ML112590339

Draft Request for Additional Information, Amendment Request to Establish Ultimate Heat Sink LCOs in TS 2.16, River Level, and Add Surveillance Requirements to TS 3.2, Equipment and Sampling Tests

ML112590339
Person / Time
Site:	Fort Calhoun
Issue date:	09/16/2011
From:	Wilkins L E Plant Licensing Branch IV
To:	Hansher B R Omaha Public Power District
Wilkins, L E, NRR/DORL/LPL4, 415-1377
Shared Package
ML112590332	List: ML112590334 ML112590339
References
TAC ME5830
Download: ML112590339 (3)

Text

REQUEST FOR ADDITIONAL INFORMATION OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION, UNIT 1 DOCKET NO. 50-285 By letter dated March 4, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML110680093), Omaha Public Power District (OPPD, the licensee) requested an amendment to the Facility Operating License No. DPR-40 for Fort Calhoun Station, Unit 1. The proposed amendment would establish the limiting condition for operation (LCO) requirements for the ultimate heat sink (UHS) in Technical Specification (TS) 2.16, River Level, and adds two new surveillance requirements (SRs) for UHS level and temperature to TS 3.2, Equipment and Sampling Tests, Table 3-5, Minimum Frequencies for Equipment Tests. Specifically, this proposed change: revises the title of LCO 2.16 from "River Level" to "Ultimate Heat Sink (UHS);" provides more explicit applicability for the LCO 2.16; removes the existing LCOs for river level in TS 2.16, Items 1) and (2); and, reformats TS LCO 2.16 to provide required actions for an inoperable UHS. In addition, two new SRs, Items 25 and 26, will be added to TS 3.2, Table 3-5, to test the river level and temperature on a daily frequency; and for consistency, the columns will be reformatted to allow adding the column header to Table 3-5 for Items 17 through 24. The Table of Contents is also revised to reflect the title change of LCO 2.16. The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided in your application and determined that the following additional information is required in order to complete its review.

1. FCS is committed to the draft GDC, which are similar to Appendix A, "General Design Criteria for Nuclear Power Plants," in 10 CFR Part 50, and are contained in Appendix G, "Response to 70 Criteria," of the FCS Updated Safety Analysis Report (USAR). FCS Design Criterion 2, "Performance Standards," states, in part: Those systems and components of reactor facilities which are essential to the prevention of accidents which could affect public health and safety or to mitigation of their consequences shall be designed, fabricated, and erected to performance standards that will enable the facility to withstand, without loss of the capability to protect the public, the additional forces that might be imposed by natural phenomena such as earthquakes, tornadoes, flooding conditions, winds, ice and other local site effects.

Regulatory Guide 1.59, "Design Basis Floods for Nuclear Power Plants," requires, in part, that structures, systems and components (SSCs) importance to safety be designed to withstand the effects of natural phenomena such as floods without loss of capability to perform their safety functions.

Enclosure In its letter dated March 4, 2011, the licensee states:

The proposed amendment would establish the limiting condition for operation (LCO) requirements for the ultimate heat sink (UHS) in the Technical Specification (TS) 2.16, River Level, and adds two new surveillance requirements (SRs) for UHS level and temperature to TS 3.2-Please provide the reason and justification to remove the high end (Flood) of the Missouri River level from the TS 2.16, and the new location of these requirements.

2. In its letter dated March 4, 2011, the licensee stated that flooding at FCS is highly unlikely and therefore, requested to remove the provision in TS requiring a plant shut down if the Missouri River level reaches 1009 feet. The licensee states that a high river level TS does not meet the requirements of 10 CFR 50.63.

10 CFR 50.63(c)(2)(ii)(D) Criterion 4 states "a structure, system, or component which operating experience or probabilistic risk assessment has shown to be significant to public health and safety." In addition, 10 CFR 50.36(c)(2)(ii)(B) requires the licensee to establish a TS limiting condition for a operating restriction that is a initial condition of a design basis accident or transient analysis. Based upon recent operating experience, please describe flooding as a risk to the plant's ability to maintain safe shutdown capabilities.

In addition, please provide the latest data on river level peaking for the Missouri River at the FCS location and explain if the latest data on river level supports the current high level setpoint. Also, please describe how removing the high river level limit still provides assurance that the plant can safely shut down prior to losing equipment at the intake structure.

3. In the FCS Design Criterion 12, the licensee states instrumentation conforms to the applicable Institute of Electrical and Electronics Engineers (IEEE) standards. The licensee is proposing to add a new TS surveillance to limit the UHS temperature to 90°F. The licensee credits existing instrumentation to monitor river temperature. The licensee states that it will encompass the loop uncertainty for UHS temperature in the surveillance test. Also, the licensee proposes to add a TS surveillance to limit the UHS to a river level of 976 feet 9 inches. However, the licensee states its current river level instrumentation is not very accurate and intends on replacing the river level instrumentation with a more reliable system. The licensee also designates a TS surveillance limit for the river water maximum temperature and minimum level at the assumed limit used in the design basis calculations which shows sufficient heat removal in order to mitigate a design basis accident.

Please provide the methods used for monitoring river water temperature and level to comply with the current licensing basis. Also, please explain how OPPD plans to capture the uncertainty in the instrumentation used for monitoring river temperature and level. 4. In its letter dated March 4, 2011, the licensee states:

Missouri River level is currently monitored by non-safety related loop L-1900.

The measurement technology is based on a bubbler system where air pressure is directly proportional to the depth of the bubbler outlet. The accuracy of this loop is very poor with an As Found/As Left loop tolerance of +/- 2 feet as documented in calibration procedure IC-CP-01-1900. This loop is in the process of being replaced with loop L-2000 via engineering change EC 35741. This instrumentation is expected to be placed in service during 2011.

Please provide the test data (accuracy) and documentation (industry experience) to support the EC 35741.

5. In its letter dated March 4, 2011, the licensee proposed a TS SR for low level of 976 feet 9 inches of the UHS - Missouri River. The licensee states that a river level of 976 feet 9 inches is required for raw water pumps minimum submergence level.

10 CFR 50.36 requires the licensee establish limiting conditions for operation, and when they are not met, the licensee shall shut down the reactor. The licensee proposes a TS limit on low river level at the same level where the raw water pumps become unavailable for use; however, the raw water pumps are required to shut down the reactor. Please describe how this TS change will affect the availability of raw water pumps to bring the plant to cold shutdown conditions.

6. Please verify that no change is being made to any containment safety analysis or any parameter that could affect the containment safety analysis as part of this license amendment request. If this license amendment request is resulting in a change to any containment safety analysis or any parameter that could affect the containment safety analysis, please describe and justify these changes.

7. Please state if the calculation for the component cooling water heat exchanger's heat removal capability to supply 160 degree return water with 90 degree river water has been reviewed by the NRC staff.