ML20202G282
| ML20202G282 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/04/1997 |
| From: | Peckham M NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLS970204, NUDOCS 9712090335 | |
| Download: ML20202G282 (4) | |
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uc--nwwxmamammm = =~~=x==wsunan=====w~=-+w===a NLS970204 December 4,1997 U.S. Nuclear Regulatory Cot amission Attention: Document Control Desh Washington, D.C. 20555 0001 Gentlemen:
Subject:
Special Report on Augmented Off Gas Outage Cooper Neclear Station, NRC Docket 50-298, DPR-46 The subject Special Repor' is forwarded as an enclosure to this letter. This Special Report is required to fulfill the requirements of the Cooper Nuclear Station (CNS) Technical Specifications whenever the Augmented Off Gas (AOG) system is isc, lated for an extended period of time.
Sincerely, et M.1. Peckham Plant Manager
/dm Enclosure ec: Regional Administrator
. _ p' USNRC - Region IV
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Senior Project Manager USNRC - NRR Project Directorate 1%1 l
Senior Resident in pector USNRC-9712090335 971204 PDR ADOCK 05000298 8
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- Attachment to i 1NLS970204 --
-Page1of2 SPECIAL REPORT FOR AUGMENTED OFF GAS OUTAGE
1.0 INTRODUCTION
In conformance with the requirements of the CNS Techrhal Specifications this report describes the effects of an extended outage of the Augmented OfTGas (AOG) system. Technical Specifications Section 3.21 C.4.c states:
"In the event radioactive gasfrom the main condenser air ejector is discharged in effluent airfor more than 7 days without treatment by charcoal adsorbers or in the event that air is discharged via an exhaust ventilation treatment systemfor more than 31 days without treatment and the limit ofSpecification 3.21.C 4.b is exceeded, prepare and submit a Special Report to the NRC, pursuant to Specipcation 6.5.3 and in lieu ofany other report, which identifles the inoperable equipment and describes the corrective action taken. "
2.0 DISCUSSION On October 14,1997 at approximately 0053 indications of a hydrogen burn in f
- mff gas system were received and appropriately acted on by the Operations Crew on watch. Prowdures were followed based upon the indications existing at that time which required the bypassing of the AOG charcoal beds and subsequently the removal of the AOG system from service. The requirements challenged by this event are to maintain the charcoal beds in service to comply with the operating license and to preclude plant challenges to the operations staff. Further investigations eliminated the possibility of a hydrogen burn and determined that the most likely cause of this event was a valve malfunction, however, no definitive cause has been determined from the investigations. It has been established that there was a steam intrusion into the 48 inch off gas. holdup line which condensed and the condensate then flowed into the Z sump. A total of -
about 250 to 300 gallons of water was then pumped from the sump to radwaste.
Since the AOG was out of service for longer than 7 days a Special Report is required to fulfill the
-Technical Specification requirements. Accordingly:
-1)
- The AOG system was isolated on October 14 cnd on November 19,1997, the AOG was placed back in senice, using the Special Procedure discussed below. Charcou beds B, C, E, and F were placed in senice with charcoal beds A and D bypassed. On November 21, the AOG charcoal beds B, C, E and F were also bypassed due to moisture content. On November 29,1997, the AOG LCO was exited since all of the charcoal beds were placed
Attachment to Niq97020,4 Page 2 of 2 back in service and are functioning normally with the Elevated Release Point (ERP) radiation monitors indicating a normally expected release. Ilowever, the hydrogen analyzers are not as yet operable and the Special Procedure is in effect to ensure that full AOG system operation is restored.
2)
An evaluation of the dose effects to the public has been performed considering the effects of operation with the AOG isolated. This evaluation projected that the dose consequences to a Member of the Public v:ill remain within the limits established by the CNS Radiological Ef0uent Technical Specifications.
3.0 CORREC.UVE ACTION 1)
Maintenance was performed on AOG system components to assure reliability of these components during the iestart process.
2)
Tbc AOG system charcoal adsorbion function is operable with the offsite radiation releases in the normally expected range. The system is still under the provision of the Special Procedure to ensure adequate monitoring of the system performance and to bring the hydrogen analyzers on line.
4.0 CONCLUSION
The projected offsite dose increase, due to the AOG outage and based on an assessment of compliance to the Technical Specification limits, indicates that the dose consequences ta a Member of the Public will remain within the limits established by the CNS Radiological Efiluent Technical Specifications.
l ATT/WH!>FtJT 3 ! ICT OF fiRC COMMITMLtJTS j
Correspondence !Jo:,J11S M0204 The$olldwing table identifies ti.ose actions condnitted to by the District in this docurwnt.
Any other actions discustsed in the su'>mittal represent intende' or planned actions by the District.
They are described to the tiRC for the rJRC's information and are not regulatory cortmitt.ient s.
Please notify the 1,1 censing Manager at Cooper IJuclear Station of any questions regarding this document or any associated regulator y cone.itmente.
COMMITTED DATE COMMITMF.tJT OR OUTAGE None 4 wassese, l
PROCEDURE NUM3ER 0.42 l
REVISION NUMBER S l
PAGE 4 OF 13 l
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