View source for CPSES-200602340, License Amendment Request (LAR) 06-012, Revision to Technical Specification 3.7.5, Auxiliary Feedwater System, TS 3.8.1, AC Sources - Operating, & TS 3.8.9, Distribution Systems - Operating.

{{Adams
| number = ML070580149
| issue date = 12/19/2006
| title = License Amendment Request (LAR) 06-012, Revision to Technical Specification 3.7.5, Auxiliary Feedwater System, TS 3.8.1, AC Sources - Operating, & TS 3.8.9, Distribution Systems - Operating.
| author name = Blevins M, Madden F
| author affiliation = TXU Generation Co, LP, TXU Power
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR/ADRO
| docket = 05000445, 05000446
| license number = 
| contact person = 
| case reference number = CPSES-200602340, TXX-06189
| document type = Inservice/Preservice Inspection and Test Report, Letter type:CPSES, License-Application for Facility Operating License (Amend/Renewal) DKT 50
| page count = 43
| project = 
| stage = Request
}}

=Text=
{{#Wiki_filter:Power TXU Power            Mike Blevins Conchnde Peak Steam Senior Vice Prsident &
Elechic Station      Chief Nudear Officer P0.0 Box 1002 (E01)
Glen Rose, TX 76043                                                                          Ref: I0CFR50.90 Tel: 254 897 5209 Faxc 254 897 6652 mike.blevins@txu.com CPSES-200602340 Log # TXX-06189 File # 00236 December 19, 2006 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

==SUBJECT:==
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 LICENSE AMENDMENT REQUEST (LAR) 06-012, REVISION TO TECHNICAL SPECIFICATION (TS) 3.7.5, "AUXILIARY FEEDWATER (AFW) SYSTEM," TS 3.8.1, "AC SOURCES - OPERATING," TS 3.8.9, "DISTRIBUTION SYSTEMS -
OPERATING," AND TS EXAMPLE 1.3-3"

==Dear Sir or Madam:==

Pursuant to 10CFR50.90, TXU Generation Company LP (TXU Power) hereby requests an amendment to the CPSES Unit I Operating License (NPF-87) and CPSES Unit 2 Operating License (NPF-89) by incorporating the attached change into the CPSES Unit 1 and 2 Technical Specifications (TS). This change request applies to both units.
The enclosed license amendment request (LAR) 06-012 proposes to revise TS 3.7.5, "Auxiliary Feedwater (AFW) System," TS 3.8.1, "AC Sources - Operating," TS 3.8.9, "Distribution Systems - Operating," and TS Example 1.3-3, to eliminate second Completion Times from the TS.
A   member       of the STARS (Strategic Teaming    and   Resource  Sharing)   Alliance Callaway
* Comanche Peak
* Diablo Canyon
* Palo Verde
* South Texas Project
* Wolf Creek 4o (

TXX-06189 Page 2 of 4 A second Completion Time was included in the TSs for certain Conditions/Required Actions to establish a limit on the maximum time allowed for any combination of Conditions that result in a single contiguous failure to meet the Limiting Condition for Operation (LCO).
This license amendment request (LAR) is consistent with NRC-approved Industry/Technical Specification Task Force (TSTF) Traveler number TSTF-439, Revision 2, "Eliminate Second Completion Times Limiting Time From Discovery of Failure to Meet an LCO," dated June 20, 2005.
TXU Power is submitting this LAR in conjunction with an industry consortium of six plants as a result of a mutual agreement known as Strategic Teaming and Resource Sharing (STARS). The STARS group consists of the six plants operated by TXU Generation Company LP, Ameren Union Electric Company, Wolf Creek Nuclear Operating Corporation, Pacific Gas and Electric Company, STP Nuclear Operating Company, and Arizona Public Service Company. Callaway, Diablo Canyon, Palo Verde, and Wolf Creek also plan to submit similar LARs.
Enclosure I contains a description of the proposed changes, the supporting technical analyses, and the no significant hazards consideration determination. Enclosures 2 and 3 contain marked-up and retyped (clean) TS pages, respectively. Enclosure 4 provides the marked-up TS Bases changes for information only. TS Bases changes are provided for information only and will be implemented pursuant to TS 5.5.14, "Technical Specifications (TS) Bases Control Program," at the time this amendment is implemented.
TXU Power has determined that this LAR does not involve a significant hazard consideration as determined per 10 CFR 50.92. Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment needs to be prepared in connection with the issuance of this amendment. In accordance with I OCFR50.9I(b),
TXU Power is providing the State of Texas with a copy of this proposed amendment.

TXX-06189 Page 3 of 4 The changes in this LAR are not required to address an immediate safety concern.
TXU Power requests approval of this LAR no later than December 31, 2007. TXU Power requests the license amendment be made effective upon NRC issuance, to be implemented within 120 days from the date of issuance.
There are no new or revised regulatory commitments in this letter.
If you have any questions or require additional information, please contact Carl Corbin at (254) 897-0121.
I state under penalty of perjury that the foregoing is true and correct.
Executed on December 19, 2006.
Sincerely, TXU Generation Company LP By:      TXU Generation Management Company LLC Its General Partner Mike Blevins By:A.                  m Yre dW. adden' Director, Oversight and Regulatory Affairs CBC Enclosures        1. Description and Assessment
: 2. Proposed Technical Specifications Changes (Marked-up)
: 3. Proposed Technical Specifications Changes (Retyped)
: 4. Changes to Technical Specifications Bases Pages (Marked-up)

TXX-06189 Page 4 of 4 c -    B. S. Mallett, Region IV M. C. Thadani, NRR Resident Inspectors, CPSES Ms. Alice Rogers Bureau of Radiation Control Texas Department of Public Health I 100 West 49th Street Austin, Texas 78756-3189

ENCLOSURE 1 to TXX-06189 DESCRIPTION AND ASSESSMENT LICENSEE'S EVALUATION

==1.0 DESCRIPTION==

==2.0 PROPOSED CHANGE==

==3.0 BACKGROUND==

==4.0 TECHNICAL ANALYSIS==

==5.0 REGULATORY ANALYSIS==

5.1  No Significant Hazards Consideration 5.2  Applicable Regulatory Requirements/Criteria

==6.0 ENVIRONMENTAL CONSIDERATION==

==7.0 REFERENCES==

Enclosure I to TXX-06189 Page 2 of 11

==1.0    DESCRIPTION==

By this letter, TXU Generation Company LP (TXU Power) requests an amendment to the CPSES Unit 1 Operating License (NPF-87) and CPSES Unit 2 Operating License (NPF-
: 89) by incorporating the attached change into the CPSES Unit I and 2 Technical Specifications (TS).
The proposed change would revise the Operating Licenses to delete second Completion Times from the affected Technical Specification Required Actions. It also revises TS Example 1.3-3 to remove the second Completion Times and to revise the discussion in that Example.
The proposed change is consistent with Technical Specification Task Force (TSTF)
Traveler TSTF-439, Revision 2, "Eliminate Second Completion Time From Discovery of Failure to Meet an LCO" (Reference 7.1). TSTF-439, Revision 2 was approved by the NRC in a letter dated January 11, 2006 to the Technical Specification Task Force (Reference 7.2).

==2.0    PROPOSED CHANGE==

TS Example 1.3-3 is revised to eliminate the second Completion Times and to replace the discussion regarding second Completion Times with the following:
                "It is possible to alternate between Conditions A, B, and C in such a manner that operation could continue indefinitely without ever restoring systems to meet the LCO. However, doing so would be inconsistent with the basis of the Completion Times. Therefore, there shall be administrative controls to limit the maximum time allowed for any combination of Conditions that result in a single contiguous occurrence of failing to meet the LCO. These administrative controls shall ensure that the Completion Times for those Conditions are not inappropriately extended."
A second Completion Time is included for certain Conditions/Required Actions to establish a limit on the maximum time allowed for any combination of Conditions that result in a single contiguous failure to meet the Limiting Condition for Operation (LCO).
These Completion Times (henceforth referred to as "second Completion Times") are joined by an "AND" logical connector to the Condition specific Completion Time and state "X hours/days from discovery of failure to meet the LCO".
The second Completion Times associated with TS 3.7.5 Required Actions A.1 and B. 1, TS 3.8.1 Required Actions A.3 and B.4, and TS 3.8.9 Required Actions A.1, B.1, and C.1 are being deleted.

Enclosure I to TXX-06189 Page 3 of II Proposed revisions to the TS Bases are also included in this application for information only. The changes to the affected TS Bases pages will be incorporated in accordance with TS 5.5.14, "Technical Specification (TS) Bases Control Program."

==3.0    BACKGROUND==

Between July and December of 1991, the NRC and the Improved Standard Technical Specification (ISTS) lead plants discussed an issue affecting a small number of TSs that could theoretically allow indefinite operation of the plant while not meeting a LCO.
If an LCO requires OPERABILITY of two systems, it is possible to enter the Condition for one inoperable system and before restoring the first system, the second system becomes inoperable. With the second system inoperable, the first system is restored to OPERABLE status. Before restoring the second system, the first system becomes inoperable again, and so on. Under this scenario, it would be theoretically possible to operate indefinitely without ever meeting the LCO. This also could occur with LCOs which require only one system to be OPERABLE, but for which the Conditions describe two or more mutually exclusive causes of inoperability.
An NRC internal memo dated August 5, 1991 described the issue. As stated in the memo, "In these Specifications the following phrase was added in the Completion Time column of the Conditions that could extend the AOT: '[10 days] from discovery of failure to meet the LCO.' The [10 day] Completion Time cap is found by adding the maximum Completion Times from the two Conditions that could extend the AOT."
The decision to add the second Completion Time is summarized in a memo from the NRC to the industry lead plant representatives dated December 16, 1991.
It is important to note that this issue of "flip flopping" between Conditions only applies if the LCO is not met. If the LCO requirements are met, even if for an instant, this issue does not occur. This is a highly unlikely scenario and the Industry argued that it would never occur, but the NRC believed it should be addressed when developing the ISTS because there were no other regulatory processes in place at that time which could prevent or respond to such a situation, should it occur.
Section 1.3 of the ISTS, Example 1.3-3, describes the use of this type of second Completion Time. The ISTS NUREGs contain these types of second Completion Times in the following Specifications:
* AC Sources - Operating
* Distribution Systems - Operating
* Containment Spray and Cooling (Not Used at Comanche Peak)
* Auxiliary / Emergency Feedwater System

Enclosure I to TXX-06189 Page 4 of 11 The addition of these second Completion Times did not originally create an operational restriction because the likelihood of experiencing concurrent failures such that the second Completion Time is limiting is very remote.
However, these second Completion Times became a problem when the Industry proposed risk-informed Completion Times for some of the Specifications which contained the second Completion Times in Industry/Technical Specification Task Force (TSTF)
Traveler number TSTF-409, "Containment Spray System Completion Time Extension,"
and TSTF-430, "AOT Extension to 7 Days for LPI and Containment Spray." These Travelers extended a Completion Time and, following the methodology described in the August 5, 1991 memo, the second Completion Time was extended by the same amount (i.e., the second Completion Time continued to be the sum of the two Completion Times.)
However, in letters to the TSTF dated November 15, 2001 and September 10, 2002, the NRC stated that the extension of the second Completion Time in TSTF-409 and TSTF-430 was inappropriate because one of the two Completion Times added to obtain the second Completion Time limit was risk based and the other was deterministic. On September 10, 2002, the NRC provided a letter making a similar statement regarding TSTF-430. Eventually, the NRC agreed that it was acceptable to add these two Completion Times and TSTF-409 and TSTF-430 were approved. However, second Completion Times complicate the presentation of the ISTS and complicate the implementation of risk-informed Completion Times. In addition, other regulatory requirements, not present when the ISTS NUREGs were originally developed, eliminate the need for these second Completion Times.

==4.0    TECHNICAL ANALYSIS==

The adoption of a second Completion Time was based on an NRC concern that a plant could continue to operate indefinitely with an LCO governing safety significant systems never being met by alternately meeting the requirements of separate Conditions. In 1991, the NRC could not identify any regulatory requirement or program which could prevent this misuse of the TSs. However, that is no longer the case. There are now two programs which would provide a strong disincentive to continued operation with concurrent multiple inoperabilities of the type the second Completion Times were designed to prevent.
The Maintenance Rule: 10 CFR 50.65 (a)(l), the Maintenance Rule, requires each licensee to monitor the performance or condition of structures, systems, and components (SSCs) against licensee-established goals to ensure that the SSCs are capable of fulfilling their intended functions. If the performance or condition of an SSC does not meet established goals, appropriate corrective action is required to be taken. The NRC Resident Inspectors monitor the licensee's Corrective Action process and could take

Enclosure I to TXX-06189 Page 5 of I I action if the licensee's maintenance program allowed the systems required by a single LCO to become concurrently inoperable multiple times. The performance and condition monitoring activities required by 10 CFR 50.65 (a)(1) and (a)(2) would identify if poor maintenance practices resulted in multiple entries into the ACTIONS of the TSs and unacceptable unavailability of these SSCs. The effectiveness of these performance monitoring activities, and associated corrective actions, is evaluated at least every refueling cycle, not to exceed 24, months per 10 CFR 50.65 (a)(3).
Under the TSs, the Completion Time for one system is not affected by other inoperable equipment. The second Completion Times were an attempt to influence the Completion Time for one system based on the condition of another system, if the two systems were required by the same LCO. However 10 CFR 50.65(a)(4) is a much better mechanism to apply this influence as the Maintenance Rule considers all inoperable risk-significant equipment, not just the one or two systems governed by the same LCO.
Under 10 CFR 50.65(a)(4), the risk impact of all inoperable risk-significant equipment is assessed and managed when performing preventative or corrective maintenance. The risk assessments are conducted using the procedures and guidance endorsed by Regulatory Guide 1.182, "Assessing and Managing Risk Before Maintenance Activities at Nuclear Power Plants." Regulatory Guide 1.182 endorses the guidance in Section 11 of NUMARC 93-01, "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants." These documents address general guidance for conduct of the risk assessment, quantitative and qualitative guidelines for establishing risk management actions, and example risk management actions. These include actions to plan and conduct other activities in a manner that controls overall risk, increased risk awareness by shift and management personnel, actions to reduce the duration of the condition, actions to minimize the magnitude of risk increases (establishment of backup success paths or compensatory measures), and determination that the proposed maintenance is acceptable. This comprehensive program provides much greater assurance of safe plant operation than the second Completion Times in the TSs.
The Reactor Oversight Process: NEI 99-02, "Regulatory Assessment Performance Indicator Guideline," describes the tracking and reporting of performance indicators to support the NRC's Reactor Oversight Process (ROP). The NEI document was endorsed by the NRC in Regulatory Issue Summary (RIS) 2001-11, "Voluntary Submission Of Performance Indicator Data." NEI 99-02, Section 2.2, describes the Mitigating Systems Cornerstone. NEI 99-02 specifically addresses emergency AC Sources (which encompasses the AC Sources and Distribution System LCOs), and the Auxiliary Feedwater system. Extended unavailability of these systems due to multiple entries into the ACTIONS would affect the NRC's evaluation of the licensee's performance under the ROP.

Enclosure I to TXX-06189 Page 6 of I1 In addition to these programs, a requirement is added to Section 1.3 of the TSs to require licensees to have administrative controls to limit the maximum time allowed for any combination of Conditions that result in a single contiguous occurrence of failing to meet the LCO. These administrative controls should consider plant risk and shall limit the maximum contiguous time of failing to meet the LCO. This TS requirement, when considered with the regulatory processes discussed above, provide an equivalent or superior level of plant safety without the unnecessary complication of the TSs by second Completion Times on some Specifications.
Each of the TSs affected are discussed below.
AC Sources - Operating Specification 3.8.1, AC Sources - Operating, has a 72 hour Completion Time for one offsite circuit inoperable (Condition A) and a 72 hour Completion Time for one diesel generator inoperable (Condition B). Both Condition A and Condition B have a second Completion Time of"6 days from discovery of failure to meet the LCO." The second Completion Time limits plant operation when Condition A or B is entered, and before the inoperable system is restored, the other Condition is entered, and then the first inoperable system is restored, and before the remaining inoperable system is restored, the other Condition is entered again.
This highly improbable scenario is further limited by Condition D which applies when an offsite circuit and a diesel generator (DG) are inoperable. It limits plant operation in this Condition to 12 hours. See Example I for an illustration.
Time = 0 Limited by second Completion Time to 6 days I     L     t I     Less than 72 hours                             Less than 72 hours Diesel Inoperable                             Diesel Inoperable Condition A                                   Condition A Inoperabilities must overlap and must be less than 12 hours by Condition D Offsite Circuit Inoperable Condition B Less than 72 hours Example 1 As stated above, the ROP monitors the availability of mitigating systems, including the emergency AC sources (DG unavailability). Such frequent,

Enclosure I to TXX-06189 Page 7 of I1 repeated failures of the AC sources would be reported to the NRC and this represents a strong disincentive to such operation.
Distribution Systems - Operating Specification 3.8.9, Distribution Systems - Operating, has an 8 hour Completion Time for one or more AC electrical power distribution subsystems inoperable (Condition A), and a 2 hour Completion Time for one or more AC vital buses (Condition B) or one or more DC electrical power subsystems (Condition C) inoperable. Conditions A, B, and C have a second Completion Time of 16 hours from discovery of failure to meet the LCO. Condition E applies if two or more electrical distribution subsystems are inoperable and, if it results in a loss of safety function, LCO 3.0.3 must be entered immediately. See Example 2.
Time = 0 Limited by second Completion Time to 16 hours I I     Less than 8 hours            Less than 8 hours AC subsystem inoperable        AC subsystem inoperable Condition A                   Condition A Inoperabilities must overlap. If loss of safety function, enter LCO 3.0.3 Vital AC bus                                              immediately by Condition E inoperable Condition B or DC            thns subsystem           than 2 inoperable          hours Condition C Example 2 The second Completion Time is not needed. First, it is unusual for an AC electrical power subsystem or AC vital bus to be inoperable without causing a reactor trip. Secondly, Completion Times are very short (8 and 2 hours) providing little time to restore systems such that the Conditions overlap and multiple inoperabilities occur. Lastly, should any overlapping inoperabilities that result in a loss of safety function occur, a plant shutdown in accordance with LCO 3.0.3 is required.
Auxiliary / Emergency Feedwater System TS 3.7.5, Auxiliary Feedwater System has a 7 day Completion Time for one inoperable steam supply to a turbine driven AFW pump (rendering the turbine

Enclosure I to TXX-06189 Page 8 of II driven AFW pump inoperable) (Condition A) and a 72 hour Completion Time for one AFW train inoperable (Condition B). Conditions A and B have a second Completion Time of 10 days from discovery of failure to meet the LCO. In order for the second Completion Time to be limiting, entry into and out of Conditions A and B must occur, which requires the turbine driven and motor driven AFW pumps to be concurrently inoperable. However, Condition C states that if AFW trains are inoperable the plant must be in MODE 3 in 6 hours and MODE 4 in 18 hours. See Example 3.
Time=O Limited by second Completion Time to 10 days I Less than 7 days                 Less! than 7 days One steam driven AFW train          One steam driven AFW train inoperable                         inoperable Condition A                        Condition A
* Inoperabilities Onemt~rI// ' ""*                     -B0* 'must       overlap.
One motor driven AFW tinonrain                              Two trains inoperable requires iondCreuiB CCni                 teaes7nim     immediate shutdown by Condition C hours Example 3 The second Completion Time is not needed. For the second Completion Time to be limiting, Conditions A and B must be entered concurrently. However, Condition C requires an immediate shutdown when two trains are inoperable.
Therefore, the second Completion Time will never be limiting and can be removed. In addition, the ROP monitors the availability of the AFW system.
Such frequent, repeated failures of the AFW system would be reported to the NRC and this represents a strong disincentive to such operation.
Based on the above discussions, the concern regarding multiple continuous entries into Conditions without meeting the LCO is addressed by the system unavailability monitoring programs described above and the administrative controls required by Section 1.3 of the TSs. Therefore, this potential concern is no longer an issue and the TSs can be simplified by eliminating the second Completion Times with no detriment to plant safety.
to TXX-06189 Page 9 of I I

==5.0    REGULATORY ANALYSIS==

5.1     No Significant Hazards Consideration The Technical Specifications (TS) for Comanche Peak Steam Electric Station (CPSES) are modified. Completion Times Example 1.3-3 is revised to eliminate the second completion times and to replace the discussion regarding second Completion Times with a new discussion. The second Completion Time associated with TS 3.7.5 Required Actions A.1 and B.1, TS 3.8.1 Required Actions A.3 and B.4, and TS 3.8.9 Required Actions A.1, B.1, and C.1 are being deleted. The Bases associated with these Required Actions are also being revised to delete the discussion of the second Completion Time.
TXU Power has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
: 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No.
The proposed changes eliminate certain Completion Times from the Technical Specifications. Completion Times are not an initiator to any accident previously evaluated. As a result, the probability of an accident previously evaluated is not affected. The consequences of an accident during the revised Completion Time are no different than the consequences of the same accident during the existing Completion Times.
As a result, the consequences of an accident previously evaluated are not affected by this change. The proposed changes do not alter or prevent the ability of structures, systems, and components from performing their intended function to mitigate the consequences of an initiating event within the assumed acceptance limits. The proposed changes do not affect the source term, containment isolation, or radiological release assumptions used in evaluating the radiological consequences of an accident previously evaluated. Further, the proposed changes do not increase the types or amounts of radioactive effluent that may be released offsite, nor significantly increase individual or cumulative occupational/public radiation exposures. The proposed changes are consistent with the safety analysis assumptions and resultant consequences.

Enclosure I to TXX-06189 Page 10 of I I Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
: 2.      Does the proposed change create the possibility of a new or different accident from any accident previously evaluated?
Response: No.
The changes do not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. The changes do not alter any assumptions made in the safety analysis.
Therefore, the proposed change does not create the possibility of a new or different accident from any accident previously evaluated.
: 3.      Does the proposed change involve a significant reduction in a margin of safety?
Response: No.
The proposed change to delete the second Completion Time does not alter the manner in which safety limits, limiting safety system settings or limiting conditions for operation are determined. The safety analysis acceptance criteria are not affected by this change. The proposed changes will not result in plant operation in a configuration outside of the design basis.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above evaluation, TXU Power concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of"no significant hazards consideration" is justified.
5.2     Applicable Regulatory Requirements/Criteria 10 CFR 50.36, "Technical Specifications." 10 CFR 50.36(c)(2) states, "When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met." The revised Actions continue to

Enclosure Ito TXX-06189 Page 11 of 11 meet the requirements of this regulation.
10 CFR 50.65, "Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants." The overall objective of this performance-based rule is to ensure that nuclear power plant structures, systems, and components (SSCs) will be maintained so that they will perform their intended function when required.
In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

==6.0    ENVIRONMENTAL CONSIDERATION==

TXU Power has evaluated the proposed amendment and has determined that the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
7.0. REFERENCES 7.1      Industry/Technical Specification Task Force (TSTF) Standard Technical Specification Change TSTF-439, Revision 2, "Eliminate Second Completion Time From Discovery of Failure To Meet an LCO," June 20, 2005.
7.2      NRC Letter dated January 11, 2006, to the Technical Specification Task Force regarding "Status of TSTF 439, 'Eliminate Second Completion Times Limiting Time From Discovery of Failure To Meet An LCO'"
to TXX-06189 Page 1 of 10 ENCLOSURE 2 to TXX-06189 PROPOSED TECHNICAL SPECIFICATIONS CHANGES (MARKED-UP)
Pages 1.3-2 1.3-6 1.3-7 3.7-12 3.8-2 3.8-4 3.8-38 3.8-39 to TXX-06189 Page 2 of 10 INSERT FOR TECHINCAL SPECIFICATIONS PAGE 1.3-7 It is possible to alternate between Conditions A, B, and C in such a manner that operation could continue indefinitely without ever restoring systems to meet the LCO. However, doing so would be inconsistent with the basis of the Completion Times. Therefore, there shall be administrative controls to limit the maximum time allowed for any combination of Conditions that result in a single contiguous occurrence of failing to meet the LCO. These administrative controls shall ensure that the Completion Times for those Conditions are not inappropriately extended.
to TXX-06189 Page 3 of 10                                                                          Completion Times 1.3 1.3 Completion Times DESCRIPTION          However, when a subsequent train, subsystem, component, or (continued)        variable expressed in the Condition is discovered to be inoperable or not within limits, the Completion Time(s) may be extended.
To apply this Completion Time extension, two criteria must first be met.
The subsequent inoperability:
: a.       Must exist concurrent with the first inoperability; and
: b.       Must remain inoperable or not within limits after the first inoperability is resolved.
The total Completion Time allowed for completing a Required Action to address the subsequent inoperability shall be limited to the more restrictive of either:
: a.       The stated Completion Time, as measured from the initial entry into the Condition, plus an additional 24 hours; or
: b.       The stated Completion Time as measured from discovery of the subsequent inoperability.
The above Completion Time extensions do not apply to those Specifications that have exceptions that allow completely separate re-entry into the Condition (for each train, subsystem, component, or variable expressed in the Condition) and separate tracking of Completion Times based on this re-entry. These exceptions are stated in individual Specifications.
The above Completion Time extension does not apply to a Completion Time with a modified "time zero." This modified "time zero" may be expressed as a repetitive time (i.e., "once per 8 hours," where the Completion Time is referenced from a previous completion of the Required Action versus the time of Condition entry) or as a time modified by the phrase "from discove         .'/"E am e 1.3- illutratesoneuse pf thisype f CompletioTime/ The /0da.)f Comletio Tim spp ifierfor Cenditi'ns Aaind Bk t Exar~pl e 1 .- 3 myy not le ex~ndec.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                   1.3-2                            Amendment No.&#xfd;&#xfd; to TXX-06189 Page 4 of 10                                 Completion Times 1.3 1.3 Completion Times EXAMPLES             EXAMPLE 1.3-3 (continued)
ACTIONS (continued)
COMANCHE PEAK - UNITS 1 AND 2      1.3-6 Amendment No.
Enclosure 2 to TXX-06189 Page 5 of 10                                                                       Completion Times 1.3 1.3 Completion Times EXAMPLES             EXAMPLE 1.3-3 (continued)
When one Function X train and one Function Y train are inoperable, Condition A and Condition B are concurrently applicable. The Completion Times for Condition A and Condition B are tracked separately for each train starting from the time each train was declared inoperable and the Condition was entered. A separate Completion Time is established for Condition C and tracked from the time the second train was declared inoperable (i.e., the time the situation described in Condition C was discovered).
If Required Action C.2 is completed within the specified Completion Time, Conditions B and C are exited. If the Completion Time for Required Action A.1 has not expired, operation may continue in accordance with Condition A. The remaining Completion Time in Condition A is measured from the time the affected train was declared inoperable (i.e., initial entry into Condition A).
INSERT (continued)
COMANCHE PEAK - UNITS 1 AND 2                 1.3-7                           Amendment No. to TXX-06189 Page 6 of 10                                                                              AFW System 3.7.5 3.7 PLANT SYSTEMS 3.7.5 Auxiliary Feedwater (AFW) System LCO 3.7.5             Three AFW trains shall be OPERABLE.
APPLICABILITY:        MODES 1, 2, and 3 ACTIONS
                                            -NOT E---------------------------------------------
LCO 3.0.4.b is not applicable.                                                                        109 (continued)
COMANCHE PEAK - UNITS 1 AND 2               3.7-12                            Amendment No.169-to TXX-06189 Page 7 of 10                                                                           AC Sources - Operating 3.8.1 ACTIONS
   -----------------                                JI    r---------------------------------------------------------
LCO 3.0.4.b is not applicable to DGs.
CONDITION                 REQUIRED ACTION                           COMPLETION TIME A. One required offsite circuit A.1        Perform SR 3.8.1.1 for                  1 hour inoperable.                         required OPERABLE offsite circuit.                      AND Once per 8 hours thereafter AND
                                          ...............-NOTE ---------
In MODES 1, 2 and 3, the TDAFW pump is considered a required redundant feature.
A.2         Declare required                       24 hours from feature(s) with no offsite             discovery of no power available                        offsite power to one inoperable when its                   train concurrent with redundant required                     inoperability of feature(s) is inoperable.              redundant required feature(s)
AND A.3        Restore required offsite circuit to OPERABLE status.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                  3.8-2                             Amendment No. 4G9,424--
to TXX-06189 Page 8 of 10                                                                AC Sources - Operating 3.8.1 ACTIONS (continued)
CONDITION                  REQUIRED ACTION                      COMPLETION TIME B. (continued)                   AND B.4   Restore DG to OPERABLE status.
C. Two required offsite circuits                         -------------           -NOTE inoperable.                        In MODES 1,2 and 3, the TDAFW pump is considered a required redundant feature.
C.1   Declare required                  12 hours from feature(s) inoperable            discovery of when its redundant               Condition C required feature(s) is           concurrent with inoperable.                      inoperability of redundant required features AND C.2   Restore one required             24 hours offsite circuit to OPERABLE status.
(continued)
COMANCHE PEAK - UNITS 1 AND 2            3.8-4                                Amendment No. 64-to TXX-06189 Page 9 of 10                                                       Distribution Systems - Operating 3.8.9 3.8 ELECTRICAL POWER SYSTEMS 3.8.9 Distribution Systems- Operating LCO 3.8.9              Train A and Train B AC, DC, and AC vital bus electrical power distribution subsystems shall be OPERABLE.
APPLICABILITY:         MODES 1, 2, 3, and 4 ACTIONS A. One AC electrical power        A.1      Restore AC electrical distribution subsystem                  power distribution inoperable.                             subsystem to OPERABLE status.
B. One AC vital bus               B.1      Restore AC vital bus subsystem inoperable.                   subsystem to OPERABLE status.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                3.8-38                           Amendment No. to TXX-06189 Page 10 of 10                                                         Distribution Systems - Operating 3.8.9 ACTIONS (continued)
CONDITION                         REQUIRED ACTION                 COMPLETION TIME C. One DC electrical power          C.1       Restore DC electrical distribution subsystem                     power distribution inoperable.                                subsystem to OPERABLE status.
D. Required Action and              D.1      Be in MODE 3.                  6 hours associated Completion Time not met.                    AND D.2      Be in MODE 5.                  36 hours E. Two trains with inoperable       E.1      Enter LCO 3.0.3.               Immediately distribution subsystems that result in a loss of safety function.
SURVEILLANCE REQUIREMENTS SURVEILLANCE                                       FREQUENCY SR 3.8.9.1       Verify correct breaker alignments and voltage to required     7 days AC, DC, and AC vital bus electrical power distribution subsystems.
COMANCHE PEAK - UNITS 1 AND 2                  3.8-39                            Amendment No. &#xfd;&#xfd; to TXX-06189 Page 1 of 9 ENCLOSURE 3 to TXX-06189 PROPOSED TECHNICAL SPECIFICATIONS CHANGES (RETYPED)
Pages 1.3-2 1.3-6 1.3-7 3.7-12 3.8-2 3.8-4 3.8-38 3.8-39 to TXX-06189 Page 2 of 9                                                                          Completion Times 1.3 1.3 Completion Times DESCRIPTION          However, when a subsequent train, subsystem, component, or (continued)        variable expressed in the Condition is discovered to be inoperable or not within limits, the Completion Time(s) may be extended.
To apply this Completion Time extension, two criteria must first be met.
The subsequent inoperability:
: a.       Must exist concurrent with the first inoperability; and
: b.       Must remain inoperable or not within limits after the first inoperability is resolved.
The total Completion Time allowed for completing a Required Action to address the subsequent inoperability shall be limited to the more restrictive of either:
: a.       The stated Completion Time, as measured from the initial entry into the Condition, plus an additional 24 hours; or
: b.       The stated Completion Time as measured from discovery of the subsequent inoperability.
The above Completion Time extensions do not apply to those Specifications that have exceptions that allow completely separate re-entry into the Condition (for each train, subsystem, component, or variable expressed in the Condition) and separate tracking of Completion Times based on this re-entry. These exceptions are stated in individual Specifications.
The above Completion Time extension does not apply to a Completion Time with a modified "time zero." This modified "time zero" may be expressed as a repetitive time (i.e., "once per 8 hours," where the Completion Time is referenced from a previous completion of the Required Action versus the time of Condition entry) or as a time modified by the phrase "from discovery. .
(continued)
COMANCHE PEAK - UNITS 1 AND 2                   1.3-2                           Amendment No. 64, to TXX-06189 Page 3 of 9                                                          Completion Times 1.3 1.3 Completion Times EXAMPLES             EXAMPLE 1.3-3 (continued)
ACTIONS CONDITION        REQUIRED ACTION        COMPLETION TIME A. One         A.1   Restore Function X 7 days Function X        train to OPERABLE train             status.
inoperable.
B. One          B.1   Restore Function Y 72 hours Function Y        train to OPERABLE train              status.
inoperable.
C. One         C.1   Restore Function X 72 hours Function X        train to OPERABLE train              status.
inoperable.
OR AND C.2   Restore Function Y One               train to OPERABLE  72 hours Function Y        status.
train inoperable.
(continued)
COMANCHE PEAK - UNITS 1 AND 2         1.3-6                     Amendment No. 64, to TXX-06189 Page 4 of 9                                                                       Completion Times 1.3 1.3 Completion Times EXAMPLES             EXAMPLE 1.3-3 (continued)
When one Function X train and one Function Y train are inoperable, Condition A and Condition B are concurrently applicable. The Completion Times for Condition A and Condition B are tracked separately for each train starting from the time each train was declared inoperable and the Condition was entered. A separate Completion Time is established for Condition C and tracked from the time the second train was declared inoperable (i.e., the time the situation described in Condition C was discovered).
If Required Action C.2 is completed within the specified Completion Time, Conditions B and C are exited. If the Completion Time for Required Action A.1 has not expired, operation may continue in accordance with Condition A. The remaining Completion Time in Condition A is measured from the time the affected train was declared inoperable (i.e., initial entry into Condition A).
It is possible to alternate between Conditions A, B, and C in such a manner that operation could continue indefinitely without ever restoring systems to meet the LCO. However, doing so would be inconsistent with the basis of the Completion Times. Therefore, there shall be administrative controls to limit the maximum time allowed for any combination of Conditions that result in a single contiguous occurrence of failing to meet the LCO. These administrative controls shall ensure that the Completion Times for those Conditions are not inappropriately extended.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                   1.3-7                        Amendment No. 64, to TXX-06189 Page 5 of 9                                                                      AFW System 3.7.5 3.7 PLANT SYSTEMS 3.7.5 Auxiliary Feedwater (AFW) System LCO 3.7.5              Three AFW trains shall be OPERABLE.
APPLICABILITY:         MODES 1, 2, and 3 ACTIONS NOTE.
LCO 3.0.4.b is not applicable.
CONDITION                      REQUIRED ACTION            COMPLETION TIME A. One steam supply to            A.1       Restore steam supply to 7 days turbine driven AFW pump                  OPERABLE status.
inoperable.
B. One AFW train inoperable       B.1       Restore AFW train to    72 hours for reasons other than                  OPERABLE status.
Condition A.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                3.7-12                   Amendment No. 4-W, to TXX-06189 Page 6 of 9                                                                    AC Sources - Operating 3.8.1 ACTIONS
                                                  -NOTE-LCO 3.0.4.b is not applicable to DGs.
CONDITION                        REQUIRED ACTION                  COMPLETION TIME A. One required offsite circuit   A. 1       Perform SR 3.8.1.1 for         1 hour inoperable.                               required OPERABLE offsite circuit.             AND Once per 8 hours thereafter AND NOTE--------- -......
In MODES 1, 2 and 3, the TDAFW pump is considered a required redundant feature.
A.2         Declare required             24 hours from feature(s) with no offsite   discovery of no power available              offsite power to one inoperable when its          train concurrent with redundant required            inoperability of feature(s) is inoperable. redundant required feature(s)
AND A.3        Restore required offsite      72 hours circuit to OPERABLE status.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                  3.8-2                      Amendment No. 40-9, 424, to TXX-06189 Page 7 of 9                                                         AC Sources - Operating 3.8.1 ACTIONS (continued)
CONDITION                   REQUIRED ACTION             COMPLETION TIME B. (continued)                   AND B.4   Restore DG to            72 hours OPERABLE status.
C. Two required offsite circuits                 NOTE-------
inoperable.                        In MODES 1, 2 and 3, the TDAFW pump is considered a required redundant feature.
C.1   Declare required         12 hours from feature(s) inoperable    discovery of when its redundant       Condition C required feature(s) is   concurrent with inoperable.              inoperability of redundant required features AND C.2   Restore one required     24 hours offsite circuit to OPERABLE status.
(continued)
COMANCHE PEAK - UNITS 1 AND 2            3.8-4                       Amendment No. 64, to TXX-06189 Page 8 of 9                                                        Distribution Systems-- Operating 3.8.9 3.8 ELECTRICAL POWER SYSTEMS 3.8.9 Distribution Systems- Operating LCO 3.8.9              Train A and Train B AC, DC, and AC vital bus electrical power distribution subsystems shall be OPERABLE.
APPLICABILITY:         MODES 1, 2, 3, and 4 ACTIONS CONDITION                      REQUIRED ACTION                  COMPLETION TIME A. One AC electrical power         A.1     Restore AC electrical          8 hours distribution subsystem                  power distribution inoperable,                             subsystem to OPERABLE status.
B. One AC vital bus                B.1     Restore AC vital bus           2 hours subsystem inoperable,                   subsystem to OPERABLE status.
(continued)
COMANCHE PEAK - UNITS 1 AND 2               3.8-38                           Amendment No. 64, to TXX-06189 Page 9 of 9                                                           Distribution Systems-- Operating 3.8.9 ACTIONS (continued)
CONDITION                         REQUIRED ACTION                  COMPLETION TIME C. One DC electrical power          C.1       Restore DC electrical         2 hours distribution subsystem                     power distribution inoperable,                                subsystem to OPERABLE status.
D. Required Action and              D.1      Be in MODE 3.                  6 hours associated Completion Time not met.                    AND D.2      Be in MODE 5.                  36 hours E. Two trains with inoperable       E.1      Enter LCO 3.0.3.                Immediately distribution subsystems that result in a loss of safety function.
SURVEILLANCE REQUIREMENTS SURVEILLANCE                                       FREQUENCY SR 3.8.9.1      Verify correct breaker alignments and voltage to required      7 days AC, DC, and AC vital bus electrical power distribution subsystems.
COMANCHE PEAK- UNITS 1 AND 2                   3.8-39                            Amendment No. 64, to TXX-06189 Page 1 of 9 ENCLOSURE 4 to TXX-06189 CHANGES TO TECHNICAL SPECIFICATIONS BASES PAGES (MARKED-UP)
(For Information only)
Pages B   3.7-30 B 3.7-31 B 3.8-7 B 3.8-10 B 3.8-79 B 3.8-81 B 3.8-82 B 3.8-83 to TXX-06189 Page 2 of 9                                                                             AFW System B 3.7.5 BASES (continued)
ACTIONS              A Note prohibits the application of LCO 3.0.4.b to an inoperable AFW           34 train. There is an increased risk associated with entering a MODE or other specified condition in the Applicability with an AFW train inoperable and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
A.1 If one of the two steam supplies to the turbine driven AFW train is inoperable, action must be taken to restore OPERABLE status within 7 days. The 7 day Completion Time is reasonable, based on the following reasons:
: a.       The redundant OPERABLE steam supply to the turbine driven AFW pump;
: b.       The availability of redundant OPERABLE motor driven AFW pumps; and
: c.        The low probability of an event occurring that requires the inoperable steam supply to the turbine driven AFW pump.
S~Ond   Comp~letion 6 aximu/i'          Ti e for time all e~ed for R, ai
                              .rable d/uing any 96ntinuous B.1 With one of the required AFW trains (pump or flow path) inoperable in MODE 1, 2, or 3 for reasons other than Condition A, action must be taken to restore OPERABLE status within 72 hours. This Condition includes the loss of two steam supply lines to the turbine driven AFW pump. The 72 hour Completion Time is reasonable, based on redundant capabilities afforded by the AFW System, time needed for repairs, and the low probability of a DBA occurring during this time period.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                B 3.7-30                                Revision   to TXX-06189 Page 3 of 9                                                                           AFW System B 3.7.5 BASES (continued)
ACTIONS C.1 and C.2 When Required Action A.1 or B.1 cannot be completed within the required Completion Time, or iftwo AFW trains are inoperable in MODE 1, 2, or 3, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours, and in MODE 4 within 18 hours.
The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.
In MODE 4, either the reactor coolant pumps or the RHR loops can be used to provide forced circulation. This is addressed in LCO 3.4.6, "RCS Loops- MODE 4. Although not required, the unit may continue to cool down and initiate RHR.
(continued)
COMANCHE PEAK - UNITS 1 AND 2              B 3.7-31                          Amendment No. to TXX-06189 Page 4 of 9                                                                 AC Sources-- Operating B 3.8.1 BASES ACTIONS             A.3 (continued)
According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition A for a period that should not exceed 72 hours. With one offsite circuit inoperable, the reliability of the offsite system is degraded, and the potential for a loss of offsite power is increased, with attendant potential for a challenge to the unit safety systems. In this Condition, however, the remaining OPERABLE offsite circuit and DGs are adequate to supply electrical power to the onsite Class 1 E Distribution System.
The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.
The seco&#xfd;&#xfd; Completi n Time f.r Require Action A.3 stablishes a/Amit on the       ximum ti e allowe rfor any c bination o equired AC pOXer source to be ingerable d ing any sin e contiguou occurence of f ing to          et the LC . If Conditi A is enter while, for inonce, a D is mop able and t at DG is su equently re med ERABL ,the LC may alrea y have bee not met for                   to 72 hour This cou lead to total of 14 hours, sin initial failur to meet the LCO, t restore t offsite cir uit. At this         e, a DG c Id again be me mop able, the ircuit rest d OPERA E, and an ditional 72                      urs (fo total of days) allo ed prior to mplete res ration of the CO.
T       day       mpletion me provide a limit on th time allowe in a pecified ondition a r discovery f failure to eet the LCO This limit i consid ed reasona e for situat ns in which onditions                nd B are/
enter concurre y. The "A               connecto etween th 2 hour an
                    \6 d Completi Times me s that both ompletion Tres apply si ultaneousl . and the m e restrictive OMDletion me must                 met. /
* eIed Action a "time z*
result in est4 illy not mt, ir (continued)
COMANCHE PEAK - UNITS 1 AND 2                  B 3.8-7                                    Revision-46--
to TXX-06189 Page 5 of 9                                                                        AC Sources-- Operating B 3.8.1 BASES ACTIONS              B.4 (continued)
According to Regulatory Guide 1.93 (Ref. 6), operation may continue in Condition B for a period that should not exceed 72 hours.
In Condition B, the remaining OPERABLE DG and offsite circuits are adequate to supply electrical power to the onsite Class 1 E Distribution System. The 72 hour Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a DBA occurring during this period.
The secon        ompletionyime for Re ,red Actio B.4 es lishes a Iioit on the mximum timealowed for :Vy combina ion of r uired AC p'wer source to be mope ble during y single                 ntiguo     occurrenc of faili   to meet th    CO. If Co ition B is ntered              ile, for ins nce, an circuit is, operable     d that cirrite it is sub equently re ored PERABLE &#xfd;e LCO m            already ye bee             ot met for p to 72 hour/.
C.1 and C.2 Required Action C.1, which applies when two offsite circuits are inoperable, is intended to provide assurance that an event with a coincident single failure will not result in a complete loss of redundant required safety functions. The Completion Time for this failure of redundant required features is reduced to 12 hours from that allowed for (continued)
COMANCHE PEAK - UNITS 1 AND 2               B 3.8-10                                  Amendment No. f54-to TXX-06189 Page 6 of 9                                                           Distribution Systems--Operating B 3.8.9 BASES ACTIONS             A.1 (continued)
Condition A worst scenario is one train without AC power (i.e., no offsite power to the train and the associated DG inoperable). In this Condition, the unit is more vulnerable to a complete loss of AC power. It is, therefore, imperative that the unit operator's attention be focused on minimizing the potential for loss of power to the remaining train by stabilizing the unit, and on restoring power to the affected train. The 8 hour time limit before requiring a unit shutdown in this Condition is acceptable because of:
: a.         The potential for decreased safety ifthe unit operator's attention is diverted from the evaluations and actions necessary to restore power to the affected train, to the actions associated with taking the unit to shutdown within this time limit; and
: b.         The potential for an event in conjunction with a single failure of a redundant component in the train with AC power.
The se&#xfd; nd Co &#xfd;pletion ime for equired Action A.1 stablish s a limit on th maxim           time/lowed f any corination o require istributi sub stems be in erable ring any ingle co guous currenc'of fa *ng to       et the CO. If C/ndition ./is entere while, fo instanc , a D uus is in erabl and sub quently6stored 0 ERABL , the LC may alread ave en not              t for up 2 Sho urs. his cou lead to total ol 1 h rssi einitialf lure oft LCO to estore t AC dist ution sy m. A his time, DCcircitcould a aimbecoe inope ble, anlA d' tributi n restore OPERAlE. This ould con nue ind initely.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                  B 3.8-79                          Amendment No. &#xfd;&#xfd; to TXX-06189 Page 7 of 9                                                          Distribution Systems-- Operating B 3.8.9 BASES ACTIONS              B.1 (continued)
The 2 hour Completion Time takes into account the importance to safety of restoring the AC vital bus to OPERABLE status, the redundant capability afforded by the other OPERABLE vital buses, and the low probability of a DBA occurring during this period.
The seco d Compl/eion Tim, for Reqied Actio B.1 estab shes a limi on the aximum/llowed fof any cor/ination                  required stribution subs tems to e inoperale durnn any sin                  contiguo occurren of faili g to me the LC). If Condi on B is e ered whil , for instan , an bus is i operabl nd subs quently r urned OP                   BILE, th LCO ay alre y have en not             t for up 8 hours.         is could I ad to a total o 0 hours ince initi failure o he LCO, t restore th vital bu distr' ution sy em. At th tie, an Ctrain co Idagain b come in erable,        d vital b   distributi n restored     PERABL . This c         Id ntinue ir efinitely.
This C mpletion me allow for an exc tion to th normal" me zero" for brginning th allowed tage time" lock." T s will res t in blishing t "time ze "at the ti           the LC      as initi y not met Sstead oft time Co ition B wa**ntered.                  he 16 h r Comple on Time is a acceptab limitation              this pot tial to fa"to meet t LCO indefinit y.
C.1 With DC bus(es) in one train inoperable the remaining DC electrical power distribution subsystems are capable of supporting the minimum safety functions necessary to shut down the reactor and maintain it in a safe shutdown condition, assuming no single failure. The overall reliability is reduced, however, because a single failure in the remaining DC electrical power distribution subsystems could result in the minimum required ESF functions not being supported. Therefore, the required DC buses must be restored to OPERABLE status within 2 hours by powering the bus from the associated battery or charger.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                 B 3.8-81                                       Revision -2 to TXX-06189 Page 8 of 9                                                          Distribution Systems-Operating B 3.8.9 BASES ACTIONS             C.1 (continued)
Condition C represents one or more electrical power distribution subsystems without adequate DC power; potentially both with the battery significantly degraded and the associated charger nonfunctioning for the affected bus(es). In this situation, the unit is significantly more vulnerable to a complete loss of all DC power. It is, therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for loss of power to the remaining bus(es) and restoring power to the affected bus(es).
This 2 hour limit is more conservative than Completion Times allowed for the vast majority of components that would be without power. Taking exception to LCO 3.0.2 for components without adequate DC power, which would have Required Action Completion Times shorter than 2 hours, is acceptable because of:
: a.       The potential for decreased safety by requiring a change in unit conditions (i.e., requiring a shutdown) while allowing stable operations to continue;
: b.       The potential for decreased safety by requiring entry into numerous applicable Conditions and Required Actions for components without DC power and not providing sufficient time for the operators to perform the necessary evaluations and actions for restoring power to the affected train; and
: c.       The potential for an event in conjunction with a single failure of a redundant component.
The 2 hour Completion Time for DC buses is consistent with Regulatory Guide 1.93 (Ref. 3).
on/ Ve maxim* time al wed for aiy combinto              of recired dimrbtin s/bsystemsio b e ino rable duri;g any singl contigu eus occ/u rence o/f failing to *'et the LJO.If Con *tion C is e tered wh*e, for ir tance, a*
AC bus " inopera e and sub           quently r urned 0      RABE, the LC (continued)
COMANCHE PEAK - UNITS 1 AND 2                 B 3.8-82                           Amendment No. to TXX-06189 Page 9 of 9                                                          Distribution Systems--Operating B 3.8.9 BASES ACTIONS              C.1 (continued)
Smay alredlyhavp&#xfd;,een not/ net foruuto 8hours/This coul (ead to a.
total o10 hor sinc ? iia        failure f the LCO to restore te DC distribution sytem. At tis time, a/1AC train/G uld again/ ecome                  \
in erable, nd DC di ribution r stored OP RABLE.               is could c   tinue idefinitel This mpletion ime allo for an ex eption to t e normal "tne zero" fo begi ning the owed out ge time "c ck." This ill result i establishin th *time zer at the ti       the LCO as initiall not met, in ead of the t e Condit' n C was tered. T 16 hour ompletion ime is an acceptabl limitation ntis pot ntial to fail o meet th LCO inde ifitely.
D.1 and D.2 If the inoperable distribution subsystem cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours and to MODE 5 within 36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.
E. 1 Condition E corresponds to inoperable distribution subsystems that result in a loss of safety function, adequate core cooling, containment OPERABILITY and other vital functions for DBA mitigation would be compromised, and immediate plant shutdown in accordance with LCO 3.0.3 is required.
(continued)
COMANCHE PEAK - UNITS 1 AND 2                B 3.8-83                           Amendment No.-64--}}