ML20006F151

Application for Amend to License NPF-3,revising Tech Spec Tables 3.3-10,4.3-10 & Tech Spec 3/4.9.2 Re post-accident Monitoring Instrumentation & Refueling Operations

ML20006F151
Person / Time
Site:	Davis Besse
Issue date:	02/02/1990
From:	Shelton D TOLEDO EDISON CO.
To:
Shared Package
ML20006F148	List: ML20006F147 ML20006F151 ML20006F153
References
NUDOCS 9002270211
Download: ML20006F151 (6)

Text

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f' " .' '* Dockat'Nu ber 50-346' Lic:nsa Nu ber NPF ~Seri,a1 1733.

. Enclosure-

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APPLICATION FOR SMENDHENT TO FACILITY OPERATING LICENSE NUMBER NPF-3 DAVIS-BESSE NUCLEAR POWER STATION UNIT NUMBER 1 Attached are requested changes to the Davis-Besse Nuclear Power Station, Unit Number 1 Facility Operating License Number NPF-3. Also included are the Technical Description and Significant Hazards Consideration.

The proposed changes (submitted under cover letter Serial Number 1733)'

concern Section 3/4.3.3.6,-Post-Accident Instrumentation, Table 3.3-10, Post-Accident Monitoring Instrumentation and Table 4.3-10, Post-Accident Monitoring ,

Instrumentation Surveillance Requirements. l Section 3/4.9.2, Refueling Operation Instrumentation I I

By:

D. C/ Shelton", Vice President, Nuclear i I

Sworn and Suberibed before me this 2nd day of February, 1990.

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to Notary Put)lic, State of ~0hio  !

EVELYN L DRESS NOTARY 0U0U0.SfATECFOHIO MyCarsi:z:cnExpireshiy29.1094 ,

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PDR ADOCK 05000346 p P O c.

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Dockat Nu ber 50-346 Lic:nsa Nu;ber NPF-3 Serial 1733 '

Enclosure-Page 2 -

The following information is provided to support issuance of the requested changes to the Davis-Besse Nuclear Power Station, Unit Number 1 Operating

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License Number NPF-3, Appendix A, Technical Specifications, Section 3/4.3.3.6, Tables 3.3-10 and 4.3-10 and Section 3/4.9.2.

A. Time Required to Implement: This change is to be implemented within 45 days after the NRC issuance of the License Amendment.

B. Reason for Change (License Amendment Request Number 88-0016):

DBNPS has been using the excore neutron flux monitors supplied with the B&V.

nuclear instrumentation system to meet TS 3/4.3.1.1 and TS 3/4.9.2. Two excore neutron flux monitors qualified to meet the requirements of Regulatory Guide 1.97 have been installed at DBNPS and vill be used to comply with TS 3/4.3.3.6 following the sixth refueling outage and TS 3/4.9.2 during the sixth refueling outage. The existing monitors vill continue to be used to meet TS 3/4.3.1.1.

C. Technical

Description:

See attached Technical Description (Attachment 1).

D. Significant Hazards Consideration: See attached Significant Hazards Consideration (Attachment 2).

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i. Seri,al Number 1733 Attachment 1 Page 1 -

TECHNICAL DESCRIPTION Description of Proposed Technical Specification Change l

l This Technical Description discusses proposed changes to Davis-Besse Nuclear Power Station (DBNPS) Technical Specification (TS) Section 3/4.3.3.6, Post-Accident Instrumentation, Table 3.3-10, Post-Accident Monitoring Instrumentation, Table 4.3-10, Post-Accident Monitoring Instrumentation Surveillance Requirements, and Section 3/4.9.2, Refueling Operations -

Instrumentation. The DBNPS has been using the excore neutron flux monitors supplied with the Babcock & Wilcox (B&V) nuclear instrumentation system to .

meet both TS 3/4.9.2 and 3/4.3.1.1, Reactor Prote: tion System Instrumentation, Table 3.3-1 and 4.3-1, Item 11 (Source Range, Neutron Flux and Rate - Startup and Shutdown). However,-the B&V-supplied nuclear instrumentation system is not environmentally qualified. Two excore neutron flux monitors (each with vide range and source range capability) qualified to meet the requirements of.

Regulatory Guide 1.97, " Instrumentation for Light-Vater-cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident", were installed during the fifth refueling outage at the DBNPS and will be available to be used to comply with TS 3/4.3.3.6 following the sixth refueling outage and also with TS 3/4.9.2 during the sixth refueling outage.

This request proposes the addition of " neutron flux (vide range)" and " neutron flux (source range)" to Tables 3.3-10 and 4.3-10 to reflect the appropriate surveillance requirements for the new monitors for demonstrating operability.

Additionally this request proposes TS 3/4.9.2 be changed to require calibration of the neutron flux monitors prior to entry into Mode 6 in order to allow either the new monitors or the existing monitors to be used to comply with this specification.

Systems Affected Nuclear Instrumentation Post-Accident Monitoring System Safety Function of System Affected The nuclear instrumentation (NI) system is designed to provide neutron flux information over the full range of reactor operations. To provide total monite ing, three ranges of neutron flux detectors are furnished: source range, intermediate range and power range. The NI system consists of two source range channels, two intermediate range channels and four power range channels. This arrangement allows continuous monitoring of neutron flux level from source range to 125% of rated power. A minimum of one decade overlap between ranges is provided. The power range detectors are required by the reactor protection system (RPS) to perform safety functions, and are part of the RPS.

During refueling (Mode 6), the operability of the source range neutron flux monitors ensures that redundant monitoring capability is available to detect reactivity changes in the core.

.: /* Do'ck3t Nu;bgr 50-346 Licinsa Nu2bar NPF-3

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Serial Number 1733.

Atta'chment 1 Page 2 -

The purpose of the post-accident monitoring system (PAMS) is.to follow the course of an accident condition with vide range instrumentation which provides the operators the essential safety status information needed to return the plant to a maintained, safe shutdown condition. The operability of the post-accident monitoring system ensures that-sufficient information is available on selected plant parameters to monitor and assess these variables following an accident.

Effects on Safety / Proposed Changes Supplement Number 1 to NUREG-0737, " Clarification of THI Action Plan Requirements", directs the installation of various instrumentation systems as specified in Regulatory Guide 1.97. Regulatory Guide 1.97 specifies that neutron flux measurements must be made to indicate whether plant safety functions are being accomplished and to provide information required to mitigate the consequences of an accident. Regulatory Guide 1.97 further specifies that'the neutron flux measurements must be made with components / devices that meet certain criteria among which are that the equipment is environmentally qualified per Regulatory Guide 1.89,

" Qualification of Class 1E Equipment for Nuclear Power Plants" and the methodology described in NUREG-0588, " Interim Staff Position on Environmental Ounlification of Safety-Related Electrical Equipment."

The B&V-supplied NI system components do not meet the Regulatory Guide 1.97 ,

criteria. However, Supplement Number 1 to NUREG-0737, Paragraph 6.1.b permits '

plants to rely on currently installed equipment even if it is presently not environmentally qualified. The equipment is required to eventually be replaced with environmentally qualified components. The new excore neutron flux monitoring system was installed to comply with Supplement Number 1 to '

NUREG-0737 and it meets the requirements that are specified in Regulatory Guide 1.97. .The components ares (a) Environmentally qualified per IEEE 323-1974, " Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations" L (b) Seismically qualified per IEEE 344-1975, " Recommended Practices for

(. Seismic Qualification of Class 1E Equipment.for Nuclear Power Generating Stations" (c) Independently separated per IEEE 384-1977, " Standard Criteria for Independence of Class 1E Equipment and Circuits" (d) System cables splices, and connections qualified per IEEE 383-1974,

" Standard for Type Test of Class 1E Electric Cables, Field Splices, and Connections for Nuclear Power Generating Stations" The new Gamma-Hetrics supplied excore neutron flux monitoring system provides neutron flux measurement from reactor shutdown to reactor full power level.

The new system consists of two independent channels each with a source range and vide range display. The source range displays the count rate in counts per second and the vide range displays the power in percent while both display the rate of change in decades per minute.

. o Dockst Nuab;r 50-346 Lic nts Nu;b2r NPF-3 Serial Number 1733 1

+ Atta'chment 1 Page 3

-Prior to the modification which installed the new excore neutron flux monitoring system in addition to the original B&V-supplied nuclear instrumentation system, the NI system also provided in the control room and containment during refueling operations an audible. indication of the source range counts. The two new excore monitors vill be used to provide the audible indication of source range counts in the control room and containment during ,

refueling operations. The two new excore monitors vill also be available to be used in addition to the original NI system to provide the visual indication of source range counts in the control room during refueling operations.

The original NI system has been utilized as permitted by Regulatory Guide 1.97 to meet the requirements of Supplement Number 1 to NUREG-0737 and the components were surveillance tested per TS 3/4.3.1.1 Surveillance Requirements. Since the new excore monitors qualified per Regulatory Guide 1.97 vill be used following the sixth refueling outage to comply with TS 3/4.3.3.6 (Post-Accident Monitoring), the new monitors should be included in '

the technical specification and appropriate surveillance testing be reflected to demonstrate operability of the monitors. Specifically, two nev line items "36. Neutron Flux (Vide Range)" and "37. Neutron Flux (Source Range)" are proposed to be added to Tables 3.3-10 and 4.3-10. -This vill require a minimum i of I channel of each to be operable in Mode 1 (Power Operation) through Mode 3 (Hot Standby), that a channel check be performed monthly and a channel calibration be performed at each refueling. These requirements are similar to those of other PAHS instruments. The neutron detectors must be excluded from the channel calibration due to their non-adjustability (channel gain is adjustable),

i Since, during refueling operations, the new monitors vill provide the audible indication of source range counts in the control room and containment and vill be available in addition to the B&V-supplied NI system to provide the visual l~

indication of source range counts in the control room, appropriate changes are required for TS 3/4.9.2. Changes to the LCO and surveillance requirements to l

demonstrate operability of the monitors for this use are proposed to be added I to TS 3/4.9.2. In order to ensure that the neutron flux in the core is appropriately monitored during refueling operations, the LCO has been modified to require that the two operable neutron monitors be from separate channels (and, therefore, from opposite sides of the core). A channel calibration (TS 4.9.2d) of the monitors will be required to be performed prior to entry into Hode 6 (Refueling), if not performed within the last 18 months. The addition l of this requirement is necessary because a channel calibration requirement for the new monitors does not exist, while the original NI system is calibrated by TS 3/4.3.3.1 requirements on a refueling basis. As the proposed Surveillance Requirement vill apply to both the original and new flux monitors, the phrase l "if not performed within the last 18 months" must be included to provide necessary flexibility in scheduling the channel calibration of the original monitors. These monitors are typically calibrated during the latter stages of a refueling outage and not prior to Hode 6 entry. It is intended that TS ~

4.0.2 (1.25 criterion) would also be applicable to the channel calibration frequency of 18 months.

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Docket-Nu ber 50-346 Lic;nss Nunb r NPF-3 Serial Number 1733 Attachment 1.

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1 It'should be noted that the original NI system vill continue to t.e utilized to meet its previous TS 3/4.3.1.1 requirements.

l Unreviewed Safety Questions / Evaluation The proposed changes would not increase the probability of occurrence of an accident previously evaluated in the USAR because the addition of the Technical Specification operability and surveillance requirements of the  ;

qualified excore neutron flux monitoring system has no bearing on the probability of an occurrence of any accident (10CFR50.59(a)(2)(1)).

The proposed changes vould not increase the consequences of an accident previously evaluated in the USAR because the monitors do not inhibit the function of existing Class lE equipment and there is no radiological consequence associated with the increased Technical Specification requiret+nts for the installed monitors. Information would continue to be provided to mitigate the consequences of an accident (10CFR50.59(a)(2)(i)).

The proposed changes vould not increase the probability of occurrences of a malfunction of equipment importaat to safety previously evaluated in the USAR because there are no decreases in Technical Specification operability and surveillance requirements. The BW supplied nuclear instrumentation will continue all its present functions and the new excore neutron flux monitoring system which is installed will provide an independent-and qualified system with additional Technical Specification operability and surveillance requirements. Testing may be scheduled for performance when the RPS will not l be adversely impacted (10CFR50.59(a)(2)(i)).

1 The proposed changes vould not increase the consequences of a malfunction of equipment important to safety previously evaluated in the USAR because the Technical Specification changes do not degrade any safety related equipment, nor do they prevent any system function as discussed in the USAR (10CFR50.59(a)(2)(i)).

L. The proposed changes vould not create the possibility for an accident of a 1 different type than any evaluated previously in the USAR because on matters ll related to nuclear safety, all accidents are bounded by previous analysis and no new accidents are involved (10CFR50.59(a)(2)(1)).

l The proposed changes would not create the possibility for a malfunction of a l different type than any evaluated previously in the USAR because failure mechanisms previously unanticipated or events not bounded by the USAR are not L introduced by these Technical Specification changes (10CFR50.59(a)(2)(li)).

The proposed changes vould not reduce the rargin of safety as defined in the basis for any Technical Specification and the change vill ensure that the new system is adequately tested at the appropriate frequency

((10CFR50.59(a)(2)(iii)).

Based on the above, it is concluded that the proposed Technical Specification changes do not constitute an unreviewed safety question.