ML20206E134

Application for Amends to Licenses DPR-77 & DPR-79, Consisting of TS Change Request 99-03, Main Control Room Emergency Ventilation Sys Verses Radiation Monitors. Change Adds LCOs 3.3.3.1 & 3.7.7 & NUREG-1431 Changes

ML20206E134
Person / Time
Site:	Sequoyah
Issue date:	04/29/1999
From:	Salas P TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20206E137	List: ML20206E134 ML20206E139
References
RTR-NUREG-1431 NUDOCS 9905050031
Download: ML20206E134 (9)

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5 Tennessee Vahey Authonty. Post Offce Dox 2000, Soddy-Daisy. Tennessee 37379 April 29, 1999 TVA-SQN-TS-99-03 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - UNITS 1 AND 2 - TECHNICAL SPECIFICATION (TS) CHANGE NO. 99-03, " MAIN CONTROL ROOM EMERGENCY VENTILATION SYSTEM VERSES RADIATION MONITORS" In accordance with the provisions of 10 CFR 50.4 and 50.90, TVA is submitting a request for an amendment to SQN's licenses DPR-77 and 79 to change the TSs for Units 1 and 2.

The proposed change adds new actions to Limiting Condition for Operations (LCOs) 3.3.3.1 and 3.7.7 to address the situation when one channel of radiation monitoring control room emergency ventilation system (CREVS) actuation equipment is inoperable. For LCO 3.3.3.1, the additional actions are l

included in Table 3.3-6, INSTRUMENT 2.c. The proposed change also expands the mode of applicability for LCOs 3.3.3.1 and 3.7.7 to include periods when movement of irradiated fuel l//

assemblies are involved and defines actions to take in these instances. In addition, this change incorporates other i features found in standard TSs, NUREG-1431. TS 3/4.3.3.1 Bases are revised to define the instrumentation actuating 0 CREVS, while TS 3/4.7.7 Bases are expanded to define the ) ) 0 32 elements of operability for CREVS as provided in the standard TSs.

SON has implemented administrative controls to address the situation when one channel of radiation monitoring CREVS actuation equipment is inoperable and the increase in applicability to include movement of irradiated fuel assemblies, in accordance with NRC Administrative

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Nuclear Regulatory Commission Page 2 April 29, 1999 i Letter-98-10. LCO 3.3.1 is currently inadequate in reference to LCO action and time for this situation. SON documented this finding and resulting actions in its corrective action program.

TVA has determined that there are no significant hazards considerations associated with the proposed change and that the change is exempt from environmental review pursuant to the U.S. provisions of 10 CFR 51.22 (c) (9) . The SQN Plant Operations Review Committee and the SQN Nuclear Safety Review Board have reviewed this proposed change and determined that operation of SQN Units 1 and 2, in accordance with the proposed change, will not endanger the health and safety of i the public. Additionally, in accordance with 10 CFR

50. 91 (b) (1) , TVA is sending a copy of this letter to the Tennessee State Department of Public Health.

Enclosure 1 to this letter provides the description and evaluation of the proposed change. This includes TVA's determination that the proposed change does not involve a significant hazards consideration, and is exempt from environmental review. Enclosure 2 contains copies of the appropriate TS pages from Units 1 and 2 marked-up to show the proposed change. Enclosure 3 forwards the revised TS pages for Units 1 and 2 which incorporate the proposed change.

TVA requests that_the revised TS be made effective within 45 days of NRC approval. If you have any questions about this-change, please telephone me at (423) 843-7170 or J. D. Smith at (423) 843-6672.

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Mr. R. W..Hernan, Project Manager-

-Nuclear. Regulatory Commission l 'One White-Flint, North 11555 Rockville Pike Rockville, Maryland.20852-2739 Mr. Michael H.-Mobley, Director (w/o Enclosures)

-Division of Radiological ~ Health Third Floor L&C Annex-401 Church Street Nashville, Tennessee 37243-1532 NRC Resident Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624.

Regional Administrator U.S. Nuclear Regulatory Commission Region'II Atlanta' Federal Center 61.Forsyth St., SW, Suite 23T85 Atlanta,.'~ Georgia-30303-3415 0

m q ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)

UNITS 1 AND 2 DOCKET NOS. 327 AND 328 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE 99-03 DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGE I. DESCRIPTION OF THE PROPOSED CHANGE TVA proposes to modify the Sequoyah Nuclear Plant (SQN)

Units 1 and 2 TSs by adding new action statements to Limiting Condition for Operations (LCOs) 3.3.3.1 and 3.7.7 to address the aituation when one channel of radiation monitoring equipment is inoperable. Additionally, TS 3/4.3.3.1 Bases are revised to define the instrumentation actuating control room emergency ventilation system (CREVS), while TS 3/4.7.7 Bases are expanded to define the elements of operability for CREVS as provided in standard TS, NUREG-1431.

The changes to LCO 3.3.3.1 are in Table 3.3-6, INSTRUMENT

2. c, Control Room Isolation, and are described as follows:

• Revise the minimum channels operable from one to two, and add, "and during movement of irradiated fuel assemblies," to the applicable modes column.

• Divide Action 29 into Actions 29a and 29b:

0 Add Action 29a that states, "With one channel inoperable, place the associated control room emergency ventilation system (CREVS) train in recirculation mode of operation within 7 days or be in at least HOT STANDBY withih 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 />."

O Change existing Action 29 into Action 29b and modify the action with two channels inoperable to also require, " enter the required Actions for one CREVS train made inoperable by inoperable CREVS 3 actuation instrumentation or place both trains in L the recirculation mode of operation within one n

! hour."

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I e Add' actions to take if the completion time of Action 29b L

.cannot be~ met' in Modes 1, 2, 3 and 4, during movement of

, -irradiated fuel' assemblies or in Modes 5 and 6. They L -

-include:

0 "If the completion time of Action 29b cannot be metLin MODES 1, 2, 3, and 4, 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 />."

0 "If the-completion time of Action 29b.cannot be met during the movement of irradiated fuel assemblies, suspend core alterations and suspend movement of~ irradiated fuel assemblies."

0 "If the completion time of Action 29b cannot be met in MODES 5 and 6, initiate action to-restore one CREVS train."

The changes to TS 3/4.7.7 are as follows:

e . Add to the LCO 3.7.7 applicability statement, "during movement of irradiated fuel assemblies."

e Add' Action c to Modes 1, 2, 3 and 4 to require, ."With both CREVS inoperable for other than Action b, be'.in at least HOT STANDBY'within the next six hours 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 />."

'*; Add to the portion of the. Action pertaining to MODES 5 and 6, "during movement of irradiated fuel assemblies" e - ' Modify MODES 5 and 6 Action a to add, "or suspend core alterations and suspend movement of irradiated fuel assemblies."

• Modify MODES 5 and 6 Action b to revise "or positive reactivity changes" to read, "and suspend movement of irradiated fuel assemblies." 3 The revision to Bases Section 3/4.3.3.1 defines the instrumentation actuating CREVS that automatically initiate control room isolation, while TS 3/4.7.7 Bases are expanded to define the elements of operability for CREVS as provided in standard TS, NUREG-1431.

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II. REASON FOR THE PROPOSED CHANGE l

TVA is proposing to revise LCOs 3.3.3.1 and 3.7.7 to l formalize a temporary and conservative (safe direction) change that SON implemented, in accordance with NRC Administrative Letter 98-10, to address a situation when one channel of radiation monitoring CREVS actuation equipment is inoperable. The situation is that_LCO 3.3.3.1 is inadequate in reference to LCO action and time j if only one (1) radiation monitor is inoperable. SQN  ;

documented this finding and resulting actions in its corrective action program. In addition, the applicability of both LCO's was conservatively enhanced to include movement of irradiated fuel assemblies, an evolution with the potential to create a radiation condition requiring CREVS actuation. The substitution of, "and during movement of irradiated fuel assemblies" for "or positive reactivity changes" in LCO 3.7.7, Modes 5 and 6, Action b, was made to provide an action that prevents events from occurring in this mode / condition, such as a fuel handling i accident, that could potentially cause a condition that  !

results in the need for CREVS and to be consistent with Standard TSs. SQN also took this opportunity to review the interaction between TS 3/4.3.3.1, Table 3.3-6, INSTRUMENT 2.c, Control Room Isolation; TS 3/4.7.7, CREVS, and their Bases. Changes are proposed for the purpose of enhancing their consistency and providing a level of detail more commensurate with the standard TSs. 1 III. SAFETY ANALYSIS I In accordance with General Design Criterion 19, the CREVS and shielding have been designed to limit deep dose equivalent during.an accident period to 5 rem. Thyroid

' dose is limited to 30 rem and beta skin dose should not exceed 30 rem.

Inthe event of a radioactive release incident, the control room will be isolated automatically by a safety I injection system signal and/or by radiation signal from I l

beta detectors (0-RM-90-125 and -12 6) located in the air intake stream common to the air intake ports at_either end of the Control Building. This initiates the CREVS. As a

. result, these redundant signals are routed to their associated train controls, which actuate air-operated isolation dampers. Operation of the emergency pressurizing fans with inline HEPA filters and charcoal adsorbers is also initiated by these signals. Thus, CREVS acts to terminate the supply of unfiltered outside air to the control room, initiate filtration, and emergency pressurization of the control room.

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. l The CREVS and the associated actuation instrumentation '

have credible failure modes that include the lack of CREVS initiation due to the inoperability of the control room intake radiation monitoring equipment or the safety injection actuation signal. In addition, the failure of i any number of components in the CREVS could inhibit the ability of the system to adequately provide filtered and conditioned air supply for the control room atmosphere.

These features of the CREVS and the associated actuation functions are fully redundant tc ensure the availability i of the required safety function considering a single failure. The proposed changes enhance this redundancy by l ensuring that the inoperability of one channel of the actuation instrumentation for radiation has appropriate actions to restore necessary functions or place the unit in a mode of operation that does not require the safety function. In addition, the CREVS applicability is enhanced to require system operability during movement of irradiated fuel, which is a condition that could result in a fuel handling accident with the potential to create a radiation condition requiring actuation of the CREVS.

This revision to the TSs is conservative as it provides additional LCO actions and increased applicability to existing LCO actions. The actions and LCO times that have been proposed are consistent with standard TSs, NUREG-1431.

IV. NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION l TVA has concluded that operation of SQN Units 1 and 2, in accordance with the proposed change to the technical specifications, does not involve a significant hazards consideration. TVA's conclusion is based on its evaluation, in accordance with 10 CFR 50. 91(a) (1) , of i the three standards set forth in 10 CFR 50.92(c). i l

A. The proposed amendment does not involve a significant l

increase in the probability or consequences of an j accident previously evaluated.

The proposed revision does not change any plant functions or equipment operating practices for the  ;

radiation monitoring system and control room emergency ventilation system (CREVS). The radiation j monitoring instruments and the CREVS are not

considered to be the source of any accident evaluated in the Final Safety Analysis Report. These features provide accident mitigation functions that will be utilized in response to postulated accident conditions. The activities and failures that could contribute to the initiation of an accident are not affected by the implementation of this revision.

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g This revision provides for more stringent requirements for operation of the facility (additional limiting condition for operation [LCO]

actions and applicability requirements). Therefore the proposed activity will not increase the probability of an accident.

The proposed activity does not affect accident mitigation capabilities or the radiation release amounts for postulated accidents. This TS change will not affect requirements that the radiation monitoring system and CREVS be maintained to support accident mitigation. The functions and testing will remain the same while operability requirements will become more stringent. This TS change enhances the requirements associated with CREVS and the initiation of this system such that inoperabilities are appropriately handled to reduce the safety impact of component inoperabilities. Therefore, the proposed change will not 'ncrease the consequences of an accident and could reduce the consequences by limiting operation with inoperable components and requiring the application of appropriate actions for all conditions that could result in a postulated accident that CREVS was designed to mitigate.

B. The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed change provides more stringent operating j requirements for operation of the facility. The proposed activity will not change any plant function or operating practice that could impact accident initiators. Therefore, these'more stringent requirements do not result in operation that will increase the probability of any postulated accidents.

In addition, CREVS and the associated actuation features are not considered to be the source of an accident. Therefore, the proposed activity will not create the possibility of an accident of a different kind. J C. The proposed amendment does not involve a significant reduction in a margin of safety.

The proposed activity does not impact plant setpoints designed to maintain the assumptions in the safety analysis or limits for the actuation of systems to El-5

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h mitigate accidents. Plant functions and operating practices will not be altered by the implementation-of more stringent requirements for operation of the i - -

facility. .These requirements, by definition, provide additional restrictionsLto enhance plant safety.

Therefore, the proposed activity will not reduce the.  ;

margin of safety.

V. ENVIRONMENTAL IMPACT CONSIDERATION The-proposed-change does not involve a significant

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l i hazards' consideration, a significant change in the

' types of or significant increase in the amounts of any I effluents that'may be. released offsite, or a significant increase in individual cu: cumulative  ;

occupational radiation exposure. Therefore, the ,

proposed change meets the eligibility criteria for I categorical exclusion. set forth in 10 CFR 51.22 (c) (9) .

Therefore, pursuant to 10 CFR 51.22 (b), an environmental assessment of the proposed change is not

. required.

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