ML19351E312

Operation Rept 112 for Apr 1970

ML19351E312
Person / Time
Site:	Yankee Rowe
Issue date:	05/20/1970
From:	YANKEE ATOMIC ELECTRIC CO.
To:
Shared Package
ML19351E311	List: ML19351E310 ML19351E312
References
NUDOCS 8011280096
Download: ML19351E312 (7)

Text

.

. ~ _ - _.. -. --

i OO O

90 n

[

~

}

m......; ?!.at Dab- - - -

l ab-i I'l

..['.N, YANKEE NUCLEAR POWER STATION f

l 1

3 (,'x

{

l, OPERATION REPORT NO. 112 A,/

...?>

x

-.y r.

/6/

"' V..... (fj f'.y f']

U $ j970'-!,IEI For the Month of

u. v >..

i

.r,r-..',t.,

j April 1970 Qj

, - ;, '" li;,l gQ/

'nj),-di-.':

/

l N'

\\

i I

i I

I i

i j

l J

f a 'v^~ s e

i S.

i O

/

h

-11 9-

s,,

,~

v i

(

t P

^

l 9

e' l

/

I

4) j l

Submitted by j

YANKEE ATOMIC ELECTRIC COMPAFY f

f i

Westboro Massachusetts May 20, 1970 0

801128004f 1587 D

e O

O[e Plant' Shutdowns Shutdown No.' 107-8-70:

h/10/ 3, plant trip due to false signal from fai ~ sr.fe.No. k loop. low flow transmitter.

l Plant-Maintenance The.following *'

list of major plann maintenance items performed f

by the. plant staff durin, the month of April,.1970.

e 1.

The No's.1 arid 2 plungers were replaced in No. 3 charging pump.

2.

The two dryers and the after cooler for the No. 2 control air compressor were replaced.

Instrumentation and' Control, l

The followin; is a list of pertinent instrumentation and control maintenance items performed by -the plant staff during the month of April,1970.

1.

The neutron detectors, which were removed from thimbles No.1 and No. 5 during the most previous report period, were refurbished.

l-

,2.

The No. k main coolant loop flow transmitter LVDT was replaced, i

l Reactor Plant Performance

{L

- The following parameters were detemined by means of incore instrumentation:

if ft 586 IGt; -526.3 Tavg; Control Rod Group A @ 84

,-B,C,D, @ 88I; 376 ppm boron.

F

=

2.0 q

l l

F AH 3.38 l

Minimum DNBR

=

Maximum Outlet Temperature = ~592.6 F Secondary Plant Performance 1Feedwater-heater terminal differences were as follows:

6.23 F h bh F No. 2 = '12.16 F No. 3 No. 1

=

=

The. Condenser perfor: nance was as follows:

I

.'.85.8 MWe; 0.98" Hg. B.P.;

587.1 MWt; 36.6 F C.W. in; TTD = 21.37 F;

leanliness factor = 98.19%.

O 'ei e

O l

i i

l i

l This report covers the operation of the Yankee Atomic Electric Company at Rowe, Massachusetts for the month of April,1970.

During the period plant load varied between 18h.5 We and 186.0 We as the circulating water inlet temperature fluctuated between 39 F and 35 F.

One, unscheduled, plant shutdown occurred during the period, initiated by a reactor scram and subsequent turbine trip at 0258 hours0.00299 days <br />0.0717 hours <br />4.265873e-4 weeks <br />9.8169e-5 months <br /> on April 10.

Further discussion of thic shutdown is presented as Abnormal Occurrence No.-70-1, this report.

The fourth Core VIII vapor container air leakage surveillance period continued through the report period. Leakage during the period was normal.

Plant Abnormal Occurrences Abnor=al Occurrence No. 70-1 " Plant Trip".

I i

On April 10, 1970 the plant was operating at a power level of 586 w t when the reactor scrammed; the turbine tripped; and the 115 KV oil circuit l

l breakers opened. The appropriate operator action of holding No. 2 and No. 3 main coolant pumps on the generator until it coasted down to 58 cycles, was l

followed.

I l

A survey of plant instrumentation confirmed that the reactor scram occurred prior to the plant trip. The primary scram sequence panel indicated a main cool ut low flow signal. The No. 4 main coolant loop flow indication I

2 was found co have decreased to the low flow reactor scram setpoint, verifying the origir. of the scram signal. Since other loop parameters were normal, the No. 4 main coolant pump was maintained in service.

Subsequent inspection in No. h main coolant loop revealed a failure of the main coolant flow sJgnal transmitter trans!'ormer caused by moisture leaking from the transmittei low. pressure vent. The No. k loop was removed l.

from service.

I f~

The plant was returned o power under three loop operating conditions.

The reactor was brought critical and the turbine generator was phased on line at 0717 hours0.0083 days <br />0.199 hours <br />0.00119 weeks <br />2.728185e-4 months <br />; and the plant was loade.i to h50 Wt.

Repair was made of the No. 4 loop flow transmitter vent valve; the loop flow signal transmitter transformer was rep:

ed and calibrated; and

~No. h loop was returned to service. Loading of the plant to full power was j

completed at 1635 hours0.0189 days <br />0.454 hours <br />0.0027 weeks <br />6.221175e-4 months <br />.

Plant Load Reductions April'17-18 (1200 - 0045):

Load reduction to 12T We for repacking of heater drain tank No. 1 and No. 2 pumps; and replacement of lower motor guide bearing in 8

the No. 2 pump.

I

g 9

Oe 3-1 Chemistry The main coolant boron concentration was decreased from 428 ppm to 361 ppm during the period to compensate for core depletion. The average main coolant pH vas 6.15.

~

-1 i

4 The main coolant average gross beta-gn=ma activity vas 1.04 x 10

(

ue/ml. The main coolant crud level averaged 0.02 ppm, except that following the plant trip on April 10 a maximum value of 3.65 ppm was recorded. Analysis on April 13 showed that normal purification had reduced the level to the j

above indicated average value.

1 I

The main coolant tritium concentration, which had been reduced l

l to 0.3h ue/ml at the end of the previous report period due to dilution, j

increased to 1.98 ue/ml at the end of the current report period.

f m

-5 The average iodine-131 specific activity was 3.50 x 10 uc/ml and the iodine 131/133 atomic ratio was 0.51 indicating the absence of detectable fuel defects.

j A representative crud sample for the month, collected on April 15, j

had the following radiochemical analyses: dp:/mg crud.

1

[

Cr-51 Mn-Sh Fe-59 T

6 6

1.52 x 10 3.70 x 10 7.20 x 10 l

i Co-58 Co-60 Ag-110M 6

5 j

2.96 x 10' 7.11 x 10 6.76 x 10 A main coolant gas.sa ple collected on April 22, had the following j

radiochemical ar e lyses : uc/cc gas l

l Xe-133 Xe-135 -

Ar h1

~,

f 5 09 x 10 "

5.81 x 10 1.01 i

l Health and Safety i

One shipmei.t of 56 drums of lov level vaste, containing a total l

activity of 109.5 me, was made during the period.

t l

Waste disposal 1P uid releases totalled 90,580 gallons containing

{

0.06 me of gross beta-gamma activity and 239.38 curies of tritium. Gaseous releases during the period totalled 714 me of gross beta-gamma activity, f

i Secondary water discharged totalled 428,166 gallons containing 0.265 me of gross beta-gamma activity and 3.01 curies of tritium.

Radiation exposure doses for Yankee plant personnel, as measured by film badge, for the month of April 1970 vere as follows.

4

)

Average accumulated exposure dose:

128 mrem i

f Maximum accumulated exposure dose.

780 mrem i

Operations f

Attached is a sunmary of plant operating statistics and a plot of daily average load for the month of April, 1970.

YANKEE ATOMIC ELECTRIC COMPANY - 0FERATING SUFNARY April 1970 ELECTRICAL MONTH YEAR T0_3 ATE Gross Generation KWH 131,262,000 480,744,900 10,696.403,400 i

Sta. Service (While Gen. Incl. Losses)

KWH 7,696,631 28,hh6,077 698,h50,9h1 Net Output KWH 123,565,319 452,298,823 9,997,952,h59 m

Station Service 5.86 5.92 6.53 W

l Sta. Service (While Not Gen. Incl. Losses) KWH 29,721 901,966 29,809,895 i

Ave. Gen. Running (714.68)

KW 183,665 ll) i Ave. Gen. For Month (719)

KW 182,562 l

i i

PLANT PERFORMANCE Net Plant Efficiency 29.79 29 75 28.4T f

Net Plant Heat Rate btu /KWH 11,h56 11,471 11,987 i

l Plant Capacity Factor 96.14 88.01 75.16 f-I Reactor Plant Availability 99.65 90.53 84.09 i

t 4

MONTH CORE VIII TOTAL l

NUCLEAR Hours Critical HRS 716.50 5,034.53 70,854.31 1

Times Scrammed 1

2 60 Burnup r

Core Average FMD/MrU 831.76 5,808.76 t

l l

Region Average MWD /MTU A (INNER) 76h.60 5,283.99 25,214.89 l

B (MIDDLE) 9h7.27 6,668.72 18,704.78 gi C (OUTER) 723.48 h,982.51 h,982.51 D (ZIRCALOY) f i

l I

4

i e.

.9 l

9 -e- !

l

^o h

l i

r

_m l

N

~

r I

ij-o N

• I c..

[

j

.cj w

.~.

c

(

s t-r r-- ;

-m,<

l

• ,7,

e

.T.

g,

,e -

o i

u r

5 4

e.

g,

[

i i

l 4

I

._ o l

c4 m

1 l

t'

'i To 1

1 w

l l

~

4 i

I---S j

i i

i i

-l

ii i

i i

i e

i l

i i

e i

o s

8 R

8

/

a

.m a

r4 f.

-(fW #8010) GYCTI 20Y1t!AY IIIVQ i

LJ. _,_ _ _ _ _ _.

1.. __.-_ _ -_,

~_.m_,,...._

---.r..,..

.J..

OO 9

O

-G-O EERE V

b

~

A B

C D

E y'F G

H J

K XXXX~

2 3

NXX XX/

XX XX 3

XX XX 4

os t X MM X _o X

IBM X

~

XX XX 7

XX XX f /XX XXN o

l 10 REGION ENRICHMENT A

4.94 %

o 1

X

_a4x c

.