B16268, Special Rept:On 970205,declared Main Stack-Wide Range Noble Gas Monitor Inoperable.Caused by Inadequate Calibr Methods. Will Revise Calibr Procedure to Technique to Demonstrate Accuracy & Linearity Over Intended Range of Monitor

Special Rept:On 970205,declared Main Stack-Wide Range Noble Gas Monitor Inoperable.Caused by Inadequate Calibr Methods. Will Revise Calibr Procedure to Technique to Demonstrate Accuracy & Linearity Over Intended Range of Monitor

ML20134Q353
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	02/19/1997
From:	Bouchard G CONNECTICUT YANKEE ATOMIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
B16268, NUDOCS 9702260399
Download: ML20134Q353 (5)

Text

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CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT 362 INJUN HOLLOW ROAD e EAST HAMPTON, CT 06424-3009 February 19,1997 Docket No. 50-213 B16268 Re: HNP Technical Specification 3.3.3.5 HNP Technical Specification 6.9.2 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Haddam Neck Plant Special Report i

The purpose of this letter is for the Connecticut Yankee Atomic Power Company l (CYAPCO) to submit a Special Report (Attachment 1). This Special Report is provided in accordance with the Haddam Nec.: Plant (HNP) Technical Specification 3.3.3.5, Table 3.3-7, item 18, Action 37 and the HNP Technical Specification 6.9.2. This report i is historical in nature, covering the period previous to July 22,1996.

On February 5,1997, routine surveillance testing of the Main Stack - Wide Range Noble Gas Monitor (RMS-14B) was completed (duration: 4 days). On  !

February 5,1977, preliminary results from an ongoing radiological effluents audit indicated that the calibration methods employed for the Main Stack - Wide Range Noble Gas Monitor were inadequate to demonstrate that the Stack Monitor would respond to i the intended range and accuracy of known values of input. HNP Technical '

Specification 3.3.3.5, Table 3.3-7, item 18 requires that the monitor be operable in Modes 1 through 4. The HNP has been shutdown since July 22,1996 and in a letter dated December 5,1996,W CYAPCO informed the NRC that the Board of Directors of CYAPCO had decided to permanently cease operations at the HNP and that the fuel had been permanently removed from the reactor.

l 2600"3 l (1) T. C. Feigenbaum letter to the U. S. Nuclear Regulatory Commission,

" Certifications Of Permanent Cessation Of Power Operation And That Fuel Has Been Permanently Removed From The Reactor," dated December 5,1996.

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97o2260399 970219 s PDR ADOCK 0500o213 l S PDR l

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, 0l S. Nuclur R gulatory Commission 816269/Page 2 l

4 The calibration methods employed do not ensure that the electronic portions of the

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circuitry are accurate throughout the entire range of the instrument, and detector calibrations do not verify the counting efficiency of the detector, therefore, linearity and response over the intended range of the channels cannot be demonstrated. Due to this miscalibration, the operability of RMS-14B is in question for the period previous to July 22,1996. Pursuant to HNP Technical Specification 3.3.3.5, Table 3.3-7, item 18, Action 37 and HNP Technical Specification 6.9.2, this report is required to be filed within ten days of the end of the seven day action statement.

If you should have any questions, please contact Mr. G. P. van Noordennen at (860) 267-3938.  ;

t Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY FOR: Jere J. LaPlatney Haddam Neck Unit Director i

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ddryll. Bbu' chard I M /

l Haddam Neck Work Services Director cc: H. J. Miller, NRC Region I Administrator M. B. Fairtile, NRC Project Manager, Haddhm Neck Plant W. J. Raymond, NRC Senior Resident inspector, Haddam Neck Plant

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Docket No. 50-213 B16268 l

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I Attachment 1 Haddam Neck Plant Special Report inoperable Main Stack - Wide Range Noble Gas Monitor i

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February 19,1997

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, 0..S. Nucl:ar Regulatory Commission l

.' 4 B16269/ Attachment 1/Page 1 I

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Soecial Reoort inocerable Main Stack - Wide Ranoe Noble Gas Monitor introduction

{ The Main Stack-Wide Range Noble Gas Monitor, RMS-14B, is intended to be used j during accident releases. It is designed to measure radioactive gas concentrations in the range of 1.0E-07 to 1.0E+05 microcuries/cc of Xenon-133. This range is significantly larger than the capabilities of the other stack monitor, RMS-14A.

RMS-14B is calibrated and functionally checked on a quarterly basis using Station j Procedure SUR 5.2-69 (" Calibration and Functional Check of the Main Stack-Wide i Range Noble Gas Monitor (RMS-14B)").

l HNP Technical Specification 3.3.3.5, Table 3.3-7, item 18 requires that the monitor be

operable in Modes 1 through 4. The HNP has been shutdown since July 22,1996 and

in a letter dated December 5,1996,W CYAPCO informed the NRC that the Board of

! Directors of CYAPCO had decided to permanently cease operations at the HNP and

that the fuel had been permanently removed from the reactor.

l Discussion j On February 5,1997, preliminary results from an ongoing radiological effluents audit ,

i indicated that the calibration methods employed for the Main Stack - Wide Range Noble  !

] Gas Monitor were inadequate to demonstrate that the Stack Monitor would respond to l

! the intended range and accuracy of known values of input. The calibration methods j

] employed do not ensure that the electronic portions of the circuitry are accurate l throughout the entire range of the instrument, and detector calibrations do not verify the ,

l counting efficiency of the detector, therefore, linearity and response over intended I

range of the channels cannot be demonstrated. Due to this miscalibration, the operability of RMS-14B is in question for the period previous to July 22,1996. Pursuant j to HNP Technical Specification 3.3.3.5, Table 3.3-7, Item 18, Action 37 and HNP

! Technical Specification 6.9.2, this report is required to be filed within ten days of the j end of the seven day action statement.

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. The calibration procedure is being revised to improve the calibration technique to i demonstrate accuracy and linearity over the intended range of the monitor, t

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(1) T. C. Feigenbaum letter to the U. S. Nuclear Regulatory Commission, j " Certifications Of Permanent Cessation Of Power Operation And That Fuel Has

Been Permanently Removed From The Reactor," dated December 5,1996.

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, ' d..S. Nucisar Regulatory Commission B16269/ Attachment 1/Page 2 During the time that the Main Stack -Wide Range Noble Gas Monitor is out of service, routine gaseous effluents are adequately monitored with the back-up stack monitor, RMS-14A. Should an event have occurred that resulted in the radioactive effluent release rate increasing beyond the range of the back-up stack monitor, back-up procedures (Emergency Plan implementation Procedures) are in place for radiation dose assessment, including the use of radiological field teams. These procedures provide adequate means to determine effluent release rates based upon calculations using field data.

On the basis that adequate alternate capabilities using the back-up stack monitor and Emergency Plan procedures are in place, the inoperability of RMS-14B imposed a low safety significance on CYAPCO's ability to assess the dose consequence of a major -

gaseous release.

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