ML17174B226
| ML17174B226 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 06/28/2017 |
| From: | April Pulvirenti Plant Licensing Branch IV |
| To: | Entergy Operations |
| Pulvirenti A | |
| References | |
| CAC MF9700 | |
| Download: ML17174B226 (5) | |
Text
LICENSEE:
FACILITY:
SUBJECT:
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 28, 2017 Entergy Operations, Inc.
Waterlord Steam Electric Station, Unit 3
SUMMARY
OF JUNE 1, 2017, PUBLIC MEETING WITH ENTERGY OPERATIONS, INC,, REGARDING PLANNED LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION (TS) TABLE 3.7-3 AND TS 3/4.7.4, "ULTIMATE HEAT SINK" FOR WATERFORD STEAM ELECTRIC STATION, UNIT 3 (CAC NO. MF9700)
On June 1, 2017, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRG) and representatives of Entergy Operation, Inc. (Entergy, the licensee). The meeting notice and agenda, dated May 15, 2017, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML17151A314. For the meeting, the licensee provided a slide presentation, which is available at ADAMS Accession No. ML17151A295. A list of attendees is enclosed.
The ultimate heat sink (UHS) at Waterlord Steam Electric Station, Unit 3 (Waterlord 3) is provided, in part, by dry cooling towers (DCTs). Each OCT contains vertical cooling coils filled with hot component cooling water, which is cooled by outside ambient air provided by three two-speed fans. Entergy is planning to install a modification to the DCTs in order to capture additional cooling efficiency of these DCTs. The purpose of the June 1, 2017, pre-submittal meeting was for the licensee to discuss with NRG staff a planned license amendment request (LAR) to credit the additional cooling efficiency provided by the modification to the DCTs.
Specifically, the proposed LAR would revise Technical Specification (TS) Table 3.7-3, "Ultimate Heat Sink Minimum Fan Requirements Per Train Dry Cooling Tower," and TS 3/4.7.4, "Ultimate Heat Sink" (UHS).
During the public meeting, the licensee discussed a heat recirculation effect in the DCTs, which had been observed during startup testing conducted in 1982, before the initial operation of the plant. The recirculation effect decreases the ability of the DCTs to dissipate heat, and represents an adverse condition compared to the plant's design basis. The licensee discussed the general design of a planned recirculation barrier, which consists of a rooflike structure partially covering both Train A and Train B of the OCT wells. The licensee then presented the preliminary results of an ANSYS computational fluid dynamics (CFO) calculation model demonstrating that this barrier will decrease the recirculation effect, thereby increasing the cooling efficiency of the DCTs.
The LAR, which is planned to be submitted by the licensee in August 2017, will credit this increased efficiency to revise TS Table 3.7-3 and TS 3/4.7.4, which describe the requirements for the UHS. At the meeting, the licensee presented preliminary TS markups for TS Table 3.7-3 and TS 3/4.7.4. The revised Surveillance Requirement (SR) 4.7.4 would require additional monitoring of the dry bulb temperature, and would require a certain number of OCT tube bundles and fans be operable when a tornado watch is in effect. The revised TS Table 3.7-3 would decrease the required minimum number operable fans per train as a function of ambient dry bulb temperature. In addition, the proposed revised TS Table 3.7-3 would add a new chart describing the required minimum number of OCT fans to be operable if backflow preventers for the fans were operable.
The licensee stated that the proposed LAA would include include an analysis of the effects of the revised TS on calculation ECM95-008, "Ultimate Heat Sink Design Basis." The analysis would focus on the effect of the revised TS during normal operations, normal shutdown, normal refueling, and during design-basis events as required by Regulatory Guide (RG) 1.27, "Ultimate Heat Sink for Nuclear Power Plants" (ADAMS Accession No. ML14107A411 ). The analysis would use site-observed bounding meteorlogical parameters.
During and after the presentation, the NRC staff and licensee discussed specific features of the presentation and the proposed LAA. The NRC staff expressed the following concerns regarding the proposed LAA, and requested that the following information be included with the amendment application:
The UHS thermohydraulic model must contain an analysis of containment heat loads under normal conditions and under accident conditions. In addition, the model should analyze the worst heat load on component cooling water during design-basis events and compare the maximum component cooling water heat exchange outlet temperature to the maximum allowed temperature.
Include information about the effect of the proposed amendment on the emergency diesel generators (EDGs), and include the temperature at which the EDGs will be qualified.
Because the CFO calculations will be performed using limited data points observed during initial plant startup testing conducted in the 1980s, the results of the calculation will be driven by the ANSYS CFO model. Therefore, provide information about the ANSYS code, including a description of the mesh size for the DCTs, and the sensitivity of the mesh size. Describe the verification and validation and benchmarking of the CFO code.
The proposed markup of TS Limiting Condition for Operation (LCO) 3.7.4 references a 3-day average temperature forecast. Per AG 1.27, typical minimum water inventory requirements for a wet cooling tower (WCT) are based on looking at the meteorlogical conditions over the past 30 years and determining the worst consecutive 30-day period (for water inventory loss) at any time during that 30-year period, and using those meteorlogical conditions for the minimum water inventory calculation. The application should discuss the basis for the 3-day average temperature.
The proposed markup of TS LCO 3.7.4c references a 7-day average ambient dry-bulb temperature. The application should explain why this timeframe was chosen.
The proposed markup of SR 4.7.4 states that "Each train of UHS shall be determined OPERABLE:... In accordance with the Surveillance Frequency Control Program."
Include the initial surveillance frequency for SR 4.7.4c and the current surveillance frequencies for SR 4.7.4a and SR 4.7.4b as stated in the current surveillance frequency control program.
The proposed markup of TS Table 3.7-3 contains conditional statements for the number of OCT fans/VI/CT fans which must be operable (e.g., "14/;?: 5 or 15/ 2::4"). The proposed markup for TS Table 3.7-3 does not explain the meaning of the "or in the table. This information should be included in the table where it is readily available and subject to NRG review.
The proposed Table 3.7-3 contains fan requirements based on ambient temperature intervals of 1 degree Fahrenheit. Because the required minimum number of fans is sensitive to such narrow temperature ranges, the application should include the instrument tolerance of the thermometers used to measure ambient temperature, including uncertainties.
The proposed markup of TS Table 3.7-3 contains a subtable titled 'With OCT Backflow Preventers." This is a table of OCT fan requirements, which will be used if OCT backflow preventers are operable. The licensee presentation for the meeting contained no description of these backflow preventers, and during the meeting the licensee stated that the design of the backflow preventers had not yet been finalized. If this portion of TS Table 3.7-3 is approved as part of the LAA, then the licensee will be permitted to employ the backflow preventers without further NRC review. Therefore, the planned LAA should contain sufficient information about the backflow preventers for review by NRC staff to determine whether there is reasonable assurance that the number of fans specified in the subtable titled, "with OCT backflow preventers," will provide sufficient UHS capacity.
The licensee proposes to submit the application for this license amendment on August 4, 2017.
No regulatory decisions were reached at this meeting. No member of the public called in to listen or provide comments to the NRC staff after the business portion of the meeting and, thus, no Public Meeting Feedback forms were received.
Please direct any inquiries to me at 301-415-1390 or via e-mail at April.Pulvirent1@nrc.gov.
Docket No. 50-382
Enclosure:
List of Attendees cc w/enclosure: Distribution via Listserv April L. Pulvirenti, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
LIST OF ATTENDEES JUNE 1, 2017, PUBLIC MEETING WITH ENTERGY OPERATIONS, INC.
REGARDING REVISION OF TECHNICAL SPECIFICATION TABLE ITS) 3.7-3 AND TS 3/4.7.4 "ULTIMATE HEAT SINK" FOR WATERFORD STEAM ELECTRIC STATION UNIT 3 Entergy Operations, Inc John Jarrell, Regulatory Assurance Manager Jason McGowan, Project Manager Alex Tejeiro, Design Engineer Dale Gallodoro, Entergy Contract Support William Steelman, Entergy Contract Support Gregory Zysk, LPI
- Maria Zamber
- John Cooper
- Leia Milster U.S. Nuclear Regulatory Commission Robert Pascarelli, Branch Chief, Operating Reactor Licensing Eric Oesterle, Branch Chief, Reactor Systems Jennifer Whitman, Branch Chief (Acting), Technical Specifications April Pulvirenti, Project Manager Matthew Hamm, Reactor Systems Engineer, Technical Specifications
- Tarico Sweat, Reactor Systems Engineer, Technical Specifications Gerard Purciarello, Senior Reactor Systems Engineer, Balance of Plant Ahsan Sallman, Senior Reactor Systems Engineer, Reactor Systems Public None
- by phone Enclosure
ML17174B226 OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA NAME APulvirenti PBlechman DATE 06/23/17 06/27/17 RidsNrrDssSbpb Resource RidsNrrDssSrxb Resource RidsNrrDssStsb Resource GPurciarello, NRR ASallman, NRR TSweat, NRR MHamm, NRR NRR/DORL/LPL4/BC NRR/DORL/LPL4/PM RPascarelli APulvirenti 06/27/17 06/28/17