ML19259D482

Nonroutine 30-Day Environ Rept 74-02 Re Tritium Content of River Water Discharge on 741124 Four Times Greater than Control Station Value.Addl Water Passing Through Mechanical Draft Cooling Tower Caused High Readings

ML19259D482
Person / Time
Site:	Three Mile Island
Issue date:	12/24/1974
From:	METROPOLITAN EDISON CO.
To:
Shared Package
ML19259D479	List: ML19259D478 ML19259D482
References
NUDOCS 7910240749
Download: ML19259D482 (2)

Text

.

Gfo sc.

C7370

• /;*,:n rowra na s *ocorss

. s METROPOLITAN EDISON COMPANY PCOT CFFICE BOX 542 READING, PENNSYLVANI A 19603 TE LEPHONE 215 - 929 3601 UT 0 4 1974

'5

, **..* g ; ;, s^ /s, \ 1 -- % fys:M

, \ /* 9 ', s

,' 7.l s

.- .%r w)

~'

Mr. J. P. O'Reilly, Director

, '-w g ap ,I. O. d .

Office of Regulatory Operations, Region 1 -

'b ^ -

U. S. Atomic Energy Commission

[fb.- S.

A ' " ---

631 Park Avenue /D, King of Prussia, Pennsylvania 19h06 ,

IM' T,?>

Dear Mr. O'Eeilly:

Docket No. 50-289 Operating License DPR-50 Nonroutine 30-Day Environmental Report Th-02 In accordance with Subsection 5.6.2.b, Item h, of the Environmental Technical Specifications for the Three Mile Island Nuclear Station, Unit 1, we are herewith submitting a report on a measured level of radiation which exceeded four times the control station average value for the October ecmposite sample of water from the Susquenanna River in the vicinity of the statien.

We would like to point out at this time that the level of radicactivity associated with this sample was less than 1/100 of the Maximum Permissible Concentration limit given in 10CFR20 for =cmbers of the public. Hence, it can be stated cenfidently that neither the health nor safety of the public was threatened by the radiolecical condition of the river renresented by this one anomalous sample.

We trust that submission of this report satisfies the reporting requirements referenced above and adequately ansvers any concerns you might have.

Sincerely, R. C. Arnold Vice President 1459 162 RCA:JF'/:lv

Enclosure:

Report of an Ancmalous Measured Level of Radiation ec: Ms. Margaret A. Reilly, Chief Director Bureau of Radiological Health Directorate of Licensing P. O. Box 2063 U. S. Atcmic Energy Com=ission Harrisburg, PA 17120 Washington, DC 205h5 eng d' File 7.7.3.6.1 20.1.1 (v/o enclosure) gg 4g

ENCLOSURE Metropolitan Edison Company Three Mile Island Nuclear Station, Unit 1 (TMI-1)

Docket No. 50-289 Operating License DPR-50 Nonroutine 30-Day Environmental Report Th-02 Report of an Ancmalous Measured Level of Radiation

1. Description of Occurrence:

A monthly composite river water sample (composed of four weekly grab samples) collected about 1/2 mile downstream from the TMI-l River Water Discharge and reported to Met-Ed on November 25, 197h, had a total tritium activity of h.95 x 10-6 pCi/ce. Compared with the control station value of 5.2 x 10-7 pCi/ce, this anomalous value is more than four times greater. (Note: The control station value referred to here is the Preliminary Reporting Level established by Met-Ed's radiological consultants). A river water sample collected a week later at the seme location as the anomalous sample showed that the tritium level was again normal.

2. Possible Cause of Occurrence:

During the period under discussion there were losses in reactor coolant inventory through various components connected to the Primary Drain Tank via leak-off lines. The heut exchanger for this tank was not designed to accomodate the volume of water involved. To overcome this problem, cold water from some reclaime1 vater tanks was added to the Drain Tank to lower the temperature of its contenta so that the heat exchanger could operate more efficiently. All of the water that passed through the heat exchanger was then precessed, diluted with Mechanical Draft Cooling Tower effluent, and discharged to the river. Additional amounts of tritium may have been contributed by the valve leakage and Drain Tank cooling water which was discharged to the river and may have, therefore, served to increase the level of tritium in the river above the background level.

3 Analysis of Occurrence:

For the following reasons, it is believed that neither the health nor strety of the public vas threatened by the radiological condition of

-he river represented by the one anomalous sample of this report:

1459 i63

a. The level of tritium activity at the nearest unrestricted area was less than 1/100 of the Maximum Permissable Concentration limit given in 10 CFR 20 for members of the public.

b. The level of tritium activity at the nearest devnstream source of public drinking water (at Columbia, Pennsylvania) was at background level (h.76 x 10-7 pCi/cc).

c. No Technical Specification limits were exceeded.

h. Corrective Actions:

Although the higher +,han-normal level of tritium in the river may not be related to plant operations, it should be noted that repairs have been effectuated on plant ec=ponents which have served to eliminate the plant as being even a potent. 1 source.

1459 i64