ML20195C814
| ML20195C814 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/02/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20195C812 | List: |
| References | |
| NUDOCS 9906080316 | |
| Download: ML20195C814 (5) | |
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'I UNITE 3 STATES :
3 NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30005 4001
- SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 20R
' TO FACILITY OPERATING LICENSE NO. DPR-16 GPU NUCLEAR. INC.. AND JERSEY CENTRAL POWER & LIGHT COMPANY OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NO. 50-219
1.0 INTRODUCTION
By letter dated November 5,1998, as supplemented February 18,1999, GPU Nuclear, Inc. (the licensee) submitted a request for changes to the Oyster Creek Nuclear Generating Station Technical Specifications (TSs). The requested changes would modify the safety limits and surveillances of the local-power range monitor (LPRM) and average-power range monitor (APRM) systems and related Bases pages to ensure the APRM channels respond within the necessary range and accuracy.and to verify channel operability, in addition, an unrelated change to the Bases of Specification 2.3 is included to clarify some ambiguous language. The February 18,1999, letter provided clarifying information within the scope of the original application and did not change the staff's initial proposed no significant hazards consideration determination.
2.0 BACKGROUND
The neutron monitoring system provides the capability to monitor neutron flux in the reactor core. For power range monitoring, selected groups of LPRMs provide input signals to the APRMs for bulk power level monitoring and automatic core protection. Four APRM channels are connected in each of the two reactor protection system (RPS) channels.
On December 28,1997, the NRC completed an integrated inspection at the Oyster Creek Nuclear Generating Station. The findings of this inspection were forwarded to the licensee by letter dated February 8,1998, (Reference 2), "NRC Integrated inspection Report No.
50-219/97-10 and Notice of Violation. During the inspection, the bypass of an APRM channel to perform LPRM calibrations on February 21,1996 was reviewed, in accordance with TS 3.1.B.3,"ProtectW Instrumentation," an APRM channel cannot be bypassed in a quadrant
. diagonally opposite a quadrant containing more than one bypassed or failed LPRM detector on the same axial level unless one of the following conditions exist:
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2-1.
The APRM channel bypass is in support of a TS required LPRM/APRM surveillance.
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Power is reduced below the 80% rod line.
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The corresponding reactor protection system (RPS) trip system is placed in the l.
tripped condition.
During the February 21,1995, LPRM calibration, APRM channel 5 was bypassed in support of an LPRM calibration at the same time that two LPRMs at the same axial level and in the diagonally opposite quadrant were inoperable. It was the licensee's interpretation at that time, that it considered the LPRM calibration to be a TS surveillance required to ensure that the APRMs were operable. According to this interpretation, the licensee concluded that TS 3.1.B.3 was met and that there was no need to decrease power below the 80% rod line or place the RPS trip system in the tripped condition. The NRC concluded during its inspection, however, that since the calibration le not listcd in the Oyster Creek TS, it is not a TS-required surveillance, and that TS 3.1.B.3 had been violated. It is the licensee's position that this type of calibration is appropriets and ensures the accuracy and operability of the APRM system. The licensee conducted a review of the Oyster Creek TS to identify any necessary changes to the TS in order to eliminate ambiguity in this area. As a result, the licensee has proposed to modify their TSs as discussed below.
i 3.0 EVALUATION The Safety Limits contained in TSs 2.1 and 2.3 have been established to protect the integrity of the fuel cladding and reactor coolant system barriers. Automatic protective devices have been i
l provided in the plant design for corrective actions to prevent safety limits from being exceeded l
during normal operation or operational transients. TS 2.3, " Limiting Safety Systems Settings,"
establishes the trip settings for these automatic protective devices. The licensee has proposed to change TS 2.3 and the associated Bases section to add limiting safety systems setting l
2.3.A.3, "APRM downscale 2 2% Rated Thermal Power coincident with IRM Upscale (high high) l-or inoperativo" The APRM downscale signal ensures that there is adequate neutron monitoring system protection if the reactor mode switch is placed in the run position prior to l
APRMs coming on scale. With the reactor mode switch in run, an APRM downscale signal, coincident with an associated IRM upscale (high-high) or inoperative, generates a reactor trip signal.
The licensee has proposed to modify the surveillance requirements of TS table 4.1.1, Minimum Check, Calibration and Test Frequency for Protective instrumentation." The current surveillance requirements specify the required check, calibration, and test of APRM scram trips.
The proposed change would specify the three APRM scram trips for which these requirements apply: flow biased neutron flux - high; fixed neutron flux - high or inop; and downscale. TS table i
4.1.1 also specifies that the APRMs be calibrated to the reactor power calculated from a heat balance equation. This ensures that the APRMs are accurately indicating the true core average power. The licensee has proposed to modify the requirement for the absolute difference between the APRM channel reading and the calculated power to indicate within 2 percent reactor power, to include any gain adjustments required by limiting safety systems setting 2.3.A,
" Neutron flux scram."
- The addition of the APRM downscale limiting safety system setting and additional surveillance requirements for APRM scram trips is more restrictive than the current TS and provides.
i additional assurance of the capability of the neutron monitoring system to perform its intended safety functions. Therefore, the proposed changes are acceptable.
The licensee has also proposed to modify TS Table 3.1.1, " Protective Instrumentation Requirements," to include the function *APRM Downscale/lRM Upscale," and to modify TS table 4.1.1, " Minimum Check, Calibration and. Test Frequency for Protective Instrumentation," to add a calibration for LPRM level. The proposed modification will add instrumentation requirements
' for LPRMs similar to the requirements specified for APRMs.
The current TS 3.1.B.3 permits bypassing an APRM channel for surveillance tests when one or more LPRM detectors in the opposite quadrant on the same axial level are bypassed. On February 21,1995, an APRM channel was bypassed to perform a LPRM calibration while two LPRMs at the same axiallevelin a diagonally opposite quadrant were inoperable. In reviewing this event, an NRC inspection team concluded that because the LPRM calibration was not listed in the Oyster Creek TS, that event violated the requirements of TS Section 3.1.B.3. To resolve this limitation the licensee proposed the addition of LPRM instrumentation to TS Table 4.1.1.
The licensee also reformatted Tables 3.1.1 and 4.1.1 to eliminate style and font inconsistencies and change table orientation to landscape format.
TS Table 3.1.1, Function 13, APRM Downscale/lRM Upscale i
This change is in conformance with APRM and other comparable channel functions specified in TS Table 3,1.1 and is, therefore, acceptable.
TS Table 4.1.1, Instrument Channel 32, LPRM Level I
i The licensee proposed to add a requirement to TS Table 4.1.1 to calibrate and test LPRM level i
electronics and detectors once every 12 months. The current TS Table 4.1.1, item 11, specifies testing and calibration of APRM Scram Trip channels once every 3 months and the licensee stated that during this APRM test the LPRM power supplies are checked for drifts, if the power supply is found to be out of tolerance, a step in the APRM test procedure directs the technician to perform a front panel check of the associated LPRM modules.
4 The licensee also stated that the LPRM front panels, including power supplies, meters, alarms, and rod block functions, are tested on a 48-week schedule in conformance with current plant procedures. This frequency was selected based on historical data. The licensee further stated that quarterly testing would require connection and disconnection of a large number of LPRMs to the test equipment that would increase the likelihood of equipment failures, j
The proposed changes are improvements to the current TS and are in conformance with the current TS requirements for APRM or other comparable instrumentation, and are based on plant experience and current plant procedures, and are, therefore, acceptable.
p-4 The licensee made some changes to the Bases section 2.3. The Bases are not subject to NRC review and approval; therefore, these changes were not reviewed but the changes are included to maintain the NRC Authority File current.
4.0 STATE CONSULTATION
in accordance_with the Commission's regulations, the New Jersey State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (63 FR 69342). Accordingly, the amendment meets the
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eligibility criteria for categorical exclusion set forth in 10 CFR S1.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: A. Cubbage S. Mazumdar Date: June 2,1999 l
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7.0 REFERENCES
- 1. Letter from Michael B. Roche (GPU Nuclear, Inc.) to NRC, " Technical Specification Change Request No. 266, APRM/LPRM Safety Limits and Surveillance Requirements," dated November 5,1998.-
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- 2. Letter from Hubert J. Miller, NRC, to Michael B. Roche, GPU Nuclear, Inc., "NRC Integrated Inspection Report No. 50/219/97-10 and Notice of Violation," dated Februaty 8,1998.
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