View source for RS-06-160, Request for Emergency Amendment to Control Room Ventilation System Technical Specification

{{Adams
| number = ML062990236
| issue date = 10/25/2006
| title = Request for Emergency Amendment to Control Room Ventilation System Technical Specification
| author name = O'Neill T
| author affiliation = AmerGen Energy Co, LLC
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000461
| license number = NPF-062
| contact person = 
| case reference number = RS-06-160
| document type = Letter type:RS, License-Application for Facility Operating License (Amend/Renewal) DKT 50, Technical Specifications
| page count = 18
}}

=Text=
{{#Wiki_filter:AmerGen Energy Company, LLC www.exeloncorp.co m 4300 Winfield Road Warrenville, IL 60555 RS-06-160 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 hours 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 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. An Exelon Company 10 CFR 50.90 October 25, 2006 U. S. Nuclear Regulatory Commission Page 2 TO 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, Thomas S. O'Neill Vice President - Regulatory and Legal Affairs AmerGen Energy Company, LLC Attachments
: 1. Evaluation of Proposed Change 2. Marked Up Technical Specifications Page 3. Marked Up Technical Specification Bases Page ATTACHMENT 1 Evaluation of Proposed Change 

==Subject:==
Request for Emergency Amendment to Control Room Ventilation System Technical Specification 

==1.0 DESCRIPTION==

==2.0 PROPOSED CHANGE==

==3.0 BACKGROUND==

4.0 TECHNICAL ANALYSIS 5.0 REGULATORY ANALYSIS 5.1 No Significant Hazards Consideration 5.2 Applicable Regulatory Requirements/Criteria 6.0 ENVIRONMENTAL CONSIDERATION 

==7.0 REFERENCES==

Page 1 of 12  

==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 one-time bask 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 hours (CDT) on October 22, 2006. The existing 7-day Completion Time for TS 3.7.3, Required Action A.1 will expire at 1839 hours (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, emending 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==
ATTACHMENT 1 Evaluation of 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: ------------------------------------------------------
NOTE -------------------------------------------------------
The 7 day Completion Time that was entered at 1939 hours 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. Attachment 2 provides a TS page markup indicating the proposed one-time change. Attachment 3 provides a TS Bases page markup for information. 

==3.0 BACKGROUND==

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 ATTACHMENT 1 Evaluation of Proposed Change 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. AmerGen has previously determined that toxic gas protection of the CR envelope is not a concern at CPS. 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 (H EPA) 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. Page 3 of 12 ATTACHMENT 1 Evaluation of Proposed Change On October 22, 2006, the `B' CR ventilation supply fan sustained a non-repairable failure while in operation. Specifically, the fan motor, fan blades and hub, fan housing, and expansion boots sustained extensive damage to the point that none of the components are reusable as a result of the failure. The failure mechanism will be identified as part of the associated and on-going root cause investigation. 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 result of the `B' subsystem being declared inoperable, TS 3.7.3, Required Action A.1 was entered at 1939 hours 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 Required Actions of TS 3.7.3 Condition B will be followed. 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. A readily available replacement fan and necessary replacement parts are not maintained onsite or within the AmerGen / Exelon Generation Company, LLC 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 testing, 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 Page 4 of 12 ATTACHMENT 1 Evaluation of Proposed Change operability, there is 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 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, A 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 exiting operating parameters of `A' subsystem are normal, and the system is operating as expected. Additionally, the `A' subsystem supply fan motor was replaced in January 2006. 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 DA requires immediate entry into TS 3.0.3, which requires placing the unit in Mode 2 within 7 hours, Mode 3 within 13 hours, and Mode 4 within 37 hours. 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 CR Ventilation subsystem unavailable is determined by the following risk metrics: 0 A Core Damage Frequency (CDF) 0 A Large Early Release Frequency (LERF) Page 5 of 12 ATTACHMENT 1 Evaluation of Proposed Change Incremental Conditional Core Damage Probability (ICCDP) Incremental Conditional Large Early Release Probability (ICLERP) These values are calculated as follows: Where CDF, is the total annual CDF with the condition/configuration in effect; CDF o is the total base annual CDF; LERF, is the total annual LERF with the condition/configuration in effect; LERF o is the total base annual LERF; t, is the duration of the condition/configuration
; and T o is one year. In this analysis, the condition is operation of CPS with one CR Ventilation subsystem unavailable. Per the Clinton Probabilistic Risk Assessment (PRA) current model of record, CDF o = 1.16 E-5/yr and LERF o= 5.25E-7/yr. Per Reference 1 Figures 3 and 4 (shown below), using the base CDF o = 1.16 E-5/yr and base LERF o = 5.25E-7/yr noted above, an acceptance criterion of 1 E-6 for ACDF and 1 E-7 for ALERF places the plant in Region III. Region III represents a very small change which allows maximum flexibility for license changes. i0 !on R"fon 11 OMMI CU av s " 7t=* a11w I p on "krn 1 a wiro-.a 10-5 Reference 1, Figure 3: Acceptance Guidelines for Core Damage Frequency (CDF) Page 6 of 12 CDF - " ACDF = (CDF, - CDFo) " ALERF = (LERF, - LERFo) " ICCDP = (CDF, - CDF o) x t,/T O " ICLERP = (LERF, - LERF o) x t,/T O 10 splon 111 " YWr BMW Chrgw Region 11 " No a PIMMIhy wflh 10'6 Region 111 Ana lysi s eg ivn 1 Region 1 No Chap Region 111 A" awad " W!f am" Chops " More FleAblift w11h Ro*PoOt to 6oomkio " yak Curnulathe ImprK:is Region ATTACHMENT 1 Evaluation of Proposed Change Region 111 10'6 5 LERF 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: 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. This analysis and 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 DBA analysis 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 " ACDF 1 E-6 (Figure 3 of Reference
: 1) " ALERF 1 E-7 (Figure 4 of Reference
: 1) " ICCDP <5E-7 " ICLERP <5E-8 Results The ACIDF, ALERF, ICCIDP 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. Co mpensatory Actions ATTACHMENT 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 CIDF or LERF Table 1 RESULTS 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. 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 in accordance with station procedures. Install signs, barrier tape, or similar markings to protect necessary components. Page 8 of 12 Risk Metric Result Acceptance Criterion ACIDF OLEO 1 E-6 (Curve Region 111) ALERF OLEO 1 E-7 (Curve Region 111) ICCDP OLEO 5E-7 ICLERP OLEO 5E-8
: 3. No elective maintenance will be performed on `A' CR Ventilation subsystem and required support systems. The Operating License Surveillance Requirements will continue to be met or the appropriate TS actions will be taken. 4. No movement of irradiated fuel will be performed in the primary or secondary containment. 5.0 REGULATORY ANALYSIS 5.1 No Significant 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 bask 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: (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or ATTACHMENT 1 Evaluation of Proposed Change Involve a significant increase in the probability or consequences of an accident previously evaluated; or 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. Page 9 of 12 Response: No ATTACHMENT 1 Evaluation of Proposed Change 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 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 analyst assumptions. The analyses assume that all required mitigating equipment 4 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 `13' 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?
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 1 0 of 12 ATTACHMENT 1 Evaluation of Proposed 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 involve 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 Page 11 of 12 amendment does not involve: (i) a significant hazards consideration, (ii) a significant change in 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==

ATTACHMENT 1 Evaluation of Proposed Change 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 Decisionmalking
: Technical Specifications," Revision 0 Page 12 of 12 ATTACHMENT 2 Marked Up Technical Specifications Page 3.7 PLANT SYSTEM 3.7.3 Control Room Ventilation System LCO 3.7.3 APPLICABILITY
: MODES 1, 2, and 3, During movement of irradiated fuel or secondary containment, During CORE ALTERATIONS, During operations with a potential vessel (OPDRVs). ACTIONS CLINTON CONDITION One Control Room Ventilation subsystem inoperable. Required Action and Associated Completion Time of Condition A not met in MODE 1, 2, or 3. 3.7-4 Control Room Ventilation System 3.7.3 Two Control Room Ventilation subsystems shall be OPERABLE. assemblies in the pr for draining the reactor REQUIRED ACTION Restore Control Room Ventilation subsystem to OPERABLE status. B.1 Be in MODE 3. AND B.2 Be in MODE 4. COMPLETION TIME 7 days 12 hours 36 hours (cont ____________________NOTE-___________________
The 7 day Completion Time that was entered at 1939 hours on October 22, 2006, may be extended by an additional 7 days to complete replacement and testing of the B subsystem supply far. ed) Amendment No. 95 ATTACHMENT 3 Marked Up Technical Specifications Bases Page 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. ACTIONS A.1 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
: During operations with a potential for draining the reactor vessel (OPDRVs); B.1 and B.2 b. During CORE ALTERATIONS
; and Control Room Ventilation System B 3.7.3 C. During movement of irradiated fuel assemblies in the primary or secondary containment. 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 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. 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 hours and in MODE 4 within 36 hours. The allowed 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. in (continued)
CLINTON B 3.7-12 Revision No. 0}}