ML19351E142
| ML19351E142 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 01/22/1968 |
| From: | YANKEE ATOMIC ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19351E138 | List: |
| References | |
| NUDOCS 8011250660 | |
| Download: ML19351E142 (8) | |
Text
_. _
(
~
YANKEE NUCLEAR POWER STATION OPERATION REPORT NO. Oh For the month of DECEMBER 1967 l
O O
Submitted by
.y-o'Q ' ?%
YANKEE ATC>MIC ELECTRIC COMPANY c,
f,3/..
,, ' ts Besten Massachusetts v
ca y
I January 22, 1968
,c7B ;,
,1 O
p:-_.
kh 5
.1 n
,u um
'v W 2
Nb /.
g
.8011250 gg
Thic report covers the operation of the Yankee Atomic Electric Company plant at Rowe, Massachusetts for the month of I
December, 1967 Plant lead at the start of the period was 178 MWe as plant stretchout operation continued; at the end of this report period plant load had decreased to 16h MWe.
At the beginning of the period, ammoniation of the main coolant for pH adjustment was in progress. The change in coolant chemistry resulted in a 0.23 % AK/K reactivity gain.
Since this reactivity increase was only one third of the expected gain, a detailed investigation of Core VI burnup rates was initiated.
It was determined that a change in the slope of the core burnup curve had occurred at 6100 MWD /MTU; the decreased burnup rate resulted in a 0.2 % AK/K reactivity gain at the end of full power life.
The 6100 MWD /MTU burnup value occurred just after the plant etartup following the July cold shutdown.
As a result of a O
miscalculation of the chemical charge required for oxygen scavenging, an overcharge of hydrazine was injected into the system prior to plant heatup. Radiolytic decomposition of the hydrazine resulted in a 70 ppm coolant ammonia concentration. A corresponding increase in the system crud level frca 0.30 ppm to 20.7 ppm occurred. During the next three days, the ammonia and crud were removed from the coolant by purification ion exchange and filtration.
The effect of this occurrence on the behavior of core 9
reactivity cannot be defined until more information on the pH-reactivity phenomena is available.
Two reductions in plant load occurred during the period.
On December 6 at 1205 hours0.0139 days <br />0.335 hours <br />0.00199 weeks <br />4.585025e-4 months <br />, load was reduced to 135 MWe to allow exercise of the turbine throttle valves; lead was restored at 1316 hours0.0152 days <br />0.366 hours <br />0.00218 weeks <br />5.00738e-4 months <br />. On December 8 at 0630 hours0.00729 days <br />0.175 hours <br />0.00104 weeks <br />2.39715e-4 months <br />, load was reduced to 150 1
MWe for No. 1 boiler feed pump maintenance; load was increased to
()
165 MWe at.000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />. Full lead was restored on December 9 at lh57 hours following the completion of pump repairs.
Contractual arrangements were completed for the spent fuel pit refurbishing program. During this report period approximately 15% of the deteriorated coating has been removed from the pit internal surface by sandblasting.
On December 1, the fifth, Core VI air charge (1000 lbs) to the vapor container was completed. The contaircent leak rate during the previous 120 days was 0.013% per day.
A control rod exercise was performed on December 6; all l
control rods operated normally.
Jontrol groups B, C and D l
were moved out one step as part of the rod step wear program.
No plant shutdowns or reactor scrans occurred during the month of December.
8
_________._...,..m
, Plant Maintenance The following is a list of pertinent plant maintenance performed by the plant staff during the month of December,1967:
1.
A section of new fuel rack containing fourteen storage positions was rer.oved from the northwest corner of the new fuel vault ; this area vill be used for the assembly of the new Zircaloy test fuel elements.
2.
A spare unit heater was fabricated into a filter unit for use during sandblasting operations in the spent fuel pit; reductions in airborne activity levels by a factor of 10 have been achieved.
3.
The mechanical seals in the evaporator rebo11er pump were replaced and a larger seal water line to the pump seals was installed.
O h.
A weep type leak in the relief valve line from the No. 1 charging pump was repaired.
5 The inboard and outboard bearings on the No. 2 purification pump motor were replaced.
6.
Investigation of an abnormal noice in the shutdown cooling pump 9
revealed that the fan had become loose on the =ctor shaft and was rubbing on the end bell; this condition was corrected.
7 A solenoid operated bypass valve was installed on the instrument air supply. This valve will automatically bypass the air dryer on a supply header low pressure signal.
Instrument and Control O
The following is a list of pertinent instrumertition and control maintenance items performed by tha plant staff during the month of December,1967:
1.
Investigation of incore flux vire system problems was continued.
2.
Piping to the incinerator stack was replaced and a water trap in the stack filter system was installed.
i Reactor Plant Performance The following parameters were determined by means of incore instrumentaticn at 578 MWt, 520.5 Tav6, 0 ppm boron, control groups B, C and D at 89 5/8 and group A at 90.
2.35 Fq
=
F AH Min. DNBR 3.31
=
587 F Maximum outlet temperature
=
J l Chemistry Ammoniation of the main coolant system was in progress at the start of the period. A mixed bed demineralizer with an ammoniated cation cycle was placed in service in the coolant purification system. Main coolant ammonia concentration averaged 12 ppm during the report period.
iodine-131specificactivitywas2.5xlogvitywas8.7x10- uc/ml; 1
The coolant average specific act ue/a1 and the iodine 131/133 atomic ratio was 0.98.
System crud levels averaged 0.38 ppm.
Coolant tritium specific activity varied between 1.Th uc/ml and 1.90 ue/ml.
A representative crud sample for the month, collected on December 11, had the following radiochemical analyses: dpm/mg crud
(:)
Cr-51 uf-181 Mn-5h Fe-59 6
3 6
6 3.0 x 10 5.6 x 10 2.0 x 10 1.9 x 10 l
l Co-58 Co-60
^8-11 E 7
6 1.h x 10 4.0 x 10 1.7 x 10 A main coolant gas sample collected on Decedber 19 had the following radiochemical analyses: uc/cc gas Ze-133 Xe-135 Ar-kl
-2 1.1 x 10~
1.7 x 10~
5.5 x 10 Health and Safety O
One shipment of radioactive waste containing ST drums with a total activity of 453 me was made during December.
Waste disposal liquid releases totaling 159,990 gallons contained 112 uc of gross beta-gamma activity and 195.29 curies of tritium.
Gaseous releases during this period were 26.04 me of gross beta-gamma activity.
Secondary plant water discharged was 18h,394 gallons and contained a total of 10.2 uc of gross beta-gamma activity and 156 me of tritium.
Included in the above releases is an inadvertent gas release that occurred en December 6.
Incorrect valving ison.ted both test tanks during a routine evaporator processing operation of class I liquid. Erratic process behavior even+ually resulted in shutdown of the evaporator by the operator. When the steam supply to the reboiler was valved out, a partial vacuum was created in the evaporator which caused cover gas to flow into the unit.
After the original valving error was corrected, the steam supply valve to the reboiler was opened; evaporator pressure increased to approximately 18 psi.
In order to relieve this pressure, the hydrogen vent was secured and the oxygen vent was opened.
_L_
3 Approximately 30 ft of the cover gas, containing 280 uo (Xe-133, Xe-135, Ar 41,11-3) was discharged to the environment through the incinerator stack; this release was below MFC when avere.ged over a 2h hour period.
Radiation exposure doses for Yankee plant personnel as j
measured by film badge for the month of December, 1967 were as follows:
Average accumulated expecure dose 55 mren Maximum accumulated exposure dose 198 mrem Operations Attached is a summary of plant operating statistics and O
a plot of daily average load for the month of December,1967.
o 1
l 1
)
1 I
1 I
I
('
u)
YANrRE ATOMIC ELEETRIC COMPANY -- OPERATDIG
SUMMARY
DECDGER 1967 M) NTH YEAR TO DATE EIETRICAL WH 126,898,800 1,3h8,h2h,100 7,710,884,600 Gross Generation Sta. Service (While Gen. Incl. Losses)
WH 7,969,766 82,6hh,111 512,666,933 10 6 I 118,929,03h 1,265,779,989 7,198,217,667 Net Output 6.28 6.13 6.65 Station Service 1,010,060 24,805,527 Sta. Service (While Not Gen. Incl. Icsses)
WH 0
Ave. Gen. For Month Thh.00 W
170,563 W
170,563 Ave. Gen. Running 744.00 PIANT PERFORMANCE 28.3h 28.08 28.39 Net Plant. Efficiency Bru/WH 12,042 12,15h 12,021 s
Not Plant Heat Rate 94.02 85.76 73.53 Y'
Plant Operating Factor Reactor Plant Availability 5
100.00 91.93 83.39 10 NTH CORE VI TOTAL NUCLEAR HRS Thh.00 9,39h.49 53,120.17 Hours Critical 0
3 55 Times Scrammed Burnup WD/MPU 8bl.71 10,521.1h Core Average WD/MPU Region Average 852 91h 10,596.353 27,368.65 A (INNER) 1001.189 12,581.117 20,256.h3 B (MIDDIE) 680.826 8,h51.180 8,b51.18 C (OUTIR)
~
i i
0 g
3 i
i i
i 5
l2 i
i i
i 0
g 2
YN i
APM O
SY C
DA DAD I
E G
,5 T
A T
1 R
R O
E
[
C V
I A
M O
Y T
L A
I AD
,o l
g W
e O
0 0
o 0
0 5
o 5
2 1
l gg A5 mH5 d4o
,1
_7_
CORE VIRWION IOCATIONS
)
REION C em "e
o REION A v
O a
l