ML20058F611
| ML20058F611 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 11/29/1993 |
| From: | Conway W ALABAMA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-TM 102-02741-WFC-R, 102-2741-WFC-R, NUDOCS 9312080199 | |
| Download: ML20058F611 (10) | |
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Arizona Public Service Company eo non nw. rwa m m on u m m 102-02741-WFC/RAB/DLK wwm r coww November 29,1993 usw.3g;7m P
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555
References:
1.
Letter 102-02464, dated March 30,1993, from W. F. Conway, APS, to USNRC, " Reply to Notice of Deviation 50-528/93-03-01" 2.
Letter dated September 3,1993, from J. H. Reese, USNRC, to W. F. Conway, APS, " Review of Palo Verde Nuclear Generating Station Response to Notice of Deviation 50-528/93-03-01" 1
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS)
Units 1,2, and 3 Docket Nos. STN 50-528/529/530 Reply to Notice of Deviation 50-528/93-03-01 File: 93-070-026 j
Arizona Public Service Company (APS) has reviewed Reference 2, and has prepared and enclosed a supplemental response to Notice of Deviation 50-528/93-03-01. APS' original i
response to the Notice of Deviation was provided in an enclosure to Reference 1. to this letter is a restatement of the Notice of Deviation. APS' supplemental response is provided in Enclosure 2. The entire revision to Section 11.5.2.1.6.2 of the i
Updated Final Safety Analysis Report is provided in Enclosure 3.
The due date for this response was extended from October 13, 1993, to December 1,1993, during a meeting and several telephone conversations with Mr. James Reese. The most recent telephone conversation was on November 10,1993.
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U'. S. Nuclear Regulatory Commission ATTN: Document Control Desk Reply to Notice of Deviation Page 2 l
Should you have any questions, please contact Richard A. Bernier at (602) 393-5882.
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Enclosures:
1.
Restatement of Notice of Deviation 2.
Reply to Notice of Deviation 3.
Revised UFSAR, Section 11.5.2.1.6.2 cc:
B. H. Faulkenberry l
J. A. Sloan
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ENCLOSURE 1 RESTATEMENT OF NOTICE OF DEVIATION 50-528/93-03-01 1
NRC INSPECTION CONDUCTED l
JANUARY 11,1993 THROUGH JANUARY 15,1993 j
AND FEBRUARY 10,1993 THROUGH FEBRUARY 12,1993 INSPECTION REPORT NOs. 50-528,529, AND 530/93-03 l
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RESTATEMENT OF NOTICE OF DEVIATION 50-528/93-03-01 During an NRC inspection conducted on January 11-15, and February 10-12,1993, a j
deviation of your Updated Final Safety Analysis Report (UFSAR) was identified. In accordance with the " General Statement of Policy and Procedure for NRC Enforcement Action," 10 CFR Part 2, Appendix C, the deviation is listed below:
Palo Verde Updated Final Safety Analysis Report (UFSAR) Chapter 11.5 committed tho licensee to follow the recommendations found in NUREG-0737, which requires that containment high-range monitors be calibrated in situ in accordance with Table ll.F.1-3.
i Contrary to the above, the licensee's current practice of using a " keep-alive" Americium (Am) source to calibrate the containment high-range monitors does not meet the recommendations found in NUREG-0737. Specifically, the use of an internally mounted Am-231 source to perform an in situ calibration is characteristic of a " source check" and not a primary calibration using the radionuclides, external to the detector, that cover the expected range and energy response defined in Table ll.F.1-3 of NUREG-0737.
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6 ENCLOSURE 2 l
REPLY TO NOTICE OF DEVIATION 50-528/93-03-01 NRC INSPECTION CONDUCTED JANUARY 11,1993 THROUGH JANUARY 15,1993 AND-FEBRUARY 10,1993 THROUGH FEBRUARY 12,1993 INSPECTION REPORT NOs. 50-528,529, AND 530/93-03 l
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REPLY TO NOTICE OF DEVIATION 50-528/93-03-01 i
t Reason for the Deviation:
Arizona Public Service Company (APS) recognizes that the method used at Palo Verde Nuclear Generating Station (PVNGS) to calibrate the containment high-range radiation monitors does not conform to the recommendations found in NUREG-0737 Table ll.F.1-3, as interpreted by NRR in a letter from M. J. Virgilio to R. A. Scarano'. The calibration method was developed using the latest vendor technical information, a state-of-the-art calibration method adapted to the high-range monitor design used at PVNGS, and a calibration method previously found acceptable at Shoreham Nuclear Power Station, in NRC inspection Report 50-322/85-04. The reason for the deviation is the result of APS' interpretation of the general calibration recommendations listed in NUREG-0737.
Corrective Actions Taken and Results Achieved:
APS has processed a revision to Chapter 11.5 of the Updated Final Safety Analysis Report (UFSAR), under the provisions of 10 CFR 50.59, that specifically describes the calibration method used for the containment high-range monitors. Enclosure 3 contains the revised wording of the UFSAR, Section 11.5.2.1.6.2, as it will appear in the 1994 UFSAR.
Lettw dated Nonnntxw 3,1992, from Martin J. Virgile, to Ross A Scarano. " Response To Technical Assistance - Palo Verde Nuclear Generating Staten Radiaton Monitoring System Requirements Pertaining To Rogulatory Guide 1.105 And Calitxaton Of Containment High Range Monitorf
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I Representatives from APS met with NRR on October 19,1993, to discuss the technical f
merits of the calibration method currently in use and provide the Technical Staff at NRR with the rationale used to develop this method. NRR agreed that the calibration method
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listed in NUREG-0737, Table ll.F
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Corrective Action That Will Be Taken to Avoid Further Deviations:
APS will revise Section 18.II.F.1.3 of the UFSAR to use the calibration method described in Section 11.5.2.1.6.2, for the containment high-range monitors, in lieu of the method recommended in NUREG-0737, Table ll.F.1-3. The technical justification for using this method will be forwarded to NRR for review prior to March 31, 1994, along with surveillance test results that correlate the performance of the containment high-range monitors to the primary calibration (performed by the manufacturer).
Date When Full Compliance Will Be Achieved:
APS is in full compliance with Section 11.5.2.1.6.2 of the UFSAR. The revision to Section 18.II.F.1.3, as discussed above, will be initiated by March 31,1994, and included in the 1995 UFSAR.
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b ENCLOSURE 3 REVISED UFSAR, SECTION 11.5.2.1.6.2 NRC INSPECTION CONDUCTED JANUARY 11,1993 THROUGH JANUARY 15,1993 AND FEBRUARY 10,1993 THROUGH FEBRUARY 12,1993 INSPECTION REPORT NOs. 50-528,529, AND 530/93-03
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REVISED UFSAR, SECTION 11.5.2.1.6.2 11.5.2.1.6.2 Calibration and Inspection. A remotely operated check source, or in the case of ion chamber detectors, an internal radioactive " keep-alive" source is provided with each detector assembly. The check source and keep-alive source are usable as convenient methods to provide a qualitative check of the associated detection and readout equipment. The check source provides a count rate sufficient to verify detector operation when the detector is near the bottom of its range. The keep-alive source provides a sufficient background current from the detector to the monitor to continuously
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verify detector operation.
Primary calibrations were performed by the manufacturer for each type of detector used in the Radiation Monitoring System (RMS). As part of the primary calibration, detectors were exposed to known radiation fields or radioactivity concentrations, as applicable, that were traceable to the National Bureau of Standards (NBS), currently known as the National Institute of Standards and Technology (NIST). These calibrations determined detector sensitivity and efficiency for each type of detector used in the RMS. Due to design configuration control and in the case of the process monitors, fixed analysis l
geometry, additional primary calibrations of the monitors used in the field are not necessary.
Subsequent calibrations need only verify that the monitor's response measured in the field correlates to the monitor's response measured during the primary calibration by using transfer calibration sources, or by direct measurement.
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The general method for performing field calibrations consists of the following steps:
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Verifying the moutor's electronic alignment.
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Evaluating monitor response to known radiation fields, field calibration sources, or electronic input in order to verify that the monitor's efficiency is similar to that measured during the primary calibration.
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Evaluating the linearity of the monitor's response using radioactive sources or electronic inputs.
The specific method of correlating a monitor's field response to the primary calibration depends on the type of detector and function of the monitor.
Scintillation (beta and gamma) detectors and Geiger-Mueller (GM) detectors used as process and effluent monitors are calibrated in the field using field calibration sources.
These calibration sources relate the detector's response mecsured in the field to the response measured during the primary calibration that used a similar model of detector and transfer calibration sources in a geometry that is the same as the field calibration sources.
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GM detectors used as area monitors (including area monitors that monitor process streams) are calibrated by placing the detector in a calibrated radiation field and verifying that the monitor readings are consistent with the radiation field.
l Due to ALARA considerations, area monitors using ion chamber detectors (including area monitors that monitor process and effluent streams) are calibrated electronically by inputting known electronic signals into the monitor and verifying response through its entire range. lon chamber detector response is verified in the field using the internal radioactive keep-alive source. For allion chamber detectors, with the exception of those used in the containment high-range area monitors (RU-148 and RU-149), detector response is evaluated by ensuring a minimum response from the keep-alive source is i
present. For RU-148 and RU-149, the ion chambers used were exposed to an NITS (NBS) traceable radiation field by the manufacturer during the primary calibration. As part of this calibration, the background keep-alive source response was measured. During subsequent field calibrations, the response of the keep-alive source is verified to be consistent with that measured during the primary calibration. This provides the necessary I
traceability and in_ situ calibration response checks for the containment high-range area monitors as required in NUREG-0737.
The RMS channels are checked and inspected periodically. Grab samples are collected l
for the isotopic analysis in accordance with the schedule in Table 11.5-3. Setpoint checks are done on a monthly basis, and calibration is performed at least every 18 months or at the indication of equipment malfunction. Instruments are serviced as required.
1 Field calibration of the indicated channels is performed following any equipment maintenance that can change the accuracy of the instrument indication. It may also be scheduled if the check source indicates an abnormal response. Critical parameters are verified as part of the calibration process.
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