85 Average Burnup of Core IWD/mtU Control Rod Position at Month Ibd Equilibrium ath20 tMt h7h.5 F Group 1 Rods out-inches 89 2/8
- Region Group 2 89 2/8 Group 3 89 2/8 Inner 82h 87 7990.99 Group h 89 2/8 Middle 72h.88 12,081.50 Group 5 89 2/8 Outer 502.77' h397.h7 i
Group 6 89 2/8 Group 7 89 2/8 Boron d 1 ppm
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