ML19351E139
| ML19351E139 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 10/31/1963 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E135 | List: |
| References | |
| NUDOCS 8011250654 | |
| Download: ML19351E139 (16) | |
Text
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O YANKEE ATOEC ELECTRIC COMPANY OPERATION REPORT NO. 33, For the month of SF'TEMBER 1963 O
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Submitted by YANKEE ATOEC ELECTRIC COMPANY Boston Massachusetts h)
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OPERATION REPOR'.' NO. 32 i
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This report covers the operation of tho Yankee Atomic Electric Company plant at Rowe, Fassachusetts for the month of September, 1963.
The scheduled tore II - Core III refueling outage commenced on September 2 with a manua' turbine trip at a plant load of 83 We following /
which the primary plant was placed in the hot standby corx11 tion in order to obtain decay heat measurements and control rod drop time data.
On September h the primary plant was cooled down, borated to 1600 ppm, and depressurized. During cooldown, the vapor container sound system indicated the possible presence of a main coolant leak.
Prior to entry into the vapor container an air sample taken via the air particulate monitor exterior to the vapor container confirmed the precence of a main coolant leak. A subsequent investigation traced the leak to failure of the inner 0-ring seal of the reactor vessel head flange and censequent discharge of main coolant through the tell-tale leak off line between the gq inner and outer seal. Closure of a valve in the tell-tale line and purging v
of the vapor container lowered the air-borne activity to acceptable limits.
Initial operations within the vapor container centered around decontamination of the stainless steel liner of the shield tank cavity.
The work was performed by an outside contracting service using a sodium cyanide jell as a decontamination agent. The procedure was similar to that utilized this past winter for clean up of tools and equipment con-taminated during the Core I - Core II refueling. A more detailed description (n')
of the liner decontamination can be found in the Health and Safety section of the report.
A leak test of the cavity liner was performed using freon as a tracer gas. Weld repairs to the liner were made as the test progressed, thereby, preventing eventual saturation of the cavity atmosphere with freon gas.
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Other work in the cavity prior to head removal included stripping of the control rod drive mechanisms, installation of the control rod drive shaft storage rack, installation of fuel hand 1dng components on the manipulator crane, modifications to the nuclea-detectors and a check out of the control rod-follower break joint mechanism.
The removal of the reactor vessel studs was facilitated by the use of a specially designed tool operated frem the manipulator crane bridge.
By locating the manned work area at the nanipulator crane instead of the shield tank cavity floor, radiation expcare was kept to a minimum. -
Some studs, whose threads were silver plated during the last refueling, were seized in place and torque multipliers and air hammers were required to effect removal. All studs which were not silver plated at that time were backed out easily.
On September 18, all maintenance work within the shield tank cavity was discontinued and the vessel head was removed and stored on a p
flatcar under the vapor container. Thereafter, approximately two days cre v
required for the removal of core internals, including control rod drive shafts, guide tubes, in-core instrumentation eggerate and the upper core barrel.
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. *e p V Because of previous experience with silver contanination of the shield tank cavity the Core II Ag-In-Cd control rods were replaced immediately with hafnium rods. Twenty-two hafnium rods were inserted in the core along with two inconel clad Ag-In-Cd rods.
Prior to Core II operation, a number of irradiation specimens contained within a series of stainless steel capsules were installed around the periphery of the core, eight high flux specimen holders within the core baffle and two low flux specimen holders between the thermal shield and the inside surface of the vessel wall. While >reparinC for the removal of the specimen holders it was noted that the lif ting bales of the eight high flux holders had broken off from their respective support plugs.
During subsequent operations four holders were retrieved in good mechanical condition. Three holders were found separated from their respective support plugs and could not be retrieved. The plugs, however, were (o) removed from the shield tank cavity. The remaining high flux specimen support plug could not be dislodged from the core baffle flange.
Due to the loss of the lifting bales, two techniques for removal of the specimen holders were attempted. Some holders were extracted by a vacuum lift and those remaining were retrieved by underwater welding.
As the work proceeded with fuel loaded in the core in the vicinity of the work, a holder support plug and a small piece of welding rod were inadvertently knocked into the core region and lodged on the top of fuel b
assemblies. Both items were retrieved.
At the end of the reporting period work was in progress on the removal of the two low flux specimen holders.
Coincident with the irradiation specimen work,a program of interchange of fixed shim rod followers was initiated. The Core II shim
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followers were boron-stainless steel and were replaced by an all stainless V
follower. Concern for the possibility of long-term growth in the boron-stainless under irradiation prompted the change to an all stainless follower.
The first shim and follower to be removed from the core were given a detailed inspection and then returned to the core since equipment modifications ware required to the break joint mechanism. While entering the core, a loud noise and shock was experienced on the manipulator crane.
An examination of the partially inserted rod was made with no unusual effects noted and it was agreed to continue insertion.
However, at approximately 12 feet above normal seated position, the rotary joint of the shim rod suddenly disconnected and the boron-stainless follower fell into its shroud tube.
The primary cause of the accident was traced to a design problem at the very bottom of the boron steci follower. Since these followers were o
originally designed for ue in either the fuel region or below, depending V
on control requirements, the bottom detail has a span of only h.6 inches while the guides for insertion to the cruciform slot between adjacent fuel assemblies are approximately 5.0 inches apart.
Consequently, as the rod was being inserted in the core it struck the top end plate'of two fuel s_________;
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^ assemblies prior to sliding into the cruciform slot, this being the noise first heard by the operator. A rotation of the TV boom for inspection following this first incident caused the main tool boom to' rotate slightly since it was not locked securely.in position. The rotation of the shim was sufficient to unlatch it from its follower whose orientation was maintained by the cruciform slot between fuel assemblies.
To determine the extent of possible damag, the four fuel assemblies surrounding the shim red were given a detailed inspection.
Three assemblies were found in satisfactory condition, however, the fourth was found to be damaged in the top nozzle a:cea.
Contact between the shim rod-follower assembly and the top end plate of the fuel assembly caused the plate to bend slightly downward which in tur caused bowirg of a number 4
of fuel tubes. No obvious clad failure was observed.
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examination of the lower shroud tube and the bolts which hold it to the j
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lower core support plate indicated no damage to the respected internals.
To prevent a recurrence of this incident the eight new shim rod extensions were modified to conform to the design of the control rod followers whose span is sufficient to permit contact with the guides on adjacent fuel assemblies.
Throughout the reporting period detailed inspections of selected core components were conducted. A description of the inspection program O
a d the Pr 11-- 7 re 1t edta 1=ed tau rar c a de fe==d ia the neaeter 3
Plant Performance section of this report.
Because of the delays incurred only 20% of the actual fuel interchange was completedat the end of the reporting period.
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new h.1% enriched and four new 3.h% enriched assemblies had been added to the core while ten spent 3.h% assemblies had been moved to their final Core III position.
4 At the end of the reporting period the plant was in the cold, borated condition as refueling operations continued.
Plant Shutdowns.
I.
Shutdown No. 62-2-lh A scheduled outage for Core II-Core III refueling, s
Maintenance To assist in the;large maintenance program planned for the refueling shutdown the normal plant staff was augumented by 30 outside personnel obtained ' sm sponsor company maintenance groups.
Follow'
- s a summary of major activities. carried out by plant maintenance personnel during September:
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1.
The exciter commutator was resurfaced.
2.
. The leaking terminal box on the generator was repaired.
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3.
The polar crane sheaves were converted to the lubricated type and the crane inspected.
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No.1 manipulator crane was checked out and made operational.
- 5. The missile shield, cable trays, coil stacks and air coolant ducts were removed from the shield tank cavity.
6.
Modifications to improve the air removal capacity of the circulating water system continued during the period.
7.
No. 3 boiler feed pump was dismantled and inspected.
8.
No. 3 condensate pump was dismantled and inspected.
9.
Modifications to the turbine moisture separators to p o it n
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higher power operation continued during the month.
10.
The shutdown cooling pump mechanical seal was replaced.
- 11. New resistor %nk wiring for the fuel chute drive was installed.
12.
The shield tank cavity liner was leak tested and defective welds repaired where necessary.
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13 Installation of four new main steam line safety valves continued during the month.
Ih. Installation of main steam line vibration suppressors continued during the period.
- 15. The four turbine control valve servo motors and gland steam f"]
regulator were removed and sent to a local machine shop for L/
reworking.
- 16. An inspection of Z-126 and Y-177 lines OCB's was completed.
- 17. No. 20 control rod drive pressure housing was removed from the reactor vessel head for internal inspection.
- 18. The coil stacks of the control rod drive mechanisms were inspected and new coils replaced where necessary.
20.
An outside contracting service radiographed the steam generator nozzle welds.
- 21. Defective tubes in the condenser tube sheet were plugged.
V 22.
The solenoid operated pressurizer spray line valve was replaced with a motor operated valve.
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- 23.. The motor operated discharge valve from the safety injection -
-kJ tank was relocated indoors. -
i' 2h..The main coolant stop valves were repacked.
Chemistry Prior to-the shutdown of September. 2, the five inch loop bypass
' valves were opened to permit flushing of the typass line. Thereafter, the main coolant crud level increased to 16 ppm being reduced to 1.2 ppa just prior to the shutdown through mixed bed purification.
On Sept' ember h, the main coolant was borated to the required shutdown concentrstion of approximately 1600 ppm.
l In anticipation of a recurrence of the silver problem as expos Lenced during the past refueling, essentially continuous main coolant purii testion was' maintained following shutdown. Gross specific activity range i between 1.7 and 2.0 x 10-3 pc/ml. Until September 9, the major contributor was Co-58. On that date 0.5 ppm oxygen was detected in the main coolant following which the contribution of the Ag-llom nuclide to the specific activity began to increase although the gross activity decreassa.
On September 18 the shield, tank cavity was flooded and the specific activity decreased to 8.h,x 10-5 pc/ml, the activity reduction being due to.
the dilution.
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Greater than 99% of the activity was due to Ag-110m.- A comparison j-of shield tank cavity water activity for comparable periods of Core I and Core II refuelings is as follows:
Core I 5.6 x 10-3 pc/ml Core II 3.h x 10-h c/ml p
1 Continuous main coolant purification was not maintained during O
the first refueling as the problem of silver activity had not become apparent. With continuous purification the activity is, as expected, j
much lower..
The chend. cal analysis of crud removed from No. 20 control rod pressure housing is as follows:
i Nickel 95%
. Iron 0.15%
Manganese 0 56 %
Chromium 0.88%
0.013%
Through the use of specially designed filters installed in the ion exchange pit, visibility through the water in both the shield tank cavity and the spent fuel pit has been excellent throughout-the reporting
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Reactor Plant Performance The reactor conditions at the end of Core II life were h11 F Tavg.
303 Nt @ 2.0" Hg 0
83.3 EleG All rods @ 88 7/8 in.
Temperature coefficient data measreed following the shutdown indicated:
0 2.5% /\\(O in xenon, 2000 psi, h75 F, boron free, all rods @ 88 7/8 in.h A p/0F 69/6T = - 1. 97 +.10 x 10-Control rod drop time data measured on selected rods following the shutdown averaged 1.53 seconds showing no significant difference from data obtained at the beginning of Core II life.
During the month selected core components were inspected in detail with underwater viewing equipment. The following is a partial summary of the results of the program:
A.
Fuel Assemblies 1.
Core I Recycled Assemblies Two Core I fuel assemblies were reused in Core II to l
observe what effects, if any, could be discerned due to the higher burnup achieved. After operating two core cycles l
both assemblies were found to be in excellent condition.
No significant mechanical defects were noted. Crud deposits were minimal. Assembly appearance was essentially unchanged from earlier examinations.
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Core II Assembly l
One Core II fuel assembly being recycled in Core III was inspected in detail and found to be in excellent condition.
3.
Control Rods and Followers As expected, extensive deterioration of the nickel plate was observed on all Ag-In-Cd rods removed from the core.
No wear was observed at the stainless to stainless joint between the control rod and follower.
General appearance of the zircaloy followers was good and they will be reused for Core III operation.
Patterns of wear were observed on some vanes of all rods (m) inspected. The wear, approximately 0.25 inches by 2 inches,
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was perpendicular to the axis of the rod and not on all vanes
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of a particular rod. In most cases the wear was found V
entirely on the stainless steel rubbing strap. However, some areas were noted where the wear had passed complete 3y thrcugh the strap until the suraface of the rod had become a bearing area. The cause of the wear was traced to contact between the control rod absorber and the guide blocks en the upper core support plate wnen the rod is in the fully withdrawn position.
The top adapters of both abscrber Ahl and A39 were examined to determine the extent of wear at the absorber drive shaft joint. Ahl showed no indication of wear while A39 showed a loss of some 3-5 mils of material on one vane while the other three vanes shewed negligible wear. A39 was the only control rod drive assembly to operate during Core II without a locking cap on the drive shaft.
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Shim Rods
,oU On all shim rods inspected during the month wear was found on the upper end of the zircaloy section. The pattern is similar to that observed on the control rods and is due to contact with the guide blocks on the upper core support plate. The wear on these sections was observed during Core I-II refueling and has progressed to a lesser degree during Core II operation.
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No. 20 Control Rod Drive Pressure Housing No. 20 pressure housing was removed from the iessel head for inspection of the internal surface and moveable gripper fingers. The inspection of the housing revealed no evidence of drive shaft locking cap interference.
Corresion effects in the housing were considered normal C')
with slight deposits of tight 3y adherent crud noted.
U A chemical analysis of the loose crud removed from the housing can be found in the Chemistry 9ection of this report.
Axial scratch marks of insignificant depth were observed.
Wear marks were also obs&.-ved on the moveable gripper fingers but appeared to be only superficial. However, new fingers were installed to perad.t a more detailed exand. nation of the worn areas.
Turbine Plant Performance In anticipation of highsr pcwer operation, modifications to secondary components continued durir.g the month. Four safety valves of higher relieving capacity were installad on the main steam lines. Gussets were added to each dished head of the moisture separators. All flanged joints in the moisture removal system were reinforced through the addition of high strength bolts. New gaskets were installed at the circumferential gn flanged midpoint of each separator to eHmimte the steam leakage p*oblem V
that occurred periodically throughout Core II operation.
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g, During Core II operation No.-3 Boiler _ Feed. Pump was found to have a 3 mi.1 vibration at the bearing housing. During a~ scheduled shutdown in
- April of this year, alignment of the pump and motor was measured and ibund to'be within specifications? lFollowing shutdown on September 2, the pusp was dismantled for an irsernal inspection under the direction of the a
. manufacturer's representative. The shaft was found to have a 6 mil runout l
thus accounting for the observed vibration. Mechanical straightening followed'and the pump was reassembled. Testing of the pump will follow startup.
In June of this year a-leak in the main condenser was noted, based on' an increased chloride concentration in the steam generators. During the month a hydro-test of the condenser pinpointed failed tubes and they were subsequently plugged. Failure was due.to steam side erosion of the-tubes. To limLt further erosion stainless shields were added to surrounding tubes in the affected areas.
General condition of the turbine was good with no excessive O
erosion noted d=e to moisture carr7 ver in the steam-The overa11 erosion rate was found to be less than that observed following Core I operation.
Modifications to the air removal system en the circulating water discharge line continued during the month. The new system provides for additional venting of the system at selected points along the discharge piping.-
During the month vibration snubbers were attached to the main steam piping both interior and exterior to the vapor container. The locations of the snubbers were selected by an outside consulting service who had measured main steam line movement while.the plant was operating at various power levels.
Instrumentation and C,ontrol During the month all narrow range main' coolant temperature' channels were iocalibrated'in anticipation of higher power operation.
A, scram-sequence panel has.been added to the memory light circuit to' identify the first scram signal to reach the scram amplifiers.
Previously, following most scramsjmore.than one light would appear on the memory circuit and consequently the cause of the scram would not be readily apparent. The new sequence panel will light upon receiving the first. signal from the' scram circuitry. All signals that follow will be locked out.
The six ion chambers containing both power range channels and startup channels were removed individually from their respective thimblec in the neutron shield tank to permit inspection and repairs.
New internals were installed in the four feedwater regulators o
1 due to the increased flow required at higher power levels.
.9-p Due to the addition of h.1% enriched fuel to Core III, control rod-group No. 6 has been broken down into two groups of four rods each.
Health and Safety Iiquid waste containing a total activity of 0.02 me was discharged from the plant during September. No gaseous waste was discharged from the site.
Thirteen drums of non-combustible radioactive waste con **inina a total activity of h7 me were prepared in September. Seventy-two drums were shipped containing an estimated 1.3. curies, being the residue from
'.he decontamination of the shield tank cavity liner.
An outside contracting service was engaged to decontaminate the shield tank cavity prior to the inception of work in the area. A sodium cyanide jell was applied to the walls followed by a rinse with domineralized water. The principal radiation source on the stainless liner has been and O
continues to be Ag-110m deposited there during the Core I-Core II refueling.
Radiation levels measured prior to decontamination were 100 - 200 mr/hr rneral area being reduced to h0 - 100 mr/hr general area. An estimated 1.3 curies of Ag-110m activity was removed from the cavity walls.
hadiation levels measured during raising of the reactor head were as follows:
O a asatio= 1 e1-Head Raised Under Head At Moat 2 inches 500 mr/hr 150 mr/hr 6 inches 2 r/hr 150 mr/hr 1 foot 5 r/hr 300 mr/hr 2 feet 5 r/hr h00 mr/hr Q
3 feet 8 r/ur 550 mr/hr Prior to raising the head, the contact radiation reading at the flange was 70 mr/hr.
Radiation levels on the flatcar as the reactor head was lownwa i
through the equipment hatch were as follows:
P Position of Head Height above flatcar Radiation mr/hr Top of equipment hatch at charging floor 81 feet 3.5 Halfway down hatch 55 feet 7.0 Bottom of hatch.
29 feet 10.0
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Halfway from bottom of hatch to flatcar 8 feet 35.0
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- l The radiation level measured directly under.the head while it was positioned on the flatcar was 500'mr/hr at 1 - 2 feet inside the flange.
Radiation levels over the shield tank cavity during flooding were as follows:
Water'Ievel Radiation Ievel mr/hr Cavity dry 50 3 feet-50-6 feet 20 9 feet '
17 12 feet 13 15 feet 10 Top of drive rod shafts 25
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Top of guide' pins 2
V 17.5 feet 2
While filling the shield tank cavity a sample valve in the cavity purifiestion line located over the ion-exchange pit was inadvertently left open. A spill of -apprnrimately 10 gallons of water from the safety injection tank resulted. Part of this water ran off the deck of tho pit and on to a section of the black top surface on the west side'of the pit.
p The radiatim level at.the immediate spill area was 70 - 100 mr/hr s
V measured at one inch.- Contamination levels were 106 to 107 dpm for areas of several square hes. Runoff water caused contaminatim levels of 20 - 60,000 dpm/ft The ion exchange _ pit are. <'.s surveyed and roped off after discovery of contamination on the snoes cf a chemist who obtained a water sample later in the day. Vacuum cleaning and mopping of the spill ation levels to 1 - 2 mr/hr and contamination levels areareducedrqi.
O to 20,000 d m/f P
A radioactive liquid spill in the P.C.A. storage building occurred during decontamination _of No. 20 con +xo1 rod drive mechanism due~to overflowing of the receiving barrel. The activity of the_ water was 2 x 10-3 pe/ce. Normal cleanup was carried cut to reduce contam-ination levels to acceptable limLts.
The discharge of 21s Ag-In-Cd centrol rods to the spent fuel pit caused activity levels of the pit water to increase by a factor of 10 to 3 7 x 10-3 ac/cc due primarily to the Ag-110m nuclide. Radiation
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J levels over the-pit increased by a factor.of two to three. To limit the amount. of silver activity released to the water the control rods were -
encapsula >4 in an aluminum storage can.
Due to the imediate removal of the control rods from the shield tank cavity, radiation levels on the charging floor are substantially.
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lower than_those measured during the Core I - Core II. refueling. Radiation
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. levels measured at the cavity edge during Core I refueling were generally
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. 15 to 25 mr/hr' being reduced during the present refueling to < 2 mr/hr, the decrease being entirely attributal to the lower level of Ag-110m in the cavity water.
Personnel exposures for Yankee plant personnel as measured by film badge for the month of September,1%3 were h85 mr Average for all station personnel
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1220 mr Maxinum individual exposure
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Design Changes Due to the availability of most system components a number of design changes were completed _during t% month to improve the operations and performance of the station.
/Q 1.- As discussed in the operating report for August,1963
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storage for spent Core II fuel was to have been provided -
by a boral-aluminum rack. However, when the rack was delivered to the site, numerous sm11 defects wera observed in the seal welds covering the edges of the boral poison material, which was included in the rack for reactivity control, and consequently the use of the rack was deferred.
To accomodate storage of Core II fuel, a 26 assembly (m) rack, relying on center to center distance for criticality control, has been fabricated and installed in the spent fuel pit. Authorization to install this rack was requested in Proposed Change No. hh which was submitted on August 30, 1963.
A.E.C. approval was granted on September 12, 1963.
2 The boron stainless sneel sections of the eight fixed shim rods have been replaced with mechanically similar. sections
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fabricated of type 301, stainless steel. Concern for the integrity of the joint t,etween the baron stainless and zir-caloy sections has prompted the change since boron stainless under irradiation has in some applications exhibited dimensional growth. Authorization for this design change was requested in Proposed Change No. h3, submitted on August 9, 1963.
A.E.C. approval was granted on September 23, 1 % 3.
3.
A one inch valved vent was installed on the Low Pressure Surge Tank safety velve discharge header. The vent was located inside the vapor container and was equipped with a i
short, capped nipple on the discharge of the vent valve.
The change was made to sLmplify maintenance on the header.
Since a hydrogen atmospharc is maintained in the tank, thorough purging of the line is needed to remove the potentially explosive hydrogen. The addition of the valved
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. vent line now provides an escape point to permit thorough V
and convenient purging of the header. Authorization for this design change was requested in Proposed Change No. bl, subuttted on July 23,1%3.
A.E.C. approval was granted on September. 6,1%3.
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- h. The 2h, nickel plated, Ag-In-Cd control rods were replaced with 22 hafninm control rods and two inconel clad, Ag-In-Cd rods.
Ettensive deterioration of the nickel plate on the precent rods and consequent release of highly radioactive Ag-110m to the reactor environment has prompted the change to hafnium rods. The mechanical desigt of the hafnium rods is similar in all respects to those rMs used previously. The new rods are equipped with stainless steel rubbing straps and riveted stainless steel adapters.
Due to its proven nuclear chracteristics, availability and low cost, Ag-In-Cd presents m ideal control rod material provided it is protected with a suitable cladding.
(V~3 The inconel clad rods have a compartmented configuration, each vane being composed of five, individual, longitudinal modules, electron beam welded to form the completed vane.
Four vanes are then electron beam welded to an inconel center plug to form the cruciform shaped rod. Stainless steel adapters are welded to the cruciform at top and bottom.
Authorization for this design change was requested in Proposed Change No. h0, submitted on July 17,1%3.
A.E.C.
g.s approval was granted on September 20, 1963.
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5.
The solenoid operated spray valve on the pressurizer has been replaced by a motor operated valve. During previous opccations the solenoid spray vc.1ve has occasionally abck ia the open position, requiring in one instance a de-pressurization and cooldown of the prinary plant to effect repairs. Its replacement by a more positive operating motorized valve will greatly improve system reliability.
m(j Authorization for this design change was requested in Proposed Change No. 35, submitted on May 28,1%3 A.E.C.
approval was granted on September 6,1%3.
6.
HDV-532 on the discharge of the safety injection tank has been moved to an indoor location. The outdoor location of the valve results in it being subjected to quite low ambient temperatures. On occasion, particularly during severe winter weather, some difficulty has been experienced in operating the valve.
Additionally, a higher pressure rating valve was installed upstream of HDV-532 to further imp 1ove the design and reliability of the systea in ^, hat this new valve will now absorb the starting pressure of the high head safety injection pump during weekly performance checks of the system. Authorization for this design change was requested 7(d in Proposed Change No. 3h, submitted on May 28 1963.
A.E.C. approval was granted on September 27,1%3.
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- 7. ' As a result of an expected power level increase during the operation of Core III, the following secondary plant modifications have been made:
a.
The dished heads of the moisture separators were rein-forced by the addition of gussets.
In addition, the flanged joints of the moisture separators were rebolted with higher strength bolts.
b.
Main steam line safety valves with an increased steam relieving capacity were installed.
8.
To assist in determining the initiating signal in a reactor
. scram, a scram sequence panel has been added to the memory light circuit. In the past, the sequence of events following a scram has occurred so rapidly that it was virtually
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impossible-in some cases to discern the initiating signal.
The new panel will identify the initiating signal.
9.
Control rod group 6, consisting of eight control rods located in the outer periphery of the core, has been broken down into two groups of four control rods each. This minor change has been made to improve power distribution control.
Changes in Operating Procedures O
Ir. accordance with Proposed Change No. 39, submitted on June 28, 1963, and approved by the A.E.C. on August 30, 1963, revised versions of Maintenance Instructions 506E2 and 506 & were issued. The modifications in the instructions were made primarily to reflect the current status of the plant.
Plant Operations O
Attached is a summary of plant operation statistics for the month
_of September 1963, and a plot of daily average plant load for the same period.
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O-IANKEE ATOMIC EIECTRIC COMPANY - OPERATDIO
SUMMARY
SEPTEMBER 1%3 EIEC1RICAL MONTH YEAR TO DATE Gross Generstion KWH 3,861,500 83h,6h6,000 2,536,118,000 Sta. Service (While Gen. Incl. Iosses)
KWH h1h,9S 56,538,h82 187,295,0h9 Net Generation KWH 3,hh6,556 778,107,518 2,3h8,822,951 Station Service 10.7h 6.77 7.38 Sta. Service (While Not Gen. Incl. Iosses)
KWH 619,800 1,6h0,838 15,609,676 Ave. Gen. For Month (720 URS-)
R 5,190 Ave. Gen.
R==ning
( h6 HRS.)
N 83,9h6 PIAlff FERFWMANCE Net Plant Efficioney 2h.16 28.39 Net Plant Heat Rate Btu /KWH 1h,126 12,021 Ibs. Steam /NetKWH 18.29 Circulating Water Inlet Temp.
p Merimum F
70
)H nium 0F 62 Plant Operating Factor 3.15 77.h1 67.15 NUCIEAR MONTH CORE II TO DATE 1
Times Critical 6
hh 306 i
Hours Critical HRS Sh.33 8305.68 21,553.11 Times Scrauned 0
8 38 Equivalent Reactor H w es 6 5hD MWt HRS 26.h 7286.2 15,203.3 Average Bumup of Core MdD/mtU 28.6 7882.1 Control Rod Position at Month End 0
Equilibrium at 0 IWt 150 F Tavg.
Group 1 Rods out-inahes O Group 2 0
Group 3 0
Group h 0
Group 5 O
i Group 6 0
o o
o o f.
YANKEE ATOMIC ELECTRIC CCMPANY DATLY AVERAE LM for SEPTEMBER 1963 150 -
n E
i
'i.
E 8
100 -
~%
a d
50 -
h (a)
(a) Shutdown No. 62-2-]h s
O g
...ii i
iii I
5 10 15 20 25 30 i
DAYS
-