L-2008-022, Proposed License Amendment Request for Additional Information Response Alternative Source Team Amendment - TAC MD6173
| ML080530389 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/14/2008 |
| From: | Johnston G Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-2008-022, TAC MD6173 | |
| Download: ML080530389 (6) | |
Text
Florida Power & Light Company, 6501 S. Ocean Drive, Jensen Beach, FL 34957 February 14, 2008 F=PL L-2008-022 10 CFR 50.90 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE:
St. Lucie Units I and 2 Docket Nos. 50-335 and 50-389 Proposed License Amendment Request for Additional Information Response Alternative Source Term Amendment - TAC No. MD6173 On July 16, 2007, Florida Power and Light Company (FPL) submitted the St. Lucie Unit 1 and 2 Alternative Source Term (AST) license amendment requests via FPL letters L-2007-085 and L-2007-087. As a result of the submittals, the NRC requested additional information. This correspondence provides the FPL response to the NRC Request for Additional Information (RAI) received by letter dated January 29, 2008.
The no significant hazard analyses submitted with FPL letters L-2007-085 and L-2007-087 remain bounding. In accordance with 10 CFR 50.91(b)(1), a copy of the proposed amendment was forwarded to the State Designee for the State of Florida.
Please contact Ken Frehafer at 772-467-7748 if there are any questions about this submittal.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on the I "
day of-2008.
Very truly yours, Jhtdo Jh on64
- ,/
Site Vice President St. Lucie Plant GLJ/KWF Attachment cc: Mr. William A. Passetti, Florida Department of Health Ao4/
an FPL Group company
St. Lucie Units 1 & 2 L-2008-022 Docket Nos. 50-335 and 50-389 Attachment Proposed License Amendment Page 1 of 5 Request for Additional Information Response Alternative Source Term Amendment - TAC No. MD6173 The license amendment request (LAR) proposes to amend Facility Operating License DPR-67 for St. Lucie Unit 1 to revise the licensing bases toadopt the Alternative Source Term as allowed by Title 10 of the Code of Federal Regulations (10 CFR), Section 50.67. To support Nuclear Regulatory Commission (NRC) assessment of the acceptability of the LAR in regard to the proposed changes, please provide the response to the following items:
NRC Question 1:
Please provide the proposed setpoint that will be used for automatic initiation of the redundant control room isolation valves on outside air intake high radiation signal. Also provide the technical specification sheet where this setpoint is proposed to be included.
FPL Response to Question 1:
Page 3 of Attachment 2 of FPL letter L-2007-085, St, Lucie Unit 1 Proposed License Amendment, Alternative Source Term and Conforming Amendment, provided the marked-up Technical Specification (TS) page (page 3/4 3-22; Table 3.3-6) where the setpoint is proposed to be included. The proposed isolation setpoint corresponds to the "alarm setpoint" shown on TS page 3/4 3-22. As shown on the mark-up, the proposed setpoint was "< 2x background".
During the January 14, 2008 teleconference with the NRC, the NRC voiced a concern that the proposed setpoint is not a fixed value but is variable based on the background value.
During the teleconference, FPL agreed to revise the proposed setpoint to a fixed value. The actual setpoint value will be determined as discussed in the response to question L.a below, and will be provided to the NRC under separate cover.
In addition, the original proposed setpoint of< 2x background was selected to be consistent with the setpoint of the Unit 2 control room outside air intake radiation monitors. FPL also proposes to revise the Unit 2 setpoint to be consistent with that proposed for Unit 1. The Technical Specification mark-ups for the proposed changes will be provided under separate cover.
NRC Questions ].a, 1.b, 1.c, and 1.d:
Please respond to the following items with regard to the proposed setpoint:
NRC Question 1.a:
Setpoint Calculation Methodology: Provide documentation (including setpoint calculation) of the methodology used for establishing the limiting setpoint (or nominal set point) and the limiting acceptable values for the As-Found and As-Left setpoints as measured in the periodic surveillance testing as described below. Indicate the related Analytical Limits and other limiting design values (and sources of these values)for each setpoint.
St. Lucie Units 1 & 2, L-2008-022 Docket Nos. 50-335 and 50-389 Attachment Proposed License Amendment Page 2 of 5 Request for Additional Information Response Alternative Source Term Amendment - TAC No. MD6173 FPL Response to Question 1.a:
The Unit 1 control room outside air intake radiation monitors are Beta scintillation detectors. The current setpoint for these detectors is < 320 cpm. This existing setpoint value is based on the expected radiation monitor response to a Kr-85 concentration of 2 x 10-6 tCi/cc. This current setpoint is known to be conservative since it does not consider the monitor count rate contribution from isotopes other than Kr-85, and since the design basis activity level is conservative with respect to the limiting case accident.
FPL intends to reconstitute the design basis for the setpoint of the control room outside air intake radiation monitors. This setpoint reconstitution effort will be performed as follows:
" The event that results in the lowest activity concentration at the controlroom air intake will be identified.
" For this event, gaseous radioisotopes and their corresponding concentrations will be tabulated.
" A detector count rate will be determined for each contributory isotope based on the detector sensitivity as a function of radioactive decay energy. A total count rate will also be determined.
" A new setpoint will be determined which provides acceptable margin to ensure the setpoint is adequate to accommodate worst case channel uncertainties.
As documented on page 9 of Enclosure 1 of FPL letter L-2007-085, dated July 16, 2007, the AST dose analyses assume that the isolation valves on the control room outside air intake and exhaust ducts close automatically upon receipt of a containment isolation actuation signal or a high radiation signal. For dose analyses purposes, the isolation time is conservatively assumed to be 50 seconds. The isolation time, including damper closure time, is equal to a maximum of 35 seconds, assuming offsite power is available. The damper closure time of 35 seconds is verified by performance of periodic damper stroke time testing. If offsite power is not available, the isolation time is 45 seconds, which includes the 10-second diesel generator start time. Note that the dampers are on the 0-second emergency diesel generator (EDG) load block.
NRC Question 1.b:
Safety Limit (SL)-Related Determination: Provide a statement as to whether or not the setpoint is a limiting safety system setting (LSSS) for a variable on which a SL has been placed as discussed in 10 CFR 50.36(c) (1) (ii) (A). Such setpoints are described as "SL-Related" in the discussions that follow. In accordance with 10 CFR 50.36(c)(1)(ii)(A), fhe following guidance is provided for identifying a list offunctions to be included in the subset of LSSS specified for variables on which SLs have been placed as defined in Standard Technical Specification (TS) Sections 2.1.1, Reactor Core SLs and 2.1.2, Reactor Coolant System Pressure SLs. This subset includes automatic protective devices in TSfor specified variables on which SLs have been placed that: (1) initiate a reactor trip; or (2) actuate safety systems. As such, these variables provide protection against violating reactor core safety limits, or reactor coolant system pressure boundary safety limits. Examples of
St. Lucie Units 1 & 2 L-2008-022 Docket Nos. 50-335 and 50-389 Attachment Proposed License Amendment Page 3 of 5 Request for Additional Information Response Alternative Source Term Amendment - TAC No. MND6173 instrument functions that might have LSSS included in this subset in accordance with plant-specific licensing-basis, are pressurizer pressure reactor trip (pressurized-water reactors),
rod block monitor withdrawal blocks (boiling-water reactors), feedwater and main turbine high water level trip (boiling-water reactors), and end of cycle recirculation pump trip (boiling-water reactors). For each setpoint, or related group of setpoints, that you determined not to be SL-Related, explain the basis for this determination.
FPL Response to Question 1.b:
The control room outside air intake radiation monitor setpoint is not a limiting safety system setting for a variable on which a safety limit has been placed. The setpoint is not related to initiating a reactor trip nor does it actuate a safety system that provides protection against violating reactor core safety limits or reactor coolant system pressure boundary safety limits. As such, the control room outside air intake radiation monitor setpoint does not meet the criteria for a LSSS as discussed in 10 CFR 50.36(d)(1)(ii)(A).
NRC Question 1.c:
For Setpoint that is determined to be SL-Related: The NRC letter to the Nuclear Energy Institute SMTF dated September 7, 2005 (ADAMS Accession. Number ML052500004),
describes Setpoint-Related TS (SRTS) that are acceptable to the NRC for instrument settings associated with SL-Related setpoints. Specifically: Part "A " of the Enclosure to the letter provides LCO [limiting condition for operations] notes to be added to the TS, and Part "B" includes a check list of the information to be provided in the TS Bases related to the proposed TS changes.
(i). Describe whether and how you plan to implement the SRTS suggested in the September 7, 2005, letter. If you do not plan to adopt the suggested SRTS, then explain how you will ensure compliance with 10 CFR 50.36 by addressing items (ii) and (iii), below.
(ii). As-Found Setpoint Evaluation: Describe how surveillance test results and associated TS limits are used to establish operability of the safety system. Show that this evaluation is consistent with the assumptions and results of the setpoint calculation methodology. Discuss the plant corrective action processes (including plant procedures) for restoring channels to operable status when channels are determined to be "inoperable" or "operable but degraded " If the criteria for determining operability of the instrument being tested are located in a document other than the TS (e.g., plant test procedure), explain how the requirements of 10.
CFR 50.36 are met.
(iii). As-Left Setpoint Control: Describe the controls employed to ensure that the instrument setpoint is, upon completion of surveillance testing, consistent with the assumptions of the associated analyses. If the controls are located in a document other than the TS (e.g., plant test procedure) explain how the requirements of 10 CFR 50.36 are met.
St. Lucie Units 1 & 2 L-2008-022 Docket Nos. 50-335 and 50-389 Attachment Proposed License Amendment Page 4 of 5 Request for Additional Information Response Alternative Source Term Amendment - TAC No. MD6173 FPL Response to Question 1.c:
As discussed in the response to 1.b above, the control room outside air intake radiation monitor setpoint has been determined to not be SL-Related.
NRC Question I.d.
For Setpoint that is not determined to be SL-Related: Describe the measures to be taken to ensure that the associated instrument channel'is capable ofperforming its specified safety functions in accordance with applicable design requirements and associated analyses.
Include in your discussion information on the controls you employ to ensure that the As-Left trip setting after completion ofperiodic surveillance is consistent with your setpoint methodology. Also, discuss the plant corrective action processes (including plant procedures)for restoring channels to operable status when channels are determined to be "inoperable" or "operable but degraded. " If the controls are located in a document other than the TS (e.g., plant test procedure), describe how it is ensured that the controls will be implemented.
FPL Response to Question 1.d:
The proposed license amendment adds Surveillance Requirements (SRs) for the control
.room outside air intake radiation monitors to Unit 1 Technical Specification Table 4.3-3.
The proposed SRs are shown on page 5 of Attachment 2 to L-2007-085, dated July 16, 2007. The proposed SRs include a shiftly channel check, a monthly channel functional test, and a channel calibration every refueling.
Periodic calibration and functional testing of the control room outside air intake radiation monitors is currently performed by existing plant procedures. The functional testing includes verification that the control room ventilation system goes into the recirculation mode of operation given a simulated high radiation signal. Existing plant procedures will be revised, as necessary, to ensure that the proposed SRs are performed as required, including the applicable surveillance frequencies.
An allowable setpoint tolerance range will be established as part of the setpoint reconstitution effort described in the response to question L.a above. This allowable setpoint tolerance range will be included in the applicable radiation monitor surveillance procedures. As-Left trip settings are required (by definition) to be within the allowable setpoint tolerance.
Performance of the SRs will ensure that the control room outside air intake radiation monitors are capable of performing their specified functions consistent with the assumptions of the AST analyses.
The proposed license amendment adds a Technical Specification (TS) Limiting Condition for Operation (LCO) for the control room outside air intake radiation monitors by adding
St. Lucie Units 1 & 2 L-2008-022 Docket Nos. 50-335 and 50-389 Attachment Proposed License Amendment Page 5 of 5 Request for Additional Information Response Alternative Source Term Amendment - TAC No. MD6173 them to the list of radiation monitors applicable to LCO 3.3.3.1 in TS Table 3.3-6. In addition, the proposed license amendment adds action statement 17 to TS Table 3.3-6.
If an As-Left setpoint value can not be adjusted to within the allowable setpoint tolerance, equipment operability will be evaluated in accordance with the plant's corrective action program (CAP). Per plant procedures, any TS equipment found to be inoperable shall be declared out-of-service and entered into the Equipment Out-of-Service log. The equipment shall not be declared back in service until appropriate testing has been performed and documented, assuring the operability of the monitors.
Should the number of Operable channels be less than that required by the proposed LCO, proposed action statement 17 will apply. Entry into TS action statements is tracked via the plant's Action Tracking database. Equipment return to service is controlled in accordance with the plant's Conduct of Operations. The Shift Manager shall authorize the return of Technical Specification, safety related, and risk significant equipment or systems to operable status provided, among others, the component or system is capable of performing its design function, and required surveillance testing is satisfactorily completed.
Equipment that is determined to be "inoperable" or "operable but degraded" is entered into, and controlled by, the plant's CAP. Per the CAP, the condition will be evaluated and appropriate corrective actions will be taken.
NRC Question 2: of the submittal provides the changes to the Bases section of the technical specifications. However, the Bases section has not been updated to include the bases for the addition of the new control room automatic isolation feature and the associated automatic actuation and manual times. The licensee is requested to update the Bases section to include the bases for the changes associated with the automatically actuated, redundant isolation valves.
FPL Response to Question 2:
FPL will update the TS Bases to reflect the closure time bases, commensurate with the level of detail in the current TS Bases.