ML20245G219
| ML20245G219 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/02/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20245G217 | List: |
| References | |
| NUDOCS 8908150276 | |
| Download: ML20245G219 (9) | |
Text
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EtiCLOSURE 4 l
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.169 TO FACILITY OPERATING LICENSE NO.- DPR 33 L
AMENDMENT N0.169 TO FACILITY OF'ERATIhG LICENSE NO. DPR-52 AND AMENDMENT NO.140 TO FACILITY OPERATING LICENSE NO. DPR-68 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2 AND 3 DOCKET N05. 50-259, 50-260,AND 50-296 1.0 ' INTRODUCTION By submittal dated January 13, 1989, the Tennessee Valley Authority (TVA) pro-posed to modify the Browns Ferry Nuclear Plant (BFN), ~ Units 1, 2 and 3, Technical Specifications.(TS) to delete certain Surveillance Requirement (SR) testing of redundant equipment during.a Limiting Condition for Operation (LCO). TVA has proposed that in place of the existing TS SR testing for the remaining opereble equipment during en LCO condition,.TVA perform periodic American Society of-Mechanical Engineers (ASME),Section XI tests coupled with monthly valve align-ment checks. These ASME tests are typically conducted once every three months for both Emergency Core Cooling System (ECCS) pumps and valves per BFN TS 1.0.MM.
These tests are more rigorous than the existing TS P operability verifications.
2.0- EVALUATION TVA has proposed, by submittel referenced above, to modify the BFN TS SR for ECCS related pumps during LCOs in which a redundant component is declared inoperable.
Specifically, during instances where an ECCS loop is declared inoperable, TVA has proposed to delete the current requirements for an immediate demonstration of operability of the remaining redundant loop and the requirement for demonstration of operability of that same redundant loop
" daily thereafter." TVA also proposes to add TS SP, for monthly verification of correct valve position for valves in the injection flow path of the operable redundant loop.
The TVA submittel supporting these proposed TS changes contains proposed changes applicable to the BFN Units 1, 2 and 3 TS. However, TVA has stated that the contents of the TS for the three units differ slightly in wording. The intent of the existing TS, however, is the same and the TVA justification provided for the proposed changes is appropriate for all three BFN Units.
The following list of proposed TS deletions and additions have been grouped together, as the justification for these changes is essentially the same.
8908150276 890802 PDR ADOCK 05000259 P
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1 CURRENT 4.5. A.2 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that one core spray-loop is inoperable, at a time.
I when operability is required, the other core spray loop, the RHRS (LDCI l
mode), and the diesel generators shall be demonstrated to be OPERABLC
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immediately. The OPERABLE core spray loop shall be demonstrated to be L
OPERABLE daily thereafter."
PROPOSED 4.5.A.2 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"No accitional surveillance required."
CURRENT 4.5.B.3 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that one RHR pump (LPCI mode) is inoperable at a time when operability is required, the remaining RHR pumps (LPCI mode) and active components in both acct:ss paths of the RHRS (LPCI mode) and the CSS and the diesel generators shali be demonstrated to be OPERABLE immediately and deily thereafter."
PROPOSED 4.5.B.3 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"No additienal surveillance required."
CURRENT 4.5.B.5 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that one RHR pump (containment cooling mode) or associated heat exchanger is inoperable at a tira when operability is required, the remaining RHR pumps (containment cooling mode), the associetec heat exchangers and diesel generators, and oil active corn-ponents in the 6ccess paths ct the F, HRS (containtrent cooling mcde) shall be cepcnstratcd to be OPERASLE 1rredietely and ve ckly thereafter until the inoperable RhR pump (containment cooling mode) and associated heat E.xchanger is returned to normal service."
PROPOSED 4.5.B.5 - ADD THE FOLLOWING S'JRVEILLANCE REQUIREMENT:
"No additional surveillance required."
CURRENT 4.5.B 6 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that two RHR pumps (contair. ment cooling mode) or associated heat exchangers are inoperable at a time when operability is required, the remaining RHR pumps (containment cooling mode), the ossociated heat excnangers, diesel generators, and all active components in the access paths of the P. HRS (containment cooling mode) shall be demonstrated to be OPERABLE immediately and daily thereafter until at least three RHR pumps (containment cooling mode) and associated heat exchangers are returned to normal service."
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FRGPOSED 4.5.B.6 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"ho additional surveillance required."
CURRENT 4.5.B.7 -' DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that one or more eccess paths of the RHRS (cen-141nment cooling moce) are inoperable when access is required, all active
.onents in the access paths of the RHRS (containment cooling mode)
- I be demonstrated to be operable immediately and all active components the access paths which are not backed by a second operable access path 1 r:
for tne same phase of the mode (drywell sprays, suppression chamber sprays and suppression pool cooling) shall be demonstrated to be operable daily thereafter until the second path is returned to normal service."
PROPOSED 4.5.B.7 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"No additional surveillance required."
CURRENT 4.5.B.12 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that one RHR ptmp or associated heat exchanger located on the unit cross-connection in the adjacent unit is inoperable at a time when operability is required, the remaining RHR pump and associated heat exchanger on the unit cross-connection and the associated diesel generator shall bo demonstrated to be operable immediately and every 15 days thereafter until the inoper-eble pump and associated heat exchanger on the unit cross-connection and the associated diesel generator shall be demonstrated to be operable immediately and every 15 days thereafter until the inoper-able pump ano essociated heat exchanger are returned to normal service."
PROPOSED 4.5.6.12 - ADD THE FOLLOWING SL'RVEILLANCE REQUIREMENT:
"No additional surveillance required."
CURRENT 4.5.C.2 - DELETE THE FOLLOWING SURVEILLANCE:
"a. If no more than two RHRSW pumps are inoperable, increased surveillance is not required.
- b. 'When three RriRSW pumps are inoperable, the remaining pumps and essociated essential control valves shall be operated weekly,
- c. When four RHRSW pumps are inoperable, the rerr.aining pumps, associated essential control valves, and associated diesel generators shell be operated daily."
PROP 0f ~D 4.5 C.2 - ADD THE FOLLO'wlhG SURVEILLANCE REQUIREMENT:
"Nn additional surveillance required."
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CURRENT 4.5.C.4 - DELETE THE FOLLOWIhG SURVEILLANCE REQUIREMEi4T:
"When it is determined that one of the RHRSW pumps supplying standby coolant is inoperable at a time when operability is required, the operable RHRSW pump on the same header and the RHR heat exchanger header and associated essential control valves-shall be demonstrated to be operable imediately and every 15 days thereafter."
FRGPOSED 4.5.C.4 - ADD TiiE FOLLOWING SURVEILLANCE REQUIREMENT:
"No additional surveillance required."
CURRENT 4.5.E.2 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that the HPCIS is inoperable the ADS actuation logic, the RCICS,. the RHRS (LPCI), and the CSS shall be demonstrated to be operable imediately. The RCICS and ADS logic shall be demonstrated to be. operable daily thereafter."
PROPOSED 4.5.E.2 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"No ;dditional surveillance required."
CURRENT 4.b.F.2 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"When it is determined that the RCICS is inoperable, the HPCIS shall be cemonstrateo to be operable immediately."
PROPOSED'4.5.F.2 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"ho additional surveillance required."
CURRENT 4.5.G.2 - DELETE THE FOLLOWING SURVEILLANCE REQUIREMENT" "When it is determined that three of the six ADS valves are incapable of automatic operation, the HPCIS shall be demonstrated to be OPERABLE immediately and daily thereafter as long as Specification 3.5.G.2 applies."
PROPOSED 4.5.G.2 - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
"No additional surveillance required."
TVA has provided justification for the above proposed TS deletions and additions.
TVA has statcc that BFN TS 235 implemented ASME Section XI testing for Class 1, 2, and 3 components that are required to perform a specific function in shutting down the reactor or in mitigating the consequences of an accident. The frequency of these inservice tests is nominally every 3 months during normal plant operations.
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5 Tne required ASME Section XI testing is a more rigorous verification of pump and valve operability than that required by the existing BFN TS operability verification for redundant operable equipment. Under the current BFN TS, the redundant operable ECCS and Reactor Core Isolation Cooling (RCIC) systems could be tested seven times a week,. for the worst case, just te verify oper-a b *.11 ty.
TVA has stated that this is excessive testing and wer the life of i
BFN could result in undue and unnecessary component wear.
Daily testing also L
increases the probability of equipment failure, and the potential for human error during system line-up, actual system testing, or returning the operable system to service.
TVA has also stated that during the performance of this additional testing, the operable ECCS or RCIC loop could be in a condition where it may not be able to perform its intended safety function.
In addition, this additional testing
-requires additional attention by the operator to line up the system for testing, perform the actual test, and restore it back to its required mode of operation.
Doing this daily while the other ECCS or RCIC loop is inoperable would provide an additional and unnecessary distraction from the operator's other activities and responsibilities in the control room.
In summary, TVA has stated that by deleting the existing surveillance tests and complying with tt,e ASME Section XI testing, BFN is in compliance with the intent of 10 CFR 50.55a and current industry standaros.
The staff has evaluated-the above TVA proposed changes and the justification provided and agrees with TVA's conclusion that ASME Section XI testing is e more rigorous verification of pump and valve operability and that daily test-ing of operable equipment could, over the life of BFN, result in undue and unnecessary component wear.
By deleting the above existing TS SR tests end complying with the ASME Section XI test requirements end frequencies per BFN TS 1.0.MM, the staff concludes that BFN is in compliance with the intent of 10 CFR 50.55a and c-ent industry standards. Thus, these changes are acceptable.
In order to provide additional verification of Ec,CS and RCIC system operability.
TVA has proposed new TS SR for verification of proper valve positions in the injection flow path.
The valve types to be position verified include manual, power-operated, and automatic valves which are not locked, sealed, or otherwise secured in position.
The SR frequency proposed for these new TS is once per month.
TVA has noted an exception for those cases where an automatic valve tapable of automatic return to its ECCS position when en ECCS signal is present may be in a position for another mode of operation.
The following list of proposed TS additions have been grouped together as the justification for these additions is essentially the same.
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6 PROPOSED 4. 5. A.1. f, 4. 5.B.1. f. 4. 5. E.1. f, and 4. 5.. F.1. f - ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
" Verify that each valve (manual, power-operated, or automatic) in the injection flowpath is not locked, sealed, or otherwise secured in position, is in its correct
- position.
This will be performed "once/ month."
"*Except that en automatic valve capable of automatic return to its ECCS position when an ECCS signal is present may be in a position for another mode of operation."
These new SRs are being added to ensure the correct position of each of the systems' valves in the injection flowpath.
This requires a monthly alignment check of the valves that are not locked or sealed in a position which may affect the ability of the system to perform its intended safety function.
1 This monthly check may be accomplished by visual inspection (where possible) or simulated automatic actuation signals in accordance with ASME Section XI pump and valve testing as required by BFN Technical Specification..].MM.
A valve that is capable of automatic return to its ECCS position, when an ECCS signal is present, can be in a position for another mode of operation during this verification.
This is applicable only if the valve auto-depositions and fully opens within the time required for its ECCS function.
In addition, verification of the valves in the injection flowpath provides a passive check of the flow pa.th to verify that the valves in the system are in their correct position.
As stated above, this verification process may be accomplished by visual inspection (where possible) or verification of flow through the appropriate flowpath when the appropriate pump is tested.
The staff finds this method of testing is consistent with current industry standards, NRC accepted practices, and is in compliance with the intent of ASME Section XI and 10 CFR 50.55a(g) testing requirements.
The addition of these SRs ensures that the subject safety injection flowpaths are aligned properly to allow the associated pumps to perform their intended safety function as analyzed by the BFN Final Safety Analysis Report and is acceptoble.
PROPOSED 4.5.B.I.g
- ADD THE FOLLOWING SURVEILLANCE REQUIREMENT:
" Verify LPCI subsystem cross-tie valve is closed and power removed f rom valve operator."
This will be done "once/nonth".
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7 TVA has stated that the low pressure coolant injection'(LPCI) system is oesigned to provide emergency coolant by flooding the reactor core in the event Lof a loss-of-coolant accident (LOCA).
Though completely independent of the core spray system (CSS), LPCI functions in combination with the CSS to prevent excessive fuel. clad temperatures.
The LPCI mode of the RHRS and the core spray system (CSS).provides adequate cooling for pipe break areas including the double ended recirculation pipe break.
A cross-tie valve exists in order to provide the capability to supply water from one loop of LPCI to the other if needed.
This surveillance is being added to verify that the LPCI subsystem cross-tie valve is closed and electric power to the operator is disconnected to ensure that a failure of the potential flowpath in one LPCI subsptem will not affect the flowpath of.the'other LPCI system.
The staff finds that this passive check provides additional assurance of operability with no adverse impact on the intended safety function of the LPCI system. Thus, this change is acceptable.
PROPOSED 4.5.C.I.c - INSERT THE FOLLOWING SURVEILLANCE REQUIREMENT:
" Monthly verify that each valve (manual, power-operated, or automatic) in the flowpath servicing safety-related equipment in the affected unit that is not locked, sealed, or otherwise secured in position, is in its correct position."
TVA has proposed to insert the above new TS 4.5.C.1.c in the BFN TS.
The justi-fication provided by TVA is the same as that provided for proposed new TS 4.5. A.1.f above, therefore, the staff conclusion is the same.
CURRENT 4.5.h. CHANGE THE FOLLOWING SURVEILLANCE REQUIREMENT:
"Every month prior to the testing..."
PROPOSED 4.5.H.1 - THE NEW CHANGE WILL READ:
"Every month and prior to testing..."
TVA stated that the existing surveillance requires that every month prior to testing the residual heat removal system (RHRS) and the CSS systems, the systems shall be vented from the high points and water flow determined.
Since these systems would now be tested quarterly, per ASME Section XI, the existing surveillance must be changed to ensure that the piping is still vented monthly and also vented prior to the testing of the RHRS to maintain the intent of the TS.
If the oischarge piping of the subject systems are not filled with water, a water hammer may oevelop in this piping when the pump and/or pumps are started. To minimize damage to the discharge piping and to ensure added margin in the operation of these systems, the revised TS would require the discharge lines to be filleo whenever the system is in an operable condition.
If a discharge pipe is not' filled, the pumps that supply the line must be essumed inoperable.
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8 The' discharge piping high point is visually checked for water flow once per ironth and. prior.to testing to' ensure that the lines are filled and therefore minimize the potential water hamner. The proposed revision to this surveil-lance will help ensure this potential effect and is acceptable.
TVA has also'propnsed to modify the applicable TS Bases Section to reflect the proposed changes documented above.
The staff has evaluated all of the above proposed TS deletions and changes and has found that over the life of BFN, these proposed TS could result in a signi-ficant reduction in excessive and unnecessary component testing. The AShE Section XI testing frequencies proposed, once per 3 months, for the ECCS and RCIC system components (as required by BFN TS 1.0 MM)-is adequate to ensure system functional operability, when combined with the monthly valve alignment checks, for instances when redundant equipment is declared inoperable. These-frequencies are equivalent to those required by NUREG-0123, Revision 3, Standcrd Technical Specifications for General Electric Boiling Water Reactors.
The.
proposed changes are also consistent with the intent of the testing required by 10 CFR 50.55a and current industry standards. Therefore, the staff finds the proposed deletions, additions and changes discussed above to be acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change to a requirement with respect n the-install-ation or use of a facility component located within the restricted 4rea as defined in 10 CFR Part 20 and changes to the surveillance requirements. The staff has. determined tnat these amendments involve no significant increases in the amounts, arid no significant change in the types, of any effluents that may be released offsite, ano that there is no significant increase in individual or cumulative occupational radiation exposure. The Comrdssion has previously issued a. proposed finding that' these amendments involve no significant hazards consideration and thore has been no public comment on'such finding. Accord-ingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environ-mental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CONCLUSION
The Commission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (54 FR 21316) on May 17, 1989 am consulteo with the State of Alabamo.
No public comments were receivec 6nd the State of Alabama did l
not h6ve any comments.
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t We have concluced, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be er. dangered by cperation in the proposed manner, and (2) such activities will te conductec in compliance with the Commission's regulations, and the issuance of the amendments will not be inirnical to the common defense and j
security nor to the health and sefety of the public.
Principal Contributor:
T. Rotella Dated:
August 2, 1989 L_-._-.-_
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