ML19343C341
| ML19343C341 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 07/03/1973 |
| From: | Hartley F CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-73-06, AO-73-6, CYH-2411, NUDOCS 8103100413 | |
| Download: ML19343C341 (3) | |
Text
R; - 9 FU2 cy,'
C.
ONNECTICUT YANKEE AT O MIC POWER COMPANY HADDAM NECK PLANT
~
- 1. BOX 127F., EAST HAMPTON. CONN. 06424 a_
July 3,1973 CYH-2411 o
A U. S. Atomic Energy Commission g
Washington, D. C.
20545 ATTENTION: Director, Directorate of Licensing Jg 3
REFERENCE:
Provisional License No. DPR-14
/Sp
~;
Docket No. 50-213 g
s.g
' g '
Abnormal Occurrence 73-6
,/ W ; $ r-
Dear Sir:
As defined by Technical Specifications for Connecticut Yankee Atomic Power Station, Section 5.3, C, the following incident involving an unplanned release of radioactive materials from the site is reported as Abnormal Occurrence 73-6.
At s1025, on 6/21/73, the control room operator noted increased reactor coolant system leakage as indicated by a decrease in volume control tank level indication. Simultaneously an increase in primary auxiliary building air particulate activity was noted by personnel in the auxiliary building, and a moderate increase in main stack gaseous activity was noted by the control room operator.
Investigation revealed a leaking valve in the purification line between the ion exchange outlet and the reactor coolant filter inlet. This valve is physically located in the pipe trench area beneath the ion excnange and filter cubicles. Liquid leakage into the pipe trench collects in the aerated drains tanks. Gaseous activity passes from the pipe trench, to the primary auxiliary building and then to the main stack by way of the ventilation and purge fans. A total of 307 gallons of radioactive liquid was determined to have leaked from the faulty valve to the aerated drains tank. Approximately 0.62 ft3 of radio-3 of active gas was released from the leaking valve. Additionally, 0.37 ft radioactive gas was simultaneously vented from the pressurizer capillary vent system. This system was being prepared for maintenance. The total release of activity from the two sources was 0.238 curies. The isotopic analysis of the released gas is shown in Attachment A to this report. The combined release resulted in site boundary concentrations within MPC values.
The faulty valve, a Grinnell-Saunders c'iaphragm type valve, was replaced and the reactor coolant letdown and charging system was returned to nonnal at 1800 the same day. The faulty valve was disassembled and inspected and the rubberized diaphragm was found torn. The cause of the torn diaphragm was determined to be over-torquing the valve. To prevent 5225
?Y6S/ 06Y(3
2-July 3,1973 i
U. S. Atomic Enerv;y Commission recurrence of thJs incident, a mechanical stopping device will be added to this valve and to valves of similar design and service.
- Very truly yours, e*- -
[gb F. W. Hartley Plant Superintendent RHG/mb i
Attachment (1) cc: Mr. James P. O'Reilly, Director Region 1, Directorate of Regulatory Operations i.
f 1
a 9
i a
'w-+
=w r
w--
e,-,-,v,-
,,.+e,
- eyc, y
r#,..p,,%.9.er,,,,.,,c,y3en
,,,,ym
,g.
y.
v
~
ATTACHMEf6 A MPC Site Boundary Total Activity Isotope uc/ml Concentration pc/ml
- Released - Curies Xe-133 3 x 10-7 '
2.9 x 10-8 044'~
~
t
- Xe-135 1 x 10 4.1 x 10-8
. 083 I
Xe-135m 3 x 10 -3.7 x 10 021 Kr-87 2 x 10-8 1.8 x 10-9 017
+
Kr-88 2 x 10 8 8.3 x'10 II-046
- Ar-41 4 x 10-8 2.7 x 10-9 027 l
'F 1
a l
4 l
1 e
t e
w 4.y,--,
--,9 3
y-e r
~
91--my-wn
-v,g
,,,,,--wy%w,m,y,wy-
-..--,y,-
py,.g4
,-w,,-y.-pr.,.,
-,.mve--yw e--
wy-m,4--
-.3,w-