ML20211H686
| ML20211H686 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 09/29/1997 |
| From: | Peckham M NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLS970172, NUDOCS 9710070073 | |
| Download: ML20211H686 (4) | |
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-=wn-NLS970172 September 29,1997 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 0001 Gentlemen:
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Subject:
Special Report on Augmented Off Gas Outage Cooper Nuclear Station, NRC Docket 50 298, DPR 46 The subject Special Report is forwarded as an enclosure to this letter. This Special Report is required to fullill the requirements of the Cooper Nuclear Station (CNS) Technical Specifications whenever the l
Augmented Off Gar (AOG) system is isolated for an extended period of time.
Sincerel'.
k hi. F. Peckham Plant hianager
/dm Enclosure cc: Regional Administrator USNRC - Region IV
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Senior Project hianager
). M USNRC - NRR Project Directorate IV 1
/g' Senior Resident inspector USNRC 9710070073 970929 PDR ADOCK 05000290 8
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Attachment to N1.S970172 Page1of2 SPECI AL REPORT FOR AUGMENTEI) OFF GAS OUTAGE i
1.0 INTRODUCTION
In confarmance with the requirements of the CNS Technical Specifications this report describes the effects of an extended outage of the Augmented OfrGas (AOG) system. Technical Specifications Section 121.C.4.c states:
"In the event radioactive gasJVom the main condenser air elector is discharged in l
efhient airfor more than 7 dco s without treatment by charcoal adsorbers or in the event that air is discharged via an exhaust ventilation treatment.sy.stemfor more than 31 days without treatment and the limit ofSpecification 3.21.C..l.b is exceeded, prepare and submit a Special Report to Ihe NRC, pursuant to Specillcation 6.3.3 and in lieu afany other report, which identifies the inoperable equipment and describes the corrective action taken. "
2.0 DISCUSSIO.N On July 13, following an unplanned halfitPS trip, the AOG system isolated in accordance with the design of the system it was noted that following the AOG isolation there was a high influx of water into the Z sump. As detailed in 1.icensee Event llepod (LEll) 97 010 this resulted in th; Standby Gas Treatment (SGT) system being declared inop;rabk. In uider to tuaintam SOT operable, the AOG system was secured. On July 21,1997, the AOG system was returned to service based on verification that the drain line from the 48 inch holdup line to the Z sump was not blocked. Subsequent performance of a surveillance procedure indicated that this corrective action was inadequate and the AOG system was again secured on July 21,1997, and the SGT system declared operable. With the AOG system secured, the ef1luent releases from the plant are increased but, based on a dose projection, the dose to a Member of the Public will remain within the limits established by the CNS Radiological Efiluent Technical Specifications.
Since the AOG was out of service Ihr longer than 7 days a Special 1(eport is required to fulfill the Technical Specification requirements. A summary of this evaluation and its conclusions is as follows:
1)
The time period during which the AOG system was isolated was July 13 to August 28, 1997. A s noted above, the AOG system was returned to service for a short pcriod, about i 1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, on July 21,1997, until it was determined that the corrective action to assure SGT operability was inadequate.
4 Attachment to NLS970172 Page 2 of 2 2)
An evaluation of the dose efTects to the public has been performed, considering the elTects of operation with the A00 isolated. This evaluation projected that the dose consequences to a Member of the Public will remain within the limits established by the CNS 1(adiological lif1luent Technical Specifications.
3)
A plant modification is being installed whose objective is to prevent a large water influx into the Z sump when the ADO system is secured.
4)
The plant modification was sufliciently implemented so that the ADO system was placed into operation on August 28,1997 and is presently operating nonnally.
3.0 COPRIICTIVl! ACTION l
The District developed and is implementing a Design Change to prevent excessive water holdup in the A00 system piping during system operation, installation of this modification is sufliciently complete to allow the ADO system to be placed in operation without alTecting the operability of the SOT system.
4.0 CONCLUSION
The projected ofTsite dose increase, due to the ADO outage and based on an assessment of compliance to the Technical Specification lirnits, indicates that the dose consequences to a Member of the Public will remain within the limits established by the CNS Itadiological lif1luent Technical Specifications.
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.ATTAcitMENT 3 1IST OF NRC COMMITMENTS I
Correspondence 110:
11LS 97 01 U i
i The following table identifies those actions committed to by the District in this document.
Any other actions discussed in the eut.nitt ai repr esent intended or platined actions by the District.
They :.se described to the NRC for the 11RC's information and are not regulatory commitments.
Please notify the Licensing Manager at Cooper 14uclear St.ation of any questions regarding this document or any associated regulatory comm tment s.
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COMMITTED IMTE COMMITMENT OR OUTAGt NONE gg l
PROCEDURE NUMliER O.42 l
k'!. VISION NUMBER 5 l
PAGE 4 OF 13 l
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