ML19351E234
| ML19351E234 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 07/21/1972 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| References | |
| NUDOCS 8011260306 | |
| Download: ML19351E234 (8) | |
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YAIiKEE NUCLEAR PO'4ER STATICII I
OPERATION REPORT NO 138
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For the Month of 1
i June 1972 t
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I Submitted by YAfiKEE ATOMIC ELECTRIC COMPNJY Westboro Massachusetts July 21, 1972
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O This report covers the operation of th'e Yankee Atomic Electric Company at Bowe, Massachusetts for the month of June,1972.
During the period plant lotui varied between 158.2 MWe and 156.8 MWe as.the circulating water temperature-fluctuated between hk F and 49 F.
During.the. period June 8-11 the plant vna placed in a scheduled, hot standby condition for the purpose of effecting repairs to the turbine generator No. 5 bearing hydrogen seal;. and the performance of scheduled control rod drop time testing. The turbine generator was phased on line at 1653 hours0.0191 days <br />0.459 hours <br />0.00273 weeks <br />6.289665e-4 months <br /> on June 11. The reactor power. level was increased to 498 MWt at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> on June 12; this level being maintained through the end of the report period.
The first, Core X vapor container air leakage surveillance period continued through the report period with normal leakage noted.
Plant Abnormal Occurrences Abnormal Occurrence No. 72-7, " Inadvertent Radioactive Gas Release From Waste Liquid Evaporator".-
I Operation of the evaporator vss initiated at 12hD hours on June 1 J
for processing of Class 2 (cxygenated) liquid. Venting of off-gases ( ton-G radioactive) during Class 2 liquid processing is to the primary vent stack.
At 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br /> the Auxiliary Operator secured processing of the Class 2 i
liquid ~ and commenced processing of Class 1 liquid.
Procedural valving during the change from Class 2 to Class 1 liquids
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re-routes the off gases (hydrcgenated and radioactive) to the low pressure i
cover gas system. A misvalving occurred during the transition permitting -
the Class 1 liquid off gases to be vented to the environs via the primary vent stack. This condition existed until 0845 hours0.00978 days <br />0.235 hours <br />0.0014 weeks <br />3.215225e-4 months <br /> on June 2 when the evaporator was secured.
l33 A total of 75.8 uc of Xe was released at a point of discharge concentration of 2.24 xl10-10 ue/cc.
Plant Load Reductions June 1-(1403-1810):
Plant 1 cad reduction to 60 MWe to allow repacking of the No. 3 boiler feed pump.
Plant Shutdowns Shutdown ~No. 122-10-72:
'6/8/72, commenced plant shutdown for repair of generator hydrogen leakage. Total outage time:
66 hours7.638889e-4 days <br />0.0183 hours <br />1.09127e-4 weeks <br />2.5113e-5 months <br />, 33 minutes.
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l Plant Maintenance l
The following is a list of pertinent plant maintenance items performed by the plant staff during the month of June, 1972.
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t 1.
The motor for the No. 2 boiler feed pump was repaired and returned to service.
2.
The No. 3 boiler feed pump inboard shaft sleeve was replaced.
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3.
The No. 1 and No. 3 charging pumps were repacked.
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A leaking tube in the No.1 auxiliary boiler was replaced.
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Instrumentation and Control l
The following is a list or pertinent instrumentation and control maintenance items performed by the plant staff during the month of June,1972.
i 1.
The pump for the vapor container air particulate monitor system was replaced.
2.
The turbine generator hydrogen vent control valve was repaired.
Reactor Plant Performance Measurements with the incore instrumentation vere performed under l
the following plant conditions:
0 495.2 !Gt; 510.3 F Tave; Control Rod Group A @ 78 ", P; C and D
@ 87 "; 1527 ppm boron; equilibrium xenon.
The results of these measurements were:
l Stainless Steel Zircaloy Clad i
Clad Assembly _
Assembly 1.93 2.11 Q
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F 1.3h 1.55 g.
Maximum Outlet F 560.5 570.2 g
j Secondary Plant Performance i
Feedvater heater terminal differences were as follows:
No. 1 = 3.5 F No. 2 = T.3 F No. 3 = 5.8 F
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9 The condenser performance was as follows:
154.h MWe; 1.29" Hg B.P.;
h88 MWt; 49.6 F'C.W. in; TTD = 18.6 F; cleanliness factor = 92.5%.
Chemistry-
-The main coolant boron concentration was reduced from 158h ppm to 1497 ppm to compensate for normal core depletion.
The main coolant pH averaged 5 10 during the period.
The main coolant beta-gamma specific activity and crud level averaged 9.99 x 10-2 ue/ml and 0.03 ppm respectively.
The main coolant tritium concentration averaged 1.33 ue/ml during the report period.
The iodine-131 specific activity averaged 9.28 x 10-5 uc/cc and the iodine 131/133 atomic ratio averaged 2.01.
A crud sample for. the month collected on June lh had the following radiochemical analyses: dpm/cg crud l
l Cr-51 Mn-Sh Fe-59 Co-58
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5 g
h.05 x 10 2.90 x 10 3 19 x 10 2.77 x 10 l
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Co-60 As-110M Zr-95 Sb-12h 6
g 5
5 1.03.x 10 2.90 x 10 6.16 x 10 1.6h x 10 s
A main coolant gas sample, collected on June 30, had the following radiochemical analyses: uc/cc gas Xe-133 Xe-135 Ar h1 1
-2 8.18 x 10 5.79 x 10 1.32
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l, Health 'and Safety l
Four shipments totalling 231 drums of-low level vaste containing 612.9 me were made during the period.
l Waste disposal liquid rele* m. totalled 73,489 gallons containing-0.070 me of gross beta-Tamma activity and 89.hh curies of tritium. Gaseous releases during the period totalled 1.191 curies of gross beta-gamma activity.
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Secondary plant water discharged totalled 387,3h7 gallons containing 0.077 me of gross beta-gamma activity Land 0.250 curies of tritium.
Fadiation exposure doses for Yankee plant personnel as measured l
_ by film badge, for the month of June,1972 vere as follows:
Average accumulated exposure dose:
h8 mrem Maximum. accumulated exposure dose: '230 mrem 1-l L
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b Operations Attached is a summary of plant operating statistics and a plot of daily average load for the month of June,1972.
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9 YA!1KEE ATOMIC ELECTRIC COMPAIiY - OPERATI"G SUf'ARY June 1972 ELECTRICAL MONTH YEAR TO DATE l
Cross Generation D!il 102,000,100 289,3h9,100 13,305,225,000 Sta. Service (While Gen. Incl. Losses) nw11 6,521,hh2 19,215,807 860,285,421 Net Output Kw11 95,478,658 270,133,293 12,hhh,939,579 Station Service 6.39 6.6h 6.47 Ave. Gen. For Month (720)
KW 141,666.8 h
Sta. Service (While ;iot Gen. Incl. Losses) KWH 380,h71 5,161,336 38,265,728 Ave. Gen. Runnin6 (653.45)
KV 156.094.7 PLANT PERFORf'ANCE Net Plant Efficiency 29.65 28.Th 28.49 Net Plant Heat Rate btu /K'n:I 11,510.12 11,874.57 11,978.76
^ 'it Capacity Factor 74.54 35.88 75 14 le tor Plant Availability 98.93 L9.98 83.79 MONTH _
CORE X TOTAL f
NUCLEl.F, Hourt, C-1tical HBS 691.38 1,097.23 86,582.22 0
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Times Scrammed h
Burnup Core Average IGD /tfrU 687.48 955 18 Region Average
!GD/FirU A (INNER) 586.00 812.91 19,168.41 B (MIDDLE) 708.06 982.99 10,952.66 C (OUTER-ZIRCALOY) 677.68 9hl.13 9hl.13 I
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nm This report covers the operation of the Yankee Atomic Electric Conpany at Rowe, Massachusetts for the month of May,1972.
j At the beginning of the period the plant was continuing its Core IX-X refueling and maintenance outage. Vapor container integrity was set, and on May 8 after establishing a main coolant temperature of 290 F using all four main coolant pumps, the four loops were isolated for g
hydrostatic testing of the system. The main coolant pressure was increased to 2485 psig with satisfactory results; following test completion the temperatu and pressure were reduced to 200 F and 300 psig, respectively.
.'lant heatup and the physics testing program were commenced on May 11.
en May 12 the reactor core was broug t critical. The reactor h
pF sies testing program was terminated on May 16 at 2130 hours0.0247 days <br />0.592 hours <br />0.00352 weeks <br />8.10465e-4 months <br />.
Steam line warmup commenced on May 18 at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />, and turbine rolling was initiated following establishment of vacuum in the main condenser.
The turbine was phased on line at 2218 hours0.0257 days <br />0.616 hours <br />0.00367 weeks <br />8.43949e-4 months <br />, May 18 and loaded to 30 MWe by 2330 hours0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br />. The reactor power level was increased to 450 MWt at 0130 hours0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br /> on May 19 On May 2h a scheduled hot standby shutdown commenced for repairs to the turbine generator No. 5 bearing hydrogen seal. During the shutdown scheduled control rod drop time tests were performed.
The turbine generator was phased on line at 0433 hours0.00501 days <br />0.12 hours <br />7.159392e-4 weeks <br />1.647565e-4 months <br /> on May 27 The reactor power level was increased to approximately 498 MWt at 2310 hours0.0267 days <br />0.642 hours <br />0.00382 weeks <br />8.78955e-4 months <br /> on that date; this level being maintained through the end of the report period.
The Core IX-X refueling and maintenance outage time was approxi-mately 96.6 days.
On May 19, the initial Core X air charge to the vapor container was completed. Leakage of air from the vapor container during the balance of the report period was normal.
Plant Abnormal Occurrences Abnormal Occurrence No. 72-5, "High Temperature in the Valve Stem Leakoff Header".
During Core X startup physics testing on May 14, 1972 a high temperature was noted in the vapor container valve stem leak off header.
Proper corrective action was taken consisting of closing the header trip valve; and reducing the main coolant pressure by operation of the motor operated pressurizer spray valve. When the main coolant pressure reached 1850 psig, the reactor vos scrammed, vnnuelly, from a sero power critical condition.
The stem leak off on the continuous spray valve HC-V-205 was found to be blowing through. The valve was backseated and the leak off was plugged.
No adverse effects on the plant were noted. On May 18 the reactor was brought critical and the turbine generator was phased to the high line at 2218 hours0.0257 days <br />0.616 hours <br />0.00367 weeks <br />8.43949e-4 months <br /> that date.
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-g-Abnormal Occurrence No. 72-6, " Failure of Control Rod No.13 to Withdraw".
On May 17, 1972 during preparations for control rod drop testing, control rod No.13 would not withdraw from a fully inserted position in the core. Increasing the volta 6e to the lift coil slightly, resulted in normal withdrawal of the control rod.
After the lift coil voltage was restored to normal the rod was withdrawn to 90" and dropped five times. No reoccurrence of the withdrawal problem occurred.
l Abnormal Occurrence No. 72-8, " Failure of Control Rod No. 18 to Drop Within the Time Assumed For the Accident Analysis".
1 On May 13, 1972, during Core X startup physics testing, control rod No.18 failed to drop from the fully withdrawn position. The cause of the occurrence is unknown.
The rod was exercised into and out of the core to verify movement capability. Drop tests were repeated at various elevations with inconsistent results.
The accident analysis was reviewed essuming a second stuck control rod.
A change to the facility license estab..ing a reduced maximum power I
level with a more stringent control rod restri. tion was approved by the
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USAEC.
Plant Load Reductions May 22 (1925-2000):
Plant lead reduction to 146 MWe due to generator hydrogen leakage.
May 23 (1330-2200):
Plant load reduction to 138 MWe due to generator hydrogen leakage.
May 31 (1325-1333):
Plant load reduction to 152 MWe due to an electrical
- storm, i
Plant Shutdowns Subsequent to the return to power from the Core IX-X refueling and maintenance outage there was one scheduled shutdown.
Shutdown No. 121-10-72:
5/2h/72, commenced plant shutdown for repair of generator hydrogen leakage. Total outage time:
39 hours4.513889e-4 days <br />0.0108 hours <br />6.448413e-5 weeks <br />1.48395e-5 months <br />, 8 minutes.
Design Changes Control Rod Replacement Prior to the placement of the reactor vessel head each control rod was with-drawn about six and one half feet to ensure they were properly coupled to i
the drive shafts. Difficulty was experienced in withdrawing two of the l
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1 Measurements with the incore instrumentation were performed under the following plant conditions:
h94 MWt; 513.2 F Tave; Control Rod Group A at 78", B, C and D at 87";
1603 Ppm boron; equilibrium Xenon.
4 The results of these measurements were:
I Stainless Steel Zircaloy Clad Clad Assembly Assembly i
F 2.00 2.2h 1
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F 1.37 1,63 H
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Minimum DNBR 3.98 3.88 1
Maximum Outlet F 560 570 l
Core X Startup Physics Test Program j
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The startup physics test program was commenced with an unadjusted I
j pH main coolant reactor chemistry on May 11 at 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> and was terminated j
May 16 at 2130 hours0.0247 days <br />0.592 hours <br />0.00352 weeks <br />8.10465e-4 months <br />.
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Hot and cold rod drops were timed using a re ording oscillograph.
l As a result of hot rod drops, rod 18 was observed to drop with erratic j
results. Rod 18 is in Group D which is a shutdown group. A proposed change
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was subsequently submitted to the USAEC to operate the plant in a derated f
l condition with a more stringent rod restriction curve. The basis for this j
j change was to re-analyze the accidents assuming two control rods stuck out of the core on reactor scram. The remaining rods were within specification.
l The hot rod drops were repeated a minimum of two times. The results j
demonstrated good repeatability of drop times for all rods except rod No.18.
l The following values were measured during the test program:
Rod Worths
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Cold Hot i
j Group A 0.93 Group B 2.72 2.48 Maximum Worth Rod (Ejected)
With Groups A and B in: Rod No. 7 = 0.73% AK/K j
l Maximum Worth Rod (Dropped) i With All Rods Out:
Rod No. 11 = 0.34% AK/K l
l Minimum as measured temperature coefficients:
(250 F, 2110 ppm boron) Af/AT = -0.4 x 10 AK/K
-0.84 x 10-b AK/K (530 F,'2365 ppm boron) Af/AT
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Inconel clad AgInCd-Ziccaloy unitized control rod assemblies. They were j
replaced with two spare Hafnium-Zircaloy unitized control rod-follover assemblies.
Plant Maintenance l
The following is a list of pertinent plant mainteaance items l
performed by the plant staff during the month of May,1972.
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The pressurizer spray valve HC-V-205 was repacked.
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The seat for CH-MOV-524 was removed, machined, reinserted and tack
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velded in place.
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Lantern rings and a seal water supply was added to eaca bearing of the low pressure safety injection pumps to reduce standby leakage.
b.
Pipe hanger readings were taken during hot and cold plant conditions.
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The gasket on the No.1 feedvater heater manway was replaced.
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6.
A loose main steam line pipe hanger was repaired.
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The motor for No. 2 boiler feed pump was removed and rant off site for repairs.
8.
The high pressure vent valves on No. 3 and No. 4 main coolant flov transmitters were repaired.
Instrumentation and Control I
The following is a list of pertinent instrumentation and control maintenance items performed by the plant staff -during the month of May,1972.
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The flow meter for the primary water supply was repaired.
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The steam heat regulator valve for the boric acid mix tank was repaired.
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The following instrument channels were calibrated:
a.
No. 3 feedvater flow transmitter.
l b.
The four steam generator low level trip channels.
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The eight sain coolant narrow range temperature channels.
Reactor Plant Performance 4
j Following completion of the low power physics test the reactor was
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brought critical and loaded to 498 MWt and a detailed' power distribution evaluation was performed. Preliminary results indicated that the power dis-tribution is more even than anticipated.
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e Temperature DefectL(250 F-530 F, 2110 ppm boron)
I A f = :1.9% AK/K All Rods'Out Boron' Concentration (530 F, 2000 psig) i B
l 2385 ppm
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= 193 pps/%.AK/K Power'and Xenon Defect (Hot Zero Power to Hot Equilibrium h98 MWt) 797-ppm boron
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Secondary Plant Performance i
Feedwater heater terminal differences were as follows:
No. 1 = 3.h F No. 2 = T.5 F No. 3 = 6.1 F lt lt Chemistry The-main coolant boron concentration averaged 2635 ppm until May l
12 when the concentration ven reduced for physics testing; and averaged l
2109 ppm until reactor startup on May 18. During the balance of the report G
period the' boron concentration averaged 1737 ppm.
The main coolant pH averaged h.79 prior to, and 5.05 following reactor staltup.
-The main coolant gross beta-gamma activity averaged 5 1 x 10- ue/ml before startup and 9.78 x 10-2 ue/ml during the balance of the period.
The main coolant crud' concentrations varied widely from a lov of l
0.06 ppm t'. 1 high of T 76 ppm.
The main coolant tritium' concentration before and after reactor 3
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startup averaged 1.63 x 10-2.uc/ml and 1.07 ue/ml, respectively.
A represe tative crud sample for the month, collected on May 95, had the following radiochemical analyses: dpm/mg crud Mn-5h Fe-59 3 co-58 6 cr-51 6 5
1.5'( x -10 3.84 x 10 8.27 x 10 1.58 x 10 l#-D n-124 co-60 Ag-110Mk 5
h 5
8.53 x 10 -
2.75 x 10 2.52 x-10 3.64 x 10 A main coolant gas seaple collected on May 22 had the following
. radiochemical. analyses:
ue/cc gas Xe-133 Xe-135 Ar-h1
-2.
-1 8.09 x 10 1,gg.x 10-1 6.77 x 10
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l Health and Safety i
One shipment of f 5 drums of low level vaste containing 177.6 me q
was made during the period.
Waste disposal liquid releases totalled 57,h51 gallons containing 0.026 me of gross beta-gn=ma activity and 20.53 curies of tritium. Gaseous i
releases during the period totalled 0.437 curies of gross beta-gamma activity.
Secondary plant water dis' harged totalled 291,379 gallons containing 0.083 me of gross beta-gamma activity and 0.094 curies of tritium. In addition to the above releases, 0.642 curies of tritium as a vapor was discharged to the j
environs via the primary vent stack.
l' Radiation exposure doses for Yankee plant personnel and NEPSCo personnel, as measured by film badge for the month of May,1972 vere as follows:
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Yankee Plant Personnel:
l Average accumulated exposure dose:
305 mrem Maximum accumulated exposure dose:
1530 mrem j
NEPSCo Personnel:
i Average secumulated exposure dose:
55h mrem j
Maximum accumulated exposure dose:
920 mrem I
Operations i
Attached is a summary of plant operating statistics and a plot of daily average load for the month of May,1972.
l The following Operating Instructions and Emergency Instructions vere revised and reissued during the month of May, 1972.
Onerating Instructions 50hAl Primary Plant Startup from Cold Condition 4
50hA2 Startup From Hot Standby Condition Shutdown to Hot Standby Condition Changing Reactor Load 50hC2 Reactor and Primary Plant Cooldown 50hB1 120 Volt A.C. Vital Bus System Emergency Instructions j
505B1 Emergency Shutdown from Power f
505B10 Total Loss of Main Coolant
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505B22 Isolation of Vital Bus Feeder Troubles 505B23 Control Rod Drop 505C2 Major Rupture of the Main Steam Line i
YANKEE ATOMIC ELECTRIC COMPANY - OPERATING SUVFARY MAY 1972 ELECTRICAL MONTH YEAR
% DATE Gross Generation IGIH 39,660,900 187,3h9,000 13,203,22h,900 Sta. Service (While Gen. Incl. Losses)
KWh 2,608,181 12,694,365 853,763,979 j
i Het Output KWH 37,052,719 174,65h,635 12,3h9,460,921 i
Station Service 6.58 6.78 6.47 Sta. Service (While Not Gen. Incl. Losses) KWH 2,4h1,604 4,780,865 37,885,257 Ave. Gen. For Month (74h)
KW 53,307.7 3
Ave. Gen. Running (262.53)
KW 151,071.9 W
PLANT PERFORMANCE Net Plant Efficiency 29.60 28.26 28.h8 Net Plant Heat Rate btu /KWH11,529 56 12,076.26 11,982.97 i
Plant Capacity Factor 28.04 28.24 75.15 y
Reactor Plant Availability 40.46 40.32 83.68 I
i MONTH CORE X TOTAL NUCLEAR Hours Critical HRS 405.85 405.85 85,890.84 Times Scrammed 1
6 67 i
Burnup Core Average K4D,'MTU 267.38 267 38 Region Average MJD/MTU A (IUNER) 226.91 226.91 18,582.h1 B (MIDDLE) 274.93 27h.93 10,244.60 C (OUTER-ZIRCALOY) 263.45 263.45 263.45 5
YANKEE ATOMIC RIC COMPANY
,g DAILY AVERAGE LOAD FOR MAY 1972 200_
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FUEL ASSEMalY LM-0UT n
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h A 4.941 w % STAINi.ESS
! h4.94 %
' STAINLESS C 4.001
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