ML20086K255

Environ RO 74-9:on 741210,effluent from Settling Basin Exceeded Environ Tech Spec Limits.Caused by Gate Between Sections of Settling Basin in Closed Position.Basin Isolated & Cause of High Turbidity Investigated

ML20086K255
Person / Time
Site:	Peach Bottom, 05002787
Issue date:	12/20/1974
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
References
RO-74-9, NUDOCS 8401260373
Download: ML20086K255 (2)

Text

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O PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET ,

PHILADELPHI A. PA.19101  ; O i.,. - l 1

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. 12151841 40oo 7, ,i

• December 20, 1974 Q)d q p,

'Fr ~ .;.'l

,-l N;)J 4 31r. A. Giambusso Deputy Director of Reactor Projects United States Atontic Energy Commission Directorate of Licensing

' Washington, D.C. 20$45

Subject:

Environmental Deviation The following deviation was reported to Mr. Walt Baunack, A.E.C. Region 1 Regulatory Operations Office on December 11, 1974.

In accordance with Section 7.4.2.A of the Environmental Technical Specifications, Appendix B of DPR-44/56 for Units 2 and 3 Peach Bottom Atomic Power Station, the following report is being submitted to the Directorate of Licensing as an Environmental Deviation.

f

Reference:

License Number DPR-44/56 Environmental Technical Specifications Appendix B Section 2.2.2

> l Report No.: 50-277/278-74-9 Report Date: December 20, 1974 Deviation Date: -December 10, 1974 Facility: Peach Bottom Atomic Power Station Units 2 and 3 R.D. #1, Delta, Pennsylvania 17314 Identification of Deviation:

l Effluent from the settling basin in excess of the Environ-mental Technical Specification limit.

~ Conditions Prior to Deviation:

i. Unit 2 operating at approximately . 90G power. Uni t 3 shutdown.

l Description of Deviation:

l l

A routine check of the effluent turbidity from the settling

( basin on December 10, 1974 disclosed a value of approximately 100 JTU's.

Comparable river water turbidi ty at this time was 9.2 JTU's. Technical Specification limits the effluent to 30 ppm greater than the concen- ,j y,')[

l tration of suspended solids in the river. Based on established p g l: 8401260373 741220 M r

PDR ADOCK 05000277 S PDR tAJt'x dENf itEGluN 12g [P' L , . ., m gg n~ "]

'T .

Mr. A. Giambusso

• December 20, 1974 Page 2 correlation data between JTU's and ppm suspended solids of the set-tling basin effluent, it is believed the 30 ppm Technical Specification limit was exceeded.

Desinnation of Apparent Cause of Deviation:

An investigation showed that the division gate between the two sections of the settling basin was in a closed position. This provided a shorter flow path thereby reducing the settling time avail-abic for the solids in the water. The division gate had been closed during the previous day to permit removal of solids from the bottom of the settling basin for offsite disposal. The shorter flow path coupled with an excess blowdown rate from the clarifier and a lighter than normal flock in the clarifier is believed to have caused the deviation.

Analysis of the Deviation:

Because of the short period of time that the settling basin effluent was out of specification and the high river flows at the time, no detrimental effects to the environment are anticipated.

Corrective Action:

The settling basin was immediately isolated in accordance with a procedure and the cause of the higher than acceptable turbidity i nves tiga ted. The gate between the two sections of the settling basin was raised and after a one hour settling period, the system was re-turned to service. Effluent quality after return to service was measured at 11 ppm suspended solids. The corresponding river water suspended solids at this time was 28 ppm. The clarifier blowdown rate was adjusted as required.

Failure Data:

None.

Very truly yours,

'l l-(> u a i fYl/

M. J. Cooney J',

Ass't. Genl. Superintendent Generation Division ec: Mr. J. P. O'Reilly Director, Region 1 United States Atomic Energy Commission 031 Park Avenue King of Prussia, PA 19406

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