W3F1-2009-0005, Response to Request for Additional Information on License Amendment Request NPF-38-279 Relocation of TS 3.7.8 and Addition of LCO 3.0.8 Regarding the Inoperability of Snubbers
| ML090370549 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 02/04/2009 |
| From: | Anders S Entergy Nuclear South, Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| W3F1-2009-0005 | |
| Download: ML090370549 (12) | |
Text
Entergy Nuclear South Entergy Operations, Inc.
'OýEntergy 17265 River Road Killona, LA 70057 W3F1 -2009-0005 February 4, 2009 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Response to Request for Additional Information on License Amendment Request NPF-38-279 Relocation of TS 3.7.8 and Addition of LCO 3.0.8 Regarding the Inoperability of Snubbers Waterford Steam Electric Station, Unit 3 Docket No. 50-382 License No. NPF-38
REFERENCE:
- 1. Entergy (Waterford 3) letter to NRC dated September 18, 2008, "License Amendment Request NPF-38-279 Relocation of TS 3.7.8 and Addition of LCO 3.0.8 Regarding the Inoperability of Snubbers" (W3F1 -2008-0059)
- 2. NRC letter dated December 22, 2008 "Request for Additional Information RE: Relocation of Technical Specifications 3.7.8 and addition of Limiting Condition of Operation 3.0.8 (TAC NO.
MD9672)"
- 3. Entergy (ANO-2) letter to NRC dated December 11, 2008, "License Amendment Request Supplemental Regarding Technical Specification Change to Add LCO 3.0.8 on the Inoperability of Snubbers and Relocate TS 3.7.8 to the TRM," TAC No. MD9483 (2CAN 120801)
Dear Sir or Madam:
In Reference 1, Entergy Operations, Inc. (Entergy) submitted a request for an amendment to the Technical Specifications (TS) in accordance with the provisions of 10 CFR 50.90 for Waterford Steam Electric Station, Unit 3 (Waterford 3). The proposed amendment would modify TS requirements for inoperable snubbers by relocating the current TS 3.7.8, Snubbers, to the Technical Requirements Manual (TRM) and adding Limiting Condition for Operation (LCO) 3.0.8.
On January 5, 2009, Entergy received an NRC Request for Information (RAI) dated December 22, 2008 to support the review of the proposed TS change request. Entergy's response to the RAI is contained in Attachment 1 of this submittal. The response to this RAI
(
W3F1 -2009-0005 Page 2 is consistent with a recent response to the same RAI question from Arkansas Nuclear One, Unit 2.
Changes to TS Bases Section 3.0.8, which were originally submitted in Attachment 5 of Reference 1, are provided in Attachment 2 (for information only). The changes in the revised mark-up are indicated by revision bars in the right-hand margin. This revised mark-up replaces Attachment 5 in Reference 1 in its entirety.
There are no technical changes proposed. The conclusions of the original no significant hazards consideration included in Reference 1 are not affected by any information contained
,in this supplemental letter. There are no new commitments contained in this letter.
If you have any questions or require additional information, please contact Robert Murillo, Manager, Licensing at (504) 739-6715.
I declare under penalty of perjury that the foregoing is true and correct. Executed on February 4, 2009.
Sincerely, S.L. Anders Acting Nuclear Safety Assurance Director Waterford 3 SLA/DBB/RLW/ssf Attachments:
- 2. Revised Markup of Affected Technical Specification Bases Pages (For Information Only)
W3F1 -2009-0005 Page 3 cc: Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector Waterford 3 P. 0. Box 822 Killona, LA 70066-0751 U. S. Nuclear Regulatory Commission Attn: Mr. N. Kalyanam MS 0-07 D1 Washington, DC 20555-0001 American Nuclear Insurers Attn: Library 95 Glastonbury Blvd.
'Suite 300 Glastonbury, CT 06033-4443 Wise, Carter, Child & Caraway Attn: J. Smith P.O. Box 651 Jackson, MS 39205 Louisiana Department of Environmental Quality Office of Environmental Compliance Surveillance Division P. O. Box 4312 Baton Rouge, LA 70821-4312 Winston & Strawn ATTN: N.S. Reynolds 1700 K Street, NW Washington, DC 20006-3817 Morgan, Lewis & Bockius LLP ATTN: T.C. Poindexter 1111 Pennsylvania Avenue, NW Washington, DC 20004
Attachment I To W3F1 -2009-0005 Response to Request for Additional Information Regarding Adoption of LCO 3.0.8 (Snubbers) to W3F1-2009-0005 Page 1 of 4 Response to Request for Additional Information Regarding Adoption of LCO 3.0.8 (Snubbers)
On September 18, 2008, Entergy Operations, Inc. (Entergy) submitted a request for an amendment to the Technical Specifications (TS) in accordance with the provisions of 10 CFR 50.90 for Waterford Steam Electric Station, Unit 3 (Waterford 3). The proposed amendment would modify TS requirements for inoperable snubbers by relocating the current TS 3.7.8, Snubbers, to the Technical Requirements Manual (TRM) and adding Limiting Condition for Operation (LCO) 3.0.8.
On January 5, 2009, Entergy received an NRC Request for Information (RAI) dated December 22, 2008 to support their review of the proposed TS change request. The RAI requested additional information relating to plant procedures and administrative controls that would ensure the Emergency Feedwater (EFW) system would remain capable of performing its safety function using various OPERABLE combinations of pumps and flow paths in accordance with TS LCO and, as required, ACTION STATEMENTS prior to removing snubbers from service on a given system. Entergy's response to the NRC's request for additional information (RAI) is included below.
RAI In accordance with the NRC staffs approval and inherent in the implementation of Technical Specification Task Force (TSTF)-372 Revision 4, licensees interested in implementing LCO 3.0.8 must commit to operate in accordance with Tier 2 restrictions. Tier 2 restrictions (Conditions) involve the identification of potentially high-risk configurations that could exist if equipment in addition to that associated with the change were to be taken out of service simultaneously, or other risk significant operational factors such as concurrent equipment testing were also involved . Section 3.0, Regulatory Analysis, Subsection 3 .2, Verification and Commitments, discusses two conditions for application of TSTF-372 specified in the model Safety Evaluation.
- 1. Appropriate plant procedures and administrative controls will be used to implement the following Tier 2 Restrictions.
(a) At least one AFW [auxiliary feedwater] train (including a minimum set of supporting equipment required for its successful operation) not associated with the inoperable snubber(s), must be available when LCO 3.0.8a is used at PWR [pressurized water reactor] plants.
(b) At least one AFW train (including a minimum set of supporting equipment required for its successful operation) not associated with the inoperable snubber(s), or some alternative means of core cooling (e.g., F&B [feed and bleed], fire water system or "aggressive secondary cooldown" using the steam generators) must be available when LCO 3.0.8b is used at PWR plants.
to W3F11-2009-0005 Page 2 of 4 Regarding Condition 1.a Entergy wrote:
Condition 1(a) assumes the availability of one Emergency Feedwater (EFW) train during application of LCO 3.0.8.a. The TSTF-372 and the model SE specify the application of LCO 3 .0.8.a is contingent on the assumption that the redundant train remains available.
Even though Waterford 3 has a unique EFW system design, the plant TS LCO and ACTION statements will ensure the system remains capable of performing its safety function with various combinations of pumps and flow paths OPERABLE. Although the TS implementation process at Waterford 3 may include this restriction in other procedures or administrative processes upon approval of this amendment, Entergy does not believe further action is required to ensure compliance with Condition 1(a) since the TS inherently prevents application of LCO 3.0.8.a due to a snubber-related condition which could render the entire EFW system inoperable.
Regarding Condition 1 .b, Entergy wrote:
Condition 1(b) requires either one EFW train or some alternative means of core cooling must be available when one or more snubbers are inoperable that affect both trains of a given system. As described in Condition 1(a) above, there are no instances where the EFW system or both trains of any system being relied upon as the only core cooling method would be removed from service or any work permitting both at the same time during its associated Modes of Applicability that require these systems. Again, such a plant configuration would result in LCO 3.0.3 entry or plant shutdown, which prevents the utilization of the 12-hour allowance of LCO 3.0.8.b. Although the TS implementation process at Waterford 3 may include this restriction in other procedure or administrative processes upon approval of this amendment, Entergy believes the TS LCO and ACTION statements will ensure the system remains capable of performing its safety function with no further action required to ensure compliance with Condition 1(b).
It is not clear to the NRC staff what these statements mean in terms of taking actions to implement Tier 2 restrictions. Conclusions made by the licensee that would result in exceptions to or deviations from TSTF-372 model SE requirements to establish plant procedures and administrative controls to implement Tier 2 Restrictions need to include an analysis basis for the conclusion. Please address this issue for Condition 1(a) and 1(b) conclusions.
Entergy Response Entergy believes there are no evident deviations from TSTF-372.
Condition 1 specifies that appropriate plant procedures and administrative controls will be used to implement the Tier 2 restrictions. As delineated in Regulatory Guide 1.177, Tier 2 restrictions (Conditions) are associated with "Avoidance of Risk-Significant Plant Configurations" and involve the identification of potentially high-risk configurations that could exist if equipment, in addition to that associated with the change, were to be taken out of service simultaneously, or other risk significant operational factors were present such as concurrent system or equipment testing.
to W3F1-2009-0005 Page 3 'of 4 As discussed in the September 18, 2008, Entergy letter, adoption of LCO 3.0.8 requires the availability of EFW (or.other core cooling method in lower modes of operation) during periods when one or more required snubbers are inoperable. While the TSs ensure an EFW train or other core cooling method is operable in accordance with .the related mode of applicability, the TSs do not address which train (of a two-train system) must be operable. The NRC Safety Evaluation (SE) for adoption of TSTF-372 clearly indicates that the train of EFW or core cooling redundant to the system train in which a snubber is removed from service or is otherwise declared inoperable must be operable in order to apply the provisions of LCO 3.0.8.
In order to ensure various OPERABLE combinations of pumps and flow paths of EFW or other core cooling method relied upon, Entergy maintains several tiers of procedures and controls that prevent intrusive activities from being performed on redundant trains of equipment. Corporate procedures that govern all Entergy sites only permit work to be scheduled on one train at a time or that the aggregate risk be assessed prior to removing various safety-related components from service on the redundant protected train or other safety related system trains simultaneously. For example, if the 'A' train Emergency Diesel Generator (EDG) were removed from service, no intrusive activities would be permitted on or in close proximity to any required 'B' train (Protected Train) component, whether or not the component is related to the EDG. This administrative control even prohibits activities that could in any way affect the availability or operability of the redundant protected train, including activities such as scaffold erection. With the 'A' train EDG removed from service, other 'B' train components may be removed from service simultaneously, provided the aggregate station risk is maintained within acceptable limits.
In addition to corporate upper-tier procedures, each station maintains lower-tier procedures to provide additional checks and balances to ensure redundant equipment is adequately protected during any System/Component maintenance window. If during an 'A' train maintenance window a 'B' train component is unexpectedly found to be inoperable, procedures require immediate corrective action to restore both trains to an operable status.
Risk is also assessed for such emergent conditions, and appropriate compensatory measures, which could include a plant shutdown, are established as warranted to reduce overall station risk.
In summary, Entergy nuclear facilities have well established controls with regard to redundant train operability which have long been a part of the Entergy culture. These controls provide ample assurance that the intent of the NRC SE requirement for ensuringthe availability and operability of a redundant EFW or core cooling system train will be maintained during snubber inoperability periods.
Notwithstanding the above, there are certain aspects of the aforementioned Condition 1(a) that must be addressed. Condition 1(a) does not address lower modes of operation when EFW is not required to be operable or Steam Generators (SGs) are otherwise unavailable.
Therefore, Entergy provides clarification to TSTF-372 such that when EFW is not required to be operable by TSs, the redundant train core cooling source being relied upon during these lower modes of operation will be considered sufficient to meet the intent of the TSTF-372 SE.
This condition was identified to the NRC following TSTF-372 approval, and a revision is currently being considered by the industry TSTF working group. As discussed previously, to W3F1-2009-0005 Page 4 of 4 Entergy procedures currently protect redundant equipment during a given train's maintenance window. Therefore, no further administrative controls are required.
However, the TS Bases for LCO 3.0.8, as presented in TSTF-372 and the September 18, 2008 Entergy submittal, does not describe EFW ACTION statements that include the various EFW OPERABLE combinations of pumps and flow paths or core cooling source requirements. Entergy believes it is appropriate to include these restrictions in the TS Bases.
In addition to providing discussion relevant to Condition 1(a) above, discussion is also included to provide guidance associated with Condition 1(b). The affected TS Bases pages have been modified to provide discussion and guidance for various modes of operation.
[Revised markups of the associated TS Bases pages are included in Attachment 2 and the added guidance is included below:
"Whien applying LCO 3.0.8.a, the various EFW flow path combinations described in the ACTION statements for Emergency Feedwater (EFW) system must be OPERABLE during MODES when EFW is required to be OPERABLE. When applying LCO 3.0.8.a during MODES when EFW is not required to be OPERABLE, the redundant core cooling method [such as Shutdown Cooling (SDC) system] must be available. When applying LCO 3.0.8.b, a means of core cooling must remain available (EFW, SDC, equipment necessary for feed and bleed operations, etc.).
Reliance on availability of a core cooling source during modes where EFW is not required by TSs provides an equivalent safety margin for plant operations when LCO 3.0.8 is not applied and meets the intent of Technical Specification Task Force (TSTF) 372."
Reliance on the redundant train core cooling source during modes where EFW is not required by TSs provides an equivalent safety margin and meets the intent of the NRC SE conditions.
Therefore, Entergy believes this guidance is acceptable.
Attachment 2 To W3F1 -2009-0005 Revised Markup of Affected Technical Specification Bases Pages (For Information Only)
/
to W3F1 -2009-0005 Page 1 of 3 BASES When a shutdown is required to comply with ACTION requirements, the provisions of Specification 3.0.4 do not apply because they would delay placing the facility in a lower MODE of operation.
Specification 3.0.5 establishes the allowance for restoring equipment to service under administrative controls when it has been removed from service or declared inoperable to comply with ACTIONS. The sole purpose of this Specification is to provide an exception to Specification 3.0.2 (e.g., to not comply with the applicable Required Action(s)) to allow the performance of Surveillance Requirements to demonstrate:
- a. The OPERABILITY of the equipment being returned to service; or
- b. The OPERABILITY of other equipment.
The administrative controls ensure the time the equipment is returned to service in conflict with the requirements of the ACTIONS is limited to the time absolutely necessary to perform the allowed Surveillance Requirements. This Specification does not provide time to perform any other preventive or corrective maintenance.
An example of demonstrating the OPERABILITY of the equipment being returned to service is reopening a containment isolation valve that has been closed to comply with Required Actions and must be reopened to perform the Surveillance Requirements.
An example of demonstrating the OPERABILITY of other equipment is taking an inoperable channel or trip system out of the tripped condition to prevent the trip function from occurring during the performance of a Surveillance Requirement on another channel in the other trip system. A similar example of demonstrating the OPERABILITY of other equipment is taking an inoperable channel or trip system out of the tripped condition to permit the logic to function and indicate the appropriate response during the performance of a Surveillance Requirement on another channel in the same trip system.
Specification 3.0.8 LCO 3.0.8 establishes conditions under which systems are considered to remain capable of performing their intended safety function when associated snubbers are not capable of providing their associated support function(s). This LCO states that the supported system is not considered to be inoperable solely due to one or more snubbers not capable of performing their associated support function(s). This is appropriate because a limited length of time is allowed for maintenance, testing, or repair of one or more snubbers not capable of performing their associated support function(s) and appropriate compensatory measures are specified in the snubber requirements, which are located outside of the Technical Specifications (TS) under licensee control. The snubber requirements do not meet the criteria in 10 CFR 50.36, and, as such, are appropriate for control by the licensee.
If the allowed time expires and the snubber(s) are unable to perform their associated support function(s), the affected supported system's LCO(s) must be declared not met and the ACTIONS entered in accordance with LCO 3.0.2.
WATERFORD - UNIT 3 B 3/4 0-4 AMENDMENT NO. 62,99,-g Changed by letter dat Aug~ust 22, U9QO CHANGE NO. 3G, to W3F1 -2009-0005 Page 2 of 3 BASES LCO 3.0.8.a applies when one or more snubbers are not capable of providing their associated support function(s) to a single train or subsystem of a multiple train or subsystem supported system or to a single train or subsystem supported system. LCO 3.0.8.a allows 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to restore the snubber(s) before declaring the supported system inoperable. The 72-hour allowed outage time (AOT) is reasonable based on the low probability of a seismic event concurrent with an event that would require operation of the supported system occurring while the snubber(s) are not capable of performing their associated support function and due to the availability of the redundant train of the supported system.
LCO 3.0.8.b applies when one or more snubbers are not capable of providing their associated support function(s) to more than one train or subsystem of a multiple train or subsystem supported system. LCO 3.0.8.b allows 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to restore the snubber(s) before declaring the supported system inoperable. The 12-hour AOT is reasonable based on the low probability of a seismic event concurrent with an event that would require operation of the supported system occurring while the snubber(s) are not capable of performing their associated support function.
When applying LCO 3.0.8.a, the various EFW flow path combinations described in the ACTION statements for Emergency Feedwater (EFW) system must be OPERABLE during MODES when EFW is required to be OPERABLE. When applying LCO 3.0.8.a during MODES when EFW is not required to be OPERABLE, the redundant core cooling method [such as Shutdown Cooling (SDC) system] must be available. When applying LCO 3.0.8.b, a means of core cooling must remain available (EFW, SDC, equipment necessary for feed and bleed operations, etc.). Reliance on availability of a core cooling source during modes where EFW is not required by TSs provides an equivalent safety margin for plant operations when LCO 3.0.8 is not applied and meets the intent of Technical Specification Task Force (TSTF) 372.
LCO 3.0.8 requires that risk be assessed and managed. Industry and NRC guidance on the implementation of 10 CFR 50.65(a)(4) (the Maintenance Rule) does not address seismic risk. However, use of LCO 3.0.8 should be considered with respect to other plant maintenance activities, and integrated into the existing Maintenance Rule process to the extent possible so that maintenance on any unaffected train or subsystem is properly controlled, and emergent issues are properly addressed. The risk assessment need not be quantified, but may be a qualitative awareness of the vulnerability of systems and components when one or more snubbers are not able to perform their associated support function.
LCO 3.0.8 does not apply to non-seismic snubbers. The provisions of LCO 3.0.8 are not to be applied to supported TS systems unless the supported systems would remain capable of performing their required safety or support functions for postulated design loads other than seismic loads.
The risk impact of dynamic loadings other than seismic loads was not assessed as part of the development of LCO 3.0.8. These shock-type loads include thrust loads, blowdown loads, water-hammer loads, steam-hammer loads, LOCA loads and pipe rupture loads.
However, there are some important distinctions between non-seismic (shock-type) loads and seismic loads which indicate that, in general, the risk impact of the out-of-service snubbers is smaller for non-seismic loads than for seismic loads. First, while a seismic load affects the entire plant, the impact of a non-seismic load is localized to a certain system or area of the WATERFORD - UNIT 3 B 3/4 0-4a AMENDMENT NO. 4 CHANGE NO. 4-2-3 to W3F1 -2009-0005 Page 3 of 3 BASES plant. Second, although non-seismic shock loads may be higher in total force and the impact could be as much or more than seismic loads, generally they are of much shorter duration than seismic loads. Third, the impact of non-seismic loads is more plant specific, and thus harder to analyze generically, than for seismic loads. For these reasons, every time LCO 3.0.8 is applied, at least one train (or subsystem) of each system that is supported by the inoperable snubber(s) should remain capable of performing their required safety or support functions for postulated design loads other than seismic loads.
-4(DRN 03-1807, Ch. 30)
Specification 4.0.1 througqh 4.0.4 establish the general requirements applicable to Surveillance Requirements. These requirements are based on the Surveillance Requirements stated in the Code of Federal Regulations, 10 CFR 50.36(c)(3):
4'-(DRN 03-1807, Ch 30)
"Surveillance requirements are requirements relating to test, calibration, or inspection to ensure that the necessary quality of systems and components is maintained, the facility operation will be within safety limits, and that the limiting condition of operation will be met."
WATERFORD - UNIT 3 B 3/4 0-4b AMENDMENTNO.