ML20215J135

Safety Evaluation Re Spill of Sulphuric Acid at Plant on 860322.Licensee Monitoring & Recovery Sys Adequate to Contain & Eliminate Existing Acid Plume.No Addl Measures Recommended

ML20215J135
Person / Time
Site:	Grand Gulf
Issue date:	05/04/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20215J124	List: ML20215J120 ML20215J135
References
TAC-61356, NUDOCS 8705070239
Download: ML20215J135 (2)

Text

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1. o,, UNITED STATES

5 E e NUCLEAR REGULATORY COMMISSION s a WASHINGTON, D. C. 20555

% . . . . . ,o

,i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION j

RELATING TO THE SPILL 0F SULFURIC ACID AT GRAND GULF UNIT 1 SYSTEMS ENERGY RESOURCES. INC.

DOCKET NO. 50-416 i

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1.0 INTRODUCTION

1 On March 22, 1986, the Grand Gulf L: lear Station detemined that approximately 2000 gallons of 98% sulfuric acid could not be accounted for. Plant personnel conducted a search and the spill was confirmed on March 23, 1986. A leak had occurred in an underground pipeline which feeds acid from a bulk storage tank to an acid day tank inside the water treatment building. System Energy j

i Resources. Inc., formerly Mississippi Power and Light Co. (the licenseel, notified the NRC and the Mississippi Department of Natural Resources (MONR).

Under MDNR direction a monitoring and cleanup operation was initiated. The recovery operation is still <}oing on.

The only safety concem with regard to the spill was safety related piping (or

} piping important to safety) which might be adversely affected by the acidic 4

soil. The applicant identified two 8 inch service water pipes which fill the

! two 3000,000 gallon fire water storage tanks as being located within the area

' of the acid located within spill.

theNo other spill area. fire protection or safety related piping is A

2.0 EVALUATION j  !

Thirteen monitoring wells, eight of which are dewatering wells, are located around the acid affected area and are monitored weekly for pH and water level elevation. Effluent pH in one well ranges from 2.5 to 3.5 and from 6.2 to 8.7

{ in the remaining 12 wells, i

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' Two wells are in the imediate vicinity of the pipe. One of these wells was j

used as an extraction point during a post incident water flushing operation, Soil samples taken during installation of the well indicate that the primary i

i acid spill was well below the pipe. However, the pipe may have been exposed to a weak acid solution at the time of the flushing. The pipe has a coal tar i enamel coating which should offer protection from weak corrosive environments.

In addition, the exposure time was relatively short, in that the groundwater

! being withdrawn around the pipe has had a pH of 6 or more since September 1986 4

The licensee has also taken precautions to assure that a similar spill will not occur. These precautions include:

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1) replacement of the existing carbon steel acid line with acid resistant piping; 8705070239 870504 PDR ADOCK 05000461

} SS PDR

2) acid venting directly to the sump rather than the floor drain; and

3) replacement of temporary acid storage tanks with permanent tanks.

3.0 CONCLUSION

S The only pipe (with a safety function) likely to have been exposed to even a weak acid solution is the plant service water line that supplies makeup water to the fire water storage tanks. The pipe is coated with a substance which is expected to have protected the pipe during the time of exposure to the weak solution and no leaks are expected.

The staff concludes that the licensee's monitoring and recovery system is adequate to contain and eliminate the existing acid plume. The staff does not recommend that any additional measures be undertaken at this time.

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