ML19318B316

Forwards LER 80-010/01T-0

ML19318B316
Person / Time
Site:	Peach Bottom
Issue date:	06/17/1980
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19318B317	List: ML19318B316 ML19318B318
References
NUDOCS 8006250240
Download: ML19318B316 (3)

Text

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O O PHILADELPHIA ELECTNIC COMPANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 (2isi e41-4000

..' . .. June.17, 1980 r

Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406

SUBJECT:

Licensee Event Report Narrative Description The following occurrence was reported to Mr. Greenman, Region I, Of fice of Inspection and Enforcement on June 3, 1980.

Reference:

Docket Number 50-277 Report No: LER 2-80-10/1T-0 Report Date: June 17, 1980 Occurrence Date: March 30 thru April 7 and

' April 21, 1980 Facility: Peach Bottom Atomic Power Station R.D. 1, Delta, PA 17314 .

Technical Specification

Reference:

Technical Specification 3.8.B.4 states that "D u rin g release of radioactive wastes, the following corditions shall be met:

a. The minimum dilution water required to satisfy 3.8.B.1 shall be met.

b. The gross activity monitor and flow monitor and their respective recorders on the waste effluent line shall be operable.

• c. The effluent' control monitor shall be set to alarm and automatically close the waste discharge valve prior to exceeding the limits specified in 3.8.B.1 above.

Description of the " vent: "" ~

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In March of 1980 with Unit 2 operating at its maximum capability, a leak developed in the Al section of the condenser. hg/

g 8006250 M O j

3r. Boyco 11. C rie r Page 2

.' Juno 17, 1900 LER 2-80-10/1T-0 The water box was successfully valred out and vented on' March 13, and condenser conductivity returned to normal levels. Venting of

, the water box showed no discernable increase in off gas flow.

Unit 2 continued to operate with this portion of the condenser out of service until the shutdown for the refueling outage on March 21, 1980. During the operating period, the condenser vacuum was maintained, preventing any leakage from the condenser ,

to the circulating water system.' , -

Following shutdown, the condenser vacuum was broken and .

atmospheric conditions established in the condensar steam space.

Condenser hotwell level was also increased during this time -

interval as a result of leakage from the condensate storage tank through a leaking makeup valve. Unter level in the hotwell was above the leaking condenser tube from March 31 through April 7, 1980. On April 7, the hotwell was drained in accordance with normal plant outage operations.

Later in April, hotwell level again increased due to leakage from the condensate system through the condenser makeup valve.

Hoewell level again increased to a level above the leaking tube for a short time period on April 21, 1980. Because the reactor head cavity was being drained just prior to this date, the water in the condenser during this time interval may have contained activity level similar to that being drained f ro m .t t.e reactor head cavity. During the periods of time that leakage occurred from the hotwell to the circulating water system, at least one circulating water pump was in operation. This diluted the radioactive water leak by at least 250,000 gallons per minute.

Consequences of Event:

Following the identification of this event, surveys were made of the tube sheets of the Al water box. Those areas which [

indicated high contamination levels were leak tested on a tube by tube basis. This leak testing procedure identified one leaking tube. The leak rate through this tube was then measured at various differential pressures. This data combined with the hotwell level during the cime interval indicates that the total release of inventory between 3/31 and 4/7/80 was 11,088 gallons.

This volume combined with the specific activity of the hotwell inventory during this time interval indicates that the activity released was 0.0088 curies. The maximum release rate during this period was 3.5 N4 of Maximum Permissible Concentration (MPC).

During the second release oeriod of April 21, 1980, a total o f 2 2 4 **g~a l'lo n s was releasid. 1Lis volume combined with the assigned specific activity during this period indicates 'that a release of 0.0011 curies occurred. The maximum release rate during..this time period was 1.5 N4 of MPC". The quantitic's of -

radiation released during this total period amounted to 0.01 curies. A dose calculation based on the isotopes involved indicat- minimal exposure dose associated with this event.

Mr. aoyco H. Grior Page 3

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• Juno 17, 1980 LER 2-80-10/1T-0 This release was analyzed against the requirements. of NRC Bulletin 80-10 " Contamination of Nonradioactiti System and Resulting Potential for Unmonitored, Uncontrolled Release to Environment." Because of the small leak race (maximum 1.46 gpm) and the small amount of activity released (0.001 Ci), the limits of 10 CFR 20, the facility's Technical Specification and the environmental radiation dose limits of 40 CFR 190 were never appro, ached. The maximum percentage of MPC was 0.035%. The r highest estimated environmental radiation dose was 0.025 mrem or 1.21% of the yearly investigation level. Based et this analysis, no environmental impact is expected.

• Cause of Event: '

The cause of this event was a failure to recognize a series of circumstances which would permit release of water from the hoewell to the circula*ing water system during shutdown conditions.

Corrective Action:

At the time this event was identified, the condens'er had been drained and the leakage stopped. Instructions have been issued to shift personnel to limit hotwell level below the condenser tubes at all times during operation and shutdown.

Appropriate procedural changes will be made.

Previous Similar Occurrences:

None, s

Yours truly,

. J

)

Cooney Sup rintendent Generation Division-Nuclear Attachment ec: Director, NRC -.0ffice of Inspection and inforcement Mr. Norman M. Haller, NRC - Office of Management &

, Program Analysis

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