ML19351E289
| ML19351E289 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 12/21/1970 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E288 | List: |
| References | |
| NUDOCS 8011260450 | |
| Download: ML19351E289 (17) | |
Text
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So - a 9 I 2'2I'N nentne vrur 112 pepa}ory
' File ~ CyT l
9 YANKEE NUCLEAR I M ER STATION OPERATION REPORT NO. 119 For the Month of November 1970 I
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I, Submitted by YANKEE ATOMIC ELECIRIC COMPANY Westboro Massachusetts i
December 21, 1970 4
Soll260 h O
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This report covers the operation of the Yankee Atomic Electric Company plant at Rowe, Massachusetts for the mcnth of November, 1970.
At the beginning of the period, the plant was continuing its Core VIII - IX refueling and maintenance outage. Removal of reactor head closure studs was completed November 1.
The reactor head was removed on November 3, and the shield tank cavity was filled to refueling level on November k.
During the filling of the cavity', a capacity test was per-formed on the safety injection pumps. All pumps functioned satisfactorily, The refueling procedure was effected November 5 and the transfer i
i of fuel was completed November 10.
Thirty six spent fuel assemblies were removed from the core and 30 new fuel assemblies were inserted into the core. The drive shafts and attached dash pots for control rods No.'s 7, 9, 10, 17, 23 and 2h were replaced with refurbished drive assemblies. All core ecmponents were in place, and the reactor head was reinstalled on November 16, following return of the shield tank cavity borated water to 4
the safety injection tank.
The installation of reactor head closure studs was commenced on November 17 and completed November 19 f
On November 21, a complete functional test of the safety injection i
system under simulated, low pressure conditions was performed. All components operated as required.
Vapor container integrity was set, and on November 25 after estab-lishing a main coolant temperature of 285 F using all four main coolant pumps, the four loops were isolated for hydrostatic testing of the system.
The main coolant pressure was increased to 2h85 psig with satisfactory results; following test completion the temperature and pressure were reduced to 180 F and 100 psig respectively.
Plant heatup and the physics tonting program were commenced on November 27.
On the same day at 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, the Core IX reactor core was brought critical. The reactor physics testing prcgrten was terminated j
November 29 at 1148 hours0.0133 days <br />0.319 hours <br />0.0019 weeks <br />4.36814e-4 months <br />.
Steam line varm up commenced on November 30 at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, and turbine rolling was initiated following establishment of vacuum in the main condenser. The turbine generator was phased on line at 0715, November 30.
l The reactor power level was increased to h85 MWt at 0930 on that date; this level being maintained through the end of the report period preparatory to j
increase to 600 Tit.
The Core VIII - IX refueling and maintenance outage time was approximately 36.5 days.
I Plant Abnormal Occurrences There were no plant abnormal occurrences during the month of i
l November, 1970.
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- Plant Load Reductions There were no plant load reductions during the period following return to power operation on November 30.
Plant Ehutdowns Chutdown No. 112-8-70:
October 24, 1970 to November 30, 1970. A 873.05 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> scheduled shutdown for Core VIII-IX refueling and maintenance.
Core VIII-IX Major Work Items 1.
The existing No. 2 feed water heater van replaced with a new feedwater heater of larger capacity.
2.
The low pressure turbine was dismantled for inspection and maintenance as required. The last row of spindle blades was grit blasted; all 196 generator end and 78 of the last row governor end blades were reste111ted.
Root velds on the inner row of stationary blades at each end of the turbine cover were repaired where necessary by grinding and the addition of new weld. Segment strips were replaced in No.'s 3 and b gland seals on the low pressure turbine, while new gland seal segment units were installed for the high pressure turbine gland seals No.'s 1 and 2.
Two blisters in the upper segment of the No. h bearing were removed and the
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babbitt material was feathered smooth. The lower half of the low pressure turbine casing was stoned, and the top half of the casing was reinstalled on November 22.
Reassembly of turbine components was completed and the turbine turning gear was placed in service on November 24.
3.
On November h, the manway covers were removed and tLa seal velds were cut on the diaphragms for the No. h steam generator primary side manway-The diaphragms were removed and two tubes leaking on the inlet side s identified for plugging. A tube integrity test utilizing an eddy c ut probe technique in this steam generator revealed five additional tut, to have very local defect penetration of greater than 50 percent of the
'a vall thickness located approximately 3" above the tube sheet. All ses tubes, the two known leakers and the five potential lenkers, wcre plugge._
utilizing explosive welding of a thimble type plug to the tube internal surface.
Subsequent hydrostatic testing of the No. h steam generator at 850 psig showed one additional leaking tube which, in turn, was plugged using the same technique. Work area radiation levels in the inlet and outlet water boxes were 10-lh r/hr, and 8-10 r/hr, respectively.
h.
One reduced diameter reactor head closure stud was installed in the No. L9 position. The 5% inch diameter stud hole was rebored and a threaded sleeve, machined to accept a stud of 4 3/h inch diameter, was installed in the vessel stud hole. This was the second such installation of a reduced diameter closure stud (See Operation Report No. 88). Temporary shielding reduced work area radiation levels from 2.0 - 2.5 r/hr to 200-250 mr/hr.
5 The two, pressurizer safety valves were removed, lapped and tested, and 4
reinstalled.
6.
A new 20 gallons per minute orifice was installed in the main coolant bleed line.
7.
Redundant isolation valves were installed for each of the four steam generator primary side differential pressure cells.
8.
The main steam line left hand throttle valve was removed for inspection; found to be in good condition; and was reinstalled.
9.
The turbine No. 1 control valve was removed for inspection. The valve stem and backseat bushing were replaced, and the valve was reinstalled.
Design Changes 1.
Utilization of Reduced Diameter Reactor Head Closure Studs A second reactor vessel flange stud hcle was rebored and tapped to accommodate a threaded sleeve which would accept a 4 3/4 inch stud.
The new reduced diameter stud was fabricated from ASTM-A320, Grade L h3 material.
2.
Core IX Core IX was loaded in tr.e same regional pattern used in the previous cores. Thirty six new, 4.94% enriched stainless steel clad fuel assemblies
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vere located in the peripheral region. Thirty six stainless steel clad
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fuel assemblics, originally 4.9h% enriched and which were cycled in Core VIII, were located in the intermediate region. Four stainless steel clad fuel assemblics, also originally h.94% enriched and which were cycled in Cores VII and VIII, were located in the center region.
3.
Reactor Coolant Recirculation Capability During the Core VIII-IX maintenance and refueling outage, piping modifications were completed to provide a means of recirculating water from the containment sump, back into the reactor coolant system. Piping changes involved the addition of a 4" line which extends from a pene-tration in the vapor container bottom manvay and seal velded diaphragm, to the suction header of the purification pumps; and a 2 " line between the purification pump discharge line and the safety injection header.
Also added were seven motor operated valves for purposes of containment isolation and recirculation capability assurance.
The recirculation system is 3esigned to provide long tenm decay heat removal from the reactor core by recirculating cooled water collected in the vapor container sump back to the reactor vessel. The system is sized to provide sufficient flow to remove reactor decay heat before the limiting inventory of safety injection water has been reached following a rupture of the main coolant system piping.
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Primary Plant Inspections The following is a list of major inspectiona performed during the Core VIII-IX refueling outage.
1.
An inservice inspection of the reactor coolant systems was performed by an outside contractor during the outage. Systems included in the inspection and the type (s) of inspection performed are presented in the table below.
Component or Inspection System Inspected Area Inspected Tyne Inspection Coverage Reactor Vessel and l Vessel Flange Weld 25%
Closure Head i
Flange Ligaments I
Between Threaded f
Stud Holes Volumetric 25%
1 Head Flange Weld i Volumetric 100%
-Head Cladding Visual and Surface 36 sq. in.
Closure Studs Visual; Volumetric 100%
Pressurizer i
Longitudinal i
Shel] Weld Visun); Volumetric 6 ft.
Circunferential Shell Weld Visual; Volumetric 2 ft.
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Heater Nozzle l
l to Shell Weld
' Visual; Volumetric 100%
One 3" Eafety f
Nozzle to Vessel i
Welds Visual; Volumetric Vent & one 4" I
surge nozzle Vessel Support Fillet Welds Visual; Volumetric Two supports Vessel Cladding
_ Remote Visual Television to
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20 ft.
Piping Pressure i
Boundary Thermal Sleeves Radiographic Seven Locations 20" Main Coolant Circumferential Welds Visual; Volumetric Feur Locations f
2h" Main Coolant Circumferential Welds Visual; Volumetric Three Locations i
8" Safety Injection l
Circumferential 1 ds Visual; Volumetric Six Locations 6" Shutdown Cooling Circumferential Welds Visual; Volumetric Two Locations 5" Loop Bypass
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Circultferential Welds Visual; Volumetric Four Locations 4" Safety Injection Circumferential Welds Visual,Volumet. c Eight Locations 2" Charging Circumferential Welds Visual; \\>1u~etric Two Locations 4" Pressurizer Se ge Line Circumferential O
Two Locations jVisual; Volumetric Welds
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-5 The inservice inspection was performed as designated in Section XI of the ASME Boiler and Pressure Vessel Code, entitled " Inservice Inspection of Nuclear Reactor Coolant Systems". Preliminary analyses of the results of the inupection revealed no existing abnormalities. The total rmliation exposure incurred during the inspection period was 12.320 Rem.
2.
A total of five fuel assemblies were inspected. No mechanical abnormal-ities were detected. Core IX will be the third cycle for two; and the second cycle for three of these assemblies.
3.
Three control rods were inspected, and exhibited only minor wenr in the vicinity of, a guide blocks.
L.
Two shim rods were inspected. No significant wear uns detected.
5.
The South source vane was inspected and found to be in good condition.
6.
The reactor vessel thermal shield seam clamps were inspected using closed circuit television equipment.
In addition to those previously noted, one primary and several secondary bolt locking cups were raised.
This condition la not considered significant; since seam clamp reference indicator readings showed no apparent change from the readings recorded during the most previous refueling inspection period.
7 The pressurizer inspection described in item No. 5, above, revealed s
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conditions consistent with those found in the most previous such inspection.
Secondary Plant Inspections 1.
The No. 2 boiler feed pump check valve was opened for inspection.
No abnormal conditions were detected.
2.
The steam side of the main condenser was inspected. No abnormal conditions were detected.
3.
Th
'ondary side of No.'s 1 and 3 steam generators were opened, int
,ed, and found to be in normal condition.
h.
The turbine lube oil resevoir, oil screens, and strainers were inspected and cleaned with no detectable abnormalities.
5 Both moisture separators were opened for inspection and maintenance as required. In the left hand separator, several nuts were replaced on the flow baffle; and the veld on the back side of the cone was repaired by grinding and revelding as necessary.
In the right hand separator veld repairs were made to the support struts at the tip of cone, and to the backup ring veld inside the exhaust line. Also in the right hand separator, the flow guide plate was found to be welded only on one aide. A new weld was added to the reverse side for better support.
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6.
A complete inspection of the exciter was made including megger readings of fields, commutator and cables. Brush holders were refurbished wi th new pins and spr!.ngs where necessary. The commutator was stoned. The l
"61ck Neutral" s as checked and the rocker ring was moved 1/8" clockwise j
to set the brushes off " Kick Neutral" as recommended by the vendor.
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Plant Maintenance i
The folls a list of pertinent plant maintenance items l
performed, additio:
.e ma,jor work items, during the month of November, i
1970.
1.
The heater drain.. ank No. 1 punp and motcr were dismanticd for inspection and maintenance. The lower housing of the motor was retushed; and a new pump chaft sleeve was installed.
2.
The No. 3 chargirg pump was repacked in entirety.
3.
The pressurizer manual spray valve CH-V-613 was replaced.
h.
Repairs were made to the separation plate in the head of the No. 3
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charging pump oil cooler.
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5 The oil was changed, and repacking was performed as required for the i
main condenser circulating water pumps.
j 6.
The body of the pressurizer drain valve VD-V-509 was replaced.
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ondder sections were installed on the inclined areas of the reactor secondary shield in the vicinity of loops 1 and 2, and the pressurizer.
i Inst runentation and Control The following is a list of pertinent instrumentation and control maintenance items performed by the plant staff during the month of November, 1970.
1.
Primary and secondary instrumentation channels were recalibrated as necessary.
j 2.
The vapor container overpressure senuing switches were relocated; and
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the overpressure trip valves were tested.
3.
Seven new vires were installed in the incore flux measurement system.
4.
New tubes were installed in the steam flow sensing system.
5.
The condenser hot-well level controller was relocated.
r 6.
The defective back-up plug seal, for the East incore instrumentation reactor head penetration, vac replaced.
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Reactor Plant Performance i
Following heatup of the primary plant, the reactor was brought critical and loaded to h85 MWt; a load value still pertinent at the end of the report period.
The following parametera vere determined by means of incore j
instrumentation:
j h85 MWt; Slh F Tavg; Control Rod Group A @ 81, B,C,D, @ 87 ;
1683 boron.
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F 2.2 Q
=
i P
- 1 AH l
l Minimum DNBR = h.3 Maximum Outlet Temperature = 569.0 F j
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Core IX Start a Physics Test Program j
i The physics test program was commenced with an ammonia adjusted I
pH main coolant reactor chemistry on November 27 at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, and was tenninnted November 29 at 1148 hours0.0133 days <br />0.319 hours <br />0.0019 weeks <br />4.36814e-4 months <br />. Preliminary test recults indicated j
as follows:
Hot and cold rod drops were timed using a recording oscillograph. All drop tiree were within permissible limits.
l Rod Worth Group A: 0.98%
Group B:
2.76%
j Maximum Worth Rod Wita Groups A and B in: Rod #7 = 0.56%
~h Minimum as neasured temperature coefficient (2h73 ppm boron): = -1.lh x 10 i
AK/K/0F.
Final analysis of low power, and at power physics testing results was in progress at the end of the report period.
Cecondary Plant Performance Feedvater heater terminal differences were as follows:
i 3.1 F 3.5 F No. 3 3.8 F No. 2 =
=
No. 1
=
1
3
, Chemistry The main coolant boron concentration averaged 2932 ppm until November 27 when the concentration was decreased by dilution for physics testing, to a low of 1619 ppm.
Concurrent with boron concentration dilution, the main coolant system was ammoniated to a concentration of 13 9 ppm.
The main coolant pH, which averaged 5.17 during the period November 1 - 27, increased to 6.55 upon ammoniation of the coolant system.
At the time of phasing the turbine generator to the high line, the main coolant boron concentration, ammonia concentration and pH were 1686 ppm, 13 9 ppm and 6.55 respectively.
2.31x10'pegrossbeta-gammaandtritiumspecificactivitiesaveraged ue/ml and 2.53 x 10-2 ue/ml, respectively during the report period.
The main coolant crud level averaged 0.31 ppm during the period.
A representative crud sample for the month, collected on November 3, had the following radiochemical analyses: dpm/cg crud Cr-51 M"-Sh Fe-59 6
5 5
1.87 x 10 1.h8 x 10 2.09 x 10 Co-58 Co-60 Ag-110M 6
5 2.00 x 10 h.56 x 10 1.85 x 105 Health and Safety Waste disposal liquid releases totalled 52,429 gallons containing 0.059 me of gross beta-gamma activity and 13.93 curies of tritium. Gaseous releases during the period totalled 0.025 curies of gross beta-gamma activity.
Secondary plant water discharged totalled 92,097 gallons containing 0.382 me of gross beta-gamma activity and 0.5h curies of tritium.
In addition to the above releases 0.621 curies of tritium as a vapor, was discharged to the environs via the primary vent stack.
Radiation exposure doses for Yankee personnel; NEPSCo personnel; and Outsiae Contractor Personnel as measured by film badge, for the month of November, 1970 were:
Yankee Plant Personnel:
Average accumulated exposure dose: 671 mrem Maximum accumulated exposure dose: 2000 mrem N.E.P.S.Co. Personnel:
Average accumulated exposure dose: 693 mrem Maximum accumulated exposure dose: 1800 mrem L
. Outside Contractor Personnel:
Average accumulated exposure dose:
h64 mrem l
l Maximum accumulated exposure dose:
2250 mrem Operations Attached is a summary of plant operating statistics and a plot of daily average load for the month of November, 1970.
Included in this report are revised " Operating Summary" Sheets for the months of August, September, and October, 1970, correcting errors in the Nuclear-Times Scrar:1ed - Month - Ccre VIII - Total.
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YANKEE ATOMIC ELECTRIC COMPANY - CPERATING SU?o'ARY November 1970 MONTH YEAR _
TO DATE ELECTRICAL Gross Generation KWH 2,320,600 1,1h5,h36,300 11,361,09h,800 69,963,512 739,968,376 Sta. Service (While Gen. Incl. Losses)
KWH 160,768 1,075,h72,788'c
.c 10,621,126,42h C
KWH 2,159,832 Net Output Station Service 6.93 6.11 6.52 Sta. Service (While Not Gen. Incl. Losses) KWH 1,003,35h 3,364,358 32,272,287 Ave. Gen. For Month (720)
KW 3,223.1 Ave. Gen. Running (16.75)
KW 138,5h3.3 PLANT PERFORMAICE Net Plant Efficiency 28.66 29.16 28.h9 Net Plant Heat Rate btu /KWH 11,908 11,70h 11,979 Plant Capacity Factor 1.75 76.69 Th.86 b
Reactor Plant Availability 5.03 83.h7 83.82
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MONTH CORE IX TOTAL NUCLEAR Hours Critical HRS 61.53 61.53 Th,96h.h0 0
0 61 Times Scra==ed Burnup Core /verage kdD/MTU 15.12 15.12 Region Average M4D/MTU A (INNER) 7.10 7.10 17,210.77 3 (MIDDLE) 16.38 16.38 8,758.23 C (0 UTER) 14.74 14.Th 14.74 D (ZIRCALOY) 1
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YANKEE ATOMIC ELECTRIC COMPANY - OPERATING SUM'GRY October 1970 ELECTRICAL MONTH YEAR TO DATE Gross Generatio:
KWH 83,764,600 1,1h3,115,700 11,358,774,200 Sta. Service (While Gen. Incl. Losses)
KWH 5,70h,670 69,802,Thh 739,807,608 Net Output KWH 78,059,930 1,073,312,956 10,618,966,592 Station Service 6.81 6.11 6.51 Sta. Service (While Not Gen. Incl. Losses) KWH 202,925 2,361,004 31,268,933 Ave. Gen. For Month (Th5)
KW 112,h35.7 Ave. Gen. Running (57h.20)
KW 1h5,880 5 PLANT PERFORMANCE Net Plcnt Efficiency 5
28.1h 29.16 28.h8 Net Plant Heat Rate LTu/KWH 12,128 11,70h
'11,983 Plant Capacity Factor 62.07 84.08 75.50 E
Reactor Plant Availability 77 21 91.21 84.47 MONTH CORE VIII TOTAL NUCLEAR Hours Critical HRG 575.25 9,083.09 74,902.87 4
61 Timec Scra==ed 0
Barnup Core Average MJD/bffU 556.38 10,141.64 Region Average M4D/hffU A (INNER) 562.07 9,5h3.95 29,h74.85 B (MIDDLE) 631 95 11,582.06 23,618.12 C (OUTER) h80.03 8,Thl.85 8,741.85 D (ZIRCALOY)
- Note: Reported in error in October, 1970 Operation Report No. 118.
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YA'MEE AT0!!IC ELECTRIC CO:?/J"I - OPERATING SU'C!ARY September 1970 V'ETII Y:1' '!
TO PE*
2 CC0~.ICf.L Gross Generation IC.'H 113.974,500 1,059,351,100 11,275,009,600 Sta. Service (While Gen. Incl. Losses)
DTH 7,469,870 64,098,074 734,102,938
- et Output WH 106,504,630 995,253,026 10,540,906,662 Station Service 6.55 6.05 6.51 Sta. Service (While Not Gen. Incl. Losses) D:H 2,158,079 31.066,008 Ave. Gen. For Month 720 KV 158,298 Ave. Gen. Running (719.78)
KW 158,346 PLANT PZRFORMANCE Net Plant Efficiency 28.k5 29.24 28.h9 Net Plcnt Heat Rate btu /KWii 11,996 11,672 11,979 Plant Capacity Factor 86.65 86.59 75.62 y
Reactor Plant Availability 100.0 92.81 84.53 MONTH CORE VIII TOTAL NUCIEJ.R Hours Critical HRS 720 8,507.84 Tk,327.62 61 0
4 Times Scra==ed Burnup K4D/Iml 750.68 9,585 26 Core Average Region Average IGD /MTU A (I:!!TER) 7h4.13 8,981.88 28,912.78 B (:aDDL;)
847.43 10,950.11 22,986.17 C (OUTER) 654.46 8,261.62 8,261.82 D (ZIRCALOY)
- !!ote: Reported in error in Septeriner, 1970 Operation Report No. 117 i
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YARKEE ATOMIC ELECTRIC COFPANY - OPERATING SU!O'ARY I
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August 1970 i
ELECTRICAL MONTH YEAR TO DATE i
Gross Generation KWH 86,633,000 945,376,600 11,1!1,035,100 i
Sta. Service (While Gen. Incl. Losses)
KWH 5,h22,8h9 i6,628,204 726,633,068 i
Net Output KWH 81,210,151 888,748,396 10,h34,h02,032 Station Service 6.26 5.99 6.51 Sta. Service (While Not Gen. Incl. Losses) KWH 619,596 2,158,079 31,066,008 i
Ave. Gen.~For Month (7hk)
KW 116,hh2 l
Ave. Gen. Running (503.23)
KW 172,154 i
PLANT PERFORMANCE Net Plant Efficiency 28.42 29.3h 28.49 Net Plant Heat Rate btu /KWH 12,008 11,632 11,979 e
Plant Capacity Factor 6h.02 86.58 75.52 P
l Reactor Plant Availability 73.85 91.92 84.ho l
t NUCLEAR MONTH CORE VIII TOTAL Hours Critical HRS Sh9.h2 7,'87.84 73,607.62 Times Scrammed 0
.h 61 i
Burnup i
Core Averace M4DhEU 573.13 8,834.58 1
Region Average M4D/NTU l
A (INNER) 569.21 8,2.C.75 28.163.6 i
n (MIDDLE) 646.92 10,10J.63 22,133.71 i
C (OUTER) 499.61 7,607.36 7,607.36 D (ZIFCALOY) l-
- Note: Reported in error in August, 1970
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i Operation Report No, 116.
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