ML17252A955

Letter Reporting a 08/02/1973 Occurrence of High Activity in Above Ground Tank B Floor Drain Sample Tank - Dresden Units 2 and 3

ML17252A955
Person / Time
Site:	Dresden
Issue date:	08/10/1973
From:	Worden W Commonwealth Edison Co
To:	Giambusso A US Atomic Energy Commission (AEC)
References
WPW Ltr. #572-73
Download: ML17252A955 (2)

Text

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g,~~~.0i:'.':'.!*~d~,~,~~e~~!~tory Docket File 90-2311249

,.J Address Reply to: Post OfficeBox 767 Chicago, Illinois 60690 wPW Ltr.i1572-73 Dresden Nuclear Power Station R. R. Hl Morris, Illinois August 10, 1973 Mr. A. Giambusso Deputy Director for Reactor Projects Director of Licensing U. S. Atomic Energy Conmission Washington, D. c. 20545

References:

1. Notification of Region Ill of AEC Regulatory Operations Telephone: G. Fiorelli, 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />, on 8-2-73.

Telegram: B. Grier, 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br />, on 8-2-73.

2. Dwgs: P & ID M-44.

Dear Mr. Giambusso:

This letter .is to report a condition relating to the operation of Unit 2/3 Radwaste at about 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br />, August 2, 1973. At this time the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period for reprocessing above ground tanks_ with radioactivity concentrations above 0.7 curies allowed by the Technical Specifications (Section 3.8.D) was exceeded by 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

PROBLEM At 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br /> on August 1, 1973 the processing.of water to "B" Floor Drain Sample Tank from the Floor Drain Collector was completed and the B.F.D.S.T. was placed on recirculation for sampling. The sample results indicated the beta-gamma radioactivity to be l.3xl07 pCi/l. This concen-tration combined with a tank level of 82% resulted in a total curie content of 0 *. 89 curies in the "B" Floor Drain Sample Tank.

Although the tankwas promptly.analyzed, there was a misunderstanding between laboratory and operational personnel concerning the radioactivity reporting. Therefore, action on reprocessing the water was delayed until the morning of August 2, 1973 when another shift foreman verified that "B" Floor Drain Sample_ Tank radioactivity was 1. 3xlo7 pCi/l. (0215 hours0.00249 days <br />0.0597 hours <br />3.554894e-4 weeks <br />8.18075e-5 months <br />).

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Mr. A. Giambusso August 10, 1973 In order to reduce the radioactivity of the water in the "B"

• Floor Drain Sample Tank to within Technical Specifications limits, at 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br /> on August 2, 1973, the "B" F.D.S.T. was partially transferred to the "B" Neutralizer Tank. At 1135 the concentration of l.3xl07 pCi/l at a tank level of approximately 631 resulted in a curie content of 0.68 curies in the "B" F. D. s. T.

Before water could be transferred from the "B!' Floor Drain Sample Tank to the "B" Neutralizer Tank, the "B" Neutralizer Tank had to be emptied. The Floor Drain Collector, which had filled up again, was transferred to the "B" Neutralizer Tank next. At 1105, August 2, the conditions eKisted that allowed the transferring.of the "B" Floor Drain Sample Tank to the "B" Neutralizer Tank.

INVESTIGATION A review was made of the procedures applicable to the incident.

It was determined that in following one operatl.ng procedure, the step requiring beta-gamma analysis of the Floor Drain Collector prior to processing was omitted. The delay in reprocessing the water in the "B",

Floor Drain Sample Tank was caused by a misunderstanding between laboratory and operational personnel about the radioactivity reporting units.

CORRECTIVE ACTION Enough water in the "B" Floor Drain Sample Tank was transferred to the "B" Neutralizer Tank to reduce the curie content*iri the "B" F;D.S.T.

to within Technical Specifications.

A review of the appropriate procedures has been made with the personnel involved. In addition, a revision of the operating procedure, 2000-XX, paragraph B, has been effected to clarify the section requiring radioactivity analysis of the Floor Drain Collector prior to processing to the Floor Drain Sample Tanks.

EVALUATION The presence of 0.89 curies in the "B" Floor Drain Sample Tank did not produce a hazard to the public since it was not released to the river and the tank beta-gamma radioactivity was reduced to below Technical Specifications 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> after the collection of the first samples. If -

a failure of the "B" Floor Drain Sample Tank had oc.curred as described in Amendment 119,Section V.C.l of the S.A.R., and the radioactivity contained in the tank had been released to the aquatic environment, the limits as specified in CFR 20.106 would not have been exceeded when averaged over one year.

Sincerely,

\\J\~*

W. P. Worden Superintendent

• WPW:do cc: F ile-AEC Corr.