ML19340A521
| ML19340A521 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/31/1967 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| References | |
| NUDOCS 8008070707 | |
| Download: ML19340A521 (18) | |
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ANNUAL REPORT OF STATION OPERATION FOR THE YEAR 1966 1
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January 31,1967
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DRESDEN NUCLEAR POWER STATION ANNI 1AL REPORT I.
INTRODUCTION This fif th annual report is submitted in compliance with paragraph 3.c (2) of Utilization Facility License DPR-2, as amended, and covers operation of Dresden Nuclear Power Station during the year 1966.
II.
SUM 1ARY OF OPERATIONS A.
Scope of Operations Plant operation continued through the year without refueling.
Ten shutdowns were experienced, including four reactor scrams. Opera tion was at reduced load during part of the year for inspection and repair of primary system piping and for feedwater heater tube leaks.
Additions to and changes in facility design included installation of two new secondary load limit trips, relocation of No. 2 environs monitoring station, and removal of the main steam drum process monitor from service.
Two hundred twenty-five spend fuel assemblies were shipped for the U. S. A. E. C.
(Savannah River Operations Of fice) to the Chemical Processing Plant of Nuclear Fuel Services, Inc. at West Valley, New York.
B.
Shutdowns The plant was shutdown ten times during the year as shown in Table 1.
Five of these were forced outages: Three due to reactor scrams caused by mal 9anction of the reactor incore system instrumentation, one due to a raactor incore system spurious scram, and one when reactor water qualiQ. exceeded operating limits. There were five scheduled outages:
One for semi-annual control rod drive testing, one for A.E.C. License Examinations, one for a feedwater heater tube leak and semi-annual control rod drive testing, one for primary system steam leak location and A.E.C. License Examinations, and one for the Unit 2 primary contain-ment over-pressure test, which was extended into a forced outage for Unit 1 primary control valve repairs.
C.
Load Restrictions The load restrictions imposed during the year are listed in Table 2.
Restrictions were due to reactor recirculation loop outages, feedwater heater outages, and to minimize the possibility of additional fuel failures.
TABLE 1 OPERATING PERFORMANCE 1966 No. Of Off System On System Outeni Date Time Date Time Outage Hours Reason For Outage 65 2/12/66 9:15 p.m.
2/13/66 7:33 a.m.
10 Hrs.
3 Min.
Reactor incore system instrumentation malfunction scram.
66 3/16/66 10:40 p.m.
3/21/66 2:14 a.m.
99 Hrs.
6 Min.
Semi-annual control rod drive tests.
67 4/23/66 1:43 a.m.
4/24/66 12:57 a.m.
23 Hrs.
2 Min.
A. E. C. license examinations and train-ing.
68 5/ 5/66 6:35 p.m.
5/ 6/66 4:10 a.m.
9 Hrs.
6 Min.
Reactor incore system instrumentation malfunction scram.
69 5/29/66 4:03 p.m.
5/30/66 6:49 a.m.
14 Hrs.
8 Min.
Reactor incore system spurious scram (6 Hrs 8 Min.) available but not operating.
70 8/11/66 4:39 p.m.
8/15/66 1:43 a.m.
81 Hrs.
1 Min.
"B" secondary feedwater heater leak and semi-annus1 control rod drive tests.
71 8/19/66 7:48 p.m.
8/20/66 4:52 a.m.
9 Hrs.
1 Min.
Reactor incore system instrumentation malfunction scram.
72 8/20/66 5:05 p.m.
8/22/66 5:44 a.m.
36 Hrs.
8 Min.
Reactor water quality beyond operating limits.
73 10/ 4/66 10:39 p.m.
10/ 9/66 3:10 p.m.
112 Hrs.
5 Min.
Primary system steam leaks and operator licensing.
74 11/25/66 11:07 a.m.
11/30/66 9:32 a.m.
118 Hrs. 4 Min.
Unit 2 primary containment over-pressure test and Unit 1 primary throttle valve repair.
TABLE 2 LOAD RESTRICTIONS FOR 1966 Reduction From Maximum Date Capability of 210 M'Je Condition January 1 - February 4 15 Primary system piping and valves February 13 - March 16 15 Primary system piping and valves March 21 - March 23 15 Primar; systes piping and valves March 30 - April 23 15 Secondary steam generator tubes June 1 - June 8 15 Secondary steam generator tubes a
e June 15 - July 1 15 "A" drain cooler tube leak July 1 - July 9 15 "B" secondary steam generator tubes leak July 9 - July 27 15 "D" secondary and "E" primsry tube leaks July 27 - July 30 15 "B" secondary heater tube leaks July 30 - August 7 25 "B" secondary and "D" primary heater tube leaks August 7 - August 11 15 "B" secondary heater tube leak August 15 - August 19 15 "B" secondary heater tube leak September 9 - October 4 20 "A",
"B", "C" and "D" secondary heaters October 9 - October 15 18 "D" secondary and "E" primary heater tube leaks October 15 - December 31 50 To minimize the possibility of additional fuel fa ilures.
PLANT ELECTRI AL LOADING DRESDEN NUCLEAR POWER STATION
____l____'_________'_______'____'_____________'_______**
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~5-III. _ DISCUSSION A.
Operating Exp trience 1.
Generation The total reactor operating (critical) time during the year was 8,392 hours0.00454 days <br />0.109 hours <br />6.481481e-4 weeks <br />1.49156e-4 months <br /> and the total power for the period was 199,213.y M7.'Dt.
The gross electrical generation during the year was 1,474,831.95 MWHe; net generation was 1,407,351.50 MWHe, as of December 31, 1966, the total gross generation since commencement of power operation.
April 15, 1960, was 6,600, 61.5120Ho.
2.
Scrams a.
At 9:15 p.m. on February 12, 1966, the reactor scrammed because of a malfunction of the reactor incore monitor system instrumentation. The reactor was critical and operating at 600 MWt (190 MWe). The cause of the scram was traced to the failure of a two watt carbon resistor in the east incore trip actuator amplifier. This was the first time in the history of Dresden that a scram was initiated by the incore monitoring system.
b.
At 6:35 p.m. on May 5,1966, the reactor scrammed because of a malfunction of the reactor incore monitor system ins trumenta tion. The reactor was critical and operating at 633 MWt (200 MWe). No positive causes were found, but a temporary open circuit in one of the 24 volt DC logic system inputs is suspected, c.
At 4:03 p.m. on May 29, 1966, a reactor scram was initiated by a spurious signal from the reactor incore monitor system.
The reactor was critical and operating at 319 MWt (96 MWe).
The spurious signal resulted from a low voltage transient on the 480 voit system.
d.
At 7:48 p.m. on August 19, 1966, the reactor scrammed because of a malfunction of the reactor incore monitor system instrument-ation. The unit was operating at 661 tuf t (203 MWe). The scram was initiated by a. shorted wire in the RE-103 amplifier chassis, e.
At 2: 92 a.m. on November 30, 1966, the reactor experienced a short period scram. The reactor was critical during the startup heating period and reactor water inlet temperature was 4100 F.
Reactor pressure was 250 psig and the heating rate was approximately 400F/ hour. A fast and short rise in reactor power during withdrawal of a control rod caused the short period scram.
3.
Incidents There were co incidents during the year which compromised the safety of continued operation.
1 4.
Control Rod Drives a.
Control Rod Drive Operation 1.
Control rod drive J-2 remained valved out of service at Position No. 12 throughout 1966.
Control rod drive C-9 remained valved out of service at Position No. 8 all year.
b.
Control Rod-Drive Tests On March 17, 1966, all control rod drives (except C-9 and J-2) were scram and friction ter*.ed as part of the semi-annual control rod drive tests. The data obtained from these tests were satisfactory on all drives. While conduct-ing the tests, the drives on Accumulator No. 18 would not scram from the fuse panel normally used for these tests, i
Investigation revealed that the tip of the teflon core assembly, which is part of the scram solenoid valve had broken of f, plugging the air relief port that allows air to bleed off and shif t the solenoid to its scram position.
l the drives on this accumulator were scram tested using the manual scram button, which actuates the scram back-up solenoid, and in turn releases the air pressure on all scram valves. This is the first malfunction of this nature to be experienced.
All control rod drives except C-9 and J-2 were again scram and friction tested on August 12, 1966. The da ta obtained from these tests were satisfactory on all drives.
5.
Control Rod Blades During periods of operation control rods have been verified for blade following on a weekly basis.
Control rod worth tests were conducted monthly, except for October and November, during which time the tests were suspended to minimize fuel failures.
During each startup control rod patterns for criticality have been predicted and all blade following verified.
6.
Changes in Facility Design a.
'New Secondarv Load Limit Trips Two new secondary load limits have been installed. A manual trip button was installed on the reactor console to provide the operator with a means of instantly stopping secondary steam flow to the turbine. In addition, an automatic trip has been installed, which will trip the secondary load limit upon tripping any or all of the reactor recirculation pumps.
This automatic trip provides oversteaming protection of remain-ing secondary steam generators in the event of tripping a recirculating pump while running at rated secondary steam flow.
b.
Relocation _of No. 2 on__ Site Environs Monitoring Station On site environs monitoring station No. 2 was temporarily moved approximately 150 feet west of its original location, to the existing location inside the security fence. The move was made to allow for disposal of spoil from Units 2 and 3 excavations.
c.
Main Steam Drum Process Monitor The main steam drum process monit:L was removed from service on July 18, 1966, The instrument provided no useful information and tue detector was an unnecessary source of radiation.
7.
Personnel Radiation Exposure Personnel exposures to radiation vera within limits specified in 10 CFR Part 20.
8.
Liquid Poison System The liquid poison system was operative at all times during the year. The boron poison was sampled on March 18, August 13, October 6, and November 28, 1966. There were no conditions which would indicate a loss of boron from the solution tank.
Boron concentrations in the reactor water remained low throughout the year.
9.
Radioactive Waste Disposal Release of radioactive liquid waste was accomplished in batch quantities at controlled release flow rates according to established procedures. The contribution to the activity of dilutior veter was always maintained within the limits specified in the applicable federal regulations. The average contribution to the unidentified activity in the water utilized for radioactive liquid waste dilution during the year was calculated to be.0354 uc/ml (35.4 uuc/ liter) compared to an average limit of 0.1 uc/ml (100 uuc/ liter) for unidentified mixtures containing no radium 226 or radium 228 as specified in 10 CFR Part 20.
Solid radioactive wastes were stored on-site pursuant to License DPR-2.
Two shipments, one consisting of 970 f t3 of dry radioactive waste with a total activity of 409 millicuries and one of 1042 f t3 with an activity of 173 curies, were shipped by truck to Nuclear Fuel Services, Inc., a subsidiary of W. R. Grace and Co., West Valley, New York, on June 15, 1966 and November 3,1966, respectively.
Concentration of noble fission gases in the stack discharge to atmosphere was maintained well within license limits of 700,000 microcuries per second. The average activity release rate for the year while the plant was operating was approximately 24,900 uc/second.
Thirty-six General Electric - Knapp Mills truck cask shipments total-ing 144 spent fuel assemblies and seven Nuclear Fuel Services, Inc.
Stanray rail cask shipments totaling 151 assemblies were made to the TABLE 1 SPENT FUEL SHIPMENT SUMfARY Number of Assemblies or Containers Total Shipment Number Date Ba:ch To Ra il Truck Sh ipped 1
2 3
4 5
Ra il Truck Date 1
6/11/65 24 0
0 0
0 24 24 2
6/30/65 24 0
0 0
0 24 48 3
7/16/65 24 0
0 0
0 24 72 4
8/ 3/65 24 0
0 0
0 24 96 5
8/16/65 24 0
0 0
0 24 130 6
9/ 2/65 24 0
0 0
0 24 154 7
9/22/65 24 0
0 0
0 24 168 1
8/ 1/66 0
0 4
0 0
4 172 8
8/ 5/66 16 0
6 0
0 22 194 2
8/15/66 0
0 4
0 0
4 198 3
8/24/66 0
0 4
0 0
4 202 4
8/28/56 0
0 4
0 0
4 206 9
8/31/66 0
0 12 8
0 20 226 5
9/ 5/66 0
0 4
0 0
4 230 6
9/12/66 0
0 4
0 0
4 234 7
9/14/66 0
0 4
0 0
4 238 10 9/16/66 0
0 0
20 0
20 258 8
9/19/66 0
0 4
0 0
4 262 9
9/21/66 0
0 4
0 0
4 266 10 9/25/66 0
0 4
0 0
4 270 11 9/26/66 0
0 4
0 0
4 274 12 9/28/66 0
0 4
0 0
4 278 13 10/ 2/66 0
0 4
0 0
4 282 14 10/ 3/66 0
0 4
0 0
4 286 11 10/ 7/66 0
0 0
24 0
24 310 15 10/11/66 0
0 4
0 0
4 314 16 10/12/66 0
0 4
0 0
4 318 17 10/20/66 0
0 4
0 0
4 322 18 10/23/66 0
0 4
0 0
4 326 19 10/26/66 0
0 4
0 0
4 330 12 10/28/66 0
0 3
16 0
19 349 20 10/30/66 0
0 4
0 0
4 353 21 11/ 1/66 0
0 4
0 0
4 357 22 11/ 6/66 0
0 4
0 0
4 361 23 11/ 8/66 0
0 4
0 0
4 365 24 11/10/66 0
0 4
0 0
4 369 25 11/13/66 0
0 4
0 0
4 373 13 11/14/66 0
0 0
23 0
23 396 26 11/15/66 0
0 4
0 0
4 400 27 11/17/66 0
0 4
0 0
4 404 28 11/20/66 0
0 4
0 0
4 408 29 11/27/66 0
0 4
0 0
4 412 30 11/29/66 0
0 4
0 0
4 416 14 12/ 2/66 0
0 4
19 0
23 439 31 12/ 6/66 0
0 4
0 0
4 443 32 12/11/66 0
0 4
0 0
4 447 33 12/15/66 0
0 4
0 0
4 451 34 12/18/66 0
0 4
0 0
4 455 35 12/20/66 0
0 4
0 0
4 459 36 12/27/66 0
0 4
0 0
4 463 Chemical Processing Plant of Nuclear Fuel Services, Inc. in West Valley, New York.
This fuel is the property of the U.S. A.E.C. per contract number AT(38-1)-315 and was shipped for and upon instruction f rom its Savannah River Operations Of fice. Table 1 is a breakdown of the shipments made during 1966. Also included in this Table is a listing of the shipments made during 1965.
10.
Recirculation Loop Piping "C" recirculation loop was out of service from the start of the year until February 4, 1966, for repairs to a leak in the discharge valve six inch bypass line. A section of the pipe containing the defect was removed and replaced with a 304 stainless steel, schedule 80, long radtus elbow and two short sections of pipe. All the welds on the six inch line were radiographed for defects.
"D" recirculation loop was removed from service on February 13, 1966, for inspection of the discharge valve six inch bypass line. Ultrasonic tests revealed no definite cracks but two small imperfections were noted. While pressurizing and heating the loop prior to placing it in serssee, a leak in a four inch decontamination flange on the suction line to the recirculating pump was found. Leak repairs were completed, and, when the loop was returned to service a leak was found in the pump flange. The flange bolts were tightened, stopping the leak, and the loop was returned to service on March 23.
While "B" recirculation loop was out of service from March 30 to April 23, 1966, for secondary steam generator tube leaks, the dis-charge valve six inch bypass line was ultrasonically tested for defects. A four inch crack was discovered on the upstream bypass valve to pipe weld.
The crack was ground out and reweided.
Ultrasonic testing af ter rewelding indicated no defects.
"A" recirculation loop was out of service from May 29 to June 8,1966, for ultrasonic inspection of the following:
all six inch bypass piping and welds, the veld to the eighteen inch pipe on the discharge aide of the secondary steam generator, the downstream weld between the discharge valve and the pipe, and a four inch decontamination flange on the twenty-two inch suction pipe. No indications of cracks or discontinuities were found.
11.
Tests a.
Temperature Coef ficient of Reactivity On March 20, 1966, temperature coefficient reactivity measurement tests were made during heating and pressurizing in the vicinity of 110, 300 and 350 degrees.
The results of these tests are compared to data obtained subsequent to refueling in Figure 1.
The turnover point or change in coefficient from positive to negative appears to hava increased from 90 degrees as determined on March 20, 1966. Temperature coef ficient measurements were again made on August 14, 1966, during hea ting. The results of these measurements are also shown in Figure 1.
The crossover point appears to have increased to 280 degrees at that time.
_ b.
Shutdown Margin Tests Shutdown margin tests were conducted on March 20, 1966 and on August 13, 1966, just prior to startup. These tests are exhibited in Figures 2 and 3.
The tests verified that the reactor core met the license requirement of the shutdown margin of at least. 01 A K.
c.
Safety Valves The five spare drum safety valves were tested for relief pressure on the new safety valve test f ixture. The fixture uses nitrogen in place of steam, thus eliminating the effect of temperature on consecutive pops. This fixture was des-cribed in the 1964 Annual Report. Valves have been tested both on the test fixture and with steam under simulated operating conditions with comparable results. The State Inspector has observed these tests and approved the new test fixture for all relief valve testing and adjustment except for setting blowdown.
All valves were set at their respective design pressure + 10 psi.
Relief pressures were checked by repeated popping, d.
Air Locks All air locks.and ventilating valves were leak tested during the year and found to be within the licensed allowable leak-age rate.
B.
License DPR-2 Table 2 lists the amendments to out License that were pending during the year or authorized. Pertinent correspondence pertaining thereto is listed in the Correspondence References.
. FIGURE 1 TEMPERATURE COEFFICIENT OF REACTIVITY
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8/14/66 -
A Measured Values Subsequent To Refueling a
3/20/66
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0 100 200 300 400 500 600 MODERATOR TEMPERATURE, O F
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of service of service ABCDEFGHJK ABC DEF GHJK 10 12 12 10 9
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8 7
7 6
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5 5
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12, out of service 12 12 out of ser-1 I
12 12 vice Subcritical - 2:00 A.M.
Suberitical - 2:10 A.M.
Stuck-valved out of service ABCDEFGHJK ABC DEFGHJK 10 10 9
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8 7
7 6
6 5
5 4
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3 r3 tuck-valved 2
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Suberitical - 2:20 A.M.
_ _ _ _ _ _ _ _ _ _ _ _ _ _. FIGURE 3 SHUTDOWN MARGIN TESTS AUGUST 13, 1966 Stuck-valved out of service ABCDEFGHJK 10 9
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C l_12 Suberitical - 8:57 P.M.
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ABCDEFGHJK 10 b2
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.. TABLE 2
SUMMARY
OF LICENSE AMENDMENTS
_PENDING DURING 1966 Date Request Authorization Request to amend Special Nuclear Material License SNM-638, to transfer urania rods of Type II Fuel. Amendment No. 3.
12/23/65 Correction to above Request.
1/ 6/66 2/ 7/66 Request to amend Special Nuclear Material License S!:H-638 to transfer Type I rod segments in container WSA-1.
Amendment No. 4.
3/12/66 3/28/66 Request to amend License DPR-2 to extend the time interval between control rod drive inspections (Change No. 12).
8/ 9/66 11/23/66 Request to amend License DPR-2 to permit operation with 106 Type V Fuel Assemblies.
10/ 6/66
. Correspondence References - 1966:
(1) Letter to AEC dated Janucry 6,1966, requesting amendment of Special Nuclear Material License SNM-638.
(2) Letter to Commonwealth Edison Company dated February 7,1966, transmitting Amendment 3 to Special Nuclear Material License SNM-638.
(3) Letter to AEC dated March 12, 1966, requesting amendment to Special Nuclear Material License SNM-638.
(4) Letter to AEC dated March 28, 1966, regarding amendment of Special Nuclear Material License SNM-635.
(5) Letter to AEC dated August 9,1966, requesting amendment of Appendix A of Operating LJeense DPR-2 ep extend the time between control rod drive inspections. (Change No.12)
(6) Letter to AEC dated October 6,1966, requesting amendment of Appendix A of Operating License DPR 2 to allow the operation of a modified fuel design, designated Type V fuel, in the Dresden Reactor.
(7) Letter to Commonwealth Edison Company dated November 23, 1966, authoriz ing Change No. 12 to Operating License DPR-2.
._.