ML19225C440

Revised Nonroutine Environ Operating Rept on 790514:room Sinks Connected to Floor Drain Sys of Wrong Unit Due to Inadequate Design Change Control.Contaminated Water Possibly Escaped to River.Surveys Taken & Personnel Monitored

ML19225C440
Person / Time
Site:	Farley
Issue date:	07/10/1979
From:	ALABAMA POWER CO.
To:
Shared Package
ML19225C439	List: ML19225C438 ML19225C440
References
NUDOCS 7907300323
Download: ML19225C440 (3)

Text

I NON-ROUTINE ENTIR0571 ENTAL CPEPATING REPORT (Revised July 10, 1973)

AN., LYSIS OF EVENT At approximately 0300 on '!ay 14, 1979 an Alabama Power Ccmpany Startup Super'.'isor actified the Chemistry & Health Physics Supervisor that it was possible that some of the decontamination room drains were routed to the Uni 2 floor drain system. By 1500 on 5/14/79 it was determined concluaively tnac 4 decontamination r o c.r sinks were connected to the Unit 2 floor drain sy: tem rather than : e Unit 1 floor drain syatem. This determination was cade by sampling of 2 Unit 2 Auxiliary Building, 77' elevation, surp.

The flow path for the effluent from the 4 decontamination room sinks ran to a semp on the 77' elevation of the Unit 2 Auxiliary Building, to the Unit 2 tendon access gallery, then to an alkaline flush pond, and then to a ravine with possible run-off to the Chattahoochee River. Radiation surveys were conducted in the Aux 11tary Building along the flow path with readings varying from 100,000 D?r to less than 100 DPMu An analysis of che alkaline l flush pond discharge revealed radioactive isotopes "not present" as defined by 10CFR20, Appendix 3, note 5 An investigatica indicated that approximately 1860 gallons of con.aminated water had entered the above flow path since 3/30/79. Operations practice pricr to 3/30/73 as -c pure the drain <aste to 55 gallon drums t- prevent entry of decca chemicals to the Unit 1 floor drain system.

A causervative estimate for an up; er limit of total activity released to the envi ro nment is approximatel; 17 millicuries. This was obtained assuming all IS60 gall'as eleased reacned the environment and aas composed of the nuclides present in the sample of Cecun Room sink licuid ca 3/30/79.

lili; curie levels for each isotopa wece:

Co 58 - 3.05 millicurie Co 60 - z.79 millicurie Cr 51 - 2.00 millicurte Zr 95 - .23 millicurie 5!n 54 - .dc mitlicurie Fe 59 - 1.~3 clllicurie lo.73 millicurie Radiation survey revealed the following-

a. Contamination was confined to discrete areas on the 77', 87' and 1C0' elevations, ficor drain system and the tendon access gallery of the Unit 2 Auxiliary Building.

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b. The Unit 2 Auxiliary Building elevations above 100' were clear of contamination. Areas above 100' that were surveyed provided the egress path from the lower Auxiliar-j Building levels.

c. Surveys of the clock alley and time card rack indicated no contamination.

d. Surveys of Construct"on personnel who were working in the immediate area at the time in .cated shoe contamination in 3 cases. The highest reading was 500 DPM- This survey was conducted after the normal c,uitting time for Construction personnel. The shoes were dispositioned in accordance with FNP-0-RCP-29.

Der:ntamination of tae Unit 2 Auxiliary lower levels commenced and the pumps in the tenden access galtery :ere placed under administrative cont'rols to prevent thet: inaavertent t pe rr. tion.

Based on the survey results of the upper lesels of the Auxiliary Building and the clock alley, it was determined that loose surface contamination was not being tracked out o f the building.

A meeting was held with Construction and Production supervisory personnel regarding Auxiliar/ Euilding clean up , survey of potentially af fected personnel and environmental monitoring. Notifications were made to the NRC, ANI and the State of Alabama.

On 5/15/79, approximately 324 Construction personnel that could have been in the affected area were monitored. Results of the monitoring indicated 11 workers had fixed contamination on their shoes varying from 400 DP:In to 10,000 DEMu .Al s o , two pairs of contaminated gloves with a reading of 6,000 DP.te and 20,000 DP.?- eere discovered. Whole body counts of the 11 workers revealed negative results. Based ou his survey, the cars in which the 11 had ridden ;.ere surveyed with no conta...;aation found. On surveying the houses of the 11 personnel, 3 pairs of pants and one shirt were found to have fixed contamination. Contamination on the pants was confined to the knee area ..ith :antamination levels /arying from 2,000 DP.?'i to 20,000 DPM* The contaminatior level on the shirt was 500 DPM* All contamintion or clothing and shoes was fixed. Various other articles of clothing were sus eyed during the eee?. of ~. fay 14th with no contamination found.

Appropriate environmental sampling was conducted the week of May 14th.

The health and cafet; of the public wet- not affected.

DESIGNATICS OF APPARE.T CACSE The decontamination room (Room 406), Auxiliary Building, Elevation 153', is located on the dividing line (Line 19) between Units 1 and 2 and is presently accessible from Unit i for security purposes only and locked and barricaded to Unit 2. This shared room is not separated by a barrier which clearly divides the room between Unit 1 and Unit 2. As a result, it was incorrectly assumed that all of the drains went to the Unit 1 floor drain system.

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l On 9/4/78 Shop Work Order 2809 was completed which installed sinks in the room, and this routed their effluent to sink drains leading to Unit 1.

Dra ings related tc the ;econtamination room are as follows:

a. Unit 1 P & ID (D-175004, sheet 1, Rev. 13) - 3 capped sink drains, I uncapped wash pan draia and I uncapped floor drain.

b. Unit 1 Drain Piping Plan (D-175207, Rev. 18) - same as c.

c. Unit 2 ? E ID (D-205004, sheet 1, Rev 7) - 3 capped sink drains and I uncapped floor dra_2.

Unit 2 Drain Piping Plan (D-205207, Rev. 5) - same as e except sink drains uncapped.

Inadequate design change control resulted in decontamination sinks being installed with their effluent rou 1 to Unit 2 drain piptag, that was shown capped on engineering drawings.

COFRECTIFE ACTION The following corrective actions have been accomplished:

a. Immediately afte. the incident, affected Unit 2 Auxiliary Building areas were roped off and posted with appropriate radiation warning signs.

b. An investtgatica was performed oy an engineer to determine if any other drair.s went from Unit I to Unit 2. A total of 6 drains, including 4 in the decontamination room, were located and plugged. Also " Hold" tags have been placed.

c. Discnarges fram the tendon a cess gallery .rere placed under administrative c^ntrol a f:er the incident. These restrictions were lifted following i decontaminatica. (

d. I:.c ide n h2s been discussed with appropriate supervisory personnel with respcasibilities in implementing design changes.

e. All affected Enit 2 Auxiliary Building areas and pipi , nave been deconcami.ated. Portions of the affected piping system have low levels >i fixed contamination that could not be removed by acid cleaning er flushing. These lines have been placed under administrative cont: hy piacing apprapriate signs (" Caution Radioactive Materials" and .o t cut, burn or otherwise disturb this pine without Health Physics approval").

NC TE -. 0 Radiation Levels at Contact with S'.rface, Taken with Eberline Count Rate Meter, Model E140/hP210.

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