ML18036B324
| ML18036B324 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/14/1993 |
| From: | Salas P TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-NUREG-1232 NUDOCS 9306180033 | |
| Download: ML18036B324 (28) | |
Text
ACCELERATE DOCUMENT DXST VTXON SYSTEM REGULATO INFORMATION DISTRIBUTION YSTEM (RIDS)
ACCESSION NBR:9306180033 DOC.DATE: 93/06/14 NOTARIZED:
NO DOCKET FACIL;Sg-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH.NAME AUTHOR AFFILIATION SALAS,P.
Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Advises of completion of Phase II essential calculation program. Program approval documented in NRC SER (NUREG-1232, Vol 2).Details of program described in encl.
DZSTRZBUTZON CODE'030D COPZES RECEZVED LTR L ENCL 2 SZZE
(
TITLE: TVA Facilities Routine Correspondence NOTES:
RECIPIENT ID CODE/NAME COPIES LTTR ENCL RECIPIENT ID CODE/NAME COPIES LTTR ENCL INTERNAL: ACRS O~C-ED'G FADGE EXTERNAL: NRC PDR 01 6
6 1
0 1
1 1
1 NRR/DSSA OGC/HDS3 RES/DE/SSEB/SES NSIC 1
1 1
0 1
1 1
1 NOTE TO, ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTETH CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-20t35) TO ELIMINATEYOUR NAME FROM DISIRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEEDI TOTAL NUMBER OF COPIES REQUIRED:
LTTR 13 ENCL 11
Qi
~'
Tennessee Valtey Authority, Post Office Box 2000. Decatur. Alabama 35609 JUN i.4 l993 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of Tennessee Valley Authority
)
Docket Nos.
50-260
)
BROMNS FERRY NUCLEAR PLANT (BFN)
COMPLETION OF PHASE ZZ ESSENTIAL CALCULATION PROGRAM FOR UNZT 2
References:
1)
TVA letter to NRC, dated May 24,
- 1993, Completion of Commitments for Unit 2 Cycle 6
Outage and Response to Related Issues 2)
TVA letter to NRC, dated March 25,
- 1988, Design Baseline and Verification Program (DBVP)
Program Plan Revision 4
3)
NRC letter to TVA, dated January 23,
- 1991, NUREG-1232, Volume 3, Supplement 2
Browns Ferry Unit 2 (Section 2.1, Page 2-1]
This letter provides notification of the completion of the Phase II Essential Calculation Program for BFN Unit 2.
TVA committed to provide this notification as part of the Unit 2 Cycle 6 outage completion letter (Reference 1).
TVA's DBVP, including the essential calculation program, was described in Reference 2.
NRC approval of this program is documented in the NRC's Safety Evaluation of the Browns Ferry Nuclear Performance Plan (Reference 3).
j,70056 9306180033 930614 PDR ADOCK 05000260 P
U. S. Nuclear Regulatory Commission JUN
% 4 1993 As described in the enclosure, numerous inspections were conducted, concerns identified, and responses to those concerns were submitted, during the evolution of the Essential Calculation Program.
Since the issuance of References 2
and 3, evolutions in plant design and documentation necessitated refinements in the implementation of some Phase II essential calculation commitments.
Therefore, the encl'osure to this letter provides a summary of the background of this issue and the applicable correspondence, a review of the previous commitments, and a discussion of the implementation of these commitments.
There are no additional commitments contained in this letter.
Zf you have any questions, please telephone me at (205) 729-2636.
Sincerel Pedro Salas Manager of Site Licensing Enclosure cc:
See Page 3
U.S'. Nuclear Regulatory Commission JUN %4 1993 cc (Enclosure)'RC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637
- Athens, Alabama 35611 Mr. Thierry M. Ross, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
ENCLOSURE BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM I.
SUMMARY
OF COMMITMENT The post-restart phase of the Essential Calculation Program will be completed by the end of the Unit 2 Cycle 6 refueling outage.
The items related to the resolution of the Unresolved Safety Issue (USI)
A-, 46 will be responded to after the receipt of the SER from the NRC for the SQUG program.
ZZ.
BACKGROUND:
Revision. 4 of the'esign Baseline and Verification Program, which included the essential calculation program, was submitted for NRC review in Reference 1 and is described'n Section III.4.0 of Revision 2 to the Browns Ferry Nuclear Performance Plan (Reference 3).
The essential calculation program was structured as a two phased program.
Phase I was completed prior to Unit 2 Cycle 6 operation and was comprised of those systems or portions of systems required for the safe shutdown of the plant, as identified in Chapter 14 of the BFN Final Safety Analysis Report (FSAR).
Phase II extended the program to include the balance of the safety related functions.
Portions of Phase II are to be addressed as part of the NRC's Seismic Qualification of Equipment Program (Unresolved Safety Issue
[USI] A-46).
The scope of systems and subsystems included in Phase II was provided by Reference 10.
NRC conducted several inspections of this program as.documented in References 2,
6, and 8.
TVA responded to the Inspection Reports in References 4, 5, and 7.
The acceptability of BFN's program and references to the post-Unit 2 Cycle 6 startup action items was.contained in Reference 9.
The status of this commitment is discussed in Reference 11.
Correspondence related to the resolution of USI A-46 is contained in References 12 through 16.
III.
REFERENCES:
1)
TVA letter to NRC, dated March 25,
- 1988, Design Baseline and Verification,Program (DBVP)
Program Plan Revision 4
- 2) NRC'etter to TVA, dated September 8,
1988, Inspection Report Nos. 50-259/88-07, 50-260/88-07 and 50-296/88-07
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM Pagi 2 of'10 3) 4)
5) 6)
7) 8)
9) 10) 12)
TVA letter to NRC, dated October 24, 1988, Nuclear Performance Plan, Revision 2
TVA letter to NRC, dated November 3,
- 1988,
Response
to NRC Inspection Report Nos. 50-259/88-07, 50-260/88-07, and 50-296/88-07 TVA letter to NRC, dated April 18,
- 1989, Supplemental Response,to NRC Inspection Report Nos. 50-259/88-07, 50-260/88-07, and 50-296/88-07.
NRC letter to TVA, dated June 30, 1989, Inspection Report Nos. 50-259/89-07, 50-260/89-07 and 50-296/89-07 TVA letter to -NRC, dated August 22,
- 1989,
Response
to NRC Inspection Report Nos. 50-259/89-07, 50-260/89-07, and 50-296/89-07 NRC letter to TVA, dated February 26,
- 1990, NRC Inspection Report No., 50-260/89-42 NRC letter to TVA, dated January 23,
- 1991, NUREG-1232, Volume 3, Supplement 2
Browns Ferry Unit 2 [Section 2.1, Page 2-1]
TVA letter to NRC', dated May 3,
- 1991, Request for Additional Information on TVA's Design Baseline Verification Program,(DBVP)
Phase II TVA letter to NRC, dated September 20, 1991, Status and Schedule for Completion of Unit 2 Post-Restart Issues
[Section III.2.0, Page 13 and Section III.4.0,.Page 21]
NRC letter to All Unresolved Safety Issue (USI) A-46 Plant Licensees who are Members of the Seismic Qualification Utility Group (SQUG), dated May 22,
- 1992, Supplement No.
1 to Generic Letter 87-02 that Transmits Supplemental Safety Evaluation Report No.
2 on SQUG Generic Implementation Procedure, Revision 2, as Corrected on February 14, 1992
- 13) 'TVA letter to NRC, dated September 21,
- 1992, Supplement 1 to Generic Letter 87-02, Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (USI) A-46 and Supplement 4 to Generic Letter 88-20, Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM, Page g of10 14)
NRC letter to TVA, dated November 19,
- 1992, Generic Letter 87-02, Supplement 1 Response Browns Ferry Nuclear Plant 15)
TVA letter to NRC, dated January 19, 1993, Generic Letter 87-02, Supplement 1,
120-Day Response, Request for Additional Information 16)
NRC letter to TVA, dated March 19, 1993, Generic Letter 87-02, Supplement 1 Response Browns Ferry Nuclear Plant IV.
PROGRAM CLOSURE Since the issuance of References 1 and 2, evolutions in plant design and documentation necessitated refinements in the implementation of some Phase II essential calculation commitments.
Therefore, listed below are the overall essential calculations programmatic and item specific commitments and a
discussion of the implementation of these commitments.
V.
'OVERALL PROGRAMMATIC COMMITMENTS:
As discussed in Reference 1, the Phase II portion of the calculation effort committed to complete:
- 1) The Unit 2 and common essential calculation activities which were technically justified as deferrable during Phase I.
Closure:
The vast majority of essential calculations were implemented prior to BFN Unit 2 Cycle 6 start-up.
Only two scaling and setpoint calculations were identified as being required only to explicitly support Phase II of the essential calculations program.
These calculations were 'for lake high level trip alarm and an evaluation of the feedwater pump trip setpoint.
These calculations-have been completed.
Numerous post-Unit 2 Cycle 6 essential calculations were generated or revised to support separate Unit 2 post-restart programs.
Examples include the long term seismic qualification of drywell platforms, miscellaneous
- steel, and small bore piping, instrument loop calculations for Regulatory Guide 1.97 instrumentation, and cable ampacity calculations.
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM Page 4 oj'0 2)
The review of essential calculations for safety related
- systems, structures, and components outside the Phase I DBVP boundary.
Closure:
As discussed in Item 1 above, only two scaling and setpoint calculations were identified as being required only to explicitly support Phase II of the essential calculations program.
These calculations have been completed.
- 3) Minor deficiencies in calculations that are discovered, such as editorial problems, improper formats, incorrect references, are being punchlisted for correction after restart.
These minor corrections will be part of the scope of Phase II under this plan.
Closure:
Minor deficiencies in calculations were punchlisted in accordance with Project Instruction 88-05, Control of SE (Site Engineering)
Action Items.
These minor deficiencies were corrected.
- 4) Calculations for safety-related structures will be reviewed to confirm the consistency with actual plant configuration.
During this process, remaining essent'ial calculations will be. identified.
Calculations will be upgraded to reflect the as-built configuration.
Closure:
Safety related structures were reviewed prior to Unit 2 Cycle 6 operation to, assure that the analysis was consistent with the actual plant configuration.
Inspection Report 89-.32, dated November 8, 1989 documents the closure of portions of this item.
Section 3.8 addresses Reactor Building-concrete.
-Section 3.9 addresses the Diesel Generator Building base slab.
Section 3.10 addresses the Primary Containment (Drywell).
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM Page S of10
- 5) Engineering Assurance will perform technical audits of this calculation effort to ensure that this effort is executed in a technically adequate manner in accordance with this plan.
Closure:
Quality Assurance reviewed the calculation effort to ensure it was executed in a technically adequate manner.
VI.
ITEM SPECIFIC COMMITMENTS:
Commitment. from Reference 4:
Revise calculation 03308766D; Verification of.Separation Criteria for Sensing Lines Calculations, to include Design Standard DS-E18.3.9, Revision 1 as an attachment.
This revision will be implemented as a post-restart commitment.
Closure:
The correct calculation number should have been 033087SD.
This calculation was voided.
The requirements for separation of instrument sensing lines are contained in Engineering Specification N1E-003, Instrument and Instrument Line Installation and Inspection.
This specification contains the 18 inch minimum separation distance between divisional instrument lines.
The basis for this separation distance is ANSI/ISA S67.02-1980, Nuclear Safety Related Instrument Sensing Line Piping and Tubing Standards for Use in Nuclear Power Plants.
~I
ENCLOSURE (CONTINUED)'ROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM Page 6of10 Commitment from Reference 5:
Complete the identification of nonrigid valves and evaluate their impact on seismic qualification of piping.
Closure:
The following corrective actions were taken to resolve this item:
1)
The Design Criteria, BFN-50-7103, was revised to include a statement for the consideration of valve flexibility.
2)
The correct approach to address the was verified in each of the restart (Long Term Torus Integrity Program, Hydraulic Piping System, Small Bore Bulletin 79-14 Program).
flexibilityissue piping programs Control Rod Drive
- Program, and 3)
The Rigorous Analysis Handbook (RHA) was revised to provide guidance to piping analysts on modeling methods for flexible valves/equipment.
Commitments from Reference 7:
1)
When pipe stress calculation package CD-Q2074-88750 is
- revised, TVA will add the correct pipe support load transmittal.
Closure:
Calculation CD-Q2074-880750 was revised to include the correct pipe support load transmittal.
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM POSED 7 of10 2)
The instructions for the diesel generator 18-month load-acceptance surveillance test will be.revised to provided for inspections and/or testing to confirm proper regulator and governor tuning.
Closure:
Technical Instruction O-TI-298, Diesel Generator Operating Data Acquisition, was issued to record diesel generator operating parameters during the performance of the Diesel Generator load acceptance Surveillance Instructions.
Proper regulator and governor response (e.g.,
Phase A to Phase B
- voltage, frequency, field voltage, voltage overshoot, and maximum current) is currently evaluated by using this information.
- 3) Review and revise as required the Technical Specification instrument set-point scaling calculations to account for a 25 percent calibration interval extension.
Complete revisions for those calculations where the effort has no affect on the conclusions.
Closure:
The scaling and setpoint calculations associated with Technical Specification requirements were reviewed.
Revisions were performed, as required, to account for the 25 percent allowance of calibration frequency.
Action Items from Reference 8:
- 1) Heavy Loads, IR 50-260/89-30, Section 3.2, Page 4, Evaluate the heavy load effects on the safety-related structures,
- systems, and components.
Closure:
The evaluation of heavy loads at BFN are performed on a case by case basis.
The current design control program and procedures require changes affecting safety related structures be reviewed by the Lead Civil Engineer.
This review includes the evaluation and approval of the movement of heavy loads.
II
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
'PHASE II ESSENTIAL CALCULATIONPROGRAM Page 8 of10
- 2) Settlement of Buildings, IR 50-260/89-32, Page 3, Monitor and evaluate the settlement potential of the vacuum pipe building.
Closure:
As documented in this Inspection Report, the Diesel Generator Buildings, Vacuum Pipe, and Standby Gas Treatment Building are the only Seismic Class I structures not founded on rock or H-piles driven to the rock foundation.
The settlements of these structures were reviewed and determined not to be a problem.
- 3) Floodi;ng, IR 50-260/89-42, Section 3.2.1, Page 16, Recheck the silt levels at critical sections of the water channel at time intervals of less than 10 years.
Closure:
Technical Instruction O-TI-246, Inspection of Ponds,
- Dikes, and Channels, requires
- ponds, dikes, and channels be inspected once every five years.
However, special inspections are required within 30 days after unusual events such as flood,.earthquakes, tornadoes, of other events that may affect the integrity of these structures.
- 4) Tanks and Heat Exchangers, IR 50-260/89-30, Section 3.3.4, Pages 6 and 7,.Qualify the tanks and heat exchangers against the USI A-46 -program guidelines.
Closure:
In TVA letter to NRC, dated January 19, 1993, Generic Letter 87-02, Supplement 1,
120-Day Response, Request for Additional Information, TVA committed to complete the seismic portion of the USI A-46 program prior to March 19, 1996.
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM Pagt 9 of10 5)
Embedments/Anchorages, IR 50-260/89-32, Qualify and modify the surface mounted baseplates
.and'nchorages, originally qualified for the interim criteria, against the long-term criteria.
Closure:
The long-term portions of the Heating, Ventilation, and Air Conditioning (HVAC) and small bore piping programs evaluated and qualified surface mounted baseplates and anchorages, which were previously qualified to interim criteria.
The required modifications have been performed.
- 6) Reactor Building Room Floor Framing, IR 50-260/89-42, Evaluate and modify, as needed, the steel structural
- elements, base plates, connections, and anchorages, which were qualified for the interim criteria, against the long-term design criteria.
Closure:
The Reactor Building steel framing and floor beams, including the base plates connections, and anchorages, have been evaluated against the long-term design criteria.
The required modifications have been performed.
It is noted that the issue of the use of a ductility ratio is still outstanding with the NRC Staff (Reference NRC letter to TVA, dated October 29,
- 1992, Supplemental Safety Evaluation of Steel, Design criteria for the Browns Ferry Nuclear Power Plant Units 1, 2, and 3).
ENCLOSURE (CONTINUED)
BROWNS FERRY NUCLEAR PLANT (BFN)
PHASE II ESSENTIAL CALCULATIONPROGRAM Page lOoflO
- 7) Control Bay Floor Steel, IR 50-260/89-30, Evaluate and
- upgrade, as needed, the control bay floor steel
- members, connections, base plates, and anchorages, which were qualified for the interim criteria, against the long-term design criteria.
Closure:
The Reactor Building (which includes the Control Bay).steel framing and floor beams, including,the base plates connections, and anchorages, have been evaluated against the long-term design criteria.
The required modifications have been performed.
It is noted that the issue of the use of a ductility ratio is still outstanding with the NRC Staff (Reference NRC letter to TVA, dated October 29,
- 1992, Supplemental Safety Evaluation of Steel Design criteria for the Browns Ferry Nuclear Power Plant Units 1, 2, and 3).
- 8) Design Criteria, IR 50-260/89-32, Section 3.10, Page 15c correct the typographical error in Table C.0-8 of the FSAR by replacing "DBE" with "OBE" in the emergency condition load combination during the next FSAR revision.
Closure:
The described change is being processed as part of the next update to the Final Safety Analysis Report (FSAR),.
0
, ii