ML20248A574

Special Rept:On 890917,quarterly Beta Dose Limit of 10 Mrad for Noble Gases Exceeded.Caused by Degasification of Reactor Coolant Coincident W/Higher than Normal Radioactive Gas Concentration.Degasification Process Completed

ML20248A574
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	09/26/1989
From:	Miller D CONNECTICUT YANKEE ATOMIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 8910020250
Download: ML20248A574 (3)

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CONNECTICUT YANKEE ATO MIC POWER COMPANY HADL.\M NECK PLANT RR#1

• BOX 127E

• EAST HAMPTON, CT 06424-9341 September 26,1989 Docket No. 50-213 U.S. Nuclear Regulatory Commission Attn: Document ContmlDesk Washington, D.C., 20555 Gentlemen:

Haddam Neck Plant Radioactive Effluents N_qble Gas Beta Dose Limit Exceeded In accordance.with the Special Reporting requirements of Technical Specification 7.1.2.2(a)

Radioactive Effluents, Connecticut Yankee Atomic Power Company is providing the NRC staff with the followinginformation:

On September 17th,1989 it was determined that the quarterly beta dose limit of 10 mrad for noble gases was exceeded. The annual beta dose to date is 12.8 mrad, below the annual limit of 20 mrad.

Cause The Haddam Neck plant commenced the Core 15 refueling and maintenance outage on September 2, 1989. During the cycle just ended the plant had experienced fuel cladding defects, which resulted in higher than normal reactor coolant activity. Degasification of the mactor coolant prior to and after the September 2 shutdown, coincident with the higher than normal radioactive gas concentration, resulted in exceeding the quarterly limit of 10 mrad. Enclosure 1 depicts the dose history for the year to date.

Corrective Action The degasification process is completed, with the remaining noble gases yet to be vented expected to contribute a dose not more than 1.0 mrad. During this refueling outage, all known leaking pins, which are in predominantly thrice-burned assemblies, will be removed from the core. First and second burn assemblics with leaking pins will be reconstituted prior to being returned to the core.

The plant is scheduled to return to power operation in early November. During the remaining two l months of the year, it is expected that the dose due to beta will be less than 2 mrad, which would msult in an annual dose of s 15 mrad, below the annual limit of 20 mrad.

8910020250 890926 PDR ADOCK 05000213 S FDC

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.. The licensee contact for this special report is Michael D. Quinn, who can be contacted at' (203) 267 .

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-Very Truly.Yours, m,  : - Connecticut Yankee Atomic ower Company l' (1 sJ77% 4y

- D. B. Miller, Jr.' f' Station Superintendent DBM:MDQ/asl'.

cc:  ;.W. T. Russell, Region I Administrator A. Wang, NRC Project Manager, Haddam Neck

T. Shedlosky, Senior Resident Inspector, Haddam Neck

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-ENCLOSURE l'

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4 l , "Ist Quarter . 0.61 0.22 -

2nd Quarter ' 1.56 0.57 -

July- 1.71 0.55- -

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.Augusti '1.9 0.42

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- Total :5.78 1.76- -

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. September (thru 9/16) .' 7.03 2.20 1.44

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- Total: 1989. 12.81' 3.96 1.44.

- Limits Quarter e 10 mrad ' .7.5 mrad - 7.5 mrem-

~ Annual 20 mrad .15 ' mrad - 15 mmm l-'

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