2CAN078504, Ro:On 850410,unmonitored Release of Radioactive Water Into Oily Water Separator Occurred.Caused by Inadvertent Opening of HX Drain During Maint Insp.Drain Closed After Approx 3 H. Dardanelle Reservoir Unaffected.Personnel Counseled
| ML20133F864 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/11/1985 |
| From: | Enos J ARKANSAS POWER & LIGHT CO. |
| To: | Hunter D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 2CAN078504, 2CAN78504, NUDOCS 8508080462 | |
| Download: ML20133F864 (2) | |
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o ARKANSAS POWER & LIGHT COMPANY POST OFFICE BCX 551 LITTLE ROCK. ARKANSAS 72203 (501) 371-4000 July 11, 1985 5hh
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JUL. 2 21985 Mr. D. R. IIunter, Chief Reactor Project Branch #2 U. S. Nuclear Regulatory Co.ission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011
SUBJECT:
Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Contamination of Oily Water Separator Gentlemen:
On April 11, 1985 at approximately 1435 hours0.0166 days <br />0.399 hours <br />0.00237 weeks <br />5.460175e-4 months <br /> a notification was made per 10 CFR 50.72 (b)(2)(vi). This notification resulted from a news release made regarding an unplanned, unmonitored release of radioactive water into the Dardanelle Reservoir. Followup investigation concluded that an unplanned, unmonitored release did not occur. This letter is intended to provide information regarding the event and the followup actions.
The occurrence took place during the ANO-2 refueling outage while in the process of inspecting the component cooling water (CCW) side of the letdown heat exchanger.
Contractor personnel were assigned to connect a temporary hose to the CCW side of the letdown heat exchanger so that it could be drained to facilitate inspection. The contractor personnel inadvertently connected the temporary hose to the primary side of the heat exchanger.
Contrary to procedures, on April 10, 1985 contractor personnel opened the drain valve in an effort to drain the CCW side of the heat exchanger. This action transferred reactor coolant system (RCS) water to a floor drain, which drained to the turbine building sump. From the turbine building sump, water could be transferred to the oily water separator and then to the Dardanelle Reservoir. Later, when contractor personnel discovered that the heat exchanger level had not decreased, plant personnel were consulted. Upon inspection of the work area, the error was discovered, and the draining operation was terminated. The drain valve was open for approximately three hours.
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.Mr. D.
R.' Hunter -July 11, 1985 Calculations were~promptly performed to determine the volume of RCS water drained from the letdown heat exchanger. These initial volume calculations coupled with Radiochemistry samples indicated a loss of 0.083 curies from the RCS. Samples from the turbine building sump and the oily water separator only accounted for 0.053 curies.
Consequently, it was' initially believed.that approximately 0.03 curies could have been released from the oily water separator to the Dardanelle Reservoir. Review of the volume calculations revealed that the volume initially provided_to Radiochemistry did not include temperature. effects in an effort to be conservative.
If the volume difference for temperature is included, a loss of only 0.0475 curies from the RCS would be indicated. This combined with oily water separator level observations during the occurrence time frame leads to the conclusion that an unplanned, unmonitored release to the Dardanelle Reservoir did not occur.
Contractor corrective actions included disciplinary action of the individuals responsible for the task, a notice to contractor personnel that only AP&L operators are allowed to operate plant equipment and unique identification to contract personnel of job orders which require Operations interface.
ANO personnel responsible for heat exchanger inspections met to discuss the event.
Items stressed were clarity of job orders and directions
'given to contractor personnel, attention to work scoping prior to writing job orders, and control room / Shift Supervisor involvement in all evolutions.
Additionally, after controlled monitored release of the radioactive water in the oily water separator, both the turbine building sump and
' the oily water separator were cleaned.
Very truly yours, J. Ted Enos Manager, Licensing JTE/PCR/djm l
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