Similar Documents at Zion |
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Category:SAFETY EVALUATION REPORT--LICENSING & RELATED ISSUES
MONTHYEARML20217J4791999-10-18018 October 1999 SER Approving Exemption from Certain Requirements of 10CFR73 for Zion Nuclear Power Station,Units 1 & 2.NRC Concluded That Proposed Alternative Measures for Protection Against Radiological Sabotage Meets Requirements of 10CFR73.55 ML20211K0401999-08-31031 August 1999 SER Accepting Approval of Defueled Station Emergency Plan & Exemption from Certain Requirements of 10CFR50.47, Emergency Plans for Plants,Units 1 & 2 ML20236U6331998-07-24024 July 1998 Safety Evaluation Supporting Amends 179 & 166 to Licenses DPR-39 & DPR-48,respectively ML20236S3281998-07-20020 July 1998 Safety Evaluation Supporting Certified Fuel Handlers Training & Retraining Program ML20198P8361998-01-0909 January 1998 SER Accepting Determination of Zone of Influnce for Coatings in Containment of Plant,Units 1 & 2 ML20198P8721998-01-0909 January 1998 Safety Evaluation Accepting Request for Alternative Insp Requirements for Augmented Exam of Reactor Presure Vessels for Zion Nuclear Power Station,Units 1 & 2 ML20202F0761997-12-0202 December 1997 Safety Evaluation Denying Licensee Proposed Alternative Contained in Request for Relief CR-13,Rev 1,of Removing Only Insulation Classified as Removable.Staff Determined That Submittal Does Not Provide Acceptable Level of Quality ML20132F5111996-12-20020 December 1996 Safety Evaluation Supporting Amends 177 & 164 to Licenses DPR-39 & DPR-48,respectively ML20135D8971996-11-25025 November 1996 Corrected SE Supporting Amends 176 & 163 to Licenses DPR-39 & DPR-48,respectively ML20134P7941996-11-25025 November 1996 Safety Evaluation Supporting Amends 176 & 163 to Licenses DPR-39 & DPR-48,respectively ML20134H6781996-11-12012 November 1996 Safety Evaluation Supporting Amends 175 & 162 to Licenses DPR-39 & DPR-48,respectively ML20134F9851996-11-0606 November 1996 Safety Evaluation Supporting Amends 174 & 161 to Licenses DPR-39 & DPR-48,respectively ML20129H2901996-10-29029 October 1996 Safety Evaluation Supporting Amends 173 & 160 to Licenses DPR-39 & DPR-48,respectively ML20059E2871993-12-30030 December 1993 Safety Evaluation Supporting Amends 57,57,45,45,93,77,152 & 140 to Licenses NPF-37,NPF-66,NPF-72,NPF-77,NPF-11,NPF-18, DPR-39 & DPR-48 Respectively ML20058G2981993-11-29029 November 1993 Safety Evaluation Supporting Amends 151 & 139 to Licenses DPR-39 & DPR-48 ML20059M7851993-11-15015 November 1993 Safety Evaluation Supporting Amends 150 & 138 to Licenses DPR-39 & DPR-48,respectively ML20059L7511993-11-10010 November 1993 Safety Evaluation Accepting Category 3 Qualification in Lieu of Category 2 for Pressure Monitoring Instrumentation ML20059L6801993-11-0909 November 1993 Safety Evaluation Re Update to Plant Reg Guide 1.97 Parameter Summary Table ML20058E6661993-10-22022 October 1993 Corrected SE Re Revised Fuel Handling Accident Inside Containment.Se Mistakenly Gives Decontamination Factor for Elemental Iodine Value of 100 Instead of 133 ML20059B1961993-10-22022 October 1993 Safety Evaluation Accepting Util 930913 Reanalysis of Fuel Handling Accident Inside Containment ML20059A7211993-10-14014 October 1993 Safety Evaluation Supporting Amends 149 & 137 to Licenses DPR-39 & DPR-48,respectively ML20059C5521993-10-13013 October 1993 Corrected Safety Evaluation Supporting Amends 148 & 136 to Licenses DPR-39 & DPR-48,respectively ML20057F8351993-10-13013 October 1993 Safety Evaluation Supporting Amends 148 & 136 to Licenses DPR-39 & DPR-48,respectively ML20057A2091993-08-31031 August 1993 Safety Evaluation Denying Addl Exemptions from Fire Protection Requirements of 10CFR50,app R.Conclusions Reached When Granting Exemptions in 830307 & 880607 SEs Still Valid ML20056H5001993-08-27027 August 1993 Safety Evaluation Re Fire Protection Open Items from Section 3.2.1 of 780310 Safety Evaluation ML20057B1711993-03-24024 March 1993 Safety Evaluation Granting Relief Requests to Licenses DPR-39 & DPR-48 Re Second 10-yr Interval Inservice Testing Plan for Pumps & Valves ML20056C0501992-06-0909 June 1992 Safety Evaluation Supporting Amends 138 & 127 to Licenses DPR-39 & DPR-48,respectively ML20058D8081990-10-31031 October 1990 Safety Evaluation Supporting Amends 120 & 109 to Licenses DPR-39 & DPR-48,respectively ML20247E7421989-09-0808 September 1989 Safety Evaluation Supporting Amends 118 & 107 to Licenses DPR-39 & DPR-48,respectively ML20245F1631989-08-0101 August 1989 Safety Evaluation Supporting Amends 117 & 106 to Licenses DPR-39 & DPR-48,respectively ML20247P9591989-05-30030 May 1989 Safety Evaluation Supporting Amends 116 & 105 to Licenses DPR-39 & DPR-48,respectively ML20247M7431989-05-22022 May 1989 Safety Evaluation Supporting Util Compliance W/Atws Rule 10CFR50.62 ML20245H8051989-04-27027 April 1989 Safety Evaluation Supporting Amends 115 & 104 to Licenses DPR-39 & DPR-48,respectively ML20244E4141989-04-14014 April 1989 Safety Evaluation Supporting Util post-accident Monitoring Instrumentation Per Reg Guide 1.97 & Generic Ltr 82-33 ML20196B8081988-12-0202 December 1988 Safety Evaluation Supporting Util Responses to Generic Ltr 83-28,Items 3.1.3 & 3.2.3 Re post-maint Testing Requirements ML20207K9971988-10-11011 October 1988 SER Supporting Amends 113 & 102 to Licenses DPR-39 & DPR-48, Respectively ML20155G5771988-06-0707 June 1988 Safety Evaluation Recommending That Util 840727 Exemption Request from Sections III.G.2 & III.G.3 of 10CFR50,App R Be Granted.One Exemption Request Determined as Unnecessary ML20154A7781988-04-15015 April 1988 Safety Evaluation Supporting Amends 112 & 110 to Licenses DPR-39 & DPR-48,respectively ML20151M1281988-04-0606 April 1988 Safety Evaluation Supporting Amends 111 & 100 to Licenses DPR-39 & DPR-48,respectively ML20148P4951988-04-0404 April 1988 Safety Evaluation Supporting Amends 110 & 99 to Licenses DPR-39 & DPR-48,respectively ML20150F0601988-03-28028 March 1988 Safety Evaluation Supporting Amends 109 & 98 to Licenses DPR-39 & DPR-48,respectively ML20147B8831988-02-26026 February 1988 SER Re Matl Properties for Fracture Toughness Requirements for Protection Against PTS Events.Nrc Concludes That Many of 30 Measurements Added to List in WCAP-10962 Not Credible ML20149H5541988-02-0505 February 1988 Safety Evaluation Supporting Amend 108 to License DPR-39 ML20237H5511987-08-17017 August 1987 Safety Evaluation Supporting Amends 107 & 97 to Licenses DPR-39 & DPR-48,respectively ML20236J3961987-07-20020 July 1987 Safety Evaluation Supporting Amends 106 & 96 to Licenses DPR-39 & DPR-48,respectively ML20235E9171987-06-23023 June 1987 Safety Evaluation Supporting Amends 105 & 95 to Licenses DPR-39 & DPR-48,respectively ML20213G6351987-05-0808 May 1987 Safety Evaluation Supporting Amends 104 & 94 to Licenses DPR-39 & DPR-48,respectively ML20215K3831987-05-0707 May 1987 Safety Evaluation Re Util 861229 Submittal Concerning Matl Properties for Fracture Toughness Requirements for Protection Against PTS Events,Per 10CFR50.61.Reported Values of Copper & Nickel Content Unacceptable ML20205Q9561987-03-26026 March 1987 Safety Evaluation Supporting Amends 103 & 93 to Licenses DPR-39 & DPR-48,respectively ML20205G7221987-03-19019 March 1987 Safety Evaluation Supporting Amends 102 & 92 to Licenses DPR-39 & DPR-48 1999-08-31
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217J4791999-10-18018 October 1999 SER Approving Exemption from Certain Requirements of 10CFR73 for Zion Nuclear Power Station,Units 1 & 2.NRC Concluded That Proposed Alternative Measures for Protection Against Radiological Sabotage Meets Requirements of 10CFR73.55 A99026, Monthly Operating Repts for Sept 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20217A1691999-09-22022 September 1999 Part 21 Rept Re Engine Sys,Inc Controllers,Manufactured Between Dec 1997 & May 1999,that May Have Questionable Soldering Workmanship.Caused by Inadequate Personnel Training.Sent Rept to All Nuclear Customers A99023, Monthly Operating Repts for Aug 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20211K0401999-08-31031 August 1999 SER Accepting Approval of Defueled Station Emergency Plan & Exemption from Certain Requirements of 10CFR50.47, Emergency Plans for Plants,Units 1 & 2 A99022, Monthly Operating Repts for July 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Zion Nuclear Power Station,Units 1 & 2.With A99021, Monthly Operating Repts for June 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Zion Nuclear Power Station,Units 1 & 2.With A99019, Monthly Operating Repts for May 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20195B2591999-05-19019 May 1999 Rev 66a to CE-1-A,consisting of Proposed Changes to QAP for Dnps,Qcs,Znps,Lcs,Byron & Braidwood Stations A99016, Monthly Operating Repts for Apr 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20195H9521999-04-30030 April 1999 Revised Monthly Operating Repts for Apr 1999 for Zion Nuclear Power Station,Units 1 & 2 A99013, Monthly Operating Repts for Mar 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20207M9231999-03-12012 March 1999 Amended Part 21 Rept Re Cooper-Bessemer Ksv EDG Power Piston Failure.Total of 198 or More Pistons Have Been Measured at Seven Different Sites.All Potentially Defective Pistons Have Been Removed from Svc Based on Encl Results A990101, Monthly Operating Repts for Feb 1999 for Zion Nuclear Power Station,Units 1 & 2.With1999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Zion Nuclear Power Station,Units 1 & 2.With ML20205M7061998-12-31031 December 1998 Unicom Corp 1998 Summary Annual Rept. with A99002, Monthly Operating Repts for Dec 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Zion Nuclear Power Station,Units 1 & 2.With A98062, Monthly Operating Repts for Nov 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Zion Nuclear Power Station,Units 1 & 2.With ML20196J0061998-11-19019 November 1998 Rev 66 to Topical Rept CE-1-A, QA Program ML20196A4191998-11-19019 November 1998 Safety Evaluation Accepting QA TR CE-1-A,Rev 66 Re Changes in Independent & Onsite Review Organization by Creating NSRB A98057, Monthly Operating Repts for Oct 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Zion Nuclear Power Station,Units 1 & 2.With A98052, Monthly Operating Rept for Sept 1998 for Zion Nuclear Power Station,Units 1 & 2.With1998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Zion Nuclear Power Station,Units 1 & 2.With A98049, Special Rept 304-123-98-001SR:on 980902,valid Failure Rept for 2A EDG Occurred.Cause Unknown.Util Submitted Written Certification of Permanent Cessation of Operations at Zion Station,Units 1 & 21998-09-25025 September 1998 Special Rept 304-123-98-001SR:on 980902,valid Failure Rept for 2A EDG Occurred.Cause Unknown.Util Submitted Written Certification of Permanent Cessation of Operations at Zion Station,Units 1 & 2 ML20195D1221998-08-31031 August 1998 DSAR, for Zion Station A98048, Monthly Operating Repts for Aug 1998 for Zion Station,Units 1 & 2.With1998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Zion Station,Units 1 & 2.With ML20237E2331998-08-21021 August 1998 Revised Pages of Section 20 of Rev 66 to CE-1-A, QA Topical Rept A98042, Monthly Operating Repts for July 1998 for Zion Station,Units 1 & 21998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Zion Station,Units 1 & 2 ML20236U6331998-07-24024 July 1998 Safety Evaluation Supporting Amends 179 & 166 to Licenses DPR-39 & DPR-48,respectively ML20236S3281998-07-20020 July 1998 Safety Evaluation Supporting Certified Fuel Handlers Training & Retraining Program A98041, Monthly Operating Repts for June 1998 for Zion Nuclear Station,Units 1 & 21998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Zion Nuclear Station,Units 1 & 2 ML20236J7911998-06-12012 June 1998 LER 98-S02-00:on 980517,first Shift Security Officer Reported Being Wounded by Unknown Subject Who Fled Area. Caused by accidental,self-inflicted Gunshot Wound.Removed Officer from Duty & Charged Officer W/Filing False Rept A98039, Monthly Operating Repts for May 1998 for Zion Generating Station,Units 1 & 21998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Zion Generating Station,Units 1 & 2 A98035, Monthly Operating Repts for Apr 1998 for Zion Station,Units 1 & 21998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Zion Station,Units 1 & 2 A98033, Monthly Operating Repts for Mar 1998 for Zion Station,Units 1 & 21998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Zion Station,Units 1 & 2 A98029, Monthly Operating Repts for Feb 1998 for Zion Station,Units 1 & 21998-02-28028 February 1998 Monthly Operating Repts for Feb 1998 for Zion Station,Units 1 & 2 A98015, Monthly Operating Repts for Jan 1998 for Zion Station,Units 1 & 21998-01-31031 January 1998 Monthly Operating Repts for Jan 1998 for Zion Station,Units 1 & 2 ML20199K1651998-01-23023 January 1998 Rev 65h to Topical Rept CE-1-A, Comm Ed QA Tr ML20198P8361998-01-0909 January 1998 SER Accepting Determination of Zone of Influnce for Coatings in Containment of Plant,Units 1 & 2 ML20198P8721998-01-0909 January 1998 Safety Evaluation Accepting Request for Alternative Insp Requirements for Augmented Exam of Reactor Presure Vessels for Zion Nuclear Power Station,Units 1 & 2 A98034, 1997 Annual 10CFR50.59 Summary Rept1997-12-31031 December 1997 1997 Annual 10CFR50.59 Summary Rept ML20216D3611997-12-31031 December 1997 Unicom Corp 1997 Summary Annual Rept A98004, Monthly Operating Repts for Dec 1997 for Zion Station,Units 1 & 21997-12-31031 December 1997 Monthly Operating Repts for Dec 1997 for Zion Station,Units 1 & 2 ML20202F1451997-12-0303 December 1997 Independent Investigation Team Rept on Safety Conscious Work Environment at Zion Station ML20202F0761997-12-0202 December 1997 Safety Evaluation Denying Licensee Proposed Alternative Contained in Request for Relief CR-13,Rev 1,of Removing Only Insulation Classified as Removable.Staff Determined That Submittal Does Not Provide Acceptable Level of Quality A97076, Monthly Operating Repts for Nov 1997 for Zion Station,Units 1 & 21997-11-30030 November 1997 Monthly Operating Repts for Nov 1997 for Zion Station,Units 1 & 2 ML20199J5931997-11-26026 November 1997 SG Insp Results,Fall 1996 Refueling Outage 14 (Z2R14) A97063, Special Rept 295-123-97-002SR:on 971014,failure of 1B EDG Occurred.Exam of Nipple Fractured Surface Revealed Failure Occurred Through Thread Root.Unit 1 Defueled & Unit 2 in Mode 5 Throughout Event1997-11-13013 November 1997 Special Rept 295-123-97-002SR:on 971014,failure of 1B EDG Occurred.Exam of Nipple Fractured Surface Revealed Failure Occurred Through Thread Root.Unit 1 Defueled & Unit 2 in Mode 5 Throughout Event A97069, Monthly Operating Repts for Oct 1997 for Zion Station,Units 1 & 21997-10-31031 October 1997 Monthly Operating Repts for Oct 1997 for Zion Station,Units 1 & 2 ML20211M0181997-10-0707 October 1997 Special Rept 295-123-97-001SR:on 970904,OA Motor Declared Inoperable Due to Pin Hole Leaks Identified on Pressure Regulating Relief valve,0FP0052.Procedure Was Rewritten to Ensure 0FP0052 Would Maintain Same Pressure When Fully Open A97058, Monthly Operating Repts for Sept 1997 for Zion Generating Station,Units 1 & 21997-09-30030 September 1997 Monthly Operating Repts for Sept 1997 for Zion Generating Station,Units 1 & 2 ML20210V2401997-09-19019 September 1997 Rev 65g to Topical Rept CE-1-A, Comm Ed QA Manual 1999-09-30
[Table view] |
Text
- ..
- o g UNITED STATES
! n NUCLEAR REGULATORY COMMISSION g .p WASHINGTON, D. C. 20555
%,...../
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PELATED TO AMENDMENT NO. 95 TO FACILITY OPERATING LICENSE PIO. DPR-39 AND AMENDMENT NO. 85 TO FACILITY OPERATING LICENSE NO. DPR-48 COMMONWEALTH EDIS0N COMPANY ZION NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-?95 AND 50-304 Introduction By letter dated February 24, 1986, Commonwealth Edison Company proposed amendments to Facility Operating License Nos. DPR-39 and DPR-48, Appendix A. Sections 2.1 and 3.1. The change reflects modification of the Nuclear Instrumentation System positive and negative flux rate trip setpoints from 15 percent with a time constant of 5 seconds to 5 percent with a time constant of 2 seconds. Because the existing setpoints of 15 percent with a time constant of 5 seconds would not provide required negative flux rate protection, the Technical Specifications would require all four of the nuclear instrumentation channels to be declared inoperable due to their inability to perform their " specific functions".
This would result in a forced shutdown of both Zion units. The amendment request proposes interim measures intended to compensate for the non-conservative trip setpoints and avoid shutdown of the power plants while the trips are being reset.
Evaluation The approved Westinghouse dropped rod methodology is described in WCAP-10297A, " Dropped Rod Methodology for Negative Flux Rate Trip Plants,"
June 1983. The conclusions of the report are that there will be no violation of the DNB design basis for 1) large reactivity worth rod combinations which cause a negative rate reactor trip assuming a nominal system setpoint of 5 percent reactor power with a time constant of 2 seconds, and for 2) lower worth rods or rod combinations which show no violation of DNB limits when analyzed by the methods described in the report. The second category requires a plant and cycle specific analyses. This methodology was implemented at Zion during January of 1985, but it was not recognized that the flux rate setpoint required alteration until February 1986. The proposed Technical Specification change implements this requirement for the negative rate setpoint and since conforms with the assumptions in the ap' proved methodolgy, it is acceptable. Credit for the positiva flux rate trip is not taken in the plant safety analysis. The trip is regarded as redundant to other trips, and since the proposed change is in the conservative direction, it is acceptable.
8603180408 860310 PDR ADOCK 05000295 P PDR
- As indicated above, full implementation of the Technical Specifications would lead to a shutdown requirement once the trip setpoints were found to be non-conservative. To compensate for this, the licensee implemented interim measures which had been employed in the past to ensure that DNB limits would not be violate? for dropped control rods. These measures require that the reactor be in manual control above 90% power when the control rods are inserted deeper than 215 steps. If the reactor is in automatic control when a rod drops, and there is sufficient control rod worth in the core, the power will overshoot when the controller restores full power. By limiting control rod insertion, and automatic control, the interim measures prevent a return to power and possible overshoot.
However, the licensee was informed by Westinghouse in a letter dated February 24, 1986 that the interim measures alone were not sufficient, but that for multiple dropped rods the more conservative trip setpoints were also required to ensure protection of the DNB limits. The licensee therefore proposed the following measures to be in effect during the period needed to reset the trip setpoints, which is estimated to be less than 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
- 1. An extra licensed reactor operator will be assigned to observe each Unit's rod bottom lights and to immediately initiate a manual reactor
--- trip if two or more rods fall.
- 2. Control rod movement will be minimized throughout this time period by imposition of the following conditions:
- a. Normal minor reactivity compensation for temperature variation and frequency altorations will be accomplished utilizing boration and/or dilution.
- b. No load changes will be initiated, c.. The rod system will be placed in manual throughout this time period.
We find the proposed manual trip to be acceptable because the extra operator assigned to each unit has no other duty except to monitor the rod bottom lights and thus should be able to detect multible dropped rods with ;
a high degree of reliability, and because the power recovery transient without control rod motion is slow enough to allow operator action.
Minimization of control rod motion will aid in reducing the probability of dropped rods, which occur most frequently during rod motion. In addition, resetting of the setpoints will take less than 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, so there is little likelihood of any problem arising in the first place.
Because the proposed trip setpoint changes are in the conservativ.e direction and are acceptable because of approved methodology, and because we agree the I
measures proposed by the licensee will ensure safety until the trip setpoints have been changed, we find the proposed amendments do no involve any significant hazards consideration, and are acceptable.
Evaluation of Significant Hazards Consideration 10 CFR 50.92 states that a proposed amendment will involve a no significant hazards consideration if the proposed amendment does not:
(1) Involve a significant increase in the probability or consecuences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
The discussion below addresses each of these three criteria and demonstrates that the proposed amendment involves a no significant hazards consideration.
~
Criterion 1 The reduction of these trip setpoints results in more conservative operation that was previously allowed by the Zion Technical Specifications. It should be emphasized that 5 percent /2 seconds refers to a total a power change of 5 percent reactor taking place over a total time period of not more than 2 seconds. It does not refer to a simple ramp rate of 22.5%/second.
Thus, the new setpoint of 5 percent power /2 seconds is clearly more limiting than the 15 percent /5 seconds that currently exists. This results in a reactor protection system that will produce a reactor trip signal under a wider range of dropped rod combinations than the present system. The consequences of multiple dropped rods are clearly reduced.
The setpoint change does not affect the actual operation of the control rod drive system. Thus, the probability of a dropped rod incident is unaffected.
Criterion 2 As discussed above, the proposed amendmer.t will impose a more conservative and restrictive flux rate trip setpoint tnan the existing Technical Specifications. There have been no modifications to the system design.
Thus, the imposition of these tighter controls will result in more conservative operation and will not create the possibility of a n,ew or different kind of accident.
Criterion 3 ,
The imposition of the more conservative positive and negative NIS flux rate !
trip setpoints will result in more conservative operation. The margin of l safety will be increased because reactor trip sianals will be produced j l
1
- ~
earlier during a postulated rod drop accident. In addition, reactor trip signals will now be generated for a broader range of dropped rod combinations. Thus, the margin of safety will not be adversely affected.
Therefore, since the proposed amendment satisfies the three criteria, the staff concli; des that the amendment does not involve a significant hazards consideration.
Finding on Existence of Emergency Situation In its submittal of February 24, 1986 Commonwealth Edison Company explains the circumstances that led to the situation where, if the existing requirements of the negative power range flux rate of the Zion Technical Specifications were fully implemented, a forced shutdown of both Zion Units would result. The staff has reviewed the submittal and concluded that the situation could not reasonably be anticipated by the Commonwealth Edison Company, the failure to act in a timely way would result in shutdown of both Zion Units, and therefore an emergency situation existed. For that reason the Commission issued the amendments under the provisions of 10 CFR 50.91(a)(5).
Conclusion These amendments involve a change in the installation or use of the facilities components located within the restricted areas as defined in 10 CFR 20. The staff has determined that these amendments involve 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 these amendments involve no significant hazards consideration and there has been no public comment on such finding. Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR Sec 51.22(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 these amendnents.
Finding We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of these amendments will not l
, be inimical to the common defense and security or to tne health and l safety of the public. -
l Dated: March 10, 1986 -
( Principal Contributor:
M. Dunenfeld 1
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