ML19351E232

Operation Rept 140 for Aug 1972

ML19351E232
Person / Time
Site:	Yankee Rowe
Issue date:	09/30/1972
From:	YANKEE ATOMIC ELECTRIC CO.
To:
References
NUDOCS 8011260299
Download: ML19351E232 (8)

Text

{{#Wiki_filter:. _ C SITUlti"O tiEGUi.A!03 CESIBAL FILEbet y a cy.- RODE 016 %WM 51 .c; 3.9 -3 7-7d YANKEE NUCLEAR POWER STATION OPERATION REPORT NO. 140 For the Month of August 1972 hffj I ) j i j f ) h'. l N Submitted by YANKEE ATOMIC ELECTRIC COMPANY Westboro Massachusetts 8-14 g e, _ 1,ze

v l l ' This report covers the operation of the Yankee Atomic Electric 6 Company at Rowe, Massachusetts fyr the month of August,.1972. During the period the plant load varied between 155.4 MWe and 151.9 as the circulating water temperature fluctuated between 560F and 61 F. Two scheduled and one unscheduled plant shutdowns occurred during l the report period. The first scheduled plant shutdown occurred on August I 18 at 2230 hours for the purpose of control rod drop time testing. Follow-ing completion of the testing the turbine generator was phased to the line 1 on August 19 at 0437 hours and the plant was loaded to 498 MWt at 0530 hours that date. The unscheduled shutdown was initiated by a reactor scram and turbine trip on August 27 at 1939 hours. Further discussion of this shut-down is presented as Abnormal Occurrence No. 72-13, this report. The second scheduled shutdown occurred on August 30 at 1400 hours for the purpose of effecting a modification to the lov main coolant flow turbine trip circuit. Further discussion of this shutdown is presented as Abnormal Occurrence No. 72-15, thic report. ? The second, Core X vapor container air leakage surveillance period continued through the report period with normal leakage noted. Plant Abnormal Occurrences l Abnormal Occurrence No. 72-12, " Failure of No. 3 Diesel to Start". On August 23 at 0900 hours during routine surveillance testing the No. 3 diesel gererator failed to start. An inspection of the diesel engine and associated accessories indicated no abnormalities. Because the engine was apparently not receiving fuel oil the governor operating lever, which regulates the flow of fuel oil, was manually held in a partially open position and the diesel then started. I Subsequently, three restarts of the diesel were successfully l performed without any manual adjustment of the governor operating lever. Abnormal Occurrence No. 72-13, " Plant Trip". During.a severe local thunderstorm actuation of the undercurrent relays on the main coolant pump motors for loops No. 2 and No. 3 resulted in a reactor scran and. turbine-trip from 498 MWt. A survey of plant equipment and systems indicated no adverse or unsafe conditions. The reactor was taken critical and the plant returned I -to power. Abnormal Oc'urrence No. 14, " Malfunction of Control Rod No.19". 9 trip, described in A.O. No. 72-13, difficulty was experienced with control During the reactor startup following the reactor scram and turbine

rod No..19. Normal hot standby procedure requires t.- safety group "D" of control rods No. 17 through No. 2h be withdrawn to 21 inches. During G the start-up procedure this group was manually ' dropped into the core. Control rod No. 19 failed to fall into the core. With the aid of the pulldown coil, the control rod was driven into the core. Subsequently, the control' rod was withdrawn to 90 inches;.however, when manually scrammed it dropped.to approximately 2h inches. With the aid of the pull- .down coil the control' rod was driven into the core. The control rod was again withdrawn to 90 inches and manually-scrammed into the core; this time falling to 'approximately 48 inches. Again with the aid of the pulldown coil the control rod was. driven into the core. Since all the control rods fell into the core when the reactor scrammed and-the plant is operated in accordance with the provisions of Proposed Change No.100, the decleion was made to withdraw the safety group "D" including control rod No. 19 to 90 inches and return'the plant to service. Abnonnal Occurrence No. 72-15, " Turbine Trip Design Deficiency". Upon completion'of a detailed scram sequence of events study, following the plant trip described in A.O. No. 72-13, it was discovered ~ that during engineering of the low main coolant flow trip circuitry, the turbine trip portion of Proposed Change No. 96 was inadvertently omitted. j Therefore, a Plant Design Change Request (PDCR) was prepared to correct-the-omission. The PDCR was reviewed and approved by Westboro Nuclear o Services Division, Engineering and Operations Departments. Preparation of -{ 4 1972 the plant was. removed from service; the approved modification was a repair procedure was immediately initiated and.on Wednesday, August 30, l completed and preoperationally tested in accordance with the written j approved procedure. t l Plant Load Reductions There were no plant load reductions during the report period. Plant Shutdowns Shutdown No. 127-10-72: 8/18/72,. plant shutdown for control rod drop time testing. Total outage time: 'h hours, 37 minutes, j. Shutdown'No. 128-10-72: -8/27/72, plant trip due to a severe local ' thunderstorm. Total outage-time: h hours, 33' minutes. 4 I 8/30/72, plant shutdown ~to effect modifications Shutdown No. 129-10-72: ( to the low main coolant flow turbine trip circuit. l~ Total outage time: 4 hours, 5. minutes. Plant Maintenance j ~ -l 9 performed by.the plant staff during the month of August, 1972. The following is a list of pertinent plant maintenance items l j l 1 -l -=

l 1 ** l l 1. The No.1 charging pump was repacked. 2. Tn* installation of pipe for the post accident hydrogen control system has been started. t 3. The No.1 Auxiliary Steam Boiler has been completely retubed and l returned to service. Instrumertation and Control I 1 Tne following is a list of pertinent instrumentation and control maintenance items performed by the plant staff during the month of l August, 1972. I A sump water level alarm has been installed in the screenwell house. Reactor Plant Performance 1 4 i Measurements with the incore instrumentation vere performed under the following plant conditions : i h97.2 1st; 510.3 F Tave; Control Rod Group A @ 86 ", B,C and D @ 87 n; 3 1365 ppm baron; equilibrium xenon. .ie results of the measurements were: 4 Stainless Steel Zircaloy Clad Clad Assembly Assembly q { Fh 1 92 1.81 1 F 1.48 1.h0* l Maximum Outlet F 568 578 1 iL

• Erratun."

The erratum reported in Operation Report No. 139 was incorrect. "OperationReportNo.137,page4,FhforZircaloyCladAssembly should be corrected to read 3.88." Secondary Plant Performance Feedvater heater terminal differences were as follows: No. 1 = h.5 F No. 2 = 7.3 F No. 3 = 7.1 F ) The condenser performance was as follows: l 15h.6 MWe; 1.75" Hg B.P. ; h98.0 ist; 60.7 F C.W. in; TTD = 18.8h F; l cleanliness factor = 73.6%. j Chemistry The main coolar.t boron concentration was reduced from lh00 ppm to 132h ppm to compensate for normal core depletion. l l o-w,-mw-e---,-e w. .> w - ._...-..,e.--c.. ..,.-,,o.--- m-m. w r e,ss-w

_h_ 1 } .The main coolant pH averaged 5.33 during the period. The main coolant beta-gn=ma specific r tivity and crud level l averaged 1.08 x 10-1 ue/ml and 0.01 ppm respectis Ty. l The main coolant tritium concentration averaged 8.12 x 10-1 j ue/ml auring the period. The iodine-133 specific activity averaged 2.05 x 10 h 1 and the i iodine 131/133 atomic ratio averaged 1 99 i l A crud sample for the month collected on August 15 had the following radiochemical ana1yses : dpm/mg crud. i i Cc-51 Mn-54 Fe-59 Co-58 T 5 5 6 k 1 98 x 10 4.02 x 10 9.h8 x 10 3.63 x 10 j Co-60 As-110Mk Z"-95 sb-124 5 5 5 8.77 x 10 9.23 x 10 2.28 x 10 1.55 x 10 l 1 j A main coolant gas sample, collected on August 8, had the i te'ioving radiochemical analyses : uc/cc gas i l Xe-133 Xe-135 Ar-h1 5.42 x 10 5.75 x 10 h.60 x 10 -1 -2 -1 1 Health and Safety j Two shiprents totalling 113 drums of low level vaste containing j 52.2 me were made during the period. 1 Waste disposal liquid releases totalled 52,300 gallons containing i 0.033 me of gross beta-gamma activity and 77.16 curies of tritium. Gaseous releases during the period totalled 0.570 curies of gross beta-gamma j activity and 0.17 me of tritium. Secondary plant water discharged totalled i 256,979 gallons containing 0.013 me of gross beta-gamma activity and 0.12 l curies of tritium. 1 l Radiation exposure doses for Yankee plant personnel as measured by filu badge, for the month of Augaat,1572 were as follows: i i Average accumulated exposure dose: 52 mrem i Maximum accumulated exposure dose: 220 mrem 1 j Operations Attached is a summary of plant operating statistics and a plot of daily average load for the month of August, 1972.

9 1

I O 6 8 l YANKEE ATOMIC ELECTRIC COMPANY - OPERATING

SUMMARY

i August 1972 l 1 ELECTRICAL MONTH YEAR TO DATE i Cross Generation IGui 111,776,000 510,588,300 13,526,h64,200 - l Sta. Service (While Gen. Incl. Losses) KWH 7,3hh,302 33,731,8 874,801,h61 l Net Output KWH 104.h31,698 476,856,453 12,651,662,739 l l Station Service 6.57 6.61 6.h7 i Sta. Service (While Not Gen. Incl. Losses) KWH 83,269 5,410,63h 38,515,026 l ) Ave. Gen. For Month 74h KW 150,236.6 l l Ave. Gen. Running 730.717 KV 152,967.6 l I i l PLANT PERFORMANCE l l l Net Plant Efficiency 28.99 28.88 28.50 l l Het Plant Heat Rate btu /KWH 11,772.16 11,817.00 11,974.56 I l Plant Capacity Factor 80.69 47.00 75.21 b heactor Plant Availability 98.59 62.2h 83.99 I MONTH CORE X TOTAL l NUCLEAR Hours Critical HRS 735.h7 2,561.40 88,046.39 1 8 69 j Times Scrammed Burnap i Core Average !GD/MrU 769.43 2,h74.43 j Region Average MWD /MTU j { A (INNER) 670.67 2,156.22 20,511.72 B (MIDDLE) 845 92 2,719.56 12,690.91 i C (OUTER-ZIRCALOY) 697.25 2,236.58 2,236.58 t i I i I l l

YAI;KEE ATOMI TRIC COMPANY i t l I DAILY A E LOAD i. FOR i AUGUST 1972

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