ML19312C939

AO-270/75-19:on 751017,pipe Connecting Unit 2 Component Drain Pump Discharge Header to Turbine Bldg Trench Leading to Units 1 & 2 Turbine Bldg Sump Found Leaking.Caused by Incorrect Installation of Line Discharging to Sump

ML19312C939
Person / Time
Site:	Oconee
Issue date:	10/17/1975
From:	DUKE POWER CO.
To:
Shared Package
ML19312C932	List: ML19312C934 ML19312C939 ML19312C943
References
NUDOCS 8001140595
Download: ML19312C939 (2)

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V DUKE p0'a'ER COMPANY

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OCONEE UNIT 2 '

JReport No. : A0-270/75-19 . - ,r; l -

Report Date: October 17, 1975 Occurrence Date: _

October 3, 1975 Facility:

Oconee Unit 2, Seneca, South Carolina Identification of Occurrence:

Unplanned Release of Radicar.tive Liquid Through Turbine Building Snmp

_ Conditions prior to Occurrence: Not Applicable ,

Description of Occurrence:

i On September 30, 1975, i routine chenistry tests performed on the Oco nce Units 1 and 2 aturbine activity, samplebuilding reruit ofsump 1.48 revealed x 10-4 a measurable amount of radio -

i recorded. pCi/ml gross beta activity being initiated. A search te locate the source of this activity was immediately The search continued until October 3,1975 when a pipe con-necting the Unit 2 couponent drain- pump discharge header to the turbine ,

building trench discovered. Icading to the Units 1 and 2 turbine buildings sump wa i the turbine building mep andFollow-up samples indicated correlation of activity be!

pipe was the source of activity.the quench tank demonstrating that this .

jDesignation of Apparent Cause of Occurrence:

sump had been incorrectly installed and should storage tank.

u nsate ng discha side of the steam generator to the condensate storage tank vi component drain pump, tl.2reby allowing for quick drainage of the steam The component drain pump is also used torom pump mp.

the radioact on the line in question to prevent leakage of radioactive liquid from the quench tank to the biced holdup s tanks. ~ T discovered to be leaking, particularly when the pump was in operation , and therefore, was allowing radioactive liquid to flow from thench que tank through

.the the component improperly installed line.drain pump and into the turbine building ump via s

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_ Analysis of Occurrence: ,

Unit 2 since construction.The pipiag arrangement, as described n earlier, has

-leak rate of 600 ml/ min, based on leak rate measurements, a i ~

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component drain pump running time and the average reactor coolant activities, for'the period January 1, 1975 to October 3, 1975. This calculation has determined that releases for -1975 were: Total beta activity, 0.6973 curies; total tritium, 19.8991 curies; and total noble gases, 0.0439 curies. Values for 1974 are considerably less due to extensive unit outages during the year. These values are well within the activity release limits and concentration units specified by Section 3.9 of the Oconee: Technical Specifications and 10CFR20

, in themselves and when combined with other known releases. Therefore, it is concluded that the health and safety of the public was not affected by this occurrence.

Corrective Action:

c A flanged orifice,. located downstream of the Icaking isolation valve, has been removed and a blank installed. This will prevent any further flow through the pipe. This same procedure has been accomplished on ,

Units 1 and 3 even though these lines have been determined to be routed 1 I correctly to the condensate storage tank on these units. In additi'on, a modification will be instituted which will completely remove the pipe.

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