ML18057A963

Application for Amend to License DPR-20,changing Tech Specs to Incorporate Change to Reactor Variable High Power Trip setpoint.ANF-90-181, Review & Analysis of SRP Chapter 15 Events for Palisades W/15% Variable High Power... Encl

ML18057A963
Person / Time
Site:	Palisades
Issue date:	05/30/1991
From:	Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML18057A964	List: ML18057A963 ML18057A965 ML18057A966
References
NUDOCS 9106180003
Download: ML18057A963 (4)

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• consumers Power GB Slade General Manager POWERiNii NllCHlliAN'S PROliRESS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 May 30, 1991 Nu cl ear Regulatory Commi ss.i on Document Control Desk Washingttin, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT 7 TECHNICAL SPECIFICATIONS CHANGE REQUEST - VARIABLE HIGH POWER TRIP SETPOINT CHANGE Enclosed is a request for change to the Palisades Technical Specification~ to incorporate a changeto the reactor variable high power trip setpoint.

• Attachment 1 of this submjttal contains the proposed Technical Spectfications pages and Attachment 2 has the exist i.ng Technical Specifications pages marked

~P to show the proposed changes. Att~chment 3, provided for your infor~ation, is a copy of ANF-90-181, "Review and Analyses of Standard Review Plan Chapter 15 events for Palisades with a 15% Variable High Power Trip Reset." It is re_quested. that this change be made effective upon. issuance.

~

Gerald B*Slade General Manager CC: Administrator~ Region Ill, USNRC NRC Resident Inspector, Palisades Attachments

( 91061800Cl:3-9TOS3-C1 I

PDR AOOCK 05000255 P . . PDR A CMS' ENER5Y COMPANY

a. Uncontrolled Control Bank Withdrawal at Power 14.2.2 MDNBR-1.420.

b. Control Rod Mis-operation 14.2.3 MDNBR-1.197.

In both events the Minimum Departure from Nucleate Boiling Ratio (MDNBR) was greater than the Technical Specification Limit for Cycle 9 (1.190 for Kand L fuel, and 1.174 for M fuel) and only changed by -1.5% and -4.0% respectively from the previous analysis (ANF-90-078). The purpose of making this set point change is to eliminate unnecessary plant trips following a rapid power reduction from high power levels. Near beginning of cycle (BOC) conditions, the positive reactivity feedback due to a S/G overcooling event, can increase the core power more than 10% above the minimum power level as steady state conditions are reached.

By changing the VHPT from 10% to 15%, reactor trips could be avoided thereby, not putting the plant through unnecessary transients. The higher delta-power of 15% is still low enough to provide the minimum departure from nucleate boiling (MDNB) margins required for all other affected transients.

2. Create the possibility of a new or different kind of accident from any previously evaluated.

The proposed technical specification change does not create the.

possibility of a new or different kind of accident from any previously evaluated. The VHPT set point is used to define the radial peaking factors as a function of power that are used in the generation of the core protection limits for the thermal margin/low pressure (TM/LP). ANF-90-181 contains ANF's disposition of Chapter 15 analysis which identifies the events that. are impacted by the proposed increase. SRP events 15.4.2, and 15.4.3 are the only two events that were identified requiring reanalysis. The plant hardware was not changed and the plant operating conditions were not changed.

3. Involve a significant reduction in the margin of safety.

The margin of safety as defined by plant licensing bases is not s i gn'i f i cant l y reduced by the proposed technical spec if i cation change. The proposed technical specification maintains 95%

probability, at a 95% confidence level, that departure from nucleate boiling (DNB) will not occur for all reactivity insertion transient calculations. Plant safety also may be increased by reducing the potential for unnecessary plant trips.

CONSUMERS POWER COMPANY Docket 50-255 Request for Change to the Technical Specifications License DPR-20 For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in the Facility Operating License DPR-20, Docket 50-255, issued to Consumers Power Company on February 21, 1991, for the Palisades Plant be changed as described in Section I below:

I. Changes A. In Table 2.3.1, "Reactor Protection System Trip Setting Limits," revise both the four and three primary coolant pumps operation "Variable High Power" set point from "~ 10% above core power," to "~ 15% above core power."

B. In 2.3, "Basis," Item 1, change the first full paragraph as indicated in Attachment 2. In the second full paragraph of the same section, change the footnote as indicated in Attachment 2.

Also change Reference 1 from "ANF-90-078, Table 15.0.7-1" to "ANF-90-181, Section 15.0.7." and change Reference 4 from "ANF-90-078, Section 15.0.7-1" to "ANF-90-078, Section 15.0.7".

II. Discussion Description of Item The variable high power trip'(VHPT) is incorporated in the reactor protection system (RPS) to provide a reactor trip for transients exhibiting a core power increase from any initial power level. The variable high power function is enabled at approximately 30% power with [

the current variable trip reset margin set at 10%. The proposed technical specification changes the variable trip reset margin to 15%.

III. Analysis of No Significant Hazards Consideration Consumers Power Company finds that activities associated with this proposed Technical Specifications change involve no significant hazards; and accordingly, a no significant hazards determination per 10CFR50.92(c) is justifted. The following evaluation supports the finding that the proposed changes would not:

1. Involve a significant increase in the possibility or consequences of an accident previously evafoated.

The proposed technical specification changes do not involve a significant increase in the probability or consequences of an accident previously evaluated. Advanced Nuclear Fuels (ANF)-

90-181, "Review and Analysis of Standard Review Plan (SRP)

Chapter 15 Events for Palisades with a 15% Variable High Power Trip Reset", is the safety analysis that bounds the proposed technical specification change. Two events were re-analyzed for increasing the variable trip set point from 10% - 15%;

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III. Conclusion The Palisades Plant Review.Committee has reviewed this Technical Specifications Change Request and*has determined'that *this* change

- does not involve.an unreviewed safety question. Further, the change involves no significant hazards consi~eration. This change

• has been .reviewed by the Nuclear Safety Services Department. A copy of this Technical Specifications Change Request has been sent to the State of Michigan official designated to receive such Amendments to the Operating License.

CONSUMERS POWER COMPANY To the best of my knowledge, information and belief, the contents of this Technical Specifications Change Request are truthful and complete.

• Sworn and' subscribed to* before* me this 4th day* of _*_J_u_n_e_ _ _ _ 1991.

[eANN MORSE, NOTARY PUBLIC

• VAN BUREN COUNTY, STATE OF MICHIGAN LeAnn Morse, Notary Public ' MY COMMISSION EXPIRES 06-06**94 .

Van Buren Co, Michigan

'My commission*expires~ June 6' 1994