ML20207G290
| ML20207G290 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/07/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20207G286 | List: |
| References | |
| NUDOCS 9906110090 | |
| Download: ML20207G290 (4) | |
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UNITED STATES g
j' NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30006 0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 207 TO E6CILITY OPERATING LICENSE NO. NPF-6 hblTERGY OPERATIONS. INC.
ABKANSAS NUCLEAR ONE. UNIT NO. 2 DOCKET NO. 50-368
1.0 INTRODUCTION
By letter dated April 9,1999 (2CAN049902), Entergy Operations, Inc. (the licensee), submitted a request for changes to the Arkansas Nuclear One, Unit No. 2 (ANO-2), Technical Specifications (TSs). The requested changes would modify the TSs to add Limiting Condition for Operation (LCO) 3.0.6 and its associated Bases. This change would allow equipment that has been removed from service or declared inoperable in compliance with the TS Action statement to be retumed to service under administrative controls solely to perform testing required to demonstrate its operability or the operability of other equipment. The proposed change is' consistent with TS 3.0.5 as discussed in NUREG-1432, Revision 1, " Standard Technical Specifications for Combustion Engineering Plants." TS 3.0.2 would also be modified to reflect that TS 3.0.6 is an exception to TS 3.0.2.
2.0 EVALUATION
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Technical Specification 3.0.2 states that upon discovery of a failure to meet an LCO (i.e.,
equipment is inoperable), the required Actions of the LCO shall be met. TS 3.0.6 provides an 1
exception for instances where restoration of the inop6rable equipment to an operable status could not be performed while continuing to comply with the required Actions for an LCO. Many I
LCO Actions require an inoperable component to be removed from service and an exception to
- these Actions is necessary to allow performance of surveillance requirements (SRs) to either demonstrate the operability of equipment being retumed to service or to demonstrate the operability of other equipment. The LCO for the proposed TS 3.0.6 reads as follows:
Equipment removed from service or declared inoperable to comply with ACTIONS may be retumed to service under adminstrative control solely to perform testing required to demonstrate its OPERABILITY or the OPERABILITY of other equipment. This is an exception to LCO 3.0.2 for the system returned to service under adminstrative control to perform the testing required to demonstrate OPERABILITY.
9906110090 990607 PDR ADOCK 05000368 P
1 2-LCO 3.0.6 establishes the allowance for restoring equipment to service under administrative controls when it has been removed from service or declared inoperable to comply with Actions.
f The sole purpose of this specification is to provide an exception to LCO 3.0.2 (e.g., to not comply with the applicable required Action (s)) to allow the performance of SRs to demonstrate:
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- a. The operability _of the equipment being returned to service; or
- b. The operability of other equipment.
The administrative controls ensure that the time the equipment is retumed to service in conflict i
with the requirements of the Actions is limited to the time absolutely necessary to perform the allowed SRs. This specification does not provide time to perform any other preventive or corrective maintenance.
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' An example of demonstrating the operabiliity of the equipment being retumed to service is reopening a containment isolation valve that has been closed to comply with required Actions and must be reopened to perform the SRs.
An example of demonstrating the operability of other equipment is taking an inoperable channel or trip system out of the tripped condition to prevent the trip function from occurring during the performance of an SR on another channelin the other trip system. A similar example of
' demonstrating the operability of other equipment is taking an inoperable channel or trip system out of the tripped condition to permit logic to function and indicate the appropriate response during the performance of an SR on another channel in the same trip system.
The licensee's April 9,1999 (2CAN049902), submittal included two site-specific examples I
associated with the proposed use of TS 3.0.6. The first such example discussed the operation of the reactor protective system (RPS) when demonstrating the operability of other equipment.
The ANO-2 excore nuclear instrumentation includes four safety channels. Each safety channel utilizes a fission chamber assembly made up of three detectors that are used to measure flux in the upper, middle, and lower regions of the core independently. Each detector feeds a linear amplifier that provides input to the RPS core protection calculator (CPC) trips for local power density (LPD)- high and departure from nucleate boiling ratio (DNBR)-low. Outputs of the three linear amplifiers (per channel) are also provided to a summer that averages the signals and provides input to the linear power level-high trip. The center detector also inputs to the log power circuitry that inputs to the logarithmic power-high trip. ANO-2 TS Table 3.3-1,
" Reactor Protective Instrumentation," requires that three of four channels of the linear power level-high, LPD - high, and DNBR - low, and CPC functions per operable in Modes 1 and 2, and that three of four channels of the logarithmic power level-high function be operable !n Mode 2 and in Modes 3,4, and 5 when the protective system trip breakers are closed, and the control element assembly (CEA) drive system is capable of CEA movement.
Technical Specification Table 3.3-1, Action 2 states,"With the number of channels OPERABLE one less than the Total Number of Channels, operation in the applicable MODES may continue provided the inoperable channel is place in the bypassed or tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, if
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the inoperable channel is bypassed for greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the desirability of maintaining this channel in the bypassed condition shall be reviewed at the next regularly scheduled PSC [ Plant Safety Committee] meeting in accordance with the QA [ Quality Assurance] Manual Operations.
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a l The channel shall be retumed to OPERABLE status prior to startup following the next COLD
- SHUTDOWN." The normal RPS trip configuration is such that 2-out-of-4 channels must actuate to initiate the protective function. Amendment No.159 to the ANO-2 license changed 3
the coincidence logic design requirement for the RPS to a 2-out-of-3 logic arrangement and approved the revision to TS Table 3.3-1, Action 2, which allowed for the indefinite bypass of one channel. In order to perform surveillance testing with a channel in indefinite bypass, the i
inoperable channel shall be placed in trip and the channel selected for testing shall be placed in bypass. This condition would result in a 1-out-of-2 coincidence logic for the RPS. The licensee proposed the use of TS 3.0.6 in this scenario to return the inoperable channel to service rather j
than placing the channel in trip. This would have the effect of changing the coincidence logic from 1-out-of 2 to a 2-out-of-2 arrangement. The licensee indicated that this action would be taken to reduce the likelihood of an inadvertent reactor trip. The NRC ctaff disagrees with the licensee's interpretation of this proposed application of TS 3.0.6. In this sc9nario, the purpose of retuming the inoperable channel to service is other than the demonstration of its operability.
Therefore, the channel may be returned to service rather than placed in the tripped condition only if failure to do so would result in a plant trip or prevent successful completion of the SR i
when testing the channelin bypass.
The second example provided by the licensee discussed the restoration of a service water (SW) pump to demonstrate its operabiiity. For this scenario, TS 3.7.3.1," Service Water System," provides the associated LCO, Actions, and SRs for this system and its components.
. TS 3.0.6 can be used to demonstrate the operability of the equipment being returned to service when failure to do so would result in the entry to TS 3.0.3.
The LCO for TS 3.0.6 is necessary to establish an allowance that is not formally recognized in
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the current TSs for ANO-2. Without this allowance, certain components could not be restored to Opetable status and a station shutdown would ensue. It is not the intent or desire that the TSs preclude the retum to service of a component to confirm its operability. This allowance is deemed to represent a more stable, safe manner for operation than requiring a station i
shutdown to complete the restoration and confirmatory testing of plant eati!pment. The time during which the equipment is returned to service is very small, therefore, the potential for an accident during that time period is also very small and can be considered to be insignificant. In addition, the staff has determined that the licensee's proposal is consistent with the guidance provided in NUREG-1432, Revision 1, " Standard Technical Specifications for Combustion Engineering Plants." Therefore, the proposed changes to TS 3.0.2, TS 3.0.6, and the associated Bases for TS 3.0.6 are acceptable.
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3.0 STATE CONSULTATION
j in accordance with the Commission's regulations, the Arkansas State official was notified cf ;he proposed issuance of the amendment. The State official had no comments.
l 4.0 f.MylRONMENTAL CONSIDERATION 1
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment invohres no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is
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'no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no
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significant hazards consideration, and the o has been no public comment on such finding (64 FR 24196, May 5,1999). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
l The Commission has concluded, based on the considerations discussed above, that (1) there is reasonable assurance tl.t. !Se 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 i
Commission's rsgulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the hesith and safety of the public.
Principal Contributor: Chris Nolan Date: June 7, 1999
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