ML19210E398
| ML19210E398 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 11/26/1979 |
| From: | Graves R CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| CYH-79-251, NUDOCS 7912040501 | |
| Download: ML19210E398 (2) | |
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CONNECTICUT YANKEE ATO MIC POWER COMPANY HADDAM NECK PLANT RR
- 1. BOX 127E. EAST H AMPTON, CONN. 06424 November 26, 1979 CYH 79-251 U. S. Nuclear Regulatu/y Ccamission Begion 1 Office of Inspection and Enforcement 631 Park Avenue King of Prussia, Pennsylvania 19406 Attn:
Mr. Boyce Grier, Director
Reference:
Facility Operating License No. DPR-61 Docket No. 50-213 ETS-NR/50-213/79-05
Dear Mr. Grier:
On November 16, 1979 approximately 460 gallons of 12" sodium hypochlorite was inadvertently released to the rivers' edge over a fifteen hour period.
' mis release was reported by telephone at 1615 on November 16, 1979 to the Region 1 Office of Inspection and Enforcement, as required by the Connecticut Yankee Environmental Technical Specifications, Section 2.3.1.5, as a result of the chlorination period exceeding the 120 mitutes per day limitation, and exceeding the allowable total residual chlorine concentration of 0.1 milligram per liter during chlorination.
Section 5.6.2a(1) requires a written report, concaining a more detailed description, be submitted to your office within ten days. Attachment "A" contains the required information.
Very truly yours,
$; p.%
Richard H. Graves Sta tion Superintendent 1475 095 C%g i k RHG:JML/j hb Attachment I
cc: Dir., Office of Nuclear Reactor Regulation, Washington, D. C.
(17) 7912040 [ O ! s
P ATTACHMENT A On November 15, 1979 at 0655 hours0.00758 days <br />0.182 hours <br />0.00108 weeks <br />2.492275e-4 months <br /> the hypochlorite system was tagged out because divers were cleaning the trash racks.
The system was put back into service at 1730 hours0.02 days <br />0.481 hours <br />0.00286 weeks <br />6.58265e-4 months <br /> on November 15, 1979. At approximately 0700 hours0.0081 days <br />0.194 hours <br />0.00116 weeks <br />2.6635e-4 months <br /> on November 16, 1979 it was discovered that the system pumps had been tunning continuously since the system was returned to service the previous evening.
The pumps were i= mediately shutdown.
It has been determined that approximately 460 gallons of 127. sodium hypochlorite was released through the tank overflow line to the river.
This release took place over a fifteen hour period.
This incident is a repetitive occurrence. A sLailar occurrence took place on May 17, 1979 and was reported under ETS-NR/50-213/79-04 dated May 25, 1979.
Investigation of this incident led to the conclusion that operator error and system design were the cause of the release.
The operator error was a combination of improper removal and return of the system tc service.
This was a procedural error.
The system design error was two fold:
1.
The overflow line dumped directly to the river, 2.
The electrical timer scheme for the pump starting and stopping appears to have a design flaw.
The first of these two problems has been eliminated by routing the overflow line into the diked area around the tank, instead of directly to the river.
The second problem is being investigated, and if determined to be a design flaw it will be corrected by January 1,1980 pending approval of design changes and possible material acquisition.
Grab samples at the intake structure showed the residual chlorine concentration to be 0.24 milligrams per liter which exceeds our limit of 0.1 milligrams per liter.
Visaal inspection of both the intake structure area and the discharge canal showed no detrimental effects to the environment or aquatic life as a result of this release.
1475 096