ML19351E333
| ML19351E333 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 10/22/1969 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E332 | List: |
| References | |
| NUDOCS 8011280128 | |
| Download: ML19351E333 (10) | |
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c YANKEE NUCLEAR P0 fir STATIO'l.y-7 ~ ') p.) f OPERATION REPORT NO. 105 OC^
J "i-Regulatory File Cy.
1 For the Month of 1
September 1969 RjccInd w,ttr cated N -k 1
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This report covers the operation of the Yankee Atomic Electric Company plant at Rove, Massachusetts, for the month of September,1969.
At the beginning of the period, the plant was continuing its Core VII - VIII refueling and maintenance outage. Transfer of fuel was complete and loading of other core components was underway preparatory to reinstalling i
I the reactor vessel head.
The drive shafts and attached dash pots for control rods No's. 7, 17, 21, and 22.were replaced with new drive assemblies. All core components j
vere in place, and the reactor vessel head was installed on September 4, following return of the shield tank cavity borated water to the safety injection tank. During draining of the shield tank cavity, a test was performed for determination of points of leakage from the cavity. Results of the test were inconclusive, other than that the major leakage was from the area of the inner l
moat ring and its expansion joint.
I Work involving removal, testing and reinstallation of the no. 1 and No. 2 safety valves on the low pressure surge tank was completed on September 3.
j On September 4, the No. 1 steam generator primary side inlet manway diaphragm seal veld developed a leak. The steam generator was drained and successful repairs to the seal veld were completed on September 5 The fuel transfer train, including upender, carriage, and carriage weight tube were removed from the vapor container for repair of damage incurred 9
during the abnormal occurrence No. 69-5 (See operation Report No.104).
In order to free tbc veight tube, shield blocks were removed from over the fuel chute in main coolant loop No. 4, and the sheave box was opened.
Cables were detached fron. the tube at this access point, and the tube was pulled into the shield ' tank cavity for subsequent removal. Unexpectedly high raalation levels in the sheave box revealed a small unidentified particle which exhibited a radiation level of approximately 10 r/hr at a distance of one foot. The particle was removed from the shaave box, reducing work area radiation le7els to 5 - 15 mr/hr. Removal of the. fuel transfer train was commenced September 8, and concluded the following day.
The installation of reactor head closure studs cctmenced September 8 and was completed on September 9 On September 12, vapor container integrity was set; the four main coolant loops were isolated for hydrostatic testing; and all four main coolant pumps were started for coolant heatup to 2680F. At this temperature, main coolant pressure was increased to 2485 psig. A slight leak developed on the North conoseal at the lover gland. Coolant pressurc was reduced to 300 psig-to permit tightening of the mechanical seal. Coolant pressure was then raised to 2h85 psig and the leak did not reappear. On September 13 the coolant temperature and pressure was' lowered to 1900F and 200 psig, respectively.
Plant heatup was not commenced until September 16 to preclude possible i
presence of steam at the lover control valves, which were being velded in place at this time..In the _ interim period, September lh - 16, control rod exercises and cold rod drops were completed, successfully. On September 16, plant heatup
.vas. commenced preparatory to completion of the physics testing program, in-cluding. hot rod. drops; and subsequent plant startup. The Ccre VIII reactor core l
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. was brought critical' on September 17 at 1525 hours0.0177 days <br />0.424 hours <br />0.00252 weeks <br />5.802625e-4 months <br />. The reactor physics
. testing program was terminated September 19' at 0705 ncurs.
1 During the physics testing period, a leak developed from a weld in the blowdown line for No. 4 steam generator, and the pressurizer low set safety valve was found to be leaking. On September 19, following completion of physics testing, plant cooldovn was initiated for repairs. The leck in I
the blevdevn line was from a veld made during modifications, as described in 3peration Report No.104, 'and was located immediately outside the steam generator shell. Successful repair of this leak was completed September 20.
Upon removal of the pressurizer safety valve, the valve stem was found to be untrue, and a hairline crack was detected in the valve disc. The faulty i
components were replaced; the safety valve was successfully tested; and J
reinstallation was completed September 23 During cooldown of the primary system commencing September 19, j
further leakage was detected at the North concseal, once again threugh the 1
mechanical seal. At this time, seal velds _ vere made at the top and bottom j
of the conoseal bell housing, thereby containing any further leakage through the mechanical seal. Surveillance of the repaired conosen1 revealed continuing j
leakage; this time from around the incore instrumentation tubes.
Inspection I
shoved, that although the conoseal bell was velded to the adapter plug at the top, the tube flare guide was attached to the adapter plug at only four tack welded points. This configuration permitted leakage inward at the Joint between the tube flare guide and the plug adapter, and then upward around 9
circumferential seal veld at the tube flare guide - plug adapter joint, the tubes pen;.ating the tube guide. Repair consisted of a complete and resealing of the veld joining the conoses.1 bell to the top of the adapter plug.
Final repairs were concluded on September 22.
A load test of the emergency diesel was performed, satisfactorily, on September 20.
On September 21, a complete functional test of the safety injection system under simulated, low pressure conditions was performed; all components operated as required.
Steam line warm up commenced on September 24 at 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />, and turbine rolling was initiated f allowing the establishment of vacuum in the cain condenser. The generator was phased on line at 0045 hcurs e September 25.
2'he reactor'pover level was increased to 480 IGt and.then 540.Wt.
September 26 at 0210 hours0.00243 days <br />0.0583 hours <br />3.472222e-4 weeks <br />7.9905e-5 months <br />, full power was attained with plant gentration at 175.2 !Ge (600 IGt). Plant load remained essentially the sama during the remainder of the period, as the circulating vater inlet temperatare fluctuated only between 600F and 620F.
The Core VII - VIII refueling and maintenance outage time was
.approximately 54 days.
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' Plant Abncrmal Occurrences There vere no plant abnormal occurrences during the mon:h of
-September,11969 l:
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Plant Load Reductions There were no plant load reductions during the period following l
return to power operation on September 25.
Plant Shutdoens, August 2, 1969 to September 25, 1969 Shutdown No. 101-7-9 A 1290.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> scheduled shutdown for Ccre VII - VIII refueling and maintenance.
Core VII - VIII Major Work Item I
j The below listed major work items are a centinuation of those listed in Operation Peport No.-104 1.
Replacement installation or two of the three turning vane elbows in the inlet piping to the moisture separators was completed. An extended I
delivery date for the third elbow made its installation impracticable.
However, the turning vane section of the existing third elbov was j
removed; the elbov was inspected and found to be sound; and a nev 4
turning vane assembly was velded in place. Replacement of the two I
deflector rings was also completed.
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. Repla ement was completed of the 18" section of piping of the No. 2 2
feedvater heater extraction line at the point of confluence of the l
two 12" lines.
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Work was completed cn replacement of the inner cylinder nozzle chamber i
for each of the four control valves on the high pressure turbine.
i Plant !!aintenance l
The following is a list of pertinent maintenance itens performed, additional to the major work items, during the month of September,1969 1.
Preventive maintenance va., performed on the vapor container purge line valves.
2.
The No. 1 & No. 2 control valve servomotor test valves were converted from hand to electrical operation. These lever control valves may now be closed by operating selector switches on the turbine start-up panel; the 'same as the two upper valves, No. 3 and ' No. h.
3.
The vapor container high pressure relay switch was convertad from I
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straight electrical operation to both hand and electrical operation by the addition of new shafts and cams.
j' 4.
An ' inspection was performed of aJl 24 control rod position indication coil stacks and maintenance was performed as required.
5 A ec=plete inspection of the exciter was made including insulation tests of fields, commutator, and cables. Pins and springs were replaced in the t
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e brush holders, as necessary.
i The co mutator slots were-undercut and the bars were beveled. The comratator was given a hand stoning and polish during reactor start-up.
6.
Inspection of the turbine ~ generator, which commenced with plant shutdown
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in August,1969, was completed during this report period. A complete set of dielectric absorption tests were performed. The polarization index of each vinding was satisfacton.
Insulation and impedance tests of the rotor were satisfactory. The generator RTD's were checked for ohmic value and for grounds.
Instrumentation and Control The following is a list of pertinent instrumentation and control
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maintenance items performed by the plant staff during the month of September, l
1969 l
1.
Five new coaxial cables were installed between the No. E main coolant loop pull box and the No. 3 neutron detector thimble, f
L 2.
A dev point detection system was installed atop the reactor head in the l
shield tank cavity. A detector was placed in each of the two cable l
trays where they penetrate the missile shield. The purpose of the l
l system is to serve as monitors for possible coolant leckage Nom
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l penetrations in the reactor vessel head.
j Reactor Plant Performance I
l Following heatup of the priman plant, the reactor was brought critical and loaded to 450 Et.
Power defect and xenon poisoning vere measured with the reactivity computer.
Following a calorimetric and six hour hold, plant load vas increased to 540 Wt and held until 0135 on September 26, when 75% of i
540 Et equilibrium xenon was satisfied. Plant load was then increased to
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600 st.
I The following parameters were determined by means of incore l
inst rumentation.
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b 581.7 W t; 525.3 F Tavg; control rod group A @ 82 ; B, C and D
@ 870; 1190 ppm boron.
t
.F
=
2.3 l
Q 2.3 F
=
g r
Minimum DNBR 3.1
=
1 5970F Maximum outlet temperature
=
Core VIII Startut Physics Test Program The physics test program was commenced September 14, at 1930 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.34365e-4 months <br /> and was terminated September 19 at 0705 hours0.00816 days <br />0.196 hours <br />0.00117 weeks <br />2.682525e-4 months <br />. Test results were as follows:
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. Rod Worth Group A:
.85%
Group B: 2.h2%
Group C: 1.81%
Maximum Worth Rod With Group A in:
Rod #h
.35%
=
36%
With. Groups A & B in:
Rod #8
=
With Groups A, B, &'C in: Rod #16 1.16%
=
Temperature Coefficient (1915 ppm boron): -1.93 x 10 h AK/K/ F 0
Inverse Boron Worth: 200 ppm /% AK/K
.A problem developed with Group D during cold rod drops. At the i
38 2/8" level during rod insertion, the primary indicating light showed that the group had dropped into the core without a scram breaker trip. Further exercising l
of the group failed to effect a repeat of the rod drop occurrence. This occurrence was similar to thet reported in Operation Report No. 88 for Group C at the start of the Core VII physics test program. The stationary gripper coil l
voltages had been set prior to the rod exercise. A check of the voltages following 9
gripper coil voltage suffered a transient, which permitted Group D to drop into the rod drop indicated no abnormal conditions.
It is possible that the stationary l
the core.
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Secondary Plant Performance Feedvater heater terminal differences were as follows:
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No. 1:
5.0 No. 2: 11.1 No. 3: 5.5 Chemistry On September 12 filling and venting of the main coolant system was completed and hydrazine was added to scavenge the residual oxygen.
l The main coolant boron:ec. centration averaged 2957 ppm until September 17 when the concentration was dec: eased by dilution' for physics testing, to a i
lov of 1201 ppm. The -concentration was increased on the 19th and averaged 2276 ppm until tne 2hth when the main coolant system was diluted to 1635 ppm preparatory to return tu tower operation. At the end of the period the boron concentration was 1190 ppm.
I The main coolant pH.at the beginning of the period was h.72.
Due to changes in coolant boron concentrations, the pH had iner.tsed to 5 0 when the
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generator was phased on line at 0045 hours5.208333e-4 days <br />0.0125 hours <br />7.440476e-5 weeks <br />1.71225e-5 months <br /> on September 25 During the balance of the period, the main. coolant pH averaged 5.15
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increased from an average of 4.57 x 10-4 ue/ml and 3.61 x 10-2 uc/ml The main coolant gross beta-gamma and' tritium specific activities respectively, prior to reactor startup, to 7.30 x 10-2 ue/ml and 2.20 ue/cl q
respectively, following return to power operation.
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The highest crud level recorded during the month was 0.5h ppm.
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Following reactor startup, main coolant iodine values increased from below detectable concentrations to an iodine - 131 specific activity of f
6.35 x 10-6 uc/ml with an iodine 131/133 ratio of 0.36.
A representative crud sample for the month, collected on September 29, j
had the following radiochemical analyses: dpm/cg crud Cr-51 Mn-Sh Fe-59 3.1h x 106 5.02 x 106 1.28 x 106 Co-58 Co-60 Ag-110M 1.50 x 107 7.60 x 106 1.30 x 103 A main coolant gas sample collectA on September 29 had the following radiochemical analyses: ue/cc gas l
Xe-133 Xe-135 Ar-bl 1.78 x 10-3 5.22 x 10-3 7.66 x 10-1
' 9 Health and Safety l
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Three shipments of radioactive vaste were made during the period, l
totalling 159 drums and containing a total activity of 355.80 me.
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Waste disposal liquid releases totalled 82,790 gallons containinc 0.06 me of gross beta-gamma activity and 30.4h curies of tritium. Gaseous
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releases during the period totalled 134.89 me of gross beta-gamma activity.
Secondary plant water discharged totalled 123,686 gallons containing 0.13 me j
of gross beta-gamma activity and 0 71-~ curies of tritium.
In addition to the above releases 1.39 curies of tritium as a vapor, was discharged to the environment through the primary vent stack.
Radiation exposure dose' for Yankee personnel and N.E.P.S. Co.
personnel as measured by film bad-3r the month of September, 1969 vere:
Yankee Plant Personnel:
1-Average accumulated exposure dose:
529 mrem Maximum accumulated exposure. dose: 2040 mrem
-N.E.P.S.Co. Personnel:
I
' Average accumulated exposure dose:
569 mrem Maximum accumulated exposure dose: 20h0 mrem Operations Attached is a summary of plant operating statistics and a plat of daily
. average load for the month of September, 1969 L
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l YANKEE ATOMIC ELECTRIC COMPANY - OPERATING SU'O'AliY I
l September 1969 l
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ELECTRICAL ff0 NTH YEAR TO DATr.
i Gross Generation KWH 2h,260,600 811,520,000 9,815,281,800 Sta. Service (While Gen. Incl. Losses)
KWH 1,542,6L4 51,501,256 646,095,515 i
Net Output KWH 22,717,956 760,018,7hh 9,169,186,285 Station Service 6.36 6.35 6.58 Sta. Service (While Not Gen. Incl. Losses) KWH 1,066,79h 2,h98,586 28,782,236 i
Ave. Gen. For Month (720)
KW 33,695 Ave. Gen. Running 1h3.75 KW 168,769 l
PLANT PERFORMANCE e
t-Net Plan., Efficiency 27.61 28.h6 28.38 Net Plant Heat Rate btu /KWH 12,361 11,991 12,025 I
Plant Capacity Factor 19 05 67 94 73.98 I
Reactor Plant Availability 21.65 77.87 83.k1 l
l NUCLEAR MONTH CORE VIII TOTAL j
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Hours Crit 1<s1 HRS 186.70 186.70 66,006.48 j
Times Scra==ed Burnup l
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Core Average ISD/MTU 16h.98 164.98 j
Region Average IGD /MTU i
i A (INNER) 169 3h 169 3h 30,612.30 f
B ( MIDDLE) 190.88 190.88 2h,124.07 i
C ( OUTER) 138.51 138.51 9,788.62 D (ZIRCALOY) 9 9
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