ML20046A017
| ML20046A017 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/15/1993 |
| From: | Storz L CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20046A018 | List: |
| References | |
| 2140, NUDOCS 9307230345 | |
| Download: ML20046A017 (3) | |
Text
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Mail Address independenceOH PO Box 94661 216-44T3100 Cleveland. 0H 44101-4661 Docket Number 50-346 License Number NPF-3 Serial Numbe'r 2140
' July 15, 1993 r
United States Nuclear. Regulatory Commission Document Control Desk Washington, D.
C. '20555 Subj ect:
License Amendment Request to Increase the Reactor Protection' System (RPS) and' Anticipatory Reactor Trip System (ARTS)
. Channel Functional Test Surveillance Interval and Channel Bypass Allowed-Out-of-Service Time Gentlemen:
By letter dated November-13, 1992.(Serial Number 2081) Toledo Edison applied for an amendment to the Davis-Besse Nuclear Power. Station ~,
Unit 1-(DBNPS), Operating License Number-NPP-3, Appendix A Technical-Specifications (TS). ' The proposed changes involve TS 3/4.3.1, Reactor Protection System (RPS)' Instrumentation," and TS 3/4;3.2.3,
" Anticipatory Reactor' Trip System-(ARTS) Instrumentation."
-The main purpose of the license amendment request is~to extend RPS and ARTS instrumentation TS testing intervals and: allowed out-of-service times'as permitted by the NRC-approved Babcock and-Vilcox (B&W) Topical' Report, BAV-10167, " Justification for Increasing the: Reactor Trip System On-Line Test Intervals," and its supplements._.0ther related:TS.
. changes were also. proposed. One of these changes vould permit an.
Inoperable RPS. channel'to be bypassed; indefinitely instead of tripped-as'is currently. required. Another change vould-revise.TS requirements for source ~and. intermediate range nuclear instrumentation to correspond to NUREG-1430 Revision 0,- Section 3.3.9 and 3.3.10, " Standard Technical Specifications for Babcock'and Vilcox Plants." The' purpose of this.
letter is-to respond to an NRC staff verbal question regarding guidance-7
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for bypassing ~ or tripping-an inoperable RPS channel and x to" resolve an-editorial discrepancy between NUREG-1430 and the TS requirement:f for source and intermediate. range instrumentation as proposed _in Toledo Edison's amendment request.
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Toledo Edison.
Docket Number 50-346-License Number NPF-3 Serial Number 2140 Page 2 Guidance for Bypassing or Tripping an Inoperable RPS Channel Toledo Edison's amendment application proposed revising the actions to j
be taken with one inoperable RPS instrument channel. Currently, TS 3/4.3.1 requires an inoperable RPS channel to be placed in the tripped condition within one hour. The proposed change vould provide the i
choice of placing a. single inoperable channel in either the_ bypassed or i
tripped condition within one hour. The NRC staff verbally. asked what i
guidance to the plant operator exists in making this choice. There currently is no specific operator guidance regarding making this choice for an inoperable channel since this option does not exist within the current TS.
After'the proposed license amendment is approved by-the NRC and implemented at the DBNPS, the shift supervisor as part of his normal control room command and control responsibilities, vill decide whether an inoperable.RPS channel is-placed in bypass or trip. The shift supervisor vill make this decision on the basis of his training,-
knowledge of the plant, current plant conditions, and experience. When these. factors are considered, a single inoperable RPS channel vould be l
bypassed as the preferred alternative in most cases. As operators are aware, the alternative of tripping an inoperable channel results in the RPS operating as a one-out-of-three trip system and increases susceptibility to a plant trip should a spurious trip' occur in any one of the three remaining operable instrument channels.
Consistency Between NUREG-1430 and Proposed Changes Toledo Edison's amendment request proposed changes to channel functional testing requirements for source and intermediate range neutron flux instrumentation contained in TS Table 4.3-1, " Reactor Protection System Instrumentation Surveillance Requirements."
Specifically the channel functional test interval for functional ~ unit 10, intermediate range neutron flux and rate instrumentation, was-revised from "S/U(5)(1)" (prior to reactor startup with Notes (1) and (5) applying) to "N.A.", and the channel functional test interval for i
functional unit 11, source range neutron flux and rate instrumentation, was revised from "M and S/U(1)(5)" (monthly while in Modes 2 through 5 and prior to reactor startup with Notes (1) and (5) applying) to "N.A.".
Note (5) requires the verification of at least one decade of overlap between the source and intermediate range. instrumentation if not verified within the previous seven days.
The NUREG-1430 restructured standard technical specifications (RSTS) no longer require channel functional tests for source and intermediate range instrumentation on the basis that they perform only a monitoring function, except for control rod withdrawal inhibit, which is only i'
required during low power' physics testing. The-control rod withdrawal inhibit function is verified under the existing'DBNPS Special Test Exception 3/4.10.2, Physics Tests, by surveillance requirement 4.10.2.2.
For source and intermediate range neutron flux instrumentation that performs a monitoring function, the RSTS consider 18 month interval channel calibrations and channel checks each shift to be the appropriate surveillance requirements. The RSTS retain the r
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Docket' Number 50-346 License Number NPF-3 Serial Number 2140 Page 3 requirement to verify at least one decade of overlap prior to each reactor start up if not verified within the previous seven days, the equivalent of Note (5) to Table 4.3-1 of the DBNPS TS.
Consistent with the RSTS, Toledo Edison's amendment request retained Note (5) in Table 4.3-1.
Although Note (5) was retained in the table notation, it was not referenced by functional units 10 and 11 in the amendment request, as submitted.
Consequently, it vas_not clear that the proposed license amendment intended that Note (5) continue to be applicable to the source and intermediate range instrumentation and required to be performed prior to each reactor startup.
The enclosed revised marked up copies of TS pages 3/4 3-7 and 3/4 3-8 clarify that Note (5) is applicable to the source and intermediate range neutron flux instrumentation. Note (5) is editorially revised to clarify that a channel functional test is not required, but verification of one decade of overlap is required prior to each reactor startup if'not verified-in the previous seven days. These editorial clarifications do not affect the Safety Assessment and Significant Hazards Consideration (SASHC) for License Amendment Request Number 90-0002 previously submitted by Toledo Edison's. letter dated November 13, 1992. The removal of the channel functional test TS-requirements for the source and intermediate' range neutron flux instrumentation was addressed by the previously submitted SASHC. The changes on the attached marked up pages to reflect the continued i
l applicability of Note (5) to the source and intermediate range instrumentation are editorial and do not change any existing TS requirements.
Therefore, the previously submitted SASHC is unaffected by these editorial revisions.
If you have any questions regarding these revisions, please contact Mr. Robert.V. Schrauder, Manager - Nuclear Licensing, at (419) 249-2366.
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Very truly yours, h
0 Louis F. Storz Vice President - Nuclear PVSidle Attachment n
cc:
.J. B. Hopkins, NRC/NRR DB-1 Senior Project Manager J. B. Martin, Regional Administrator, NRC Region III-S. Stasek, NRC Region III, DB-1 Senior-Resident Inspector Utility Radiological Safety. Board
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