ML19351E043
| ML19351E043 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 07/13/1961 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| References | |
| NUDOCS 8011250518 | |
| Download: ML19351E043 (9) | |
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YANKEE NUCLEAR PCWER STATION l
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5 OPERATION REPCRT NO. 6 for the month of JUNE 1961 j
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I Submitted by YANKEE ATCtAIC ELECTRIC CCtAPANY Boston flassachu etts July 13, 1961
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The following report covers the operation of the Yankee Atomic Electric Company plant at Rowe, Massachusetts, for the month of June, 1961.
With the exception of two outaces in the latter part of the month, one a scheduled outage and the other an unsc'ieduled outage, the plant operated continuously during June. Effective June 23, an 1ncrease in power level from 392 MW' o 485 fl#t was authori. zed in conjunction with issuance of a 40-year operating license. Before increasing the plant powar level, however, two j
changes were made in.the plant protective system. The char ges, involving the t
installation of circuitry for a reactor scram on high pressurizer level and modification of the safety injection system initiation, were ef fected during a i
plant shutdown June 24 to 26.
On June 26, after the generator was phased and loading of the unit t
was in progress, No. 2 turbine control valve failed to open. The load at the l
l time was 80 PSie. Several attempts were made to open the valve, but the inabil-ity to pick up load persisted. Load was decreased and the unit was taken off the line. Repeated attempts at opening the valve from the turbine test station finally resulted in its operating properly. After checking and testing the l
turbine trips, the unit was returned to the line and loaded to 123 fSle.
No. 2 j
turbine control valve operated satisfactorily during the startup. Modification j
of the turbine control valve oil relays is planned for July, and it is expected i
j that this will correct the unsatisfactory valve operation that has been noted l
In recent months.
! g On June 28, the plant load was increased to 138 MWe, equivalent to 440 ?#it, the decision having been made to increase the power level in two incre-
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ments rather than one. Flux wire and secondary plant calorimetric runs were j
made and analyzed at this time. Observation of plant conditions at 138 MWe for approximately 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. indicated that both the reactor and secondary systems 4
l were operating properly.
4 On June 30, the plant power level was increased to the licensed f h limit of 485 Dit corresponding to a gross electrical load of 150 MW.
Although j
only thirteen and one half bours operation at 485 MWt was recorded by the end of June, primary and secondary plant performance appeared to be satisfactory.
l On June 28, wh le making adjustments on the electro magnetic con-t verter of No. 1 steam generator feedwater control, the narrow range level pen j
engaged the wide range pen moving it in such a direction as to indicate high steam generator water level. The load at the time was 123 ?Sle 2nd the operator j
was controlling steam generator level manually using the wide range instrument i
to maintain the proper level. Assuming the wide range level indication to be correct, the operator reduced feedwater flow to the steam generator resulting i
in a momentary uncovering of approximately four feet of steam generator tubes.
i The false reading was corrected within a matter of seconds and the feedwater i
level was returned to normal. No visual effect on the primary system was noted.
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To avoid recurrence of this incident, the wide range pen will be i
relocated to a new position in the recorder case to provide more clearance between pens.
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-of.Junei
Shutdown No. 36 6/24/61-to 6/26/61'-'a'40 h'ur 37 minute scheduled:
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.. outage for plant; protective 4 system changes,1-inspection within the vapor' container and:. control =
i' rod group' interchange.,
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Shutdown'No.'37 - 6/26/61_ -
-La.10 hourj26' minute outage-resulting from,the failure l
of-No. 2 turbine control' valve to open and resultant' inability to=
- pickup l load.
I There were no reactor scrams.during the month of June.-
' plant Maintenarice and Modifications
' As' the result o.f a' leak _ check on the vapor container, a leak was discoverdd'at a gasket in the air, articulate monitor' filter box.-Correction of;this condition hastreduced air-leakage from the vapor container;by a factor:--
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of:three.
During June the following maintenance. operations were carried out:
Renewed the'-balancing drum line'on No.L1 boiler' feed. pump and the l
packing leak;off line on-No. 1 heater drain' pump. Both, lines were.
replaced to eliminate leaking joints.
Repacked'No. 3 charging pump and added packing to No.'l charging pump.
Renewed the shaft sleeves of_No.L2.. component. cooling: water-pump.
Replaced shutdown cooling valve'SC-V-611.
Re' paired turbine-. speed and valve' position indicator..
Replac'ed slideswire ~on No. 4 steam generator wide range level l-transmitter.
Maintenance personnel performed-the-piping chancescrequired to modify No'.-2 feedwater; heater vent and also completed work onJthe distillate;
< accumulator, vent system'.
Maintenance and' instrument-department personnel installed the cir-L cults tregt: ired for ' the pressurizer high ;1evel' scram and safety -injection system.
changes.
Consideration;is being given to possible methods'of: alleviating or:
-eliminating steam line. vibration.-
-Desicn Channes-
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' The. followingichanges and modifications.. in plant design were made l
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during June: ~
L.- Installed-an additional scram initiaticn circuit providing for-
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~..a reactor scram inLthe-event..of high Water level-(approximately 1
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275 inches) in the pressurizer. Anal) sis of conditions at 485 MWt and at end of core life indicated that upon loss af load without an accompanying reactor scram, a main coolant surge would oc.;r and wou.d be of sufficient magnitude to fill the pressurizer and relieve a small volume of water through the pressurizer relief valves. The installation of the pressu:12er high level scram will prevent such an occurrence. This change is in accordance with proposed Change No. 6 which was approved by the Division of Licensing and Regulation on 5/25/61.
2.
Changed the circuitry and set points of the safety injection system. This modification provides for automatic opening of the motorized valves in the cafety injection system if the primary system pressure drops below a minimum of 600 psig; automatic startup of the safety injection pumps if the primary system pressure f alls below 270 psig; and elimi-nation of the coincident provision that the vapor container pressure shall also have risen above 5 psig in order to initiate the Safety Injection System auto-matica11y. This change is in accordance with proposed Change No. 8 which was approved by the Division of Licensing and Regulation on 5/25/61.
3.
Installed a vent system from the distillate accumulator tank in the radioactive waste disposal system. As a result of the change the tank is vented through a vent condenser and a vent scrubber to the inlet side of the purge and ventilation fans. The new vent system will prevent the accumulation of non-condensible gases in the distillate accumulator tank and will filter such gases and provide for eheir dilution prior to release.
This change is in accordance with proposed Change No. 3 which was approved by the
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DivisionofLicensingandRegulationon6/6/61.
Two low temperature alarms were also installed, one on the exterior vent piping run and the other on the interior vent piping run. Both are set to alarm at a vented mixture temperature of 190 F.
4.
Revised piping and orifice size on No. 2 feedwater heater vent to conform to original installation. The vent system was modi-fied originally to improve heater performance. Expected _ improvement did not materialize and as a result the vent system has been restored essentially to its original layout.
Chemistry Operation of the waste disposal evaporator continues to be held to a minimum as a result of carryover in the evaporator effluent. Modification of the evaporator will be made as soon as possible after delivery of a new separator and demister.
Installation of a vent system from the distillate accumulator tank in the radioactive waste disposal system was completed and placed in operation during June.
Main coolant analyses for Iodine and specifi< activity made before and after the load increase from 123 MWe to 138 MWe indi ated no significant change in either Iodine concentration or specific activf.y.
9 Secondary side steam generator specific activity measurements co..
tinue to indicate no significant activity above the background level.
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' Tests conducted during June at a power level of 392 MWt, indicated. main coolant specific activity values from 4.6 tc, 7.1 x 10 323 MWe, pc/ml, I
Iodine 131 activity of 4.5 x 10-4 pc/ml, and the absence of detectable oxygen
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in the main coolant bleed.
I Analyses made during June indicated the following:
Main Coolant C ud Analysis Fe-59 5.0 x 10 dpm/mg 4
Ag-110 9.6 x 10 dprt/mg Co-60 7.6 x 10 dpm/mg 6
Co-58 1.9 x 10 dpm/mg 6
Cr-51 2.5 x 10 dpm/mg Mn 1.0 x 10 dpm/mg Crud Level 0.11 ppm J
Main Coolant Gas-Analysis
-1 A - 41 5.9 x 10 c/ccgas
-2 Kr - 85m 2.3 x 10 c/ccgas I
- pc/ccgas Xe - 133 1.1 x 10 j h
-2 Xe - 135 3.7 x 10 pc/ccgas i
.The averacc. ion exchange decontamination factor ranged from 1266 to 1766 during June, l
Health and Safety Liquid Waste with a total activity of 106 pc was discharged from j h the plant during June..At all times the concentration was well below.he maxi-mum permissible.
i No gaseous waste was discharged during the month. Nine barrels of solid waste with a total activity of 20 mil 11 curies were drummed during June.
No solid waste was shipped.
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Radiation levels measured on contact with the drummed solid waste j-ranged from 2 to 70 mr/hr. General radiation levels in the drumming pit were 5to20mr/hr.
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Radiation levels in the shutdown cooling pump cubicle during re-
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placement of a valve in the shutdown cooling line were less than 0.1 mr/hr.
2 Contamination levels were in the order of 200 to 500 dpm/ft i'
Gamma radiation levels were measured in the steam generator
- cubicles at a power level of 392 MWt. The following results were obtained:
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Steam Gerarators t o. 2 No. 3 No. 4 j
Location:
No. I 4
Top of steam generator 35mr/hr 12 mr/hr 22 mr/hr 30mr/hr b.
On a level with the top 800mr/hr 900 r. /hr 800 mr/hr 800mr/hr of the "U" tubes c.
In vicinity of horizontal centarline 2-3 r/hr 3.5 r/hr 2.5 r/hr d.
Walkway, 7 ft. below 2-3 r/hr 4 r/hr 2.5-3r/hr horizorital centerline e.
In vicinity of tube sheet 4-5 r/hr 5 r/hr 6 r/hr f.
Walkway below steam 8 r/hr 7-9 r/hr 9-10 r/hr 7-8 r/hr generator g.
On contact with main 15 r/hr 12-15r/hr 17 r/hr 12 r/hr coolant pipe
/, 1 Continuous monitoring of off site airborne activity during June indi-(
mated levels consistent with pre-operational values.
In conjunction with the plant safety program, a safety meeth.g and fire drill were conducted in June.
Reactor Plant Performance
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The results of tests conducted after the increase in reactor power level to 485 MWt are:
FQ, Heat Flux GI 3.3 F/hT, Coolant Rise 1E 2.6 Temperature u t outlet of the hot channel <f 600 F DNB ratio ?> 3.0 g
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Since very few hours operation at 485 MWt were recorded by the end of the month, test data are necessarily limited. The preceding results, however, are an indication of reactor performance as determined during the initial hours of operation at 485 MWt.
Power coefficient data were obtained during the plant loading on June 26.
The data will not be analyzed ur.11 af ter the 4000 EFPH shutdown when experimental rod worths will be available.
Tests were performed during the month in an attempt to improve the present estimate s of core life. Two general methcds were employed. The first was based on determining the change in main coolant temperature corresponding to a change in control rod position and the second on the cnange in main coolant temperature corresponding to an increase in core burnup. These two methods gave reasonable agreement, indicating a total core lifetime of approximately 6730 equivalent hours at 392 MW thermal.
Previous analyses indicate that these experimental results are probably low, since no effect is included for changes 7.s
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in control rod worth brougnt about by non-uniform core burnup.
It is felt that these rod worths have changed in such a manner as to increase the total worth of the control rod groups remaining in the core. Additfanal tests will L; performed during the scheduled July shutdown in an attempt to further define core lifetime.
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Turbine plant performance C./
Routine calorimetrics were run during June and several additional calorimetrics were run to establish the effect of condenser.back pressure
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changes on the reactor fMt to generator gross Wie relationship.
Testing and analysis of results. pertaining-to the feedwater heaters continued during June. Revisions to the No. 2 heater \\ent failed to produce any noticeable improvement in performance. Vibration of the heater under certain conditions is still present and the tuminal temperature difference on the heater is greatly in excess of.the design value.
It is expected that the No. 2 heater will be opened during the scheduled plant shutdown in July. Meanwhile, the heater manufacturer has been asked to submit corrective recommendations.
Chances in Oceratino procedures During the month of June, a new emergency instruction procedure
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(No. 505 C2) was issued. The new procedure outlines the action to be taken in the event of a complete rupture or severance of the 24 inch main steam line.
A portion of emergency instruction 505 D2 has been rewritten and issued. This instruction is related to the action to be taker-upon a total loss of--A.C. supply resulting from complete separation of th alant from the interconnected system. The revision ancompasses deleting the teps concerning energizing buses and equipment (these steps to be covered in a separate check off list) and adding steps which detail and clarify the provisions for supplying
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water to the component cooling system.
V Chances in plant Oroanization Two new plant operating positions (Alternate Control Room Operators) were established and filled in June. The Alternate Control Room Operators will have part time assignments as Control Room Operators for the purpose of training q
for the AEC Reactor Operator examination. When adequately trained they will bl also serve as relief Control Room Operators.
In-Plant Trainino Notification has been received that five station personnel success-fully passed the written AEC Reactor Operator license examination given in May.
Four technical representatives of Yankee Atomic Electric Company spon,r companies commenced a period of in-plant training in June.
plant Operations Attached is a plot of daily average plant load and a summary of plant operating statistics for the Tonth of June.
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ANKEE ATCMIC ELECTR IC COMPANY DAILY AVERAGE LOAD for JUNE 1961 S
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(b) Shutdown No. 37 c:
(c)
Load increase to I.b]
138 ff#e (440 MWt) h h
50-(c) Load increase to g
150 Wie (485 ff#t)
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-YANKEE ATOMIC ELECTRIC COMPANY
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OPERATING
SUMMARY
MONTH:
JUNE 1961
__ Month-to Date Gross Generation KWH 8'3,211,100 457,727,200 Station Service- (While Gen. inc. Losses)
' KWH -
6,593,558 39,398,761 Net-Generation KWH 76,617,542 418,328,439 Station Service -- Percent 7.92 8.61-Station Service (Whi1e Not Gen. inc. Losses)
KWH 389,340 7,555,626-
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Ave. Gen.' --- For Month
( 720 Hrs.)
Net KW 106,413
-Ave. Gen. --~ Running
-( _668.95 Hrs.')
. Net KW 114,534
-Equivalent Reactor Hours at 392 MWT HRS 682.2
-3690.0-at 485 MNT HR S 542.8 2985.3 Use Factor -- Fercent 89.72 66 10 Circulating Wat r Temperature -- F
' Max. F 58
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Min.
F 49
~ Control' Rod Position at Month End ~-
Equilibrium and Full Power (at 150 MWE' Gross)
Group - Rod Out Inches -------
0
-90 Group'2'- -
90 g
Group 3'--
90 Group.4 --
12-6/8 Group 5 --
90 Group 6 --
6 231' Timas Critical Hours Critical
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692.13 5606.'19 Times Scrammed 0
25 29.1 Net Plant Ef,ficiency'--. Percent 966,264,000 Steam-Flow --Lbs.
Lbs. Steam /NetKWH
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YANKEE NUCLEAR POWER STATION 1 -
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P OPERATION REPORT NO. S for the month of MAY 1961 j s\\ \\ - I
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I YANKEE ATOMIC ELECTRIC COMPANY Boston Massachusetts I
June 9,1961 i
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- The f'ollowing report covers the operation of the Yankee Atomic-M.
_ Electric Company plant;at-Rowe,' Massachusetts for the_ month of May,_1961.
The,perio'd.from May 1 to May 9,was characterized by a series.of
- turbine control; problems. ~0n May:1 some irregularity in the position and
, operation lof No.tl:and No.~2 turbine control valves was noted.- The field service' representative:of.the turbine manufacturer was notified and was present
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Lon.May 2-for al scheduled shutdown for control rod interchange and vapor con-tainer inspection.;.No.'2 turbine control valve _ operation was erratic during
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the load reduction. preceding:the shutdown. As a result the turbine throttle
! valve was tripped %anually_ at.a load of approximately 78 MW electrical.-
1 Inspection within the' vapor ~ container indicated a leak in the-
. steam' connection to the pressurizer > narrow ra ge level control. The leak occurred at a shop 4abricated pipe nipple te valve socket weld and was repaired
~by peening.to stop the-leak and.then welding a sleeve over.the affected area.
On May 4 the generator was phased on the line.twice only to be
..takenfoff the~line as a result of huntin'g of No. 1--turbine control valve.
Between May 5. and. May 8 corrective adjustments were made on the control valve servo.. motors but valve hunting and oscillation continued to occur. On May 9 further adjustments on No. 1 control valve servo motor were made and the unit-was, returned to service. Operation of the turbine has been satisfactory since.
j that time.
On May 29 a. scheduled shutdown occurred for inspection within the vapor container and control rod interchange.
Some difficulty is.still encountered with the-condenser circulat-ing, water system..At times load has.been reduced; temporarily to re-establish full; siphon vacuum in the circulating water discharge line.. The cause of this problem and: remedial measures are under li.vestigation.
Following is a listing of turbo-generator outages for the month of May:
- Shutdown No. 28 '5/2/61 to 5/4/61
- a 39 hour4.513889e-4 days <br />0.0108 hours <br />6.448413e-5 weeks <br />1.48395e-5 months <br /> 12 minute cutage for vapor container-inspec-tion, control rod interchange, pressurizer instrument connection repair and
- turbine control valve. repairs.
Shutdown No. 29 5/4/61 - a 37. minute outage to repair a leak-ing1 flange on No. 2 turbine' control valve drain.
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' Shutdown No. 30 5/4/61 - a 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 4 minute outage caused by high level flux scram. (See scram tabulation.)
Shutdown No'.~31 5/4/61 to 5/5/61
- a 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> 31 minute outage for turbine control valve repairs ~and adjustments.
Shutdown Mo. 32 5/6/61 to 5/7/61
- a 13 hour1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> 1 minute outage J
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for turbine control valve repairs and adjustments.
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Shutdown No.-33 5/7/61:
a-14 hour 48/ minute outage for turaine.
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V control valve repairs and'adjustmentc.
Shutdown No. 34L 5/9/61 - a-10 hour'24 minute outage for~ turbine control valve repairs and adjustments.
Shutdown No.~35 5/29/61
'a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 56 minute scheduled outage for
~ inspection within the vapor container and control rod interchange.
-Two scrams occurred during May.. Follow 3ng is a brief-description?
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of each-scram.
LScram-No. 24.-
5/2/61 - -- a scram from a' power level of 254 MW thermal. The
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'ccram occurred as a result of a manual trip ofsthe turbine throttle' valve.- Erratic operation of the turbine control valves during.
the load reduction. preceding Shutdown No. 28 led to.a decision to trip the.
throttle. valves to accomplish turbine unloading.
Scram'No. 25: : 5/4/61 -
a - scram from a power level of 190 MW thermal. This scram occurred as a result of failure to adjust the gain on the power range channels. The' scram was caused by a false 115% power reading on 2 of the 3 power range channels.
The power range channels required gain adjustment to '
compensate for the new flux distribution resulting from the control rod inter--
change.and from the insertion of control rods necessitated by Xenon decay during.
the reactor shutdown.
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Plant Maintenance and Modifications During the early part of May, maintenance efforts were concentrated on correcting turbine control valve difficulties. Representatives of_the-turbine-manufacturer were present_during this. period. Since 'the cause of the instability
)vas not readily apparent, a _ complete _ inspection of the valve servo motors was -
r'equired. 'In the course of the maintenance operation.a new upper guide bushing A
was installed in No. 2 servo motor following which a complete alignment check V.
was.made. Sa vo motor _ piston rods were polished-'and guides resurfaced on both No.1: and. No. 2 valves.. The oil relays.were checked and cleaned and a vent hole on No.-1 servo motor ~ as unplugged..
w As described in the introduction, a' pressurizer instrument connec-:
tion ~ leak was repaired during the May'2.to May 4 outage. Where necessary; valve packings were adjusted on'normallyl inaccessible valves.
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Packing was replaced on_the charging pumps and on No. 3 boiler
. feed pump during May.- Valves and diaphragms' in No. 2 waste gas compressor were also replaced during the' month.
Instrument department' personnel performed minor maintenance on the Teleflex flux wire' equipment.-
h Seepage along a construction joint from the spent fuel pit into the new fuel vault was_ detected af ter filling the spent fuel pit. Considera-
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tion is_being given to a. lining material for the pit or sealing the construc-t
- E tion -joint.
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f The vapor container expansion joints were filled with water to g
check for leakage. The top and bottom joints on the two inner columns and the bottom joints on the six outer columns were checked with no evidence of 6
_ leakage, j
plant Chemistry I
Since the waste disposal evaporator operation has not been con-sistent with specifications regarding re-use of evaporator ef fluent, make-up feed to the primary system continues to be demineralized water primarily.
Modification of the evaporator is to be effected in the near future in order to improve its performance.
Durigg the month of May r.1ain coolant specific activity ranged from 3.8 to 5.0 x 10 pc/ml. During the same period there was no detectable oxygen in the main ecolant bleed.
Analyses made during May indicated the followings Main Coolant Cr,ud Analysis Fe-59 2.2 x 10 dpm/mg Co-60 5.2 x 10 dpm/mg 6
Co-58 1.3 x 10 dpm/mg
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0 C r-51 1 7 x 10 dpm/mg 6
Mn-54 6.8 x 10 dpm/mg Ag-110 4.1 x 10 dpm/mg Crud Level 0.098 ppra A tain coolant crad analysis made during the week of May 14 Indi-cated traces of Ag-110 for the first time. Earlier in the month analysis of a pipe sample from No. I loop corrosion specimen showed evidence of Ag-110 con-tained in the surface deposits. Careful analysis and evaluation 'ndicate that the amount of Ag-110 found is well within that expected.
Main Coolant Gas Analy_sh A-41 3.5 x 10"I pc/ccgas Xe - 133 9.5 x 10' pc/ccgas l
Xe-135 6.5 x 10' jic/ccgas 3.1 x 10' pc/ml Main Coolant I-131 specific activity
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The average ion excnange decontamination factor ranged from 1017 to 1749 during May.
Secondary side steam generator specific activity measurements in-dicated no significant activity above the background level.
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? Health and' Safety:
V Liquid waste with a(total activity of.235 pc was discharged from-
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_ the plant lduring May. :At allLtimesLthe= concentration was well below the-
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' maximum. permissible.
1.No gaseous; waste was discharged during the month. No solid waste-
-was shipped nor:wasiany solid, waste drummed during May.
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The pump which.islused for' collecting air particulate samples from the primary-vent stack was replaced:during May.'
Radiation levels measured-in.the steam generator. cubicles immedi-
- ately af ter the May 2' shutdown'were 400-700 mr/hr on contact with the main.
coolant pipes and 1100-400 mr/hr in the. general area.
.The following were determined in the pressurizer ~ cubicle before
- the leaking connection:to'the' pressurizer narrow range. level controller was repaired:'
-10
-9 Air sample activity 8 x 10 to 8 x 10 pc/cc Contamination level
.6,000 to 60,000 dpm/ft f~}-
Radiation Levels:
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On contact with pressurizer 15mr/hr In general area 5-8mr/hr Radiation: levels measured at the bottom of the Low Pressure Surge-Tankrangedfrom*250-1000_mr/hr.-
Contamination levels measured in a charging pump cubicle gn con-junction with a repacking operation-ranged from 5,000 15,000 dpm/ft with a general radiation level of 2 ~- 5 mr/hr. Radiation level on contact with 4
the removed packing did not exceed 150 mr/hr.
In addition to the above, routine surveys and calibration checks
~ of ths radiation monitoring system were made~ during May.
Reactor Plant Performance Lh Temperature coefficient-of reactivity _ calculations based on-data obtained during the April low power physics testing have been comple_ted.
Re-sults indicate that the temperature coefficient after 1900 equivalent full.
power hours.of reactor operation 11s 8.51 less negative than at start of life.
.This is approximate 1y equal to the magnitude of the change as predicted.from
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-analytical calculations arising from the withdrawal of control rods.from the -
core during this period..
Temperature Coefficient (1900 EFPH).
-(2.810.1)x10.dKo jy
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0 EFPH) k -(3.lf0.2)x10 h Kjo.
- Temperature Coefficient (
g K
No.significant. change in the power coefficient as-a function of'-
core lifetime:has been~ detected.,
-4 IPower Coefficient
.(1900 EFPH)
-(0.3510.13)x10 K7g,dT
--Power Coef ficient
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Turbine Plant Performance
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Secondary plant calorimetrics run during May. continue to show M
excellent agreement with. the established MW thermal to M# electrical rela-tionship.
L' Testing.and anlysis of results were carried out during the month
. relative to the' performance of No. 2 feedwater heater. Thermal performance of the heater has been poorer than expected and occasional periods of heater vibration have been experienced..
A test to determine effectiveness of the moisture separators was.
run during May.-.Results are not complete at this time.
~A condenser circulating water flow test was run during'the month as part of a program to resolve operating problems connected-with the 'circu-lating water system.
Desion Chanaes There were no' plant design changes or modifications during May.
In Plant Training On May 25 ~and 26, the written portion of the AEC reactor operator license examination was given'at the Yankee plant.. Six station personnel.
took the examination.
Plant Operations s
Attached is a plot of daily average plant load and a summary of plant operating statistics for the month of May.
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YANKEE ATOMIC ELECTRIC COMPANY D-s v-
.L OPERATING
SUMMARY
MONTH:
MAY 1961 Month to Date Gross Generation WH 74,142,600 374,516,100 Station Service (While Gen. inc. Losses)
WH 5,945,876 32,805,203 Net Generation WH 68,196 724 341,710,897 Station Service -- Percent 8.02 8.76 Station Service.(WhileNotGen.'inc.-Losses)
WH 874,228 7,166,286 Ave. Gen. -- For Month
( 744 Hrs.)
Net W 91,662 O Ave. Gen. -- Ronnine
( 625.5 Hrs.)
set W 109,02e Equivalent. Reactors Hours at 392 MNT HRS 592.26 3,007 46 Usa Factor -- Percent 79 72 63.20 Circulating Water Temperature -- F Max. F 53 Min. F 38 Control Rod Position at Month End --
Equilibrium and Full Power (at 125 MWE Gross)
Group 1 -- Rod Out Inches ------
90" 0
Group 2 --
?O" Group 3 --
54-6/8" O
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0 Group 5 --
90" Group 6 --
2 225 Times Critical 734.43 4914.06 Hours Critical 2
25 Times. Scrammed 29.4 Net Plant Efficiency -- Percent 887,154,000 Steam Flow - Lbs.
Lbs. Steam /NetKWH 13.01 OO u
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YANKEE NUCLEAR' POWER STATION OPERATION REPORT NO. h
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YANKEE ATOMIC ELECTRIC COMPANY Boston Massachusetts May 10, 1961 J
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The following report c, overs the operation of the Yankee Atomic Electric-Company plant at Rowe, Massachusetts, for the month of April,1961.
From-April 1 to April P, the plant was shut down for low power physics testing. 'Specifically, the purpose of the testing was to determine the effect of Plutonium build-up in the reactor core on the over-al1~ core coeffielents. As required by the plant operating license, such tests will be conducted at intervals during core life.
Coincident with the physics testing, maintenance work on the turbine control valves and other pieces of plant equipment was carried out.
While the preceding was the only plant shut down during April, difficulties in maintaining circulating water discharge line vacuum neces-sitated reducing load to 100 We at times.
Load was reduced temporarily in orde to remove one half of. the condenser from service and allow air to be withdrawn from the outlet water box and discharge piping.
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Loss of vital bus frequency control on April 17, required a temporary load reduction until emergency power switching was effected.
Upon restoring the plant to full power the No. 2 feedwater heater experienced some vibration. A slight load reduction eliminated the vibration and manipu-lation of the by-pass valve around the heater allowed the unit.to be returned to full power without further vibration problems, fm Except for the one outage and temporary load reductions, the d
plant continued to operate at a level of '125 Welectric during the month, which corresponds to the licensed reactor power of 392 W thermal.
As mentioned above only one plant shutdown occurred in April.
Following is'a description of.the outage.
Shutdown No.-27 h/1/61 to h/8/61 A 185 hour0.00214 days <br />0.0514 hours <br />3.058862e-4 weeks <br />7.03925e-5 months <br /> 1 minute outage for scheduled low power physics testing to determine
.p) the effect of Plutonium build-up on the over-all; core coefficients.
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In a previous report, under the uescription of Shutdown No. 22 on 2/19/61, it was reported that the outage was the result of a power range level scram and that the cause of the scram was under' investigation.
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Following is a description of the scram, its cause and measures taken to prevent its recurrence.
The scram occured during startup of.the plant while transferring from manual to automatic feedwater control.- The load level at the time was 10 We.
Introduction of cold feedwater at a higher than required rate, sufficiently cooled the primary plant to cause a nuclear power increase and subsequently, a 35% power level scram. An additional administrative procedure has been developed and issued, which enumerates the specific
-steps to be taken by the operator in transferring from manual to automatic feedwater control for turbo-generator startup and shutdown.
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O' Plent' Maintenance.an'd Modifications During the plant outage of April 1 to April 8, the turbine control. valve bonnets (No. 'l and No. 2 valves) were rebored and new bushings and stems installed. The servo motor piston bushinga on No.1 and No. 3 control valves were removed and cleaned and valve travel on the control valves and throttle valve was checked and adjusted.
Inspection.ofithe moisture separators indicated that they were clean and required no maintenance. Flowmeters were : installed in the moisture
- separator drain lines for test purposes. The meters will be removed when testing is completed..
No. 2 andJo. 3 feedwater heaters were inspected and pressure
' tested with no leakage detected. Modifications were made in the venting and heater leval controls on the recommendation of the manufacturer. The changes were made in an attempt to improve heater performance.
During the plant shutdown the rod control panel was thoroughly inspected. The rod control resistors were moved to the top of the rod control panel in order to provide better ventilation.
The exciter.and its air filters were cleaned and new brushes were fitted.
As indicated earlier in this report, vital bus frequency control 4
trouble occurred on April 17. The malfunction was traced to a defective diode in the bias control of the-magnetic amplifier in the circuit.
Routine inspection and maintenance procedures were. carried out during the month as well as calibration and maintenance of plant instrumenta-tion.
h Plant-Chemistry As described in earlier reports, the waste disposal evaporator operation is'not consistent with design objectives. Testing and evaluation of results continue in an effort to improve the evaporator perfonnance.
Consequently, inake-up feed to the primary system consisted mainly of de-mineralized water during April.
The specific activity of the primary coolant ranged from 14.3 x 10-2 to 5.3 x 10-2/ fc/ml during the month. Checks of secondary side
- steam generator specific activity continue to indicate no significant build-up.
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Routine primary and secondary water analysis and treatment procedures were carried cut during April. Oxygen levels in the main coolant have been below the point of detection. A main coolant crud analysis indicated:
Fe-59 1.9x105dpm/mg Co-60 2.9x105 dpm/cg Co-58 8.6x106apm/mg Mn-5h 2.6x106 dpm/mg Crud level: 0.36 ppm Iodine-131 concentration:
2.9x10-b M /ml r
A main coolant gas analysis indicated:
A-bl 6.0x10-1/c/ccgas Xe-133 h.8x10-3 /c/cc gas Xe-135 3.hx10-2 fc/cc gas Health and Safety Liquid waste with a total activity of 189/"c and gaseous waste with a total activity of 337/c were discharged during April. Thirty-five drums of solid radioactive vaste were shipped from the site during the same period. The tokl activity of the solid waste was $h millicuries.
Concentra-tions of waste products discharged or removed from the site were well below h.s the maximum permissible level at all times.
A site survey at 125 Kde indicated no significant difference in neutron or gamma radiation levels from previous surveys at a power level of 120 M'de.
The radiation level over the ion exchange resin storage pit was reduced from a 'lavel of 15 mr/hr to 0.7 mr/hr by filling the pit with water to a height of two feet above the resin containers.
Routine calibration checks of the Radiation Monitoring System and site and local radiation surveys were made during April.
In conjunction with the continuing plant safety program, the monthly station safety meeting was held in April.
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Reactor Plant Performance As required by license, the first of a series of tests to detemine the (ffect of Plutonium buildup in the reactor core was conducted in April. Preliminary resulte indicate no significant change in power coefficient and moderator temperature coefficient values from start of core life measurements.. Work is in progress to provide a revised startup rate to reactivity convercion factor taking into account fuel burnout effects. When results are available, reactivity coefficients will be reanalyzed.
Control rod scram time checks were made during the plant shutdown.
A total of h6 rod drops were timed with the reactor hot and under pressure.
Scram times showed excellent agreement with those obtained during the initial plant test period.
In addition to the special test program carried out in April,'
routine checks and data analysis continued.
Turbine Plant Performance Sec'ondary plant calorimetrice run during April continue to show excellent agreement with einilar checks run during March.
Analysis of feedwater heater perfomance data and the follow up of vent and level control modifications continued in an effort to resolve O
di creP =cie det eea etu 1 nd desia= he ter Perrorm #ce-Further appraisal of the circulating water discharge line vacuum difficulties and possible solutions continue to be made.
Design Changes The-following minor changes were made in plant design during the I
1.
In:t m ation of a permanent temperature indicator on the valve stem leak-off line from the vapor container.
2 Increase in vent size and relocation of level control connections on No. 2 feedwater heater.
In-Plant Training Classes were conducted through the month of April for plant personnel who are to take the A.E.C. operator licensing examination. Three additional plant personnel successfully completed qualifying.exarinations in April and have received A.E.C. reactor operator licenses. There are now
-15 Yankee. employees at the plant who have received these licenses.
1 Two representatives of the Consumers Power Company, Big Rock Point-Station, commenced a period of training at the Yankee plant in April.
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O Plant Operations Attached is a. graph of daily average plant load and a summary of plant operating statistles for the month of April.
The " Times Scrammed, To Date" entry on the Operating Summary has
- been revised as a result of a redefinition of the term " scram" as applied to the Yankee reactor. This term is now defined as an automatic or manual' rod drop occurring with the reactor critical as the result of a non-standard
'or emergency condition.-
Previously, a scram was defined as any automatic or manual rod drop from a suberitical or from a critical state. Technically, this included rod drops from a suberitical or critical state incurred in experimental pro-cedures, instrumentational check out and intentional shutdown for maintenance or other non-emergency pp.g oses.
Redefinition of the term " scram" results in a reduction of the
" Times Scrammed, To Date" from over 200 to 23 as of April 30, 1961.
One scram occured in April. Following is a brief description of the scram.
Scram No. 23 - h/1/61 An auto scram resulting from operator error in operating source range Start-Up-Rate cutout switch.
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YA!IKEE ATOMIC ELECTRIC COMPAtrl I'
i DAILY AVERAGE LOAD j
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9 YANKEE ATOMIC ELECTRIC COMPANY OPERATING
SUMMARY
MONTHt APRIL, 1961 4
Month to Date Gross Generation KWH 65,115,500 300,373,500 Station Service (While Gen. inc. Losses)
KWH 5,05h,736
-26,859,327 Net Generation KWH 60,060,76h 273,51h,173 Station Service -- Percent 7.8 8.9 Station Service (While Not Gen. inc. Losses)
MWM 990,312 6,292,058 4
Ave. Gen. -- For Month
(
719 Hrs.)
Net KW 83,53b
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' Ave. Gen. -- Running
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53h Hrs.)
Net KW 112,h73 Equivalent Reactors Hours at 392 MWT HRS 521.82 2,h15.20*
Use Factor -- Percent 72 60 Circulating Water Temperature -- F Max. F h1 Min. F 35 Control Rod Position at Month End --
Equilibrium and Full Power (at 125 MWE Gross)
Group 1 -- Rod Out Inches -------
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90" Times Critical 12 223-~
Hours Critical Times Scrammed
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665 bl?9.63**
1 23 Net Plant Ef,ficiency -- Percent 29.h Steam Flow - Lbs.
776,232,000 Lbs. Steam / Net KWH -
13.0 Revised as result re-evaluation of conversion of electrical to thermal power - see March Operation report, " Turbine Plant Performance".
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