ML19351E193
| ML19351E193 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 12/21/1966 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E192 | List: |
| References | |
| NUDOCS 8011260134 | |
| Download: ML19351E193 (11) | |
Text
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Ello Copg YANKEE NUCLEAR POWIR STATION (pg OPIRATION REPmT NO. 71 For the month of NOVEMBIR 1966 n
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Submitted by YANKEE ATOMIC ELECTRIC COMPANY Boston Massachusetts December 21, 1966 l
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r This report covers the operation of the Yankee Atomic Electric Company plsnt at Rcwe, Massachusetts, for the month of November, 1966.
O At the start of the reporting period, the Core V-VI fuel handling program had been completed, and plant heat-up was in progress. At 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> on November 1, the heat-up was stopped at h000F, and 550 psig, and for the next 2h hours the main coolant system was " soaked" at this temper-ature to allow complete effusion of hydrogen from the reactor vessel.
Af ter the wait, main coolant system hydrostatic pressure tests were satis-factorily completed, the reactor was taken critical, and the physics testing program was started.
At 0230 hours0.00266 days <br />0.0639 hours <br />3.80291e-4 weeks <br />8.7515e-5 months <br /> on the morning of November 3, the main coolant system average temperature was $250F arxi system pressure was 2000 psi.
The all-rods-cut boron concentration had been determined and control rod drop tests were in progress when a leak developed on the reactor head.
Emergency primary plant depressurization and cooldown was initiated. The
,D leak was at the mechanical seal on the north in-core instrumentation thimble and the *ailure probably occurred because the spire was slightly out-of-plumb whtu the seal was installed. When the cooldown was completed on the evening C 'he 3rd, the seal was loosened and a seal bell was welded in position to enclose the seal. Repairs were completed on the morning of November h and a hydrostatic pressure test at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> re-vealed a slight leak at the weld on the spire. This leak was rewelded, and ifter a successful pressure test at 2h85 psi, plant heat-up was started.
As a result of cor;1ensation from the leak, several control rod
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drive mechanism coils developed low ress stsnee to ground. In the process of pl9nt heat-up, the grounds cleared from all but one of the coil stacks.
The replacement of t > efective stack was completed on the morning of November 6.
At 02h0 hours on Noveaber 6, the physics testing program was re-sumed. Control rod exercises and rod drops were completed, the reactor was
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taken criticsl, and the measurement of reactivity coefficients continued
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until 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> on November 7 The generator was phased on the line at lh00 hours on November 7, ending the 3h-day refueling and maintenance outage.
Power level was in-creased to 150 We, held at that level overnight, and then increased to 16h We ($h0 Nt). It was necessary to delay the increase to maximum power because of a problem with No. 2 condensate pump. The pump had been over-hauled du.ing the shutdown, and when started was found to have an internal rub. An adjustment to the coupling corrected the problem, and at 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on November 9 load was increased to 183 We.
Plant load remained at this level until November 15 when load was reduced to 90 We for about three hours to allow the repair of a pinhole cak in the high pressure turbine exhaust line leading to the lef t hand moisture separator. With the exception of another three hour load reduc-tion on the 29th to allow repacking of the glands on No. 2 boiler feed pump, power level was maintained at 16h We for the remainder of the report-ing period.
. On the evening of November 1, a rainor spill occurred, releasing llg less thtn ten gallons of contaminated water to the storm f ain served by the east culvert system.
The occurrence took place during the routine draining of the discharge line of the fuel chute pump. Apparently the heat tracing on the pump discharge line had heated the water in the line to s temperature high enough to soften the plastic hose being used in the draining operation. The hose broke at a coupling, releasing the water to the storm drain. Based on the activity of the spilled water, a total of 113 ue was released.
The International Atomic Energy Agency inspection continued through the period until the plant was placed in service. The IAEA seals were placed on the reactor head missile shield on November 7 On November 10, control rod groups B, C, arid D were banked at 87 0/8 inches to establish the start of the maximum withdrawal limitation program. The rods will be withdrawn one step periodically throughout the
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oper: tion of Core V! in order to distribute guide block wear evenly along the rod surface.
On Neverber 30, the monthly control rod exercise was performed; no abnormal rod operation was noted.
One 41pment of spent fuel was made during the manth of November.
On the lhth the spent fuel shipping cask was loaded with ten elements, and the cask was shipped on November 17 This shipment is the fif teenth in
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the series of spent feel shipments, bringing the number of elements shipped in the ten-element cask to lh6 2nd the totel of elements shipped to date to 162.
The initLal Core 7I air charge to the vapor container was started on November 21. Air charging continued intermittently on a daily basis, dependent upon tvailability of the service air compressor, and was completed
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i on Nover.ber 28. The chargirg was completed when the total weight of dry air in the vapor container reached approximately 66,000 pounds.
The vapor container penetration leakage testing program continued through the reporting period. Among those penetrations and lines success-fully tested during the period were the vanor container drain line, the shield tsnk civity fill line, the neutron shield tank sample line, the fuel chute pumpb ck system, and the vapor container open and closed bulb system.
Following the dismantling, inspection, and overhaul of the main generator during the refueling outige, it has been noted that the hydrogen consumption of the unit has been reduced from four bottles of hydrogen per day to less than two bottles per day.
Plant Shutdowns Shutdown No, 85-5-6 10-h-66 Continuation of scheduled to Core V-VI refueling shutdown.
11-7-66 Total outage time: 826.23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br />
_3 Plant Phlntenance The following is a list of the major items performed by the plant staff during the month of November,1966:
- 1. The No. 2 boiler feed pump was reassembled. The pump had been disassemoled for inspection in September,1966, and it was then noted that the balancing sleeve had nine radi'l cracks on its surface. The cracks were removed by machin-ing the sleeve, and the sleeve was then rebuilt and chrome plated. New shaf t sleeves and bearings were installed in the pump.
- 2. No.1 control air compressor was operating wi'.h incorrect cycling action at the start of the reporting period. Valve replacement did not solve the problem, and further investi-gation revealed leakage in the aftercooler due to a general
-s tubing failure. A new aftercooler was fabricated and in-stalled, and the carbon steel piping between the new after-cooler and the air receiver was replaced with stainless steel piping.
- 3. To reduce pump leakage, the carbon ring packing and one plunger were replaced on No. 3 charging pump.
- h. The diaphrague in No. 2 waste gas compressor were replaced.
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- 5. An oil leak in the east side of the turbine oil cooler was
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repaired by plugging a leaking cooler tube.
- 6. The auxillary boilers vcre cleaned and inspected.
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Instrumentation and Centrol The following is a list of major items performed by the plant staff during the month of Ncvember, 1966:
- 1. The EF6 detector in Climble 6.wsgyeplaced.
- 2. The Visicorder equipment was connect ed for use in determin-ing control rod drop tines during the physics testing
- program,
- 3. In preparing the Teleflex system for operation, more time than usual was required due to an accumulation of minor problems.
In making the system operable, two motor drive gears were replaced, six drive wires were replaced, and one motor control relay was replaced.
- h. The low pressure surge tank pressure controls were recali-brated.
- 5. secondary plan... crumentation recalibration was completed with the recalibration of the narrow range steam generator level recorders.
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Reactor Plant Performance-The Core VI start-of-life physics test program was started on October 31, 1966 and. completed on November 7,1%6. A reactivity com-puter was used throughout the. test program. The overall. program of control rod testing and reactivity coefficient determination can be summarized as follows:
Af ter completing cold control rod exercising and cold control l
rod drop time measurements, the reactor was taken critical. Main coolant system heat-up was followed with the determination of temperature coefficients and rod worths. The system was then borated to all-rods-out concentration and hot' control rod testing was started. At this point the j
- plant was cooled down for the repair of the 3 sak on the reactor head.
l Upon resumption of the test program, hot control rod drops and exercises were completed, and temperature coefficients were measured at j
the all-rods-out boron concentration. A series of boron dilution steps l
were.then made with rod worths and boron concentration coefficients being determined during the dilution, and temperature coefficients being deter-l mined at tha step boron concentration.
After the final dilution step, in-l core thermocouple correction factors were determined under isothermal l
conditions.
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The Core VI all-rods-cut boron concentration was determined to be 2613 ppm at a main coolant pressure and temperature 6f 2020 psig and 523.6oF,respectively.
During the first 650 WtD/MTU bu nup of Core VI operation, l
reactivity depletion was measured at approximately 0 77% 4 K/K per 1000 W tD/MTU.
1 The following parameters were determined by means of in-core
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instrumentation at $98 Wt, $26.3oF Tavg, lh50 ppm boron, control rod groups B, C &' D @ 87 0/8 and group A @ 79 7/8:
F 2.6 q
F 2.0 4H 3.2 Min. DNIR iMaximum outlet temperature
- 5920F Secondary Plant Performance feedwater heater teminal differences @ 18h W e, 1.8 "Hg backpressure, 5250F Tcvg:
- 1 8.50F
- 2 17.50F-
- 3 15 0oF Condenser terminal difference:
31.70F
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gt. Chemistry During the plant startup, purification flow was through a new cation demineralizer in the No. 3 position. After the start of power operation the anion cycle of a new mixed bed unit in the No.1 position was borated and normal purification was established through this demin-eralizer and the No. L filter.
Prior to the plant heatup, hydrazine was added to the main coolant and oxygen concentrations were less than 50 ppb when coolant temperature passed 2500F. System oxygen levels remained at less than 50 ppb (detection limit when system is borated) throughout the period.
Increases in the coolant crud level during plant heat-up raised the gross specific activity from h.8 x 10-3 ue/ml to 1.1 x 10-1 ue/ml. The average crud level and specific activity during power s
operation were 0.25 ppm and 1.1 x 10-1 uc/ml, respectively.
i The equilibrium average iodine-131 concentration was 2.h x 10-5 uc/ml and the I-131/I-133 atcmic ratio was 0.77.
These values indicate that there are no significant defects in the present core loading at this time.
Af ter the start of power operation, the equilibrium main coolant tritium concentration was 3.2 uc/ml.
Using tritium as a tracer the primary to secondary leak rate in the steam generators was 3h gallons per day at the end of this report period; at the conclusion of Core V opera-f - s tion this leak rate was approximately 17 gallons per day.
The primary to secondary leak, coupled with boren shim operation, has resulted in an equilibrium boron concentration of 25 ppm in tne steam generator bottom waters. This has made it necessary to deviate from past practice in feed and boiler water chemistry. Po11er water pH now will be controlled at apprcximately 9 3 and phosphate concentratien will be increased; higher (S
conductivity and solids values will be maintained. The effect of volatile and carryover Nron, which in many respects behaves as silica, on high pressure turoine performance will be evaluated, A main coolant crud sample on November lh had the following radiochemical analysis: dpm/mg crud Cr-51 1.9 x 106 Fe-59 2.h x 106 Hf-181 2.6 x 105 co-58 2.h x 107 Mn-5h 5.9 x 106 co-60 9.0 x 106 A min coolant gas sample on November 17 had the following radiochemical analysis: ue/cc gas Ie-133 1.1 x 10-2 Xe-135 1.7xloi A-hl 6.2 x 10-1 4
Health and Safety Sixty drums of radioactive waste were shipped during the period. The total activity contained in the shipment was 181.8 me.
In Operation Report No. 70 for October, 1966, it was reported that no shipments of radioective waste were made during that perii a.
A shipment of h8 drums was made during that period and was inadvertintly omitted from the operation report; the total activity in that shipment was 300.2 me.
One shipment of spent fuel was mado during the period con-sisting of ten assemblies with a tot al activity of 1.2h megacuries.
Osama radiation levels on contact wi:,h the cask were generally less than 1.5 mr/hr with a maximum of 2 5 mr/la at the valve box. Neutron levels at one meter were approximately 0.1 mrad /hr fast with no detectable slow
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neutron levels. Beta-gamma contamination levels showed a maximum of 2
l.9 x 10-9 curies per 100 cm. There was no detectable alpha contamination.
During November the waste disposal liquid releases totaled 66,200 gallons containing 0.37 me of gross beta-gamma activity and 32.20 curies of tritium. Gaseous waste releases during the same period totaled h95 me of gross beta-gamma activity.
In addition to the above liquid waste releases a total of 111,500 gallons of water were discharged from the secondary plant. The total gross bets-gamm: and tritium activities released from the secondary j
plant were less than 5 uc and 2.h6 curies, respective?.y.
An additional 295 mc of tritium in the form of a vapor was purged fron the vapor container to the primary vent stack during November.
O Semi-ennual environnental soil samples were collected md (I
shinped off site for routir.e analyses.
During the post-refuelirg draining of the fuel transfer chute, the effects of the draining on the radiation levels in the lower lock valve compartment were noted. Before draining, the radiation level in the general cubicle area was 1 r/hr and the maximum level on contact with the lock valve was 20 r/hr; after draining, these levels were reduced to 0 5 - 0.9 r/hr and 10 r/hr, respectively.
Approximately 25 gallons of liquid were drained from the fuel chute. The drum containing the drainage liquid had radiation levels of 10-15 r/hr on contact.
. Radiation exposure doses for Yankee plant personnel, as measured by film badge, for the month of dovember,1%6 were:
m, Plant Personnel:
Average accumulated exposura dose 230 mrem.
Maximm accumulated exposure dose 1375 mrem.
Service Ccmpsny Personnel:
Average accumulated exposure dose h0$ mrem.
Maximam accumulated exposure dose 892 mrem.
Design Changes 1.
Flanges hr.ve been installed en the pressurizer spray line n'
near the pressurizer manway. The flanged connections will enable removal of the manway without the cutting and re-welding of the spray line.
2.
A stainless steel sump tank has been installed under the first flcor of the primary auxiliary building between the No. 1 and Nm 2 safety injection pumps. The tank will receive the floor drains from that section of the building and a sump pump in the tark will pump the drainage into the vaste disposal system. This installation will isolate these D cor drains from the culvert system.
3 An integratir.g water meter hae been installed in the inlet piping to the demineralized water tank. The meter will measure any water added to the tark, and thus improve the inventory on water make-up to the secondary plant.
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A lcv pressu e alarm has been installed on the filtered bearing water supply to the circulating water pumps. The alarm annunciates on the water treatment plant control panel, and will indicate that the bearing water filters are beccming plugged., The inspection of the circulating water pumps during the refueling cutage indicated that the water passage through the pump bearings was partially plugged; therefore the filtering system is being improved and the low pressure alarm was adaed.
Operations Attached is a summary of plant operating statistics and a plot of daily average load for the rtonth of November,1%6.
YANKEE ATOMIC EIETRIC COMPANY -- CPERATING
SUMMARY
NOVEMBER,1966 EIETRICAL 10 NTH YFAR TO DATE Gross Generation WH 101,295,600 1,2hh,913,100 6,235,75h,000 Sta. Service (While Gen. Incl. Losses)
WH 6,058,h56 76,103,hlh h22,515,908 Net muu m ttsr Output WH 95,237,1hh 1,168,809,686 5,813,238,092 Station Service 5 98 6.11 6 78 Sta. Service (While Not Gen. Incl. Iosses)
WH 686,9h0 1,53h,681 23,776,259 Ave. Gen. For }bnth (720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br />)
W lh0,688 Ave. Gen. Running (562.00 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />)
W 180,2h1 PIANT PERFORFANCE Net Plant. Efficiency 28.89 28.h7 28.h5 Net Plant Heat Rate Bru/WH 11,813 11,987 11,996
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Plant Operating Factor 76.31 85.36 71.02 Reactor Plant Availability 5
78.5h 88.65 31.75 WCmR 10 NTH.
CORE VI TOTAL Hours Critical HRS 600.25 600.25 hh,325 93 Times Scrammed 0
0 52 Burnup Core Average MD/MPU 661.10 661.10 Region Average ND/MPU A (INN E) 685.85 685.85 17,h58.3h B (MIDDLE) 801.Oh 801.Oh 8,h76.3h c (00Tm) 518.h1 518.h1 518.h1 ITE TTETTTESTY1ESIMB12ES
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