ML061040397
| ML061040397 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 04/14/2006 |
| From: | Crouch W Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MC4070, TAC MC4071, TAC MC4072, TVA-TS-447 | |
| Download: ML061040397 (11) | |
Text
April 14, 2006 TVA-TS-447 10 CFR 50.90 U.S. Nuclear Regulatory Commission Mail Stop: OFWN P1-35 ATTN: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
In the Matter of ) Docket Nos. 50-259 Tennessee Valley Authority ) 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - UNITS 1, 2, AND 3 -
TECHNICAL SPECIFICATIONS (TS) CHANGE TS-447 - FOLLOW-UP TO SECOND REQUEST FOR ADDITIONAL INFORMATION (RAI) - EXTENSION OF CHANNEL CALIBRATION SURVEILLANCE REQUIREMENT PERFORMANCE FREQUENCY AND ALLOWABLE VALUE REVISION (TAC NOS. MC4070, MC4071, and MC4072)
On August 16, 2004, TVA submitted a license amendment request (TS-447, ADAMS Accession No. ML04237061) to extend the calibration surveillance frequency for the high pressure coolant injection (HPCI) system, reactor core isolation cooling (RCIC) system, and reactor water clean-up (RWCU) system high area temperature isolation instrument channels on BFN Units 1, 2, and 3.
On January 10, 2005, NRC informed TVA via letter (ADAMS Accession No. ML043640556) that additional information was required in support of the requested amendments. On March 11, 2005, TVA provided a response (ADAMS Accession Nos. ML050770370 and ML050770379) to this RAI. TVAs response addressed the specific NRC RAI questions, and additionally provided
U.S. Nuclear Regulatory Commission Page 2 April 14, 2006 excerpts from relevant instrument scaling and setpoint engineering calculations and a copy of the TVA nuclear program instrument setpoint methodology document.
On August 15, 2005, NRC informed TVA via letter (ADAMS Accession No. ML052130135) of two additional RAI questions. These questions were answered in TVAs response of November 4, 2005 (ADAMS Accession No. ML053110343).
Subsequently, in a December 5, 2005 telecon, NRC made an additional, verbal request for information. The enclosure to this letter provides the information as requested in the telecon.
This letter provides additional information only, and no information in the original submittal nor the previous RAI responses is being revised. The proposed finding of no significant hazards considerations and environmental impact consideration as submitted in TVAs August 16, 2004 letter remain valid.
With regard to the instrumentation methodology issues discussed in the March 31, 2005, NRC letter to NEI, which provided NRCs position related to resolving Method 3 instrument setpoint methodology issues, as stated in our November 4, 2005, response letter, the instruments affected by TS-447 do not provide a limiting safety system settings (LSSS) function in accordance with 10 CFR 50.36(c)(1)(ii)(A). Therefore, no additional changes are needed to address the March 31, 2005, letter.
Each of the three previous TVA submittals has noted that the current calibration intervals are contrary to good ALARA and industrial safety practices for plant personnel. Therefore, TVA requests NRC approval of TS-447 as soon as possible. TVA also requests that the implementation of the revised TS be within 60 days of NRC approval.
There are no regulatory commitments associated with this submittal. If you have any questions about this change, please contact me at (256)729-2636 or Paul Heck at (256)729-3624.
Sincerely, Original signed by:
William D. Crouch Manager, Site Licensing and Industry Affairs
Enclosures:
- 2. Instrumentation setpoint scaling information table
U.S. Nuclear Regulatory Commission Page 3 April 14, 2006 Enclosures cc (Enclosures):
State Health Officer Alabama Dept. of Public Health RSA Tower - Administration Suite 1552 P. O. Box 303017 Montgomery, AL 36130-3017 (Via NRC Electronic Distribution)
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-3415 Mr. Malcolm T. Widmann, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-3415 NRC Senior Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, AL 35611-6970 Margaret Chernoff, Senior Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Eva A. Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739
U.S. Nuclear Regulatory Commission Page 4 April 14, 2006 DTL:PSH:BAB Enclosures cc (Enclosures):
B. M. Aukland, POB 2C-BFN M. Bajestani, NAB 1A-BFN A. S. Bhatnagar, LP 6A-C J. C. Fornicola, LP 6A-C R. G. Jones, POB 2C-BFN R. F. Marks, PAB 1C-BFN G. W. Morris, BR 4X-C B. J. O'Grady, PAB 1E-BFN K. W. Singer, LP 6A-C E. J. Vigluicci, ET 11A-K NSRB Support, LP 5M-C EDMS WT CA - K s:lic/submit/Techspcs/TS 447 RAI
ENCLOSURE 1 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI
1.0 BACKGROUND
INFORMATION AND RAI
SUMMARY
TVAs August 16, 2004, letter (Reference 1) requested amendments to Operating Licenses DPR-33, DPR-52, and DPR-68 for BFN Units 1, 2, and 3, respectively.
The proposed changes are to revise the operating licenses to extend the performance frequency of required calibration surveillance testing on instrumentation channels associated with high area temperature system isolation of the high pressure coolant injection (HPCI), reactor core isolation cooling (RCIC), and reactor water clean-up (RWCU) systems. Allowable values for the trip setpoints for some of these channels would also be revised. The Technical Specifications (TS) currently require performance of these calibration activities on a more frequent interval than is technically necessary, and the continued performance of these calibrations on the current frequency is contrary to both ALARA principles and good industrial safety practices.
NRCs January 10, 2005 letter to TVA (Reference 2) communicated an RAI to TVA, and in a March 11, 2005 letter (Reference 3), TVA responded to the RAI.
NRC then, on August 15, 2005, notified TVA via letter (Reference 4) that further additional information was required. TVAs November 4, 2005 letter (Reference 5) provided this information. Subsequently, in a December 5, 2005 telecon, NRC verbally requested that the additional information described below be provided:
- 1. Identify the controls used at BFN which ensure the instrumentation setting is returned to the acceptable as-left value during calibration.
- 2. For the affected instrumentation, provide the setpoints, acceptable as-left values, and the acceptable as-found values. Describe the band between the acceptable as-found value and the TS allowable value.
- 3. What is the action that BFN would take should this instrumentation be found outside of the acceptable as-found values?
- 4. Provide a discussion regarding the backup equipment available in case of loss of function of the affected instruments.
- 5. What impact does this instrumentation have on core damage frequency (CDF) and Large Early Release Frequency (LERF)?
Each of these areas are addressed below.
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ENCLOSURE 1 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI 2.0 TVA RAI RESPONSE
- 1. Identify the controls used at BFN which ensure the instrumentation setting is returned to the acceptable as-left value during calibration.
TVA response:
These administrative controls are contained within the associated TS surveillance requirement (SR) calibration procedures. Calibration of the HPCI and RCIC area high temperature switches is accomplished by physically replacing the switches in the field at each calibration interval with like switches which have been bench calibrated in the maintenance shop. The bench calibration verifies and documents the as-left setpoint value of the switches being installed to be within the acceptable range. The as-found trip setpoints of the switches removed from the field are then determined by bench-testing in the maintenance shop, and the as-found trip setpoints are documented within the calibration procedure. For the RWCU area high temperature loops, following determination of the as-found setpoint values and documentation of these values within the procedure, the rack-mounted analog trip unit (ATU) modules are recalibrated, if necessary, to meet the loop as-left scaling requirements. For each of these instruments, the as-left value is documented within the calibration procedure to be within the specified value range before the instrument/loop is returned to service.
In no case is an instrument returned to service with an as-left setpoint outside the acceptable range.
- 2. For the affected instrumentation, provide the setpoints, acceptable as-left values, and the acceptable as-found values. Describe the band between the acceptable as-found value and the TS allowable value.
TVA response:
Enclosure 2 provides the requested information in a tabular format. The values listed would be put in place upon approval and implementation of TS-447.
- 3. What is the action that BFN would take should this instrumentation be found outside of the acceptable as-found values?
TVA response:
Each of the associated SR calibration procedures includes reference(s) to TVA procedure SPP-8.1, Conduct of Testing. Steps 3.6.A and 3.6.B of SPP-8.1 are excerpted below:
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ENCLOSURE 1 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI 3.6 Problems During Testing The individual(s) performing the test shall be responsible for actions in this subsection as noted. The responsible supervisor is to be consulted if additional guidance is required.
A. Operations must be immediately notified if a problem is encountered that affects the operability of TS equipment or it is determined that a component or system operation is degraded. If the individual performing the test is uncertain, Operations should be notified.
B. Problems identified during the test shall be annotated on the CTL
[chronological test log] including a description of the problem, the procedure step when/where the problem was identified, corrective action steps taken to resolve the problem, and the number of the corrective action document, if one was required.
Additionally, TVA procedure SPP-6.7, Instrumentation Setpoint, Scaling, and Calibration Program, specifies a Maintenance Management System (MMS) database where required recalibrations of safety-related, TS, post-accident monitoring, and TS compliance instrumentation are documented for trending purposes.
These documentation methods for instrument out-of-tolerance instances (within testing data packages, the BFN corrective action program, and the MMS, as appropriate), provide a high confidence that any negative trend in instrumentation performance will be identified and addressed.
- 4. Provide a discussion regarding the backup equipment available in case of loss of function of the affected instruments.
TVA response:
The subject TS change does not impact the functional testing intervals of the associated area temperature instruments. Functional testing which demonstrates the isolation capability of the associated instrumentation will continue at the current frequency, therefore any functional issues which might arise with the isolation logic will be readily identified in the same way as under the current TS. The BFN licensing basis assumes only the loss of a single redundant instrument or logic channel, and the TS change requested in TS-447 does not impact the validity of this basis.
There is no identified mechanistic way that the changes being requested by this TS submittal could effect simultaneous failures of this high area temperature instrumentation such that the one-out-of-two-twice isolation logic becomes non-functional. However, if such simultaneous failures are postulated, as in the RAI question being addressed, the following plant response would be expected.
E1-3
ENCLOSURE 1 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI Postulated Event Backup equipment Anticipated plant response (coincident with multiple available isolation instrument failures)
HPCI steam line break high steam flow automatic isolation on high outside primary detection flow for larger breaks or containment instrumentation and manual isolation of the plant indication of system by plant staff using temperature and area existing abnormal and radiation emergency procedures RCIC steam line break high steam flow automatic isolation on high outside primary detection flow for larger breaks or containment instrumentation and manual isolation of the plant indication of system by plant staff using temperature and area existing abnormal and radiation emergency procedures RWCU loop piping plant indication of manual isolation of the break outside primary temperature and area system by plant staff using containment radiation existing abnormal and emergency procedures For each of the pipe break events listed in the preceding table, multiple safety and non-safety related systems remain available which are fully capable of supplying makeup water to the reactor. Achieving and maintaining a hot shutdown condition as described in the BFN licensing basis is in no way impacted by implementation of TS-447.
- 5. What impact does this instrumentation have on core damage frequency (CDF) and Large Early Release Frequency (LERF)?
TVA response:
The BFN probabilistic risk assessment (PRA) model includes initiating events associated with rupture of the Main Steam, HPCI, RCIC, or RWCU lines outside of primary containment. Collectively, this set of initiators is called breaks outside containment (BOC). The model results are insensitive to calibration issues involving the isolation instruments, though the results are affected if isolation of a hypothetical break is considered unsuccessful.
As stated above in the response to question 4, there is no identified mechanistic way that the changes being requested by this TS submittal could effect simultaneous failures of this high area temperature instrumentation such that the one-out-of-two-twice isolation logic becomes non-functional. The probability of successful isolation remains unchanged. Since the PRA model is only sensitive to the success/failure of the break isolation, and it is insensitive to the precise point at which the isolation is accomplished, there will be no impact to either CDF or LERF from the approval of TS-447.
E1-4
ENCLOSURE 1 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI
3.0 REFERENCES
- 1. August 16, 2004, Letter from TVA to NRC transmitting Browns Ferry Nuclear Plant (BFN) - Units 1, 2, and 3 - Technical Specifications (TS) Change TS-447
- Extension of Channel Calibration Surveillance Requirement Performance Frequency And Allowable Value Revision (ADAMS accession number ML04237061)
- 2. January 10, 2005, Letter from NRC to TVA transmitting Results Of Acceptance Review Regarding Request To Extend Technical Specification Channel Calibration Frequencies (MC4070, MC4071, and MC4072) (TS-447)
(ADAMS accession number ML043640556)
- 3. March 11, 2005, Letter from TVA to NRC transmitting Browns Ferry Nuclear Plant (BFN) - Units 1, 2, And 3 - Technical Specifications (TS) Change TS-447 Request For Additional Information (RAI) - Extension Of Channel Calibration Surveillance Requirement Performance Frequency And Allowable Value Revision (ADAMS accession numbers ML050770370 and ML050770379)
- 4. August 15, 2005, Letter from NRC to TVA transmitting Browns Ferry Units 1, 2, and 3 - Request for Additional Information Regarding Channel Calibration Test Interval (TAC NOS. MC4070, MC4071, AND MC4072) (TS-447)
(ADAMS accession number ML052130135)
- 5. November 4, 2005 Letter from TVA to NRC transmitting Browns Ferry Nuclear Plant (BFN) - Units 1, 2, And 3 - Technical Specifications (TS) Change TS-447 Second Request For Additional Information (RAI) - Extension Of Channel Calibration Surveillance Requirement Performance Frequency And Allowable Value Revision (TAC NOS. MC4070, MC4071, and MC4072) (ADAMS accession number ML053110343)
E1-5
ENCLOSURE 2 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI The following page contains a table which, for each instrument affected by this TS amendment, details the setpoints, acceptable as-left values, acceptable as-found values, and the associated TS allowable value.
Each of these instruments is listed below by its TVA unique identifier (UNID) tag. The plant area monitored by the instrument is also listed.
UNID (Units 1, 2, and 3) Monitored Area in U1/U2/U3 Reactor Building TS-073-02A, B, C, D HPCI pump room area TS-073-02E, F, G, H HPCI steamline - torus area (exit)
TS-073-02J, K, L, M HPCI steamline - torus area (midway)
TS-073-02N, P, R, S HPIC steamline - torus area (entry)
TS-071-02A, B, C, D RCIC pump room area TS-071-02E, F, G, H RCIC steamline - torus area (exit)
TS-071-02J, K, L,M RCIC steamline - torus area (midway)
TS-071-02N, P, R, S RCIC steamline - torus area (entry)
TIS-069-835A, B, C, D RWCU pipe trench area TIS-069-836A, B, C, D RWCU pump room A TIS-069-837A, B, C, D RWCU pump room B TIS-069-838A, B, C, D RWCU Heat Exchanger room (east and west walls)
TIS-069-839A, B, C, D E2-1
ENCLOSURE 2 BROWNS FERRY (BFN) TS-447 REQUEST FOR ADDITIONAL INFORMATION (RAI)
RESPONSE TO THE DECEMBER 5, 2005 TELECON RAI Minimum Maximum Minimum Maximum TS as-found as-found as-left as-left allowable UNIDs (U1/U2/U3) Monitored Plant Area value Setpoint value value value value TS-073-02A, B, C, D HPCI pump room area 174.8 185.0 195.2 182.4 187.6 200.0 TS-073-02E, F, G, H HPCI steamline - torus 155.9 165.0 174.1 162.7 167.3 180.0 area (exit)
TS-073-02J, K, L, M HPCI steamline - torus 155.9 165.0 174.1 162.7 167.3 180.0 area (midway)
TS-073-02N, P, R, S HPIC steamline - torus 155.9 165.0 174.1 162.7 167.3 180.0 area (entry)
TS-071-02A, B, C, D RCIC pump room area 155.9 165.0 174.1 162.7 167.3 180.0 TS-071-02E, F, G, H RCIC steamline - torus 155.9 165.0 174.1 162.7 167.3 180.0 area (exit)
TS-071-02J, K, L, M RCIC steamline - torus 155.9 165.0 174.1 162.7 167.3 180.0 area (midway)
TS-071-02N, P, R, S RCIC steamline - torus 155.9 165.0 174.1 162.7 167.3 180.0 area (entry)
T -069-835A, B, C, D RWCU pipe trench area 128.7 131.0 133.3 129.8 132.2 135.0 T -069-836A, B, C, D RWCU pump room A 145.7 148.0 150.3 146.8 149.2 152.0 T -069-837A, B, C, D RWCU pump room B 145.7 148.0 150.3 146.8 149.2 152.0 T -069-838A, B, C, D RWCU Heat Exchanger 136.7 139.0 141.3 137.8 140.2 143.0 room, East Wall T -069-839A, B, C, D RWCU Heat Exchanger 163.7 166.0 168.3 164.8 167.2 170.0 room, West Wall E2-2