ML14190B134
| ML14190B134 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 07/23/2014 |
| From: | Wang A Plant Licensing Branch IV |
| To: | Entergy Operations |
| Wang A | |
| References | |
| TAC MF3601 | |
| Download: ML14190B134 (4) | |
Text
Vice President, Operations Entergy Operations, Inc.
River Bend Station 5485 US Highway 61 N St. Francisville, LA 70775 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 23, 2014
SUBJECT:
RIVER BEND STATION, UNIT 1 --WITHDRAWAL OF REQUESTED LICENSING ACTION, LICENSE AMENDMENT REQUEST RE: ULTIMATE HEAT SINK DESIGN BASIS (TAC NO. MF3601)
Dear Sir or Madam:
By letter dated February 10, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14051A170), Entergy Operations, Inc. (Entergy, the licensee),
submitted a license amendment request (LAR) for the River Bend Station, Unit 1 (RBS). The proposed LAR would revise the RBS Updated Final Safety Analysis Report (UFSAR) to credit makeup to the ultimate heat sink (UHS) in less than 30 days to account for system leakage and for operation with more than one division of standby service water (SSW) in operation. Bye-mail dated May 29, 2014 (ADAMS Accession No. ML14149A484), the U.S. Nuclear Regulatory Commission (NRC) issued a Non-Accept with the Opportunity to Supplement letter to Entergy.
By letter dated May 29, 2014 (ADAMS Accession No. ML14157A037), the licensee supplemented the LAR. The purpose of this letter is to provide the results of the NRC staff's acceptance review of this amendment request. The acceptance review was performed to determine if there is sufficient technical information in scope and depth to allow the NRC staff to complete its detailed technical review. The acceptance review is also intended to identify whether the application has any readily apparent information insufficiencies in its characterization of the regulatory requirements or the licensing basis of the plant.
Consistent with Section 50.90 of Title 10 of the Code of Federal Regulations (1 0 CFR), an amendment to the license (including the Technical Specifications) must fully describe the changes requested, and following as far as applicable, the form prescribed for original applications. Section 50.34 of 10 CFR addresses the content of technical information required.
This section stipulates that the submittal address the design and operating ~haracteristics, unusual or novel design features, and principal safety considerations.
By letter dated July 7, 2014, Entergy requested to withdraw the application from NRC review.
The NRC staff acknowledges your request to withdraw the application. NRC staff activities on the review have ceased and the associated Technical Assignment Control number has been closed.
The NRC staff notes that its review to date has identified that your application did not provide the technical information in sufficient detail to enable the NRC staff to complete its detailed review. RBS's licensing basis for UHS capacity is that it shall have a 30-day inventory to mitigate a design basis event. In 2002, the licensee revised its licensing basis under the auspices of 10 CFR 50.59 with a UFSAR change such that the RBS could make up for leakage in its UHS/SSW systems using its normal non-safety makeup system and three alternative non-safety methods. During a 2011 Component Design Basis Inspection, the NRC issued a non-cited violation of 10 CFR 50.59 for changing the UHS licensing basis requirements to credit makeup in less than 30 days without prior NRC staff review and approval.
In the February 10, 2014, LAR, Entergy requested that the NRC staff approve a revision to the current licensing basis to not meet the 30-day inventory requirement: (1) if the cause is system leakage and/or (2) if operating both divisions of emergency core cooling system (ECCS) and SSW when mitigating a design basis accident. The licensee justified these additions by claiming that leakage losses are beyond the design basis for UHS inventory and that loss ofone
- division, caused by a single failure of an emergency diesel generator, is the design basis accident scenario for computing design basis inventory requirements for the UHS. However, the licensee's submittal did not specify how much leakage would be allowed nor did it identify where the leakage occurs. In the May 29, 2014, supplement to the LAR, the licensee stated that the leakage occurs across the normal service water (NSW)/SSW isolation valves. Entergy also noted that there is an administrative leakage limit for these isolation valves of 15 gallons per minute (gpm) per valve. The NRC staff notes that assuming this leakage rate (30 gpm for both valves), without makeup, would reduce the UHS inventory by over 20 percent during the 30..,day accident mitigation period.
The NRC staff has concluded that the licensee did not provide sufficient information to support its position that UHS/SSW leakage is beyond the design basis. In its letter dated May 29, 2014, the licensee cited NUREG-0800, "Standard Review Plan [SRP] for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition," Section 9.2.1, "Station Service Water System," as part of the basis for its position that leakage is not a criteria for design of the UHS.
However, SRP Section 9.2.1 also states that the SWS shall have the capability to isolate components, subsystems, or piping if required so that the system safety function will not be compromised. As such, the NRC staff believes that the licensee's position appears contrary to the guidance in SRP Section 9.2.1. Therefore, if Entergy decides to re-submit the request, it must include the following information:
- 1)
Provide the basis for why accounting for leakage, which compromises a safety function, is not part of RBS's design basis for UHS inventory.
- 2)
If leakage is determined to be part of the licensing basis, specify a leakage limit from the SSW to NSW.
- 3)
Provide the basis for why the operation of one division of ECCS and SSW is the bounding single failure when determining UHS inventory requirements.
- 4)
From the submittals provided, the NRC staff could not verify that the alternative sources of makeup water to the UHS provide acceptable methods to replenish the UHS. Provide more detail on the three alternate sources of makeup water with regards to capacity, implementation, and design.
If you have any questions, please contact the RBS Project Manager, Alan Wang at Alan.Wang@nrc.gov or (301) 415-1445.
Docket No. 50-458 cc: Distribution via Listserv Sincerely,
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Alan B. Wang, ProJect Manager Plant Licensing IV-2 and Decommissioning Transition Branch Division of Operating Reactor Licensing
. Office of Nuclear Reactor Regulation
ML14190B134 OFFICE NRRIDORULPL4-2/PM NAME ABWang DATE 07/15/14 OFFICE NRR/DORULPL4-2/BC NAME DBroaddus DATE 07/23/14 Sincerely,
/RAJ
. Alan B. Wang, Project Manager Plant Licensing IV-2 and Decommissioning Transition Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation NRRIDORULPL4-2/LA NRR/DSS/SBPB/BC JBurkhardt GCasto (GPurciarello for) 07/10/14 07/11/14 NRR/DORULPL4-2/PM ABWang 07/23/14