NOC-AE-04001697, Proposed Exigent Change to Technical Specification 3/4.7.7

Proposed Exigent Change to Technical Specification 3/4.7.7

ML040850488
Person / Time
Site:	South Texas
Issue date:	03/18/2004
From:	Jordan J South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-04001697, STI: 31713142
Download: ML040850488 (19)

Text

'If Nuclear Operating Company South krasPhea Elcric Cenoa ing Station PO Bar 282 t1dniv*th. Ts 77483 March 18, 2004 NOC-AE-04001697 10CFR50.90 STI: 31713142 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 and 2 Docket Nos. 50-498 and 50-499 Proposed Exigent Change to Technical Specification 3/4.7.7

Reference:

Letter from E. D. Halpin, STPNOC, to NRC Document Control Desk, dated March 18, 2004, "Enforcement Discretion for Technical Specification 3/4.7.7 and 3.8.1.1" (NOC-AE-04001696)

STP Nuclear Operating Company (STPNOC) is submitting the attached proposed temporary change to Technical Specification (TS) 3/4.7.7, "Control Room Makeup And Cleanup Filtration System" as an exigent Technical Specification change. STPNOC has identified points on the boundary of the control room envelope that do not meet the 1/8 inch Water Gauge surveillance requirement 4.7.7.e.3. On March 17, 2004, STPNOC requested and received the enforcement discretion from taking the Technical Specification actions required if Surveillance Requirement 4.7.7.e.3 is not met. Based on information submitted in the referenced correspondence, STPNOC committed to submit a proposed change to the Technical Specification.

Exigent approval of the proposed license amendments is needed in accordance with the enforcement discretion granted on March 17, 2004. Entry into the required action of TS 3.7.7 resulted from a revised position on the application of the Technical Specification that STPNOC could not reasonably have foreseen or anticipated. Therefore, STPNOC requests approval of this license amendment application on an exigent basis and issuance of the amendment as described in the terms of the enforcement discretion.

The proposed changes are temporary and will expire in 18 months (i.e., 0800 CST on September 19, 2005).

NOC-AE-04001697 Anachment 1 Page 2 The STPNOC Plant Operations Review Committee has reviewed and concurred with the proposed change to the Technical Specifications.

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 there are any questions regarding the responses, please contact Mr. S. M. Head at (361) 972-7136 or me at (361) 972-7902.

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

Executed on MarchL/ g, Foo00 date Vice President Engineering & Technical Services awh/

Attachments:

1. Description of Changes and Safety Evaluation

2. Annotated Technical Specification Pages

3. Revised Technical Specification Page

4. Bases Insert

NOC-AE-04001697 Attachment I Page 3 cc:

(paper copy) (electronic copy)

Bruce S. Mallett A. H. Gutterman, Esquire Regional Administrator, Region IV Morgan, Lewis & Bockius LLP U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 L. D. Blaylock Arlington, Texas 76011-8064 City Public Service U. S. Nuclear Regulatory Commission Michael K. Webb Attention: Document Control Desk U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike R. L. Balcom Rockville, MD 20852 Texas Genco, LP Richard A. Ratliff A. Ramirez Bureau of Radiation Control City of Austin Texas Department of Health 1100 West 49th Street C. A. Johnson Austin, TX 78756-3189 AEP Texas Central Company Jeffrey Cruz Jon C. Wood U. S. Nuclear Regulatory Commission Matthews & Branscomb P.O. Box 289, Mail Code: MN 16 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704

NOC-AE-04001697 Attachment I Description of Changes and Safety Evaluation

NOC-AE-04001697 Attachment 1 Page I 1.0 Description During the performance of an engineering test for control room envelope inleakage, 6 of 300 points tested in Unit 1 and 7 of 300 points tested in Unit 2 were found to not meet the test acceptance criterion (i.e., 1/8 in water gauge (wg) relative pressure). However, all test points were positive with respect to adjacent areas. These test points were not points measured by the Technical Specification (TS) surveillance procedure; nonetheless, it has been determined that the criteria of Surveillance Requirement (SR) 4.7.7.e.3 should be applied.

With the surveillance requirement not met, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> shutdown action of TS 3.7.7 ACTION c. would apply. STPNOC has consequently obtained enforcement discretion in order to submit an exigent Technical Specification change to the surveillance requirement to incorporate a provision for evaluation and compensatory actions.

The test points less than 1/8 in wg are degraded conditions that will be corrected under the 10CFR50, Appendix B corrective action process. Testing of the control room envelope has demonstrated that the STP design basis and General Design Criterion (GDC) 19 of 10CFR50, Appendix A are still met.

Exigent approval of the proposed license amendments is needed in accordance with the enforcement discretion granted on March 17, 2004. Entry into the required action of TS 3.7.7 resulted from a revised position on the application of the Technical Specification that STPNOC could not reasonably have foreseen or anticipated. Therefore, STPNOC requests approval of this license amendment application on an exigent basis and issuance of the amendment as described in the terms of the enforcement discretion.

The change is proposed to be temporary and expire at 0800 CST on September 19, 2005.

2.0 Description of Change STPNOC proposes to change the surveillance test requirement 4.7.7.e.3 to add a footnote that will allow an evaluation for points that do not meet the 1/8 inch Water Gauge criterion of the current TS. The proposed surveillance would read as shown below.

e. At least once per 18 months by:

3) Verifying that the system maintains the control room envelope at a positive pressure of greater than or equal to 1/8 inch Water Gauge at less Ji ~jiq or equal to a pressurization flow of 2000 cfm relative to adjacent areas during system operation [Li; and...

easuredpon stt ea i[T3 1/8 inch augp arelacceptable if an evaluationconsidering appropriate compensatory

~tion~','dem" strates that dition, ees the requirements'of DC-l9.

eprovisionis of this'ho exiet 0800:onS eptitnibU~

NOC-AE-04001697 Attachment 1 Page 2 In addition to the change related to adding the provision for the evaluation, the word "that" in the second line above is changed to "than" to correct an existing typographical error.

The revised TS is attached.

3.0 Background

The Control Room (CR) Envelope ventilation system consists of three 50% trains, which are designed to:

a. Assure habitability of the CR envelope and permit safe shutdown of the plant as may be required under any normal or emergency conditions.

b. Maintain ambient temperature conditions to provide operator comfort and to satisfy environmental requirements of equipment. The design bases of ambient conditions, safety class, and seismic category are listed in Table 9.4-1 and Section 3.2 of the UFSAR.

c. Maintain the CR envelope at positive pressure to minimize any inleakage of possible contamination from the outside.

d. Satisfy the design requirements of limiting dose to CR operators following the Design Basis Accident (DBA) in accordance with GDC 19 of 10CFR50, Appendix A.

The function of the control room HVAC system, in its emergency mode lineup, is to maintain a positive pressure within the envelope with respect to adjacent areas in order to minimize unfiltered inleakage. This assures that the radiological dose to the control room operator remains within the limits of General Design Criterion 19 of 10CFR 50, Appendix A.

On March 6, 2004, STP completed a test to verify inleakage into the Unit 1 control room envelope in accordance with Generic Letter 2003-01. The test is the Component Test Method described in NEI 99-03, "Control Room Habitability Guidance." This test measures the pressure inside the control room envelope with respect to adjacent areas in a series of locations so that the test points represent the control room boundary. The test is conducted to verify that the pressure within the control room envelope with respect to adjacent areas is positive so that any leakage across the boundary should be outleakage.

The test results from the Component Test Method were planned to be compared to the test results from the Tracer Gas Test Method to validate that the Component Test Method is a valid test for determining control room envelope inleakage. The comparison of these two test methods is endorsed in NRC Regulatory Guide 1.197.

The Component Test Method is a more comprehensive test than the Technical Specification surveillance to verify that the control room HVAC system can maintain a

NOC-AE-04001697 Attachment 1 Page 3 positive pressure with respect to adjacent areas. The test is performed with two trains of the control room HVAC system in the emergency pressurization and cleanup filtration mode of operation. Since STP has three 50 percent capacity ventilation trains, the test is performed three times to include each of the possible two train HVAC combinations (i.e.,

A-B train, A-C train, and B-C train).

During the performance of the test in Unit 1, 6 of 300 points tested did not meet the test acceptance criterion (i.e., 1/8 in water gauge (wg) relative pressure). However, all test points were positive with respect to adjacent areas. These test points were not points measured by the Technical Specification surveillance procedure; nonetheless, it has been determined that the criteria of SR 4.7.7.e.3 should be applied. With the surveillance requirement not met, the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> shutdown action of TS 3.7.7 ACTION c. would apply.

A similar condition was identified for seven points in STP Unit 2 when Component Testing was performed in February and March 2003.

When in the pressurization and cleanup filtration mode of operation, the control room ventilation system is designed to maintain the control room 1/8 in wg positive pressure relative to adjacent areas. The degraded conditions associated with the test points that do not meet the surveillance requirement will be corrected under the 10CFR50, Appendix B corrective action process. The positive pressure condition from the Component Test demonstrated that there is no unfiltered inleakage across these test points.

Strict application of the 1/8 inch wg criterion imposes an unnecessary burden by requiring entry into a restrictive shutdown action statement even though the design basis function of the system is being met.

4.0 Technical Evaluation The proposed change to the surveillance requirement would allow an evaluation to be performed for conditions where the differential pressure is positive but less than 1/8 inch wg. The condition would be acceptable if the evaluation demonstrates that the requirements of GDC-19 are met, which provides assurance that STP is operating within its design basis. The proposed change includes a provision to allow credit for compensatory action to meet the requirements.

No completion time is required for the evaluation in the surveillance because failure to meet the 1/8 inch wg criterion requires entry into the appropriate TS 3.7.7 action.

Compliance with the TS will require the evaluation to be completed within that allowed outage time.

The provisions of the footnote expire at 0800 CST on September 19, 2005. This time limitation provides sufficient time to address the current STP conditions and allows the opportunity to develop and implement a more complete resolution of this issue.

NOC-AE-0400 1697 Attachment I Page 4 Application of the Proposed Change to the Current STP Conditions:

For each unit, the control room envelope remains at a positive pressure with respect to adjacent areas in the current degraded condition. The control room pressure meets acceptance criteria (i.e., 1/8 inch wg positive pressure) in all locations tested with the exception of a limited number of points described above. The pressure at these locations remains positive relative to adjacent areas. Although not meeting Technical Specification acceptance criteria, the positive relative pressure condition still assures that any leakage across these boundary locations would be outleakage. Therefore, the functionality of the control room HVAC system is maintained with the degraded pressure condition within the envelope. The analyzed radiological dose to the control room operator remains unaffected by this condition. Therefore, the consequences of this condition remain consistent with the licensing basis analyses.

STPNOC recently completed Tracer Gas Testing on STP Unit 1. The results of the testing were submitted with the request for enforcement discretion in the letter referenced in the cover letter. The results show that the Control Room HVAC system meets its design basis and the requirements of GDC-19 are maintained.

Compensatory Action:

The compensatory actions described below are consistent with the guidance of NEI 99-03, "Control Room Habitability Guidance", and Regulatory Guide 1.196, "Control Room Habitability at Light-Water Nuclear Power Reactors." These actions may be applied with the proposed change to SR 4.7.7.e.3 in the unlikely case that the potential for inleakage was found to be higher due to low or marginal differential pressure. The actions would apply until the affected parts of the Control Room ventilation system are restored to meet the 1/8 inch wg criterion. The use of the proposed footnote for a condition where the points are less than 1/8 inch wg is intended to be a temporary application until the points are restored to the design 1/8 inch wg in accordance with the corrective action program.

Compensatory actions may be applied based on the results of the evaluation provision of SR 4.7.7.e.3. The evaluation, including appropriate compensatory actions, must demonstrate that the dose limits of GDC 19 of Appendix A of IOCFR50 are met, including a 30 rem limit to the thyroid. If compensatory measures include self-contained breathing apparatus (SCBA) and potassium iodide (KI) tablets, then the requirements of Regulatory Position 2.7.3 of NRC Regulatory Guide, 1.196, "Control Room Habitability at Light-Water Nuclear Power Reactors" must be met.

The procedural infrastructure to apply the compensatory actions is in place for both units.

KI is available to the Control Room crews and SCBA units are staged and ready for use by Control Room personnel. STP's emergency plan implementing procedures require that personnel radiation exposure in the control room be monitored so that appropriate personnel protective measures will be taken by the operators during accident conditions.

NOC-AE-04001697 Attachment I Page 5 Future Action:

NRC Generic Letter 2003-01, dated June 12, 2003, requested that licensees provide confirmation of their design inleakage into their control room by testing. The Generic Letter acknowledged that licensee's existing Technical Specification surveillance requirements may not be adequate to meet their design bases. The Generic Letter stated that if a licensee determines that their technical specification differential pressure surveillance requirement is no longer adequate to verify inleakage, then the licensee should provide a schedule for revising the technical specification surveillance requirement.

STP responded to Generic Letter 2003-01 by stating that a Component Test and a Tracer Gas Test would be performed in one unit's control room to verify inleakage assumptions.

STP also responded to Generic Letter 2003-01 that in light of Tracer Gas test results, inleakage testing appears to be the best method to confirm boundary integrity. STP committed to submit a Technical Specification change to include periodic verification of control room inleakage consistent with the model generic TS change, TSTF-448, "Control Room Habitability." The changes proposed by TSTF-448 include a surveillance requirement for inleakage testing.

The change proposed in this exigent submittal is considered an interim resolution to address the immediate condition at STP. STPNOC still plans to submit the proposed Technical Specification change consistent with TSTF-448 as described above.

NOC-AE-04001697 Attachment I Page 6 5.0 Regulatory Evaluation Determination of No Significant Hazards:

STPNOC has reviewed the proposed amendment request and determined that its adoption does not involve a significant hazards consideration, 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 does not involve a significant increase in the probability or consequences of a previously evaluated accident. The Control Room ventilation system has no significant role as a potential accident initiator. The Control Room ventilation system continues to remain functional and provides positive pressure with respect to adjacent areas. The test results demonstrate that the operator dose limits of General Design Criterion 19 of IOCFR50, Appendix A are met.

2. Does the proposed change create the possibility of a new or different accident from any accident previously evaluated?

Response: No.

The proposed change does not create the possibility of a new or different accident from any previously evaluated. No new accident precursors will be created by adding a provision to allow compensatory action to mitigate the margin lost if the control room envelope is degraded. The Control Room ventilation system continues to remain functional and provides positive pressure with respect to adjacent areas and to limit inleakage so that the operator dose limits of General Design Criterion 19 of 10CFR50, Appendix A are met.

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

Response: No.

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

Three trains of Control Room ventilation remain functional and continue to provide positive pressure with respect to adjacent plant areas. The proposed condition of the plant meets the operator dose limits of General Design Criterion 19 of IOCFR50, Appendix A.

NOC-AE-04001 697 Attachment I Page 7 Applicable Regulatory Criteria:

The proposed change to the STP Technical Specifications will ensure that the requirements contained in 10 CFR 50, Appendix A, GDC 19 are maintained. The proposed change will ensure that control room habitability is maintained. 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 viii be conducted in compliance with the Commission's regulations, and (3) the approval of the proposed change will not be inimical to the common defense and security or to the health and safety of the public.

6.0 Environmental Evaluation STPNOC has evaluated the proposed changes and determined the changes do 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), and an environmental assessment of the proposed changes is not required.

NOC-AE-04001697 Attachment 2 Annotated Technical Specification Pages

NOC-AE-04001697 Attachment 2 Page 1 of3 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: All MODES.

ACTION:

MODES 1,2,3, and 4:

a. With one Control Room Makeup and Cleanup Filtration System inoperable, restore the inoperable system to OPERABLE status within 7 days 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, restore at least two systems to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 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 />.

c. With three Control Room Makeup and Cleanup Filtration Systems inoperable, suspend all operations involving movement of spent fuel, and crane operation with loads over the spent fuel pool, and restore at least one system to OPERABLE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 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 />.

MODES 5 and 6:

a. With one Control Room Makeup and Cleanup Filtration System inoperable, restore the inoperable system to OPERABLE status within 7 days or initiate and maintain operation of the remaining OPERABLE Control Room Makeup and Cleanup Filtration Systems in the recirculation and makeup air filtration mode, or suspend all operations involving CORE ALTERATIONS, operations involving positive reactivity additions that could result in loss of required SHUTDOWN MARGIN or required boron concentration, movement of spent fuel, and crane operation with loads over the spent fuel pool.

b. With more than one Control Room Makeup and Cleanup Filtration System inoperable, or with the OPERABLE Control Room Makeup and Cleanup Filtration Systems required to be in the recirculation and makeup air filtration mode by ACTION a. not capable of being powered by an OPERABLE emergency power source, suspend all operations involving CORE ALTERATIONS, operations involving positive reactivity additions that could result in loss of required SHUTDOWN MARGIN or required boron concentration, movement of spent fuel, and crane operations with loads over the spent fuel pool.

NOC-AE-04001697 Attachment 2 Page 2 of 3 PLANT SYSTEMS SURVEILLANCE REQUIREMENTS 4.7.7 Each Control Room Makeup and Cleanup Filtration System shall be demonstrated OPERABLE:

a. At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying that the control room air temperature is less than or equal to 780 F;

b. At least once per 92 days on a STAGGERED TEST BASIS 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 least once per 18 months 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 i 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 300C 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 300C and a relative humidity of 70%.

e. At least once per 18 months 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 i 10% for the cleanup units and 1000 cfm + 10% for the makeup units;

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;

NOC-AE-0400 1697 Attachment 2 Page 3 of 3 PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

3) Verifying that the system maintains the control room envelope at a positive pressure of greater than or equal to 1/8 inch Water Gauge at less JiTan or equal to a pressurization flow of 2000 cfm relative to adjacent areas during system operation A,); and I

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 i 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.

leasuredipints ata positive pressurebut Iessthan 118 inch WaterGauge are acceptablei-f ln evatdation, iinsideirin'gappro;pri;ate -co-mtyaio; If* onstratesht the

odto-et terqiee 'sfGbC,-19.Ee'provisionsf thIstnote ,'e at Oe8OO° on eptember'1 9t 2005 !

NOC-AE-0400 1697 Attachment 3 Revised Technical Specification Page

PLANT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

3) Verifying that the system maintains the control room envelope at a positive pressure of greater than or equal to 1/8 inch I Water Gauge at less than or equal to a pressurization flow of 2000 cfm relative to adjacent areas during system operation (1); and I

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.

(1) Measured points at a positive pressure but less than 1/8 inch Water Gauge are acceptable if an evaluation, considering appropriate compensatory action, demonstrates that the condition meets the requirements of GDC-19. The provisions of this note expire at 0800 on September 19, 2005.

SOUTH TEXAS - UNITS 1 & 2 3/4 7-18 Unit 1 - Amendment No. 7-,88 Unit 2 - Amendment No. 15

NOC-AE-04001697 Attachment 4 Bases Insert

NOC-AE-04001 697 Attachment 4 Page 1 of I The information below will be included in the TS Bases for TS 3/4.7.7 Control Room Makeup And Cleanup Filtration System:

Surveillance Requirement 4.7.7.e.3 verifies the integrity of the control room enclosure, and the assumed inleakage rates of the potentially contaminated air. The control room positive pressure, with respect to potentially contaminated adjacent areas, is periodically tested to verify proper functioning of the Control Room HVAC. During the emergency mode of operation, the Control Room HVAC is designed to pressurize the control room to at least 1/8 inch water gauge (wg) positive pressure with respect to adjacent areas in order to prevent unfiltered inleakage. The Control Room HVAC is designed to maintain this positive pressure with two trains at a makeup flow rate of 2000 cfm. The frequency of 18 months is consistent with the guidance provided in NUREG-0800. If the surveillance results are less than 1/8 inch wg and the pressure differential is not positive, the surveillance requirement is considered not met and the appropriate action of TS 3.7.7 must be applied.

The surveillance includes a footnote allowing an evaluation of conditions where the differential pressure is positive but less than 1/8 inch wg. Although not meeting Technical Specification acceptance criteria, the positive relative pressure condition still assures that any leakage across this boundary location would be outleakage. Therefore, the functionality of the control room HVAC system is maintained with the degraded pressure condition within the envelope. The use of the footnote for a condition where the points are less than 1/8 inch wg is intended to be a temporary application until the points are restored to the design 1/8 inch wg in accordance with the corrective action program.

Compensatory actions may be applied based on the results of the evaluation provision of SR 4.7.7.e.3. The evaluation, including appropriate compensatory actions, must demonstrate that the dose limits of GDC 19 of Appendix A of 10CFR50 are met, including a 30 rem limit to the thyroid. If compensatory measures include self-contained breathing apparatus (SCBA) and potassium iodide (KI) tablets, then the requirements of Regulatory Position 2.7.3 of NRC Regulatory Guide, 1.196, "Control Room Habitability at Light-Water Nuclear Power Reactors" must be met.

The procedural infrastructure to apply the compensatory actions is in place. KI is available to the Control Room crews and SCBA units are staged and ready for use by Control Room personnel. STP's emergency plan implementing procedures require that personnel radiation exposure in the control room be monitored so that appropriate personnel protective measures will be taken by the operators during accident conditions.