ML063040295

Request for Emergency Amendment to Control Room Ventilation System Technical Specification

ML063040295
Person / Time
Site:	Clinton
Issue date:	10/25/2006
From:	Jury K AmerGen Energy Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML063040295 (19)

Text

10 CFR 50.90 RS-06-xxx October 25, 2006 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461

Subject:

Request for Emergency Amendment to Control Room Ventilation System Technical Specification In accordance with 10 CFR 50.90, "Application for amendment of license or construction permit," AmerGen Energy Company, LLC (AmerGen) requests an amendment to Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit 1. The proposed change requests an amendment to Technical Specification (TS) 3.7.3, "Control Room Ventilation System." Specifically, the proposed change would increase the TS Completion Time for one inoperable Control Room (CR) Ventilation subsystem (i.e., TS 3.7.3, Required Action A.1) from seven (7) days to fourteen (14) days, on a one-time basis.

AmerGen requests approval of the proposed amendment by 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br /> on October 29, 2006.

AmerGen is requesting NRC approval of the proposed change on an emergency basis to prevent an unnecessary plant shutdown at the expiration of the existing Completion Time, as sufficient time is not available to allow for public comment associated with an exigent TS change. As described in Attachment 1, extending the TS 3.7.3, Required Action A.1 Completion Time to avoid the risk incurred by a plant shutdown will not compromise plant safety. An explanation of the emergency and why it could not be avoided is included in Attachment 1.

Once approved, this amendment will be implemented prior to the expiration of the current Completion Time.

This request is subdivided as follows:

• Attachment 1 provides an evaluation supporting the proposed change.

• Attachment 2 contains the marked up TS page with the proposed change indicated.

• Attachment 3 contains the marked up TS Bases page with the change indicated. The TS Bases page is provided for information.

The proposed change has been reviewed by the Plant Operations Review Committee, and approved by the Nuclear Safety Review Board in accordance with the Quality Assurance Program.

October 25, 2006 ~-~-r /7 U. S. Nuclear Regulatory Commission Page 2 We are notifying the State of Illinois of this application for a change to the TS by transmitting a copy of this letter and its attachments to the designated State Official.

If you have any questions concerning this letter, please contact Mr. David Gullott at (630) 657-2819.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 25th day of October 2006.

Respectfully, Keith R. Jury Director - Licensing and Regulatory Affairs AmerGen Energy Company, LLC Attachments:

1. Evaluation of Proposed Change

2. Marked Up Technical Specifications Page

3. Marked Up Technical Specification Bases Page

bcc: NRC Regional Administrator- Region III NRC Senior Resident Inspector - Clinton Power Station NRC Project Manager, NRR - Clinton Power Station Illinois Emergency Management Agency - Division of Nuclear Safety Director - Licensing and Regulatory Affairs West Manager - Licensing, Clinton, Dresden, and Quad Cities Site Vice President - Clinton Power Station Plant Manager - Clinton Power Station Regulatory Assurance Manager - Clinton Power Station Brenda Fore - Clinton Power Station (Electronic Copy)

Exelon Document Control Desk - Licensing T. Byam

V K SI ATTACHMENT 1 Evaluation of Proposed Change

Subject:

Request for Emergency Amendment to Control Room Ventilation System Technical Specification

5.0 REGULATORY ANALYSIS

5.1 No Significant Hazards Consideration 5.2 Applicable Regulatory Requirements/Criteria

7.0 REFERENCES

Page 1 of 12

ATTACHMENT 1

\i IA~2Evaluation of Proposed Change

1.0 DESCRIPTION

In accordance with 10 CFR 50.90, "Application for amendment of license or construction permit," AmerGen Energy Company, LLC (AmerGen) requests an amendment to Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit 1. The proposed change requests an amendment to Technical Specification (TS) 3.7.3, "Control Room Ventilation System." Specifically, the proposed change would increase the TS Completion Time for one inoperable Control Room (CR) Ventilation subsystem (i.e., TS 3.7.3, Required Action A.1) from seven (7) days to fourteen (14) days, on a onetime basis. This additional Completion Time is required to support replacement and testing of the 'B' Control Room Ventilation Supply Fan, OVC03CB.

The 'B' Control Room Ventilation Supply Fan sustained a non-repairable failure and was subsequently declared inoperable at 1939 hours0.0224 days <br />0.539 hours <br />0.00321 weeks <br />7.377895e-4 months <br /> (CDT) on October 22, 2006. The existing 7-day Completion Time for TS 3.7.3, Required Action A.1 will expire at 1839 hours0.0213 days <br />0.511 hours <br />0.00304 weeks <br />6.997395e-4 months <br /> (CST) on October 29, 2006. AmerGen is requesting NRC approval of the proposed change on an emergency basis to prevent an unnecessary plant shutdown at the expiration of the existing Completion Time, as sufficient time is not available to allow for public comment associated with an exigent license amendment. As described below, extending the TS 3.7.3, Required Action A.1 Completion Time to avoid the risk incurred by a plant shutdown will not compromise plant safety.

2.0 PROPOSED CHANGE

The proposed change provides for a one-time revision to the Completion Time for TS 3.7.3, Required Action A.1. Specifically, this change adds the following Note to the Completion Time for Required Action A.1:

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NOTE -----------------------------

The 7-day Completion Time that was entered at 1939 hours0.0224 days <br />0.539 hours <br />0.00321 weeks <br />7.377895e-4 months <br /> on October 22, 2006, may be extended by an additional 7 days to complete replacement and testing of the B subsystem supply fan.

This proposed change is limited to the current period of 'B' Control Room Ventilation Supply Fan, OVC03CB, inoperability entered on October 22, 2006. provides a TS page markup indicating the proposed one-time change.

=

System Description===

The CPS Control Room Ventilation system is an engineered safety feature that provides a radiologically controlled environment from which the unit can be safely operated following a Design Basis Accident (DBA). The system is safety related and active components are designed with redundancy to meet single active failure criteria. The safety related function of the system, used to control radiation exposure, consists of two independent and redundant high efficiency air filtration subsystems for treatment of recirculated air or outside supply air. The Page 2 of 12

i<* 1 I " ATTACHMENT Evaluation of Proposed1Change LJ_

high radiation mode of system operation is assumed to operate following a loss of coolant accident, main steam line break, fuel handling accident, and control rod drop accident.

The CPS Control Room Ventilation system is comprised of two full-capacity, redundant heating, ventilation, and air-conditioning (HVAC) equipment subsystems. Each subsystem has a supply air handling unit (supply fans, cooling/heating units, and recirculation air filter units), return air fans, makeup air filter units, and chilled water units. The two redundant subsystems are physically separated and active components are protected from internally and externally generated missiles. The power for the redundant equipment is supplied from separate essential power sources and is therefore operable during a loss-of-power event.

The makeup air filter units provide filtered outside air supply to the control room envelope during an accident with an offsite airborne release to maintain CR habitability. There are two 100%

seismic Category I makeup air filter units consisting of a moisture separator, prefilter, electric heating coil, high efficiency particulate air (HEPA) filter, charcoal adsorber and a downstream HEPA filter. The two 100% redundant recirculation air filter units consist of a prefilter and charcoal adsorber. In the high radiation mode, the CR outside air intake, the makeup air filter units, and recirculation air filter units are aligned, so that all outside air must pass through both charcoal adsorbers of the operating filter train before it enters the control room envelope.

The Control Room Ventilation system is provided with two redundant outside air intakes that are physically separated from each other. Radiation monitors continuously monitor the two redundant outside air intakes. In the event of high radiation detection, the radiation monitoring system will activate the alarm in the main CR, automatically start the makeup air filter train, route the supply air stream through the charcoal beds in the recirculation air filter unit associated with the operating HVAC air handling unit, and trip the locker room exhaust fan. The CR operator can operate handswitches to select one of the two redundant air intakes, whichever has a lower airborne contamination level, and minimize radioactivity intake. This high radiation mode of operation continues to pressurize the CR to greater than or equal to 0.125 inch water gauge with respect to the adjacent areas with filtered makeup air. The CR is maintained at positive pressure with respect to adjacent areas when operating in the normal and high radiation modes to minimize the ingress of unfiltered outside air.

The entire CR boundary is designed for low leakage. All boundary penetrations are sealed. The access doors are of airtight design with self-closing devices. The common access door is provided with an airlock vestibule (i.e., double doors in series).

Reason for Requesting an Emergency Amendment 10 CFR 50.91 "Notice for public comment; State consultation," paragraph (a)(5) states that where the NRC finds that an emergency situation exists, in that failure to act in a timely manner would result in derating or shutdown of a nuclear power plant, it may issue a license amendment involving no significant hazards consideration without prior notice and opportunity for a hearing or public comment. The regulation requires that a licensee requesting an emergency amendment explain why the emergency situation occurred and why the licensee could not avoid the situation.

On October 22, 2006, the 'B' CR ventilation supply fan sustained a non-repairable failure while in operation. Based on CR indications and plant walkdowns, the 'B' CR ventilation subsystem was declared inoperable and the 'A' CR ventilation subsystem was placed in operation. As a Page 3 of 12

Evaluation of Proposed Change JL result of the 'B' subsystem being declared inoperable, TS 3.7.3, Required Action A.1 was entered at 1939 hours0.0224 days <br />0.539 hours <br />0.00321 weeks <br />7.377895e-4 months <br /> on October 22, 2006. This Required Action stipulates that the inoperable CR ventilation subsystem must be restored to operable status within 7 days. If the inoperable subsystem is not restored to operable status within the 7-day Completion Time, the TS 3.7.3 Required Actions are to place the unit in Mode 3 (Hot Shutdown) within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and in Mode 4 (Cold Shutdown) within the following 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

The additional time proposed by this emergency request could not have reasonably been identified earlier. Verification of the system's ability to perform its design basis function is demonstrated satisfactorily on a periodic basis in accordance with TS 3.7.3 Surveillance Requirements. This included verification of the system's ability to maintain flow through both the makeup filter and the recirculation filter, and the system's ability to maintain a positive control room envelope pressure of greater than or equal to 0.125 inch water gauge during the high radiation mode of operation. Additionally, to monitor and trend the supply fan performance, periodic vibration testing is performed in accordance with the Performance Centered Maintenance program. Therefore, this unforeseen failure and immediate entry into TS 3.7.3, Required Action A.1, coupled with the results of the periodic testing and monitoring, provides reasonable confirmation that more timely action could not have been taken to avoid the need for this emergency TS amendment.

In response to this failure, in accordance with the corrective action program, CPS is conducting a root cause analysis and is taking action to replace the damaged supply fan. Based on the obsolescence of this equipment, a readily available replacement fan and necessary replacement parts are not maintained onsite or within the AmerGen / Exelon Generation Company fleet. A replacement fan of similar design has been located, however, even on an expedited schedule, the necessary certification testing, installation repairs/modifications, post-maintenance and surveillance testing to establish operability may not be completed prior to the expiration of the 7-day Completion Time.

This emergency situation results from the unforeseen failure of the supply fan and the extent of repair given the limited availability of replacement equipment. Under these conditions, AmerGen could not have reasonably applied for this amendment in advance of the event or in a more timely manner following the event. Therefore, the requirements for an emergency situation stipulated in 10 CFR 50.91, paragraph (a)(5) have been met.

Replacement Options The current schedule for replacing the failed CR Ventilation supply fan assembly includes completion of vendor testing of the replacement unit, fit-up modifications to the fan housing, and final vibration testing prior to air transport to the station. Preparations and minor fit-up modifications are in progress to allow for physical differences in the replacement assembly.

Following receipt at the station, the replacement fan assembly will be transported, rigged into place, and reinstalled. Post-installation testing and restoration of operability is currently scheduled for October 28, 2006. Considering the nature of actions required to restore operability, there is significant schedule uncertainty associated with completing these actions within the existing TS Completion Time.

In parallel to this primary replacement option, AmerGen is in the process of obtaining an additional replacement fan assembly. In the event the primary replacement option described Page 4 of 12

ATTACHMENT 1 Evaluation of Proposed Change above is not successful, this secondary option will be implemented within the additional time requested by the proposed change.

4.0 TECHNICAL ANALYSIS

AmerGen is requesting this emergency TS amendment in order to effect necessary repairs to the 'B' Control Room Ventilation Supply Fan. The additional 7 days to support the repairs and testing will avoid shutting down the unit to Mode 4, and cycling the unit through an unnecessary thermal transient. Since the integrity of the reactor vessel and components of the primary system of a nuclear plant can be adversely affected by the number of thermal transients experienced, it is prudent to avoid such transients provided the health and safety of the public is preserved. Additionally, cycling the unit though a thermal transient cycles the secondary plant systems, as well as increases challenges to the operators. Placing CPS, Unit 1 in Mode 4 requires additional routine surveys and inspections that increase personnel exposure.

The 'A' CR Ventilation subsystem is presently operable and all required TS Surveillance Requirements and Preventive Maintenance actions are current. The CPS CR Ventilation system consists of two independent and redundant high efficiency air filtration subsystems, each independently capable of performing the safety related functions credited in the TS. CPS intends to maintain the 'A' subsystem operable during the initial 7-day Completion Time provided by the TS and the additional 7 days requested. The existing operating parameters of

'A' subsystem are normal, and the system is operating as expected. In the event of an unforeseen failure of the 'A' CR Ventilation subsystem, CPS will follow the TS Required Action D.1 for two inoperable CR Ventilation subsystems. TS Required Action D.1 requires immediate entry into TS 3.0.3, which requires placing the unit in Mode 2 within 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />, Mode 3 within 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br />, and Mode 4 within 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br />.

The current 7-day Completion Time provided for TS 3.7.3, Required Action A.1 is based on the low probability of a DBA occurring during this time period, and that the remaining operable subsystem can provide the required system function and capabilities. AmerGen has concluded that the proposed additional 7 days will not significantly affect health and safety of the public.

This conclusion is based on the bases for the current 7-day Completion Time and the following risk assessment.

Risk Assessment Approach The risk significance of operation of CPS with one subsystem of Control Room Ventilation system unavailable is determined by the following risk metrics:

0 A Core Damage Frequency (CDF) 0 A Large Early Release Frequency (LERF)

• Incremental Conditional Core Damage Probability (ICCDP)

• Incremental Conditional Large Early Release Probability (ICLERP)

These values are calculated as follows:

Page 5 of 12

ATTACHMENT I

,,l ,Evaluation of Proposed Change

" ACDF = (CDF 1 - CDFo)

" ALERF = (LERF1 - LERFo)

" ICCDP = (CDF1 - CDFo) x t1/To

• ICLERP = (LERF 1 - LERF 0 ) x tj/To Where CDF, is the total annual CDF with the condition/configuration in effect; CDFO is the total base annual CDF; LERF, is the total annual LERF with the condition/configuration in effect; LERFO is the total base annual LERF; t j is the duration of the condition/configuration; and To is one year. In this analysis, the condition is operation of CPS with one subsystem of Control Room Ventilation system unavailable. Per the Clinton PRA current model of record, CDFo =

1.16 E-5/yr and LERF 0 = 5.25E-7/yr.

Per Reference 1 Figures 3 and 4 (shown below), using the base CDF 0 = 1.16 E-5/yr and base LERFO = 5.25E-7/yr noted above, an acceptance criterion of 1E-6 for ACDF and 1 E-7 for ALERF places the plant in Region Ill. Region III represents a very small change which allows maximum flexibility for license changes.

Regin-1

- No Chne Aloe 10-5 10-4 CDF-0 Reference 1, Figure 3: Acceptance Guidelines for Core Damage Frequency (CDF)

Page 6 of 12

ATTACHMENT 1 Evaluation of Proposed Change I:

10-10o-7 106 o- LERF -0 Reference 1, Figure 4: Acceptance Guidelines for Large Early Release Frequency (LERF)

Furthermore, according to Reference 2, the ICCDP and the ICLERP associated with the one-time change should be < 5E-7 and <5E-8, respectively.

The risk acceptance thresholds for these metrics for CPS are:

" ACDF 1E-6 (Figure 3 of Reference 1)

" ALERF 1E-7 (Figure 4 of Reference 1)

• ICCDP <5E-7

• ICLERP <5E-8 The determination of the risk impact is performed based on knowledge of the current CPS PRA models and assumptions. As discussed below, this risk analysis did not require explicit model manipulation and quantification.

Analysis This analysis, and the TS 3.7.3, are based on the radioactivity filtering function of CR Ventilation system. The only scenario of concern is the fission product infiltration scenario.

This scenario involves abandonment of the main control room due to fission product infiltration.

Whereas the CPS design-basis accident assumes a certain release of fission products occurs immediately at the start of a postulated accident, the more realistic PRA does not. The PRA assumes a significant release of fission products to containment occurs only post-core damage.

This is consistent with standard PRA assumptions and core damage accident phenomenology.

In addition, a significant release from containment to the environment, and therefore the control room, occurs only if there is a containment failure or bypass event. This is also consistent with standard PRA assumptions and core damage accident phenomenology.

Page 7 of 12

F LTh LlL- i~ii

[)If: :-ATTACHMENT LI 1

Evaluation of Proposed Change As such, per standard PRA assumptions and the current CPS PRA model, by the time fission products are released to the environment and challenge the control room ventilation function, core damage and radionuclide release have already occurred. Since the filtration function of the Control Room Ventilation system is not challenged until core damage and fission product release have occurred, the reduced estimated reliability of the Control Room Ventilation function due to loss of the 'B' subsystem has no impact on CDF or LERF.

Results The ACDF, ALERF, ICCDP and ICLERP. risk metric results from this risk assessment are summarized in Table 1. As shown in Table 1, all risk metrics calculated in this assessment are within the applicable acceptance criteria.

Table 1 RESULTS Risk Metric Result Acceptance Criterion ACDF O.OEO 1E-6 (Curve Region Ill)

ALERF O.OEO 1E-7 (Curve Region I11)

ICCDP O.OEO 5E-7 ICLERP O.OEO 5E-8 Risk Assessment Conclusions The results of the risk assessment show that, for operation with one CR Ventilation subsystem unavailable for the proposed 7 days, all risk-informed TS change criteria are met.

Compensatory Actions CPS will implement the following compensatory actions while operating in the extended TS 3.7.3, Require Action A.1 Completion Time.

1. Continue to assess and manage the increase in risk that may result from planned maintenance activities and emergent issues in accordance with the CPS program and procedures that implement 10 CFR 50.65, "Requirements for monitoring the effectiveness of maintenance at nuclear power plants," paragraph (a)(4).

2. Maintain 'A' CR Ventilation subsystem and required support systems protected. Install signs, barrier tape, or similar markings to protect necessary components.

Page 8 of 12

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_ATTACHMENT 1 Evaluation of Proposed Change

3. No elective maintenance will be performed on 'A' CR Ventilation subsystem and required support systems. Surveillance activities required by the Operating License will continue to be performed as scheduled.

4. No movement of irradiated fuel will be performed in the primary or secondary containment.

5.0 REGULATORY ANALYSIS

5.1 No Siqnificant Hazards Consideration In accordance with 10 CFR 50.90, "Application for amendment of license or construction permit," AmerGen Energy Company, LLC (AmerGen) requests an amendment to Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit 1. The proposed change requests an amendment to Technical Specification (TS) 3.7.3, "Control Room Ventilation System." Specifically, the proposed change would increase the TS Completion Time for one inoperable Control Room (CR) Ventilation subsystem (i.e., TS 3.7.3, Required Action A.1) from seven (7) days to fourteen (14) days, on a one-time basis. This additional Completion Time is required to support replacement and testing of the 'B' Control Room Ventilation Supply Fan.

According to 10 CFR 50.92, "Issuance of amendment," paragraph (c), a proposed amendment to an operating license involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not:

(1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.

AmerGen has evaluated the proposed change for CPS, Unit 1 using the criteria in 10 CFR 50.92, and has determined that the proposed change does not involve a significant hazards consideration. The following information is provided to support a finding of no significant hazards consideration.

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The probability of an evaluated accident is derived from the probabilities of the individual precursors to that accident. The consequences of an evaluated accident are determined by the operability of plant systems designed to mitigate those consequences.

The probability of an accident occurring will not be significantly affected by granting the proposed change. The Control Room Ventilation system is not an initiator to any accident previously evaluated. Rather, the high radiation mode of the Control Room Ventilation system is assumed to operate following a loss-of-coolant accident, main Page 9 of 12

o) ATTACHMENTI1 Evaluation of Proposed Change steam line break, fuel handling accident, and control rod drop accident. The proposed change does not affect the design features of the Control Room Ventilation system, the operational characteristics or function of the system, or the interfaces to other plant systems.

The consequences of an accident, in terms of offsite dose, will not be significantly changed provided the mitigating actions credited in the accident analyses are accomplished in accordance with the analysis assumptions. The analyses assume that all required mitigating equipment is operable at the onset of the transient. No provisions are made for allowed outage times and associated shutdown requirements in the accident analyses. Compensatory measures have been implemented and will be maintained to protect the 'A' Control Room Ventilation subsystem while replacement and testing are completed on the 'B' Control Room Ventilation subsystem.

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 Creation of the possibility of a new or different kind of accident requires creating one or more new accident precursors. New accident precursors may be created by modifications of plant configuration, including changes in allowable modes of operation.

The proposed change does not involve any plant configuration modifications or changes to allowable modes of operation.

The proposed change will not impact equipment failures. The proposed change deals with equipment allowed outage times and associated shutdown requirements, not equipment operation. There is no change in the design, configuration, or method of operation of the plant. The proposed change will not alter the manner in which equipment operation is initiated, nor will the functional demands on credited equipment be changed. The proposed change allows plant operation to continue while the 'B' Control Room Ventilation subsystem is repaired and tested. The proposed change does not affect the interaction of the Control Room Ventilation system with any system whose failure or malfunction can initiate an accident. The proposed change does not result in a new system configuration being introduced, and no equipment is being operated in a new or different manner. The proposed change does not alter assumptions made in the safety analysis. No alteration in the procedures, which ensure that the plant remains within analyzed limits, is being proposed, and no changes are being made to the procedures relied upon to respond to off-normal events. Accordingly, no new or different failure modes are being introduced.

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

Page 10 of 12

! *t iATTACHMENT Evaluation of Proposed1 Change

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

Response: No Adequate compensatory measures will ensure that there is sufficient control room ventilation. Since there are no changes to the plant design and safety analysis, and no changes to the Control Room Ventilation system design, including any instrument setpoints, no margin of safety assumed in the safety analysis is affected.

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

Based upon the above, AmerGen concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c).

Accordingly, a finding of no significant hazards consideration is justified.

5.2 Applicable Regulatory Requirements/Criteria 10 CFR 50.36, "Technical specifications," provides the regulatory requirements for the content required by a licensee's TS. Criterion 3 of 10 CFR 50.36(c)(2)(ii) requires a limiting condition for operation be established for a system that is part of a primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier. The function of the Control Room Ventilation System is included in the TS as it satisfies this criterion. 10 CFR 50.36(c)(2)(i) requires that when a limiting condition for operation is not met, the licensee shall shutdown the reactor or follow the remedial actions permitted by the TS until the condition can be met.

10 CFR 50, Appendix A, General Design Criterion (GDC) 19, "Control room," requires a control room be provided from which actions can be taken to operate the plant safely under normal conditions and to maintain it in a safe condition under accident conditions.

Adequate radiation protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposure in excess of limits provided in GDC 19. No changes to the CR Ventilation system design are being made as part of the proposed change. Therefore, the system will continue to meet the requirements of GDC 19.

In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

6.0 ENVIRONMENTAL CONSIDERATION

AmerGen has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, "Standards for Protection Against Radiation." However, the proposed amendment does not involve: (i) a significant hazards consideration, (ii) a significant change in Page 11 of 12

P UiD,/_ \ATTACHMENT Evaluation of Proposed1Change the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22, "Criterion for categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review," paragraph (c)(9). Therefore, pursuant to 10 CFR 51.22, paragraph (b), no environmental impact statement or environmental assessment needs be prepared in connection with the proposed amendment.

7.0 REFERENCES

1. Regulatory Guide 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis,"

Revision 1

2. Regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," Revision 0 Page 12 of 12

ATTACHMENT 2 Marked Up Technical Specifications Page

Control Room Ventilation System 3.7.3 3.7 PLANT SYSTEM 3.7.3 Control Room Ventilation System LCO 3.7.3 Two Control Room Ventilation subsystems shall be OPERABLE.

APPLICABILITY: MODES 1, 2, and 3, During movement of irradiated fuel assemblies in the primary or secondary con.tainment, During CORE ALTERATIONS, During operations with a potential for draining the reactor vessel (OPDRVs).

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One Control Room A.I Restore Control Room 7 days Ventilation subsystem Ventilation subsystem inoperable. to OPERABLE status.

B. Required Action and B.1 Be in MODE 3. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Associated Completion Time of Condition A AND not met in MODE 1, 2, or 3. B.2 Be in MODE 4. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (continued)

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-NOTE The 7 day Completion Time that was entered at 1939 hours0.0224 days <br />0.539 hours <br />0.00321 weeks <br />7.377895e-4 months <br /> on October 22, 2006, may be extended by an additional 7 days to complete replacement and testing of the B subsystem supply fan.

CLINTON 3.7-4 Amendment No. 95

L2,i ATTACHMENT 3 Marked Up Technical Specifications Bases Page

Control Room Ventilation System B 3.7.3 BASES (continued)

APPLICABILITY In MODES 1, 2, and 3, the Control Room Ventilation System must be OPERABLE to control operator exposure during and following a DBA, since the DBA could lead to a fission product release.

In MODES 4 and 5, the probability and consequences of a DBA are reduced due to the pressure and temperature limitations in these MODES. Therefore, maintaining the Control Room Ventilation System OPERABLE is not required in MODE 4 or 5, except for the following situations under which significant radioactive releases can be postulated:

a. During operations with a potential for draining the reactor vessel (OPDRVs);

b. During CORE ALTERATIONS; and

c. During movement of irradiated fuel assemblies in the primary or secondary containment.

ACTIONS A.1 With one Control Room Ventilation subsystem inoperable, the inoperable Control Room Ventilation subsystem must be restored to OPERABLE status within 7 days. With the unit in this condition, the remaining OPERABLE Control Room Ventilation subsystem is adequate to perform control room radiation protection.. However, the overall reliability is reduced because a single failure in the OPERABLE subsystem could result in loss of Control Room Ventilation System function. The 7 day Completion Time is based on the low probability of a DBA occurring during this time period, and that the remaining subsystem can provide the required capabilities.

B.1 and B.2 In MODE 1, 2, or 3, if the inoperable Control Room Ventilation subsystem cannot be restored to OPERABLE status

.within the associated Completion Time, the unit must be placed in a MODE that minimizes risk. To achieve this status, the unit must be placed in at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed (continued)

The 7 day Completion Time is modified by a Note that allows for a one-time extension by an additional 7 days to complete replacement and testing of the B subsystem supply fan.

CLINTON B 3.7-12 Revision No. 0