ML13094A216
| ML13094A216 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/12/2013 |
| From: | Boska J Plant Licensing Branch II |
| To: | Gillespie P Duke Energy Carolinas |
| Boska, J P NRR/DORL/LPL2-1 301-415-2901 | |
| References | |
| TAC ME9877, TAC ME9878, TAC ME9879 | |
| Download: ML13094A216 (8) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 12, 2013 Mr. Preston Gillespie Site Vice President Oconee Nuclear Station Duke Energy Carolinas, LLC 7800 Rochester Highway Seneca, SC 29672-0752
SUBJECT:
OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3, REQUEST FOR ADDITIONAL INFORMATION REGARDING AMENDMENT APPLICATION FOR USE OF A REVERSE OSMOSIS PURIFICATION SYSTEM (TAC NOS. ME9877, ME9878, AND ME9879)
Dear Mr. Gillespie:
On October 30,2012, as supplemented on January 21,2013, Duke Energy Carolinas, LLC (Duke), submitted an application for a proposed amendment for the Oconee Nuclear Station, Units 1, 2, and 3, which would allow the use of a reverse osmosis system to purify the borated water storage tanks and the spent fuel pools during power operation.
The Nuclear Regulatory Commission staff is reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). On April 5, 2013, the Duke staff indicated that a response to the RAI would be provided within 60 days of the date of this letter.
If you have any questions, please call me at 301-415-2901.
Sincerely, hn P. Boska, Senior Project Manager lant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION REGARDING USE OF A REVERSE OSMOSIS SYSTEM DUKE ENERGY CAROLINAS, LLC OCONEE NUCLEAR STATION, UNITS 1,2, AND 3 DOCKET NOS. 50-269, 50-270 AND 50-287 Duke Energy Carolinas, LLC (Duke or the licensee) originally submitted a license amendment request (LAR) dated November 15, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML103220101) requesting approval to operate a reverse osmosis (RO) purification system at Oconee Nuclear Station (ONS), Units 1, 2, and 3, to purify the borated water storage tanks and the spent fuel pools during power operation. Duke then submitted responses to the NRC's request for additional information (RAI) on the following dates:
February 18,2011 (ADAMS Accession No. ML110550616), May 12, 2011 (ADAMS Accession No. ML11137A112), August 2,2011 (ADAMS Accession No. ML11215A198), October 10, 2011 (ADAMS Accession No. IVIL11285A302), and December 15, 2011 (ADAMS Accession No. ML11354A253). Based on discussions between Duke and the NRC, by letter dated April 3, 2012, Duke requested to withdraw this LAR, and the NRC staff agreed by letter dated April 12, 2012. In a letter dated October 30,2012 (ADAMS Accession No. ML12307A219), as supplemented on January 21,2013 (ADAMS Accession No. ML13025A254), Duke submitted a revised LAR for the use of the RO system. The Nuclear Regulatory Commission (NRC) staff is reviewing the submittals and has the following questions.
The Health Physics and Human Performance Branch performed a review of the human performance associated changes in the LAR and has the following questions:
RAI-1
In section 4.1, the submittal states, "Duke Energy evaluated the effect of potential failures, identified precautionary measures that must be taken before and during RO System operation, and identified specific required operator actions to protect affected structures, systems, and components important to safety." These operator actions are not identified in the submittal.
Please provide the specific required operator actions.
RAI-2
The LAR does not indicate whether the proposed technical specification (TS) changes will present any new or increased opportunities for operator error. Please provide information as to whether the new changes might present increased opportunities for operator error and if there are administrative controls in place to prevent or mitigate such errors.
RAI-3
In the previous LAR submittal, the NRC asked in an RAI regarding how the 33 minutes required for the credited manual action were calculated and what kind of task analysis was used to run scenarios. Duke responded on August 2, 2011, however, that response is inadequate. Please describe what kind of task analysis was used, and how many scenarios were run, for this manual action.
Enclosure
- 2
RAI-4
- a. The LAR submittal states that an operator will be available to manually close the boundary valve if a loss-of-coolant accident (LOCA) were to occur with the purification system in operation. It is unclear whether this operator could be assigned additional tasks that may distract them, or where the operator will be located in the plant while the purification system is in operation. Please describe the location, role, and other duties of the operator. The NRC staff is concerned that with the lack of automatic isolation valves, the duties of this operator should be closely tied to the task of closing the isolation valves.
- b.
Please describe the qualifications of the operator which will ensure that he/she is able to perform the manual action.
- c.
During a LOCA, will there be other operators available to mitigate the LOCA conditions and also allow for an operator to perform this manual action? Please describe how Duke plans to address this.
RAI-5
Section 4.0 of Attachment 1 contains very little information regarding Human Performance review activities. Please answer the following:
- a. What operator actions have been added, deleted or changed as a result of this LAR submittal?
- b. In several locations, the submittal states that operating experience was used to support this LAR. Please provide that relevant operating experience information.
- c. Have there been changes to training? Please provide any information regarding changes to training or qualifications as a result of this LAR.
- d. Please describe any changes to physical interfaces, such as monitoring instruments for radioactivity, boron concentration, etc.
- e. Will there be any changes required to the normal, abnormal and emergency operating procedures? If so, please provide a list of those changes.
- f.
Is a new function allocation needed as a result of this change? If so, please provide any relevant information regarding this analysiS.
- g. Describe the on-site validation of the manual action with the revised procedures, and trained dedicated operators.
- h. Please describe the long term human performance monitoring program, if any, which will protect the modification from inadvertent change.
RAI-6
Demonstrate that the plant shielding design is sufficient to allow the vital operator actions being credited (to isolate the purification system and thereby prevent unanalyzed configurations of radioactive water from the containment sump during LOCA recirculation) can be performed within
- 3 the dose criterion of general design criteria 19 as prescribed in NUREG 0737 TMI Action Item II.B.2.
The Accident Dose Branch has the following questions:
RAI-7
The LAR states that the RO system supply piping will be connected to the spent fuel pool purification system using two safety-related seismic boundary valves and a flow limiting orifice. In lieu of automatically actuated isolation valves, the LAR proposes to use a time-critical operator action {TCOA} to ensure the RO system supply piping boundary valves are closed before initiation of containment sump recirculation after a LOCA to prevent potentially highly radioactive water from entering the RO system, which is an unanalyzed configuration. Proposed TS 3.7.19 includes a note that states that the RO system may be unisolated intermittently under administrative control. The proposed TS Bases state that:
The opening of a closed valve in the RO System flow path on an intermittent basis under administrative control includes the following: (1) stationing an operator, who is in constant communication with control room, at the valve controls, (2) instructing this operator to close these valves in an accident situation, and (3) assuring that environmental conditions will not preclude access to close the valves and that this action will prevent the release of radioactivity outside the RO System.
The actions stated in the TS Bases are consistent with the NRC staff's position in Generic Letter 91-08 regarding acceptable administrative controls for intermittent opening of normally closed containment isolation valves. However, the response to NRC Issue 4 in the letter dated January 21,2013, states that a dedicated operator will not be used to ensure the RO system boundary valves are closed, because the action will be driven by the Emergency Operating Procedures (EOPs). Resolve the discrepancy between the administrative controls proposed in the TS Basis and the response dated January 21, 2013. Include the basis for how the proposed administrative controls are adequate to ensure the RO system boundary valves are closed if a design basis accident were to occur.
RA18:
Proposed TS 3.7.19 states that the RO system may be un isolated intermittently under administrative control. The proposed TS Bases state that a TCOA will be used to ensure the system is isolated so that the plant stays within the bounds of its design basis LOCA analysis.
However, the proposed TS and its Bases do not include any limitations on the duration for which the boundary valves may be open {how long is intermittent} or the time limit for the TCOA. Define the duration the RO system will be unisolated under administrative control and provide the basis for this duration. Revise the TS Bases to include limitations on the duration for which the RO system may be unisolated and to include the time limit for the TCOA.
- 4 RA19:
The LAR states that the RO system return piping is isolated from the BWST using a single safety related check valve. The licensee's NRC-approved design basis Alternate Source Term (AST) analysis for a LOCA (ADAMS Accession No. ML041540097), assumes 5 gallons per minute (gpm) back leakage of sump water into the borated water storage tank (BWST) during recirculation. It is unclear to the NRC staff whether failure of or leakage past the safety-related check valve on the return piping could create an unanalyzed release path for BWST water. Describe the impact of failure of or leakage past the check valve on the emergency core cooling system (ECCS) leakage considered in the licensing basis accident analysis and the resulting consequences.
The Mechanical and Civil Engineering Branch has the following questions:
RA110:
Please verify whether responses to NRC staff's RAI 1 and RAI 2, as stated in the licensee's letter dated February 18, 2011, are applicable to the new LAR provided in the licensee's letter dated October 30, 2012. If not, please revise and submit any changes.
RA111:
In the licensee's letter dated February 18, 2011, the response to RAI 1 indicated that RO piping going through the Hot Machine Shop was not completed. Consequently, the NRC staff audited ONS calculation No. OSC-10167, Revision 2, written for that section of RO piping, and found it acceptable. Please verify whether OSC-10167, Revision 2 is still applicable and valid for the new LAR provided in the licensee's letter dated October 30, 2012. If this calculation has been revised, please provide the level of revision and discuss revised changes.
RA112:
For the interaction of non-seismic structures, systems, and components (SSCs) with SSCs designed for seismic conditions, please provide the following:
- a.
Describe the method and criteria used which ensure that non-seismic piping connecting to seismic piping will not adversely affect the structural integrity of the seismic piping (Le.
overlap analysis requirements).
- b.
Describe the method and criteria used in the piping analysis for connecting proposed newly added piping to existing piping (Le. overlap and/or decoupling requirements).
- c.
For the interaction of newly proposed SSCs to existing SSCs and vice versa, discuss how the licensee ensures that excessive movement, collapse or failure of non-seismic SSCs will not adversely affect the structural integrity of seismically qualified SSCs (Le., seismic two-over-one criteria).
- 5 The Component Performance and Testing Branch has the following questions:
RA113:
The following valves are addressed by proposed TS 3.7.19, (RO system Isolation from BWST:
Units 1 and 2:
SF-181 and SF-196, RO System BWST supply manual isolation valves.
SF-57, BWST Recirculation Pump suction valve.
Unit 3 3SF-181 and 3SF-196, RO System BWST supply manual isolation valves.
3SF-57, BWST Recirculation Pump suction valve.
- a.
The submittals indicate that these valves will be included in the Oconee Inservice Testing Program, and will therefore be tested in accordance with the applicable requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code). Will all of these valves be categorized as manual, active, and Category A valves?
- b.
If these valves will all be categorized the same, is there a reason that the proposed surveillance requirement (SR) 3.7.19.2 and SR 3.7.19.3 for the RO System BWST supply manual isolation valves and the BWST recirculation pump suction valves, respectively, are written differently?
- c.
If these valves are not all categorized the same, please provide an explanation of why not?
The Technical Specifications Branch has the following questions:
RA114:
Logical connector AND between REQUIRED ACTIONS A.1 and A.2 for CONDITION A, "RO system not isolated," in proposed LCO 3.9.8, "Reverse Osmosis (RO) System Operating Restrictions for Spent Fuel Pool (SFP)," is shown between the text of the ACTIONS statements.
Since both of these ACTIONS must be completed when in CONDITION A, logical connector AND needs to be shifted to the left between ACTIONS A.1 and A.2 as shown in example 1.2-1 in Oconee's TSs.
RA115:
The licensee's proposed SR 3.7.19.1 verifies the RO System seismic boundary valve that is not locked, sealed, or otherwise secured, is closed, except when the valve is open during RO System operation. The licensee's proposed SR 3.9.8.1 requires verification that the RO System is isolated by breaking the siphon from the SFP.
Regarding the Frequency for SR 3.7.19.1, the licensee states:
The Frequency is in accordance with the Surveillance Frequency Control Program (SFCP). The initial 31 day Frequency specified in the Surveillance Frequency List (SFL)
- 6 will be 31 days. This periodic frequency is based on engineering judgment and was chosen to provide added assurance of the correct valve position.
Regarding the Frequency for SR 3.9.8.1, the licensee states:
SR 3.9.8.1 requires verification that the RO System is isolated by breaking the siphon from the SFP with a Frequency in accordance with the Surveillance Frequency Control Program. The initial Frequency specified in the SFL will be 7 days. This periodic frequency is considered reasonable since the siphon can only be re-established by deliberate actions and RO operation will be controlled by unit procedures and are acceptable, based on operating experience.
The licensee's TS Section 5.5.21, "Surveillance Frequency Control Program [SFCP]," specifies controls for Surveillance Frequencies. It further states, "The program shall ensure that Surveillance Requirements specified in the TSs are performed at intervals sufficient to assure the associated Limiting Conditions for Operation are met."
Please provide details on the engineering judgment which determined that the Surveillance Frequencies for the seismic boundary valve and verification of RO system isolation should be 31 days and 7 days, respectively, and provide justification consistent with the level of information required to establish the SFCP for placing the seismic boundary valve Frequency in the SFCP.
April 12, 2013 Mr. Preston Gillespie Site Vice President Oconee Nuclear Station Duke Energy Carolinas, LLC 7800 Rochester Highway Seneca, SC 29672-0752
SUBJECT:
OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3, REQUEST FOR ADDITIONAL INFORMATION REGARDING AMENDMENT APPLICATION FOR USE OF A REVERSE OSMOSIS PURIFICATION SYSTEM (TAC NOS. ME9877, ME9878, AND ME9879)
Dear Mr. Gillespie:
On October 30,2012, as supplemented on January 21,2013, Duke Energy Carolinas, LLC (Duke), submitted an application for a proposed amendment for the Oconee Nuclear Station, Units 1, 2, and 3, which would allow the use of a reverse osmosis system to purify the borated water storage tanks and the spent fuel pools during power operation.
The Nuclear Regulatory Commission staff is reviewing the submittal and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). On April 5, 2013, the Duke staff indicated that a response to the RAI would be provided within 60 days of the date of this letter.
If you have any questions, please call me at 301-415-2901.
Sincerely, IRA!
John P. Boska, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:
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