NOC-AE-10002605, License Amendment Request to Revise the Application of Risk-Managed Technical Specifications to Technical Specification 3.7.7, Control Room Makeup and Cleanup Filtration System.

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License Amendment Request to Revise the Application of Risk-Managed Technical Specifications to Technical Specification 3.7.7, Control Room Makeup and Cleanup Filtration System.
ML103330172
Person / Time
Site: South Texas  STP Nuclear Operating Company icon.png
Issue date: 11/22/2010
From: Bowman C
South Texas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-10002605, TAC MD2341, TAC MD2342, TAC ME4198, TAC ME4199
Download: ML103330172 (26)
v • d • e


Text

Nuclear Operating Company South Tas Pro/ectElectric GeneratinSStation P.. Box 289 Wadsworth. Texas 77483 -

November 22, 2010 NOC-AE- 10002605 10CFR50.90 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 License Amendment Request to Revise the Application of Risk-Managed Technical Specifications to Technical Specification 3.7.7, "Control Room Makeup and Cleanup Filtration System"

References:

1. Letter dated December 28, 2006, from David W. Rencurrel, STPNOC, to NRC Document Control Desk, "Revised Broad Scope Risk-Informed Technical Specification Amendment Request." (ML070040247, NOC-AE-06002036, TAC Nos. MD2341 & MD2342)
2. Letter dated July 13, 2007, from Mohan C. Thadani, NRC, to James J.

Sheppard, STPNOC, "South Texas Project, Units I and 2 - Issuance of Amendments Re: Broad-Scope Risk-Informed Technical Specifications Amendments." (ML071780186, ML071780191, ST-AE-NOC-07001652, TAC Nos. MD2341 and MD2342)

3. Letter dated May 28, 2008, from Scott M. Head, STPNOC, to NRC Document Control Desk, "Clarification of the Applicability of Risk Managed Technical Specifications to Technical Specification 3.7.7." (ML081720133, NOC-AE-08002291)
4. Letter dated June 28, 2010, from Charles T. Bowman, STPNOC, to NRC Document Control Desk, "License Amendment Request to Revise the Action Requirement for an Inoperable Control Room Envelope Boundary to Technical Specification 3.7.7, "Control Room Makeup and Cleanup Filtration Systems."'(ML102170470, NOC-AE- 10002538, TAC Nos. ME4198 and ME4199)

STI: 32755223 A. 2

NOC-AE-10002605 Page 2 The STP Nuclear Operating Company (STPNOC) is submitting this License Amendment Request to revise the application of Risk-Managed Technical Specifications (RMTS) to Technical Specification (TS) 3.7.7, "Control Room Makeup and Cleanup Filtration System."

This change will correct a misapplication of the Configuration Risk Management Program (CRMP) that is currently allowed by the Specification.

In Reference 1, STPNOC submitted a revised License Amendment Request for a broad scope risk-informed set of Technical Specification (TS) changes. The proposed amendment was approved in Reference 2 with the issuance of Amendment 179 and Amendment 166 to the STP Unit 1 and Unit 2 Operating Licenses, respectively. Amendments 179 and 166 approved the use of the STP CRMP for calculating a risk-informed completion time only in Mode 1 and Mode 2 for specified TS Limiting Condition for Operations.

In Reference 1, STPNOC stated that the CRMP would only be applied to the cooling function of TS 3.7.7 and not to the dose mitigation function. In addition, Reference 1 stated that the dose mitigation function of the Control Room Makeup and Cleanup Filtration System (CRHVAC) is not dependent on the cooling function. In Reference 3, STPNOC submitted a letter to correct this statement in that the dose mitigation function is dependent on the cooling function. The Reference 3 letter clarified how the RMTS would be applied to TS 3.7.7 by administratively restricting the application of the CRMP to Action a only, for one inoperable CRHVAC system due to a loss of cooling function.

This request changes how RMTS will apply to TS 3.7.7. The change describes how the CRMP will be applied to address the loss of cooling function of the CRHVAC. The change will allow the elimination of the current administrative restriction that STPNOC imposed on application of TS 3.7.7.

The Enclosure to this letter provides an evaluation of the proposed change. The annotated Technical Specification pages are provided as Attachment 1 to the Enclosure. Although there are no changes proposed to the TS on the second and third pages, all three TS pages will need to be part of the approved amendment because some specifications from each preceding page moved to the succeeding page as a result of the proposed change on the first page.

By Reference 4, STP proposed another change to TS 3.7.7 that does not impact the bases and conclusions of this license amendment request. Conversely, this license amendment request does not impact the bases and conclusions in the amendment request provided in Reference 4. The numbering scheme of the approved TS change for both amendment requests may require some coordination to ensure that the approval of one request does not unintentionally result in an incorrect numbering scheme for the second request, when approved.

STPNOC requests approval of the proposed license amendment by November 30, 2011, with a 60-day implementation period to provide time to revise STP licensing documents.

This letter contains no regulatory commitments.

NOC-AE- 10002605 Page 3 In accordance with 10 CFR 50.91(b), STPNOC is notifying the State of Texas of this request for license amendment by providing a copy of this letter and its attachments.

If you should have any questions regarding this submittal, please contact Ken Taplett at (361) 972-8416 or me at (361) 972-7454.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on /4',t-*e- 2 2olo Date Charles T. Bowman General Manager, Nuclear Safety Assurance KJT

Enclosure:

Evaluation of the Proposed Change

NOC-AE- 10002605 Page 4 cc:

(paper copy) (electronic copy)

Regional Administrator, Region IV A. H. Gutterman, Esquire U. S. Nuclear Regulatory Commission Morgan, Lewis & Bockius LLP 612 East Lamar Blvd, Suite 400 Arlington, Texas 76011-4125 Mohan C. Thadani U. S. Nuclear Regulatory Commission Mohan C. Thadani John Ragan Senior Project Manager Catherine Callaway U.S. Nuclear Regulatory Commission Jim von Suskil One White Flint North (MS 8B1A) NRG South Texas LP 11555 Rockville Pike Rockville, MD 20852 Ed Alarcon Senior Resident Inspector Kevin Pollo U. S. Nuclear Regulatory Commission Richard Pena P. O. Box 289, Mail Code: MNl16 City Public Service Wadsworth, TX 77483 C. M. Canady Peter Nemeth City of Austin Crain, Caton & James, P.C.

Electric Utility Department 721 Barton Springs Road C. Mele Austin, TX 78704 City of Austin Richard A. Ratliff Texas Department of State Health Services Alice Rogers Texas Department of State Health Services

Enclosure NOC-AE- 10002605 Enclosure Evaluation of the Proposed Change

Subject:

License Amendment Request for Revision to Technical Specification 3.7.7 1.0 Summary Description 2.0 Detailed Description 3.0 Technical Evaluation 4.0 Regulatory Evaluation 5.0 Environmental Consideration 6.0 References Attachments:

1. Annotated Technical Specification Page
2. Annotated Technical Specification Bases Changes

Enclosure NOC-AE-10002605 Page 1 Description of Change and Safety Evaluation 1.0 Summary Description This evaluation supports a request to amend Operating Licenses NPF-76 and NPF-80 for the South Texas Project (STP), Units 1 and 2.

License Amendment 179 and Amendment 166 to the STP Unit 1 and Unit 2 Operating Licenses, respectively, approved a broad scope risk-informed set of Technical Specification (TS) changes.

The amendments approved the use of the STP Configuration Risk Management Program (CRMP) for calculating a risk-informed completion time only in Mode 1 and Mode 2 for specified TS Limiting Condition for Operations.

This proposed change allows the CRMP to be applied to the loss of the cooling function of the Control Room Makeup and Cleanup Filtration System (referred to as CRHVAC hereafter) as specified in the proposed Limiting Conditions for Operations Action requirements. The change is based on a calculation that shows the impact of the loss of cooling function on the dose mitigation function for Technical Specification (TS) 3.7.7, "Control Room Makeup and Cleanup Filtration Systems." The loss of cooling function for the CRHVAC is currently modeled in the STP Probabilistic Risk Assessment (PRA).

2.0 Detailed Description

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On July 13, 2007, License Amendments 179 and 166 approved the Risk Managed Technical Specification (RMTS) to allow the CRMP to be applied to various STP TS for determining allowed outage times (AOT) for inoperable trains. The amendments permitted the CRMP to be applied to TS 3.7.7 on a limited basis.

The CRHVAC includes a recirculation and filtration function that maintains the design basis accident radiation dose to the operators within the limits of General Design Criterion 19. The system also provides required room cooling for the operators and equipment. The dose mitigation function is not modeled in the STP PRA because it does not have an impact on the likelihood of a core damaging event, and thus has no impact on core damage frequency (CDF) and large early release frequency (LERF), which are the metrics for application of RMTS. The cooling function of CRHVAC is modeled in the PRA. Based on discussion with the NRC reviewers, it was determined during the license amendment application review for the original RMTS that the dose mitigation function could not be included in the scope of RMTS because it is not modeled in the PRA.

Enclosure NOC-AE-10002605 Page 2 At the time the amendment was approved, STPNOC believed the dose mitigation function was independent of the cooling function and the CRMP could be applied to TS 3.7.7 for conditions where only the cooling function is affected. The "limited" basis approved in the license amendment allowed the CRMP to applyto conditions where only the cooling function of the CRHVAC is affected. The cooling function is provided by Essential Chilled Water (EchW) supported by Essential Cooling Water (ECW). Reference 6.1 addressed this by stating that the wording below would be included in the TS Bases for TS 3.7.7, and the TS Bases were changed as follows:

The dose mitigation function governed by TS 3.7.7 does not depend on the cooling function governed by TS 3.7.7 that is supported by TS 3.7.14 for EchW. Therefore, if a TS 3.7.7 action applies because EchW is not available or the cooling coil for CRHVAC is not operable, the provision to apply the CRMP may be used.

During a review of the basis for application of RMTS in February 2008, STPNOC determined that at least one train of EchW supported by ECW is required to maintain humidity levels to support achieving the filter efficiency assumed in the accident dose analysis. (Reference 6.2)

Based on this information, the dose mitigation function governed by TS 3.7.7 has some dependence on the cooling function.

Administrative restrictions were put in place to limit the use of RMTS for CRHVAC for Action a only.

/

STP TS 3.7.7 requires the operability of three independent trains of CRHVAC. The current TS required actions of TS 3.7.7 are shown below.

a. With one Control Room Makeup and Cleanup Filtration System inoperable for reasons other than condition d, within 7 days restore the inoperable system to OPERABLE status or apply the requirements of the CRMP, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
b. With two Control Room Makeup and Cleanup Filtration Systems inoperable for reasons other than condition d, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> restore at least two systems to OPERABLE status or apply the requirements of the CRMP, or be at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
c. With three Control Room Makeup and Cleanup Filtration Systems inoperable for reasons other than condition d, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> restore at least one system to OPERABLE status or apply the requirements of the CRMP, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Enclosure NOC-AE- 10002605 Page 3

d. One or more Control Room Makeup and Cleanup Filtration Systems inoperable due to inoperable Control Room Envelope (CRE) boundary perform the following:
1) immediately initiate action to implement mitigating actions, and
2) within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> verify mitigating actions ensure CRE occupant exposures to radiological, chemical and smoke hazards will not exceed limits, and
3) within 90 days restore CRE boundary to OPERABLE status Note that the CRMP is not applied to Action d where the CRHVAC is inoperable due to an inoperable CRE boundary.

An engineering calculation determined that two trains of CRHVAC pressurization (fans) with one train of cooling are adequate for the dose mitigation function based on maintaining the required control room envelope positive pressure and maintaining the relative humidity of the control room air below the 70% acceptance criterion required to support design basis assumptions for carbon filter efficiency. The calculation shows that with one train of CRHVAC inoperable for a loss of cooling (i.e., the associated train of ECW or EChW is inoperable), either of the two operable trains of CRHVAC provides adequate cooling to maintain the filter efficiency for the CRI-HVAC system to perform its design function to mitigate dose.

This change proposes the following:

" A new Action b is proposed for the condition where one train of CRHVAC is inoperable only due to unavailability of cooling. The new Action allows the application of the CRMP because at least two trains of the CRHVAC cooling function remain operable where only one train of the cooling function is required to meet the safety function. The new Action is proposed to read as follows:

b. With one Control Room Makeup and Cleanup Filtration System inoperable only due to unavailability of cooling, within 7 days restore the inoperable system to OPERABLE status or apply the requirements of the CRMP, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
  • A new Action d is proposed for the condition where two trains of CRHVAC are inoperable only due to unavailability of cooling. While the Action does not allow the application of the CRMP, it does extend the previous time to restore at least two systems to OPERABLE status from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days. This is because with one remaining CRHVAC train of cooling available, failure of the remaining train's cooling capability would not support the safety function. This condition is comparable to that allowed by Action a where one CRHVAC train is inoperable for dose mitigation reasons. The new Action is proposed to read as follows:

Enclosure NOC-AE-10002605 Page 4

d. With two Control Room Makeup and Cleanup Filtration Systems inoperable only due to unavailability of cooling, within 7 days restore the inoperable system to OPERABLE status, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
  • Action a is modified to separate the Action required for a loss of dose mitigation function from the Action required for a loss of only the cooling function and from the Action for a loss of only the Control Room Envelope boundary. The option to apply the requirements of the CRMP is deleted. The modified Action is proposed to read as follows:
a. With one Control Room Makeup and Cleanup Filtration System inoperable for reasons other than condition b or condition f, within 7 days restore the inoperable system to OPERABLE status, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
  • The current Action b is moved to Action c and modified to separate the Action required for a loss of dose mitigation function from the Action required for a loss of only the cooling function and from the Action for a loss of only the Control Room Envelope boundary. The option to apply the requirements of the CRMP is deleted. The modified Action is proposed to read as follows:
c. With two Control Room Makeup and Cleanup Filtration Systems inoperable for reasons other than condition d or condition f, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> restore at least two systems to OPERABLE status, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
  • The current Action c is moved to new Action e. The option to apply the requirements of the CRMP is deleted.

" The current Action d is renumbered as new Action f. No other changes are made to the Action requirements.

The proposed change only allows the CRMP to be applied where one Control Room Makeup and Cleanup Filtration System is inoperable only due to unavailability of cooling. All other options to apply the requirements of the CRMP to TS 3.7.7 are deleted.

The proposed changes are provided in Attachment 1 to this Enclosure.

A mark-up of the affected Bases pages to TS 3.7.7 is provided in Attachment 2 to this Enclosure for information.

Enclosure NOC-AE- 10002605 Page 5 3.0 Technical Evaluation 3.1 Evaluation of the Application of the CRMP The CRHVAC is comprised of three 50-percent redundant trains that share a common intake plenum and exhaust plenum. Each train is comprised of a makeup fan, a makeup filtration unit, a cleanup filtration unit, a cleanup fan, a control room air handling unit, a supply fan, a return fan, and associated ductwork and dampers. Two of the three 50% design capacity trains with one train of cooling are required during an accident to ensure that the system design function to maintain control room habitability is met.

The CRHVAC ensures that: (1) the ambient air temperature does not exceed the allowable temperature for continuous-duty rating for the equipment and instrumentation cooled by this system, and (2) the control room will remain habitable for operations personnel during and following design-basis accident conditions. The CRHVAC maintains the design-basis accident radiation dose to the operators within the limits of General Design Criterion 19.

The CRHVAC also provides required room cooling for the operators and equipment. An engineering calculation determined that two trains of CRHVAC pressurization (fans) with one train of cooling are adequate for the dose mitigation function based on maintaining the required control room envelope positive pressure and maintaining the relative humidity of the control room air below the 70% acceptance criterion required to support design-basis assumptions for carbon filter efficiency. The calculation shows that with one train of CRHVAC inoperable for a loss of cooling (i.e., the associated train of ECW or EChW is inoperable), either of the two operable trains of CRHVAC provides adequate cooling to maintain the filter efficiency for the CRHVAC system to perform its design function to mitigate dose.

Postulation of a single failure while in the action statement is used to demonstrate that the CRMP is being applied for the cooling function and is not being applied to extend the allowed outage time to restore necessary redundancy for the required dose mitigation function. Therefore, application of the CRMP to TS 3.7.7 Action b for one inoperable train of CRHVAC is permissible.

For those TS where application of the CRMP is allowed, the operator has the option of using the existing TS AOT for routine plant activities and emergent conditions that would not be expected to require an extension of the AOT. This existing AOT is referred to as the "frontstop" time. The frontstop time provides the operator sufficient time to determine and apply an appropriate extended time from the application of the CRMP for those situations where it is determined that an extended AOT, as allowed by the RMTS, is necessary. Once the CRMP is applied and a component has exceeded its frontstop time, the CRMP is applied to all subsequent inoperable TS components within the scope of the CRMP to determine the time of the extended AOT for the new configuration until no components are in ACTIONS beyond the frontstop time.

Enclosure NOC-AE- 10002605 Page 6 The CRHVAC room cooling function is modeled in the PRA. An extended AOT can be calculated for one inoperable train of CRHVAC cooling. Therefore, the CRMP can be applied for the condition of a single train of CRHVAC inoperable only due to the unavailability of cooling.

The dose mitigation function is not modeled in the PRA because it has no effect on core damage frequency or large early release frequency. Consequently, there is no direct quantifiable technical basis for calculating an extended AOT for an inoperable condition involving the dose mitigation function. Therefore, the CRMP can not be applied to the condition of inoperable CRHVAC train(s) where the dose mitigation function is adversely impacted.

3.2 Evaluation of the Loss of Redundancy The CRHVAC is comprised of three 50-percent redundant trains that share a common intake plenum and exhaust plenum. Two of the three 50% design capacity trains with one train of cooling are required during an accident to ensure that the system design function to maintain control room habitability is met.

During the condition where one train of CRHVAC is inoperable due to an adverse impact on the dose mitigation capability, TS AOT requirements limit operation during this condition for up to 7 days, followed by shutdown to COLD SHUTDOWN conditions. This is because the accident analysis assumes a single failure of one of the remaining OPERABLE trains so that the safety function would not be met. This allowance is acceptable because of the low probability of a design basis accident while the affected train is out of service.

During the condition where one train of CRHVAC is inoperable only due to unavailability of cooling, sufficient redundancy remains since either of the two operable trains of CRHVAC provides adequate cooling to maintain the filter efficiency for the CRHVAC system to perform its design function to mitigate dose. When two trains of CRHVAC are inoperable only due to unavailability of cooling, the redundancy no longer exists. Therefore, a failure of the remaining train's cooling capability would not support the safety function. The condition where two trains of CRHVAC are inoperable only due to unavailability of cooling is analogous to the condition where one train of CRHVAC is inoperable due to an adverse impact on the dose mitigation capability. The condition where two trains of cooling are unavailable does not make the design basis accident any more probable. Therefore, it is reasonable to limit operation when two trains of CRHVAC are inoperable only due to unavailability of cooling for up to 7 days as well.

3.3 Conclusion Two trains of CRHVAC pressurization (fans) with one train of cooling are adequate for the dose mitigation function based on maintaining the required control room envelope positive pressure and maintaining the relative humidity of the control room air below the 70% acceptance criterion required to support design basis assumptions for carbon filter efficiency. The CRHVAC room cooling function is modeled in the PRA. An extended AOT can be calculated for one inoperable train of CRHVAC cooling. Therefore, the CRMP can be applied for the condition of a single

Enclosure NOC-AE-10002605 Page 7 train of CRHVAC inoperable only due to the unavailability of cooling and a risk-informed completion time can be calculated.

The condition where two trains of CRHVAC are inoperable only due to unavailability of cooling is analogous to the condition where one train of CRHVAC is inoperable due to an adverse impact on the dose mitigation capability. The condition does not make the design-basis accident any more probable. Therefore, it is reasonable to limit operation when two trains of CRHVAC are inoperable only due to unavailability of cooling for up to 7 days as well.

4.0 Regulatory Evaluation 4.1 Applicable Regulatory Requirements/Criteria This change reduces the scope of applying the CRMP to TS 3.7.7.

10CFR50.36 requires that TS contain Limiting Conditions for Operations. 10CFR50.36 requires that: "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 STP TS allow for a risk-informed process for determining required remedial actions. A CRMP for determining required actions and AOTs based on a risk-managed action time (RMAT') and a risk-informed completion time (RICT 2) up to a 30-day limit is allowed. Individual LCOs will indicate if the CRMP is applicable. Consequently, the provisions of 10CFR50.36 are met for the CRMP application to TS 3.7.7.

The implementation of the STP RMTS for the identified scope of TS LCO action requirements is consistent with the guidance of NEI 06-09, Revision 0. (Reference 6.4)

The AOTs beyond the front-stop times for structures, systems, or components in TS are controlled by the CRMP. The CRMP methodology for assessing the risk impact of extending AOTs is accomplished by using a full-scope PRA model of sufficient technical adequacy as described in NEI 06-09, Revision 0, and based on consistency with the guidance of NRC RG 1.200, Revision 1. (Reference 6.3) 1The time interval from the discovery of a condition requiring entry into a Technical Specification Action for a system, structure or component (SSC) within the scope of the RMTS and which results in a plant configuration other than the zero maintenance state until the 1.OOE-6 incremental core damage probability (ICDP) or 1.OOE-7 incremental large early release probability (ILERP) risk-managed action threshold is reached, whichever is the shorter duration (i.e., the threshold where additional actions should be taken to manage risk).

2 The SSC plant configuration completion time or AOT calculated based on maintaining plant operation within allowed risk thresholds or limits and applying the CRMP and associated PRA.

Enclosure NOC-AE-10002605 Page 8 The CRMP used to determine the AOT of the TS also meets the requirement of 10CFR50.65(a)(4) for performing a risk assessment for equipment removed from service for maintenance.

Based on the discussion above, STPNOC concludes that the proposed change will ensure that application of the CRMP to TS 3.7.7 is in compliance with regulatory requirements.

4.2 Precedent A broad scope risk-informed set of Technical Specification (TS) changes was approved with the issuance of Amendment 179 and Amendment 166 to the STP Unit 1 and Unit 2 Operating Licenses, respectively. (Reference 6.5) 4.3 Significant Hazards Consideration STPNOC has evaluated whether or not a significant hazards consideration is involved with the proposed amendments 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 change allows the Configuration Risk Management Program (CRMP) to be applied to Technical Specification (TS) 3.7.7, "Control Room Makeup and Cleanup Filtration Systems" for the condition where one train of CRHVAC is inoperable only due to the unavailability of cooling. The proposed change extends the AOT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for the condition where two trains of CRHVAC are inoperable only due to the unavailability of cooling. The CRMP can not be applied to the loss of two trains of cooling.

The change does not involve a significant increase in the probability of an accident previously evaluated because the change does not involve a change to the plant or its modes of operation. In addition, the risk-informed configuration management program will be applied to effectively manage the availability of required structures, systems, and components to assure there is no significant increase in the probability of an accident.

This proposed change does not increase the consequences of an accident because the design-basis mitigation function of the affected systems is not changed and the risk-informed configuration management program will be applied to effectively manage the availability of structures, systems, and components required to mitigate the consequences of an accident.

Enclosure NOC-AE-10002605 Page 9 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 kind of accident from any accident previously evaluated?

Response: No The proposed change allows the Configuration Risk Management Program (CRMP) to be applied to Technical Specification (TS) 3.7.7, "Control Room Makeup and Cleanup Filtration Systems" for the condition where one train of CRHVAC is inoperable only due to the unavailability of cooling. The proposed change extends the AOT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for the condition where two trains of CRHVAC are inoperable only due to the unavailability of cooling. The CRMP can not be applied to the loss of two trains of cooling.

The proposed change will not alter the plant configuration (no new or different type of equipment will be installed) or require any unusual operator actions. The proposed change will not alter the way any structure, system, or component functions, and will not significantly alter the manner in which the plant is operated. The response of the plant and the operators following an accident will not be different. In addition, the proposed change does not introduce any new failure modes.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed change involve a significant reduction to a margin of safety?

Response No The proposed change allows the Configuration Risk Management Program (CRMP) to be applied to Technical Specification (TS) 3.7.7, "Control Room Makeup and Cleanup Filtration Systems" for the condition where one train of CRHVAC is inoperable only due to the unavailability of cooling. The proposed change extends the AOT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days for the condition where two trains of CRHVAC are inoperable only due to the unavailability of cooling. The CRMP can not be applied to the loss of two trains of cooling.

The CRMP implements a risk-informed configuration risk management program in a manner to assure that adequate margins of safety are maintained. Application of the configuration risk management program to TS 3.7.7 complements the risk assessment required by the Maintenance Rule and effectively manages the risk for limiting condition for operation when the Control Room Makeup and Cleanup Filtration Systems are inoperable.

The condition where two trains of CRHVAC are inoperable only due to unavailability of cooling is analogous to the condition where one train of CRHVAC is inoperable due to an

Enclosure NOC-AE- 10002605 Page 10 adverse impact on the dose mitigation capability. The condition does not make the design basis accident any more probable. The safety function can still be achieved assuming no single failure during the AOT should a low probability DBA occur. Therefore, the extension of the AOT for the loss of two cooling trains to the same AOT as that for the loss of one train impacting the dose mitigation function does not significantly reduce the margin of safety.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, STPNOC concludes that the proposed amendments do not involve a 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.

4.4 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.

5.0 Environmental Consideration STPNOC has reviewed the proposed amendment and determined that it does not involve (1) a significant hazards consideration, (2) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (3) a significant increase in the individual or cumulative occupational exposure. Accordingly, the proposed changes meet the eligibility criteria 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.

6.0 References 6.1 Letter dated December 28, 2006, from David W. Rencurrel, STPNOC, to NRC Document Control Desk, "Revised Broad Scope Risk-Informed Technical Specification Amendment Request." (ML070040247, NOC-AE-06002036, TAC Nos. MD2341 &

MD2342) 6.2 Letter dated May 28, 2008, from Scott M. Head, STPNOC, to NRC Document Control Desk, "Clarification of the Applicability of Risk Managed Technical Specifications to Technical Specification 3.7.7." (ML081720133, NOC-AE-08002291)

Enclosure NOC-AE-10002605 Page 11 6.3 Nuclear Regulatory Commission Regulatory Guide 1.200, Revision 1, "An Approach for Determining the Technical Adequacy of Probabilistic Assessment Results for Risk-Informed Activities," dated January 2007.

6.4 NEI 06-09 (Revision 0) - A, "Risk-Informed Technical Specifications Initiative 4b, Risk-Managed Technical Specifications (RMTS) Guidelines, Industry Guidance Document,"

November 2006.

6.5 Letter dated July13, 2007, from Mohan C. Thadani, NRC, to James J. Sheppard, STPNOC, "South Texas Project, Units 1 and 2 - Issuance of Amendments Re: Broad-Scope Risk-Informed Technical Specifications Amendments (ML071780186, ML071780191, ST-AE-NOC-07001652, TAC Nos. MD2341 and MD2342)"

Enclosure Attachment 1 NOC-AE-10002605 Enclosure, Attachment 1 Annotated Technical Specification Page Technical Specification 3/4.7.7 Control Room Makeup and Cleanup Filtration System Note: Although there are no proposed changes on TS pages 3/4 7-17 and 3/4 7-18, specifications from the preceding page moved to these succeeding pages so that an approved amendment would need to include TS pages 3/4 7-16 through 3/4 7-18.

Note: By Reference 4 (see cover letter to this Enclosure), STP proposed another change to TS 3.7.7. The numbering scheme of the approved TS change for both amendment requests may require some coordination to ensure that the approval of one request does not unintentionally result in an incorrect numbering scheme for the second request, when approved.

Enclosure Attachment 1 NOC-AE- 10002605 PLANT SYSTEMS 3/4.7.7 CONTROL ROOM MAKEUP AND CLEANUP FILTRATION SYSTEM LIMITING CONDITION FOR OPERATION 3.7.7 Three independent Control Room Makeup and Cleanup Filtration Systems shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4:

ACTION:

7 With one Control Room Makeup and Cleanup Filtration System inoperable for reasons other than co6diton bor condition 41, within 7 days restore the inoperable system to OPERABLE status or apply the, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

b. Withone Control Room Makeup and Cleanup FiltrationsSystem -inoperable only due to
unavailability of cooling, within, 7 days restore the inoperable system to OPERABLE status or apply the requirements-of the CRMP. or be in atleast HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following30t hours.

C. With two Control Room Makeup and Cleanup Filtration Systems inoperable for reasons other than condition dForic dit'on f, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> restore at least two systems to OPERABLE status re

-e" V"p*plyte

- fmnthiCte or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SL With two Control Room Makeup and Cleanup -FiltrationSystems inoperable only due I to OPERABLE system to unavailability of cooling, wlthin 7 days restore the ino.erable status, or be, in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />!

With three Control Room Makeup and Cleanup Filtration Systems inoperable for reasons other than condition df, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> restore at least one system to OPERABLE status npply thFrequi.reents of theICR , or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

f. One or more Control Room Makeup and Cleanup Filtration Systems inoperable due to inoperable Control Room Envelope (CRE) boundary perform the following:
1) immediately initiate action to implement mitigating actions, and
2) within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> verify mitigating actions ensure CRE occupant exposures to radiological, chemical and smoke hazards will not exceed limits, and
3) within 90 days restore CRE boundary to OPERABLE status.

SOUTH TEXAS - UNITS 1 & 2 3/4 7-16 Unit 1 -Amendment No. 59, 125, 128, 1 Unit 2 - Amendment No. 113,11,

  • 7, 1,

For information only - no Enclosure Attachment 1 changes proposed NOC-AE-10002605 PLANT SYSTEMS SURVEILLANCE REQUIREMENTS 4.7.7 Each Control Room Makeup and Cleanup Filtration System shall be demonstrated OPERABLE:

a. At a frequency in accordance with the Surveillance Frequency Control Program by verifying that the control room air temperature is less than or equal to 78°F;
b. At a frequency in accordance with the Surveillance Frequency Control Program by initiating, from the control room, flow through the HEPA filters and charcoal adsorbers of the makeup and cleanup air filter units and verifying that the system operates for at least 10 continuous hours with the makeup filter unit heaters operating;
c. At a frequency in accordance with the Surveillance Frequency Control Program or (1) after any structural maintenance on the HEPA filter or charcoal adsorber housings, or (2) following painting, fire, or chemical release in any ventilation zone communicating with the system by:
1) Verifying that the makeup and cleanup systems satisfy the in-place penetration and bypass leakage testing acceptance criteria of less than 0.05% for HEPA filter banks and 0.10% for charcoal adsorber banks and uses the test procedure guidance in Regulatory Positions C.5.a, C.5.c, and C.5.d of Regulatory Guide 1.52, Revision 2, March 1978, and the system flow rate is 6000 cfm +/- 10% for the cleanup units and 1000 cfm +/- 10% for the makeup units;
2) Verifying, within 31 days after removal, that a laboratory analysis of a representative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of ASTM D3803-1989, "Standard Test Method for Nuclear-Grade Activated Carbon," for a methyl iodide penetration of less than 1.0% when tested at a temperature of 30°C and a relative humidity of 70%; and
3) Verifying a system flow rate of 6000 cfm +/- 10% for the cleanup units and 1000 cfm +

10% for the makeup units during system operation when tested in accordance with ANSI N510-1980.

d. After every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of charcoal adsorber operation, by verifying, within 31 days after removal, that a laboratory analysis of a representative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, meets the laboratory testing criteria of ASTM D3803-1989 for a methyl iodide penetration of less than 1.0% when tested at a temperature of 30°C and a relative humidity of 70%.
e. At a frequency in accordance with the Surveillance Frequency Control Program by:
1) Verifying that the pressure drop across the combined HEPA filters and charcoal adsorber banks is less than 6.1 inches Water Gauge for the makeup units and 6.0 inches Water Gauge for the cleanup units while operating the system at a flow rate of 6000 cfm +/- 10% for the cleanup units and 1000 cfm +/- 10% for the makeup units; SOUTH TEXAS - UNITS 1 & 2 3/4 7-17 Unit 1 -Amendment No. 4-2-71-88 Unit 2 - Amendment No. -146 4-75

For information only - no Enclosure Attachment 1 changes proposed NOC-AE- 10002605 PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

2) Verifying that on a control room emergency ventilation test signal (High Radiation and/or Safety Injection test signal), the system automatically switches into a recirculation and makeup air filtration mode of operation with flow through the HEPA filters and charcoal adsorber banks of the cleanup and makeup units;
3) Perform required CRE unfiltered air inleakage testing in accordance with the Control Room Envelope Habitability Program; and
4) Verifying that the makeup filter unit heaters dissipate 4.5 + 0.45 kW when tested in accordance with ANSI N510-1980.
f. After each complete or partial replacement of a HEPA filter bank, by verifying that the HEPA filter bank satisfies the in-place penetration and bypass leakage testing acceptance criteria of less than 0.05% in accordance with ANSI N510-1980 for a DOP test aerosol while operating the system at a flow rate of 6000 cfm + 10% for the cleanup units and 1000 cfm + 10% for the makeup units; and
g. After each complete or partial replacement of a charcoal adsorber bank, by verifying that the charcoal adsorber bank satisfies the in-place penetration and bypass leakage testing acceptance criteria of less than 0.10% in accordance with ANSI N510-1980 for a halogenated hydrocarbon refrigerant test gas while operating the system at a flow rate of 6000 cfm + 10% for the cleanup units and 1000 cfm + 10% for the makeup units.

SOUTH TEXAS - UNITS 1 & 2 3/4 7-18 Unit 1 -Amendment No. 7, 88, 161,82,-185 Unit 2 -Amendment No. 75, 151, 169,47-2

Enclosure Attachment 2 NOC-AE- 10002605 Enclosure, Attachment 2 Annotated Technical Specification Bases Changes For Information (5 pages)

Enclosure Attachment 2 NOC-AE-09002441 Page 1 PLANT SYSTEMS BASES 3/4.7.7 CONTROL ROOM MAKEUP AND CLEANUP FILTRATION SYSTEM The Control Room Makeup and Filtration System is comprised of three 50-percent redundant systems (trains) that share a common intake plenum and exhaust plenum. Each system/train is comprised of a makeup fan, a makeup filtration unit, a cleanup filtration unit, a cleanup fan, a control room air handling unit, a supply fan, a return fan, and associated ductwork and dampers. Two of the three 50% design capacity trains withone tram of cooli are required to remain operable during an accident to ensure that the system design function to maintain control roo-mn ha' i/ is met. The toilet kitchen exhaust (excluding exhaust dampers), heating, and computer room HVAC Subsystem associated with the Control Room Makeup and Filtration System are non safety-related and not required for operability.

The OPERABILITY of the Control Room Makeup and Cleanup Filtration System ensures that: (1) the ambient air temperature does not exceed the allowable temperature for continuous-duty rating for the equipment and instrumentation cooled by this system, and (2) the control room will remain habitable for operations personnel during and following most credible accident conditions. Operation of the system with the heaters operating for at least 10 continuous hours in a 92-day period is sufficient to reduce the buildup of moisture on the adsorbers and HEPA filters. The OPERABILITY of this system in conjunction with control room design provisions is based on limiting the radiation exposure to personnel occupying the control room to 5 rem total effective dose equivalent (TEDE). This limitation is consistent with the requirements of General Design Criterion 19 of Appendix A, 10 CFR Part 50.

ANSI N510-1980 will be used as a procedural guide for surveillance testing.

There is no automatic actuation or Surveillance Requirements of the Control Room Makeup and Cleanup Filtration System for toxic gas or smoke because the analysis for the South Texas Project has determined no actuation is required.

The accidents postulated to occur during core alterations, in addition to the fuel handling accident, are: inadvertent criticality (due to a control rod removal error or continuous rod withdrawal error during refueling or boron dilution) and the inadvertent loading of, and subsequent operation with, a fuel assembly in an improper location. These events are not postulated to result in fuel cladding integrity damage. Since the only accident to occur during CORE ALTERATIONS that results in a significant radioactive release is the fuel handling accident and the accident mitigation features of the Control Room Makeup and Cleanup Filtration System are not credited in the accident analysis for a fuel handling accident, there are no OPERABILITY requirements for this system in MODES 5 and 6.

ACTION a, b, 4d c, d, and o.

The time limits associated with the ACTIONS to restore an inoperable trainW to OPERABLE status are consistent with the redundancy and capability of the system and the low probability of a design basis accident while the affected train(s) is out of service

Enclosure Attachment 2 NOC-AE-09002441 Page 2 PLANT SYSTEMS BASES I-ntT Q ': 7i GCOIIHO fUnotlon IS modIed#Qrt BASES . n . flepR-/. . n;;d -AF.

. R I . C;r-eAn. nhpehtdtrnIoe

. . . . . . be.-

t~ainof GRHVAC coo ling., The~dese mii Iofuctioni pot' modeled inthe P~RA.bcueth lpffec~t on crcdmg frequency Or large~early rees reuny onsequently, there is no terchniEýi aisfor ca'GU lating a RICT for an nprbecndto novR the dese mitigation function and thJ

-L.. L ' 'RR? ~7 L~Ijt . __ _ ~.

___-b- tHni eC rii i nttwi nyu pieU to) tne GOOIIng ýcjut A~thoghGTlO)Ns a. b;,anAcaII-jnGude-th6,-pion of calulating a risk informied Gonipletion tim~e XU!1-TNiT LJn J 1.cL-L I ,AAj~ h +kTU I IrI .m9LAIN r r I1..f p ILIf 'Jr LE2 D Ih t4C71'Ur7rPrII nfJ~'nfV Rrxv IDA SJ'AIrAirc aLT Oermnitte only fer AC~TION[a becau~se S-TPNIGG determnined that application of the CFRM' to TS 3.7.

'ACTION bor ACTION Gwould be to ext~end the timne to restore the required redundajncy fer the dosea

ýnain;tigano function, which would not be permitted under the licenSing basis. STPNOC, evaluations-sh,6W-wiIa train of CRHVAC in TS 2,7--7, Actfion a for loss of cooling (aSSOoated train 6f EVY or EGhW i Mhath inoerbl),the systemn is capable of mneetingit dose; mitgaio the ability to

-M6ioicldn Owthstand a single failurd of a traipnprovidi"ng pr-eSSUriZtign4*9-fitatin or a train pro)VidinrI"4eEI4, support of filteF efficiendy despite th6e uaailability of the trai'n'n m'aintena;nrce. Pos7ýtulatin of q&igi falue hile in the action statement is used to demnonstrate that the GRMP1 iscbing applied foF the cooling funcin -nd-is knot beingj ap~lied-to xtend tho allwed outage tini to restore nocossary redundancy for the requi red dose mitigation function. Thereoeppiain of the GRN4,P to TS 3.7.7

,A~tien a fo 'jgpr-able r 6GRHM~ i prý,

~n:o e+;-R~~

-- toapyte CRMP to TS 3'.,7.7 CINaapisol otecdigfnto ft6s~

boI.np~td by the Essential Chilled Water Systcm-(Ec" ý(TS 3.7.14) and may not beapie fGF enitions thb;t aqffecrt the operabi~lity of the systen+m ,wtjsett doMitigafien (j-. :qRHVAC tra inoperable due toi fkAf C~r darner) in Gae rhe6ehnhfint innfns are aiffeeteidh'(eg;r C D + r-- +k A +; -F II

.... ~ L.~..

____l~§G ___~a~th __ n~t~ GO .S~L ILIIIp~Mý~p

  • ~e I IIL.d I

%dct Io n b Engineering7ýcalculation MC6504'determined that', wo trains of CRHVAC (same as Control Room Makeup and Cleanup Filtration,System) pressurization (fans) with one train of cooling are adequate for the dose mitigation function based on maintaining the required control room envelope positive pressure and maintaining the relative humidity of the control room air below the 70%o acceptance criterion required ftosupport design basis assumptions for carbon filter efficiency. The calculation shows that with one train of CRHVAC inoperable for a loss of

,cooling (i.e.,the associated.train of essential cooling water (ECW) or essential, chilledwater (EChM) is inoperable), either ofthe two operable trains of CRHVAC provides adequate cooling

  • 0 maintain the filter efficiency for the CRHVAC.system to-perform it-desian function to

'mitigatedose!

helh*TS 3.7.7 cooiing function is modeled in the Probablistic Risk Assessment MRA)and a risk-informed completion time (RICT) can be calculated for an inoperable trainofCRHVAC cooling. The dose mitilation function is not nmodeled, n the PRA because it has no effect on core damage frequency or large early release frequency. Consequently, there is no technical basis fotrcalculating a RICT for an inoperable condrition involving the dose mitigation function and the basis for application ofthe CRMP to TS 3I7I7 is that it.will Onlybe applied tothe cooling ifunction.

Enclosure Attachment 2 NOC-AE-09002441 Page 3 PLANT SYSTEMS BASES ACTION4b-ali -Wfo~c l Wat, n -la

&-MT -na cowk d th~

fiithe u-1ý m ht theZIRM- 9 STPNOC evaluations show thatwith a train of CRHVAC in TS 3.7.7 Action b inoperable for ,Ids of coolingf(asSo0ciated train ofEWe or'EChW is inoperable), the system is capable of performind its dose miltigation function, including the ability to withstand a sitgle failure of a train providing pressurization/filtration or a train providing cooling in support of filter efficiency. Postulation of a single failure whilde in the action statement is used to demonstrate thatthe CRMP is being aýppliedtfor the cooling function and is not being applied to extend the allowed outagetime td restore necessary redundancy for the required dose mitigation functtion. Therefore, application of the CRMP to TS 3.7.7 Action b for one inoperable train ofUCRHVACBis permissible.

Action d Action d afos fortw~oinoperable train~s o~f CRHVAC due to a loss of.coiau t ai This condition issimilar tobthe condition of one inoperable train of CRHVIVAC used to provide

'forcontrol room envelope positive pressure allowed by Action a. The application of the CIRMpt

,for this condition is. not allowed for reasons stated above.,

Action e ACTION gj allows all three trains of Control Room Makeup and Filtration System to be inoperable for a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Although not all possible configurations can be anticipated, this ACTION is expected to occur when:

  • An inoperable component is identified common to all three trains, or

" All three train fans are rendered inoperable by placing the fans in PULL-TO-LOCK to allow a material condition to be corrected that may be in a common ventilation plenum.

Note: Ifthe ventilation plenum is required to be breached, then ACTION Kf is also entered because the Control Room Makeup and Filtration Systems become inoperable due to an inoperable Control Room Envelope (CRE) boundary.

The Containment Spray System can be used as a compensatory measure to reduce the potential for radioactive material release under accident conditions when multiple trains of Control Room Makeup and Filtrations Systems are out of service. Procedures will preclude intentionally removing multiple trains of Control Room Makeup and Filtration Systems from service if Containment Spray is not functional or intentionally making a train of Containment Spray unavailable when multiple trains of Control Room Makeup and Filtration Systems are out of service. For purposes of this compensatory action, Containment Spray is considered functional if at least one train can be manually or automatically initiated.

Enclosure Attachment 2 NOC-AE-09002441 Page 4 PLANT SYSTEMS BASES Action df:

If the unfiltered in-leakage of potentially contaminated air past the CRE boundary and into the CRE can result in CRE occupant radiological dose greater than the calculated dose of the licensing basis analyses of DBA consequences (allowed to be up to 5 rem total effective dose equivalent (TEDE)), or inadequate protection of CRE occupants from hazardous chemicals or smoke, the CRE boundary is inoperable. Actions must be taken to restore an OPERABLE CRE boundary within 90 days.

An inoperable CRE boundary results in making one or more Control Room Makeup and Cleanup Filtration Systems inoperable. However, absent of an additional condition that results in the System(s) being inoperable other than for an inoperable boundary, only entry into ACTION d is required.

During the period that the CRE boundary is considered inoperable, action must be initiated to implement mitigating actions to lessen the effect on CRE occupants from the potential hazards of a radiological or chemical event or a challenge from smoke., OPGP03-ZE-0030, "Control Room Envelope Habitability Program" discusses appropriate mitigating actions.

As stated in OPGP03-ZE-0030, the mitigating actions are verified to ensure that CRE occupant radiological exposures will not exceed the calculated dose of the licensing basis analyses of DBA consequences, and that CRE occupants are protected from hazardous chemicals and smoke. These mitigating actions (i.e., actions that are taken to offset the consequences of the inoperable CRE boundary) should be preplanned for implementation upon entry. into the condition, regardless of whether entry is intentional or unintentional. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time for implementation of the mitigating actions is reasonable based on the low probability of a DBA occurring during this time period, and the use of the mitigating actions. The 90 day Completion Time is reasonable based on the determination that the mitigating actions will ensure protection of CRE occupants within analyzed limits while limiting the probability that CRE occupants will have to implement protective measures that may adversely affect their ability to control the reactor and maintain it in a safe shutdown condition in the event of a DBA. In addition, the 90 day Completion Time is a reasonable time to diagnose, plan and possibly repair, and test most problems with the CRE boundary.

For purposes of the compensatory measure, described above when multiple trains of Control Room Makeup and Cleanup Filtration Systems and Containment Spray are affected, the purpose of the compensatory measure is met when the mitigating actions of Action #f.(2) are in place. If multiple trains of Control Room Makeup and Cleanup Filtration System are inoperable solely because the CRE boundary is~inoperable, then the affected trains can be considered to be in service when Action gf.(2) is met and there are no restrictions in making a train (i.e. multiple trains are not allowed) of Containment Spray unavailable unless the mitigating actions require all Containment Spray Systems to be functional.

Similarly, there are no restrictions on making multiple trains of Control Room Makeup and Cleanup Filtration Systems inoperable solely because the CRE boundary is inoperable if or when Containment Spray is not functional.

Surveillance Requirement 4.7.7.e.3 verifies the OPERABILITY of the CRE boundary by testing for unfiltered air in-leakage past the CRE boundary and into the CRE. The details of the testing are specified in the Control Room Envelope Habitability Program. The CRE is considered habitable when the radiological dose to CRE occupants calculated in the licensing basis analyses of DBA consequences is no more than 5 rem total effective dose equivalent (TEDE) and the CRE occupants

Enclosure Attachment 2 NOC-AE-09002441 Page 5 PLANT SYSTEMS BASES are protected from hazardous chemicals and smoke. This SR verifies that the unfiltered air in-leakage into the CRE is no greater than the flow rate assumed in the licensing basis analyses of DBA consequences. When unfiltered air in-leakage is greater than the assumed flow rate in MODES 1, 2, 3, and 4, Action af must be entered. Action Kf allows time to restore the CRE boundary to OPERABLE status provided mitigating actions can ensure that the CRE remains within the licensing basis habitability limits for the occupants following an accident.

Compensatory measures are discussed in Regulatory Guide 1.196, Section C.2.7.3, which endorses, with exceptions, NEI 99-03, Section 8.4 and Appendix F. These compensatory measures may also be used as mitigating actions as required by Action @. Temporary analytical methods may also be used as compensatory measures to restore OPERABILITY. Options for restoring the CRE boundary to OPERABLE status include changing the licensing basis DBA consequence analysis, repairing the CRE boundary, or a combination of these actions.

Compensatory actions (in support of Action _f) also include administrative controls on coordinating opening or breaching the CRE boundary such that appropriate communication is established with the control room to assure timely closing of the boundary if necessary. Extended opening of the boundary is coordinated with the control room with appropriate plans for closure and communication.

Since the Control Room Envelope boundary integrity -also affects operability of the overall system, entry and exit is administratively controlled. Administrative control of entry and exit through doors is performed by the persons entering or exiting the area. Entry and exit through doors under administrative controls does not require entry into Action Af.

Depending upon the nature of the problem and the corrective action, a full scope in-leakage test may not be necessary to establish that the CRE boundary has been restored to OPERABLE status.

There is no GR...FSontrolR oomMakeupandC loan up FiltrationSystem actuation for hazardous chemical releases or smoke and there are no surveillance requirements that verify operability for hazardous chemical or smoke. The hazardous chemical analyses for the South Texas Project do not assume any control room isolation and assumes air enters at normal makeup ventilation flow rates. No in-leakage test is required to determine unfiltered in-leakage from toxic gas since this would be a value much less than that currently assumed in the toxic gas analyses. There is no regulatory limit on the amount of smoke allowed in the control room. The plant's ability to manage smoke infiltration was assessed qualitatively. The conclusion is that the operator maintains the ability to safely shutdown the plant during a smoke event originating inside or outside the control room.

Therefore, no in-leakage test is required to be conducted to measure the amount of smoke that could infiltrate into the control room.

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