ML19289F241

Nonroutine Environ Operating Rept Discussing 790330-0514 Drainage of 1,860 Gallons Contaminated Water Onto Unit 2 Floor Drain Sys.Caused by Inadequate Design Change Control. Drains Were Plugged

ML19289F241
Person / Time
Site:	Farley
Issue date:	05/25/1979
From:	ALABAMA POWER CO.
To:
Shared Package
ML19289F240	List: ML19289F239 ML19289F241
References
TR-790525, NUDOCS 7906050287
Download: ML19289F241 (3)

Text

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NON-ROUTINE ENVIRONMENTAL OPERATING REPORT May 25, 19 79 ANALYSIS OF EVENT:

At approximately 0800 on May 14,1979 an Alabama Power Co=pany Startup Supervisor notified the Chemistry & Health Physics Supervisor that it was possible tha t some of the decontamination room drains were routed to the Unit 2 floor drain sys tem.

By 1500 on 5/14/79 it was determined conclusively that 4 decontamination room s inks were connec ted to the Unit 2 floor drain system rather than the Unit 1 floor drain syste=. This determination was made by sampling of a Unit 2 Auxiliary Building, 7 7 ' Eleva tion, su=p.

The flow path for the ef flu 2nt from the 4 decontamination room sinks ran to a sump on the 77' eleva tion 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-of f to the Cha ttahoochee River. Radia tion surveys were conducted in the Auxiliary Building along the flow path with readings varying from 70,000 DPM*to less than 103 DPM". An analysis of the alkaline flush pond discharge revealed radioac tive isotopes "not present" as defined by 10CFR20, Appendix B, note 5.

An investigation indicated that approximately 1860 gallons of contaminated water had entered the above flow path since 3/ 30/79. Operations prac tice prior to 3/30/ 79 was to pump the drain waste to 55 gallon drums to prevent entry of decon chemicals to the Unit 1 floor drain system.

Radiation surveys revealed the following:

a. Contamina tion was confined to discrete areas on the 7 7 ' , 8 7 ' a n d 100 '

Elevations, floor drain system and the tendon access gallery of the Unit 2 Auxiliary Building.

b. The Unit 2 Auxiliary Building elevations above 100' were clear of con-tamina tio n . Areas above 100' that were surveyed provided the egress pa th frca the lower Auxiliary Building levels .

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

d. Surveys of construction personnel who 'were working in the immediate area at the time indica ted shoe contamina tion in 3 cases. The highest reading was 500 DPM*. This survey was conducted after the normal quitting tite for construc tion personnel. The shoes were dispositioned in accordance with FNP-0-RCP-29.

Decon tamina tion of the Unit 2 Auxiliary lower levels conmenced and tne pumps in the tendon access gallery were placed under administrative controls to preven t their inadvertent operation.

Based on the survey results of the upper levels of the Auxiliary Building and the clock alley, it was determined that loose surf ace contamination was not being tracked out of the building.

790605037 A?SG 053

A meeting was held with Construction and Production supervisory personnel regarding Auxiliary Building clean up, survey of potentially af fected personnel and en-vironmen tal monitoring. Notifications were made to the NRC, ANI and the State of Alabama.

On 5/15/ 79, approximately 324 construc tion personnel that could have been in the a f fec ted area we re monito red. Results of the monitoring indicated 11 workers had fixed con tamina tion on their shoes varying f rom 400 DPM* to 10,000 DPM*. Also, two pairs of centaminated gloves with a reading of 6,000 DP:I* and 20,000 DPM* were dis cove re d. Ynoic body counts of the 11 workers revealed negative results. Based oa this survey, the cars in which the 11 had ridden were surveyed with no con-tamination found. On surveying the houses of the 11 personnel, 3 pairs o f pan ts and one shirt were found to have fixed contamination. Contamina tion on the pants was confined to Qe knee area with contamination levels varying from 2,000 DPM*

to 20,000 DPM* . The contanination level on the shirt was 500 DPM*. All con-tamination on clo thing and shoes was fixed. Various other articles of clo thing were surveyed during the week of May 14th with no contamination found.

Appropriate environmental sampling was conducted the week of >by 14th. At this time, decon tamina tion of the Unit 2 Auxiliary Building and floor drain system is continuing.

The health and safety of the public were not affected.

DESIGNATION OF APPARENT CAUSE:

The decontamination room (Room 406), Auxiliary Building, Elevation 155 ', is located on the dividing line (Line 19) between Units 1 and 2 and is presently accessible from Unit 1 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 be tween 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.

On 9/4/ 73 Shop Ucrk Order 2309 was completed which installed sinks in the room, and this routed their effluent to sink drains leading to Unit 2.

Drawings rela ted to the decontamination room are as follows:

a. Unit 1 P & 1D (D-175004, shee t 1, Rev. 13) - 3 capped sink drains, 1 uncapped '; ash pan drain and 1 uncapped floor drain.

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

c. Unic 2 P & 1D (D-205004, shee t 1, Rev. 7) - 3 capped sink drains and 1 uncapped floor drain.

d. Unit 2 Drain Piping Plan (D-205 20 7, Rev. 5) - Same as e except sink drains uncapped.

Inadequate design change control resulted in decontamination sinks being installed with their effluent routed to Unit 2 drain piping, tha t was shown capped on engineering drawings.

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_ CORRECTIVE ACTION:

The following corrective actions have been accomplished:

a. Ir=ediately af ter the incident, affected Unit 2 Auxiliary Building areas were roped off and posted with appropriate radiation warning signs.

b. An investigation was perforced by an engineer to deternine if any other drains went from Unit 1 to Unit 2. A total of 6 drains, including 4 in the decontamination room, were located and plugged.

c. Discharges from the tendon access gallery uere placed under administrative control.

d. Incident has been discussed with appropriate supervisory personnel with responsibilities in implementing design change.

An investigation of the incident is continuing and a supplemental report will be issued.

NOTE:

• Radiation Levels at Contact with Surf ace, Taken with Eberline Count Ra te Me ter, Model E140/HP21J .