ML20084Q775

Ao:On 731003 & 04,release Rate from Reactor Bldg Ventilation Stack Exceeded Limit for I-131 & Particulates W/Half Lives Longer than 8 Days.Caused by Minor Steam Leak

ML20084Q775
Person / Time
Site:	Quad Cities
Issue date:	10/12/1973
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084Q697	List: ML20084Q724 ML20084Q756 ML20084Q766 ML20084Q770 ML20084Q775 ML20084Q778 ML20084Q784 ML20084Q787 ML20084Q791 ML20084Q794 ML20084Q798 ML20084Q800 ML20084Q809 ML20084Q816
References
NUDOCS 8306140068
Download: ML20084Q775 (2)

Text

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• / Com nith Edison P Ouid- Generating Station Post Offica Box 216 Cordova,Ilknois 61242 Telephone 309/654-2241 l

October 12, 1973

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Mr. John F. O' Leary, Director 97

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OCT15I973" Sl Directorate of Licensing gy U. S. ATOMIC ENERGY COMMISSION eM**qtm C' A(

Washington, D. C. 20545 b j[$$a p

SUBJECT:

4 H QUAD-CITIES NUCLEAR POWER STATION w Docket Numbers 50-254 & 50-265 DPR 29 & 30, Appendix A Sections 1.0.A.2, 3.8.B.3.a and 6.6.B.

Dear Mr. O' Leary:

On October 3 and 4, 1973, the release rate from the reactor build-int ventilation stack exceeded the limit for iodine-131 and par-ticulates with half lives longer than 8 days specified in section 3.8.B.3.a of the Technical Specifications. This abnormal occur-rence can be primarily attributed to a steam leak on the Unit 1 RCIC testable check valve and was reported previously by telegram on October 4, 1973 -

PROBLEM AND INVESTIGATION 4

On October 33 1973 a seal ring leak developed on the testable check valve of the Unit 1 ,R,CIC system. At about 3 p.m. on that date the vent stack sample carteidge was removed and counted to estimate the release rate. The ventilation system was isolated and the Standby Gas Treatment System initiated. The results of the sample indicated the release rate of iodine-131 to be 118% of the LCO for the 3rd. The vent system was started again on'the 4th in an attempt to' reduce the iodine inventory in the reactor building.

The leak was isolated and the piping drained by 4 a.m. on the 4th, however, operation of the vent system for 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> on that date ,

resulted in a release rate of 124% of the limit. The final re-sults of the particulate samples indicated that the release rates were 126 and 13{%ofthe limit for the 3rd and 4th respectively.

EVALUATION AND CORRECTIVE ACTION _

Safety Implications This abnormal occurrence is similar to those previously reported and as stated in my most recent report we do not consider the safety implications to be significant. This is substantiated by the continued negative findings of our, environmental monitoring program. -

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8306140068 731115

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Mr. John F. O' Leary, Director October 12, 1973 Determination of Cause and Corrective Action This particular occurrence was caused by a minor steam leak. Since the release rate on October 2, 1973 was 97% of the limit, this leak was sufficient to result in the limit being exceeded again. The problems affecting our ability to take corrective action to pre-vent occurrences of this nature are outlined in my letters of September 21, 1973 and October 3, 1973. ,

Respectfully, ,

5. B. Stephenson Station Superintendent cc: Regional Director

. Directorate of Regulatory Operations - Region III i BBS:RAN/dkp .

BBS-73-216 I

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