ML20091E846: Difference between revisions

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#REDIRECT [[HL-1925, NPDES Noncompliance Notification:On 911107,sample from Cooling Tower Basin Recorded Value Greater than 2 Ppm Free Available Chlorine/Total Residual Chlorine.Caused by Malfunction of Valve Torque Switch.Valve Manually Secured]]
| number = ML20091E846
| issue date = 11/15/1991
| title = NPDES Noncompliance Notification:On 911107,sample from Cooling Tower Basin Recorded Value Greater than 2 Ppm Free Available Chlorine/Total Residual Chlorine.Caused by Malfunction of Valve Torque Switch.Valve Manually Secured
| author name = Beckman J
| author affiliation = GEORGIA POWER CO.
| addressee name =
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05000366
| license number =
| contact person =
| document report number = HL-1925, NUDOCS 9111220001
| document type = NPDES NONCOMPLIANCE NOTIFICATION, TEXT-ENVIRONMENTAL REPORTS
| page count = 4
}}
 
=Text=
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neor                t HL-1925 002522 November 15, 1991 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 PL ANT HATCH - UtilT 2 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 HPDES PERMIT NONCOMPLIANCE Gentlemen:
In accordance with the requirements of Plant Hatch Environmental Technict i                Specifications, Section 4.3, attached is a copy of a report made s                    to tP ueorgia Department of Natural Resources concerning a noncompliance s                    with rlPDES permit number GA.0004120.                        This report is applicabic to Plant      k Hatch - Unit 2.
Should you have any questions, please contact this office.
Sincerely, a yrL L                              -
J.T.Beckham,Jr.M b/
JKB/cr 002522 Enclosure cc: 0_eorcia Power Company Mr. H. L. Sumner, General Manager - Nuclear Plant NORMS U.S. Nuclear Rgaulatory Commission. Washinoton. D.C.
Mr. K. Jabbour, Licensing Project Manager - Hatch V . S . Nuc1 e a.r_Legul a t o r y C ommi s s i on . RestigrLil Mr. S. D. Ebneter, Regional Administrator Mr. L. D. Wert, Senior Resident inspector - Hatch
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U r,e;er utennnga,9ccc e,, rice                      November 12, 1991 ELANT HATCl!
NPDES Permit No. GA0004120 Unit 2 Cooling Tower Blowdown Valve Mr. Lawrence W. Hedges Program Manager, Industrial Waste Water Program 205 Butler Street, SE - Room 1070 Atlanta, Georgia 30334
 
==Dear Mr. Hedges:==
 
Attached la a description of the Unit 2 Cooling Tower Blowdown Valve malfunction and unplanned release of chlorine to the Altamaha River which was previously reported to you on November 7, 1991. This report is submitted in accordance with Part II A.2. of the above referenced NPDES permit.
If you have questions or comments, please advise.
Yours very truly, b.h  hkw~
C. M. Hobson
                                                                                                                                              ~
GNG:kd Attachment xc:      Mr. Larry P. Kloot, Environmental Engineer
 
Plant E. I, llatch HPDES Permit No. GA0004120 Descrintion of Event on Thursday November 7, 1991, at approximately 08n0 EST, Plant Hatch began a normal chlorination cycle for the Unit 2 circulating water system. The cooling tower flume level had been previously lowered and sodium hypochlorite was injected into the system until approximately 0815 EST. After closing the valve on the sodium hypochlorite tank, Plant Hatch chemistry personnel obtained a sample from the cooling tower basin and recorded a value of greater than 2 ppm Free Available Chlorine / Total Residual Chlorine (FAC/TRC), Chemistry personnel then proceeded to obtain a sample from the flume. At this time it was observed that the flume level had decreased significantly. Operations personnel investigated the situation and determined that the Unit 2 cooling tower blowdown valve was open. The Unit 2 control room was immediately notified, and the valve was manually closed locally.
As a result of the valve being open, not all of the NPDES Permit requirements for monitoring of the Unit 2 cooling tower blowdown line during periods of chlorination were satisfied. Samples are not required to be routinely taken from the cooling tower blowdown line; therefore, there were no samples taken from the line during the approximato 50 minute period of unplanned chlorine discharge.
The discharge from the blowdown valve was diluted with other effluent water streams prior to discharge to the Altamaha River.
No adverse environmental impact w..s observed to have occurred as a result of the period of unmonitored chlorine discharge, cause of Event The primary cause of the event is attributed to malfunction of the Unit 2 cooling tower blowdown valve torque switch. Failure to follow procedure contributed to the cause of the event. The Operations procedure requires the operator to observe the flume level when the blowdown valve is open and to observe the flume level for one hour following manipulation of the valva until the flume level stabilizes.          In this case the operator returned to the control room for shift change without waiting the prescribed time of one hour. This resulted in the decrease in flume level remaining unobserved during the discharge to the river.
Prior to b-, ginning the chlorination process the cooling tower blowdown valve had " red and " green" position indicating lights illuminated. The normal indication for valve position is " red" for open and " green" for closed. A
* red" and " green" indication reflects the valve being in an irmediate position.                          The valve was confirmed to be in the closed position earlier in the shift with both lights on the panel illuminited. Though not required this confirmation was normally performed as a good practice and consisted of a verification that lilution flow from the valve as
 
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zero as read in the radwaste control room. On the morning of November 7, 1991, the valve was returned to the closed position following operation of the valve to lower the flume level. At this time both indicating lights again were illuminated.                                  The cooling tower blowdown valve torque switch malfunctioned such that the valve did not properly close. This failure to close was not proporly identified due to the malfunction of limit switches which provide the open and closed valve indication in the control room.
The torque switch senses valve closure and terminates valve movement. No additional verification of the valvo position as previously described was conducted when both indicating lights were illuminated. The operator assumed the valve was closed and approved the initiation of circulating water system chlorination.
However, the torque switch had malfunctioned and the valve remained in an intermediate position.
As a rusult of the torque switch malfunction and the failure to properly follow the procedure the valve remained open during the chlorination cycle.
Entiod of Event The duration of the event was approximately 50 minutes.
Chlorination of the Unit 2 circulating water system began at approximately 0800 EST and was terminated at 0815; the blowdown valve was secured at approximately 0850 EST.
Actions Taken to Reduce, Eliminate, and Prevent RecurrRD92 Upon discovery of the open condition, the blowdown valve was manually secured. Chlorination of the circulating water systen was suspended pending investigation into the cause of the problem. No additional mitigative action was necessary. No adverse environmental impact to the Altamaha River was observed as a result of the incident.
Georgia Power Company Environmental Affairs was notified upon confirmation of details associated with the incident.
Environmental Affairs notified Mr. Lawrence Kloot, State of Georgia Environmental Protection Division (EPD), of the incident at approximately 1415 EST. The Nuclear Regulatory Commission vac subsequently notified.
The torque svitch and the position indication circuitry for the Unit 2 cooling tower blowdown valve have been repaired.
Appropriate personnel will be counseled with regard to the failure to follow the referenced procedure.
EUFEJ:Y Based on assessment of the above information, no adverse environmental impact to the Altamaha River occurred as a result of this incident.                                Plant Hatch has taken appropriate actions to ensure the incident does not recur.
The above information is submitted in accordance with the provisions of Part II A. 2. of the Plant Hatch NPDES Permit                                (No.
GA0004120).
_}}

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