ML14258B089
| ML14258B089 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 09/18/2014 |
| From: | Lyon C Plant Licensing Branch IV |
| To: | |
| Lyon C | |
| References | |
| TAC MF4777 | |
| Download: ML14258B089 (5) | |
Text
PUBLIC NOTICE NRC STAFF PROPOSES TO AMEND OPERATING LICENSE AT THE WOLF CREEK GENERATING STATION The U.S. Nuclear Regulatory Commission (NRC) staff has received an application dated September 10, 2014, from Wolf Creek Nuclear Operating Corporation, for an exigent amendment to the operating license for the Wolf Creek Generating Station, located in Coffey County, Kansas.
The proposed amendment would revise Technical Specification (TS) 3.4.15, RCS
[reactor coolant system] Leakage Detection Instrumentation. Specifically, the amendment would add a Note to the 30-day Completion Time of Required Action A.2 to extend the Completion Time to allow the continued operation for Cycle 19 with the instrument tunnel sump level indication inoperable until a plant shutdown or restart from Refueling Outage 20 (spring 2015).
In accordance with Title 10 of the Code of Federal Regulations, Part 50, section 50.91(a)(6)(vi), the licensee provided in its application an explanation of the exigent circumstances:
On August 31, 2014 at 2317 CDT [central daylight time] the instrument tunnel sump level transmitter was declared inoperable when the transmitter failed high and was found in the failsafe mode. After troubleshooting the transmitter, the fault was cleared and returned to normal mode. The transmitter failed high an additional four times between September 1, 2014 and September 3, 2014. After the last failure on September 3, 2014, the transmitter was no longer able to be reset. With the instrument tunnel sump level transmitter declared inoperable on September 1, 2014 at 1816 CDT, Condition A of LCO [limiting condition for operation] 3.4.15 was entered with Required Action A.2 requiring restoration of the containment sump level and flow monitoring system to OPERABLE status in 30 days.
Completion of troubleshooting on the level transmitter on September 3, 2014, determined that a complete failure of the level transmitter had occurred and that replacement of the level transmitter is required to restore the containment sump level and flow monitoring system to OPERABLE status. As the instrument tunnel sump level transmitter is in close proximity to the bottom of the reactor vessel, replacement of the
level transmitter at power cannot be performed due to radiological conditions in this area that prohibit access by plant personnel. Required Action A.2 of LCO 3.4.15 requires restoring the containment sump level and flow monitoring system to OPERABLE status in 30 days (October 1, 2014 at 1816 hours0.021 days <br />0.504 hours <br />0.003 weeks <br />6.90988e-4 months <br />). Condition E of LCO 3.4.15 requires the plant to be in MODE 3 in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in MODE 5 in 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> if the containment sump level and flow monitoring system is not restored to OPERABLE status on October 1, 2014 at 1816 hours0.021 days <br />0.504 hours <br />0.003 weeks <br />6.90988e-4 months <br />.
The licensee and the NRC staff have evaluated this proposed change with regard to the determination of whether or not a significant hazards consideration is involved. Operation of Wolf Creek Generating Station, in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed change does not make any hardware changes and does not alter the configuration of any plant system, structure, or component (SSC). The proposed change allows the continued operation for Cycle 20 with the instrument tunnel sump level transmitter inoperable until a startup from a plant shutdown or startup from Refueling Outage 20. The containment normal sump level indication remains functional and the monitoring of the frequency of operation of the containment instrument tunnel sump pumps would provide indication of RCS leakage. Although not required by TS, additional diverse means of leakage detection capability are available as described in the Updated Safety Analysis Report (USAR) Section 5.2.5. The TS will continue to require diverse means of leakage detection equipment, thus ensuring that leakage due to cracks would continue to be identified prior to propagating to the point of a pipe break and the plant shutdown accordingly. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed amendments will not create the possibility of a new or different kind of accident from any previously analyzed. With respect to any new or different kind of accident, there are no proposed design changes nor or there any changes in the method by which any safety related plant SSC performs its specified safety function. The proposed change will not
affect the normal method of plant operation or change any operating parameters. No new accident scenarios, transient precursors, failure mechanisms, or limiting single failures will be introduced as a result of this amendment. The proposed change will not alter the design or performance of the 7300 Process Protection System, Nuclear Instrumentation System, Solid State Protection System, Balance of Plant Engineered Safety Features Actuation System, Main Steam and Feedwater Isolation System, or Load Shedder and Emergency Load Sequencers used in the plant protection systems. The change does not have a detrimental impact on the manner in which plant equipment operates or responds to an actuation signal. The proposed change allows the continued operation for Cycle 20 with the instrument tunnel sump level transmitter inoperable until startup from a plant shutdown or startup from Refueling Outage 20.
The containment normal sump level indication remains functional and the monitoring of the frequency of operation of the containment instrument tunnel sump pumps would provide indication of RCS leakage. Although not required by TS, additional diverse means of leakage detection capability are available as described in USAR Section 5.2.5. The TS will continue to require diverse means of leakage detection equipment, thus ensuring that leakage due to cracks would continue to be identified prior to propagating to the point of a pipe break and the plant shutdown accordingly. Therefore, the proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed amendment will not involve a significant reduction in a margin of safety.
There will be no effect on those plant systems necessary to assure the accomplishment of protection functions associated with reactor operation or the Reactor Coolant System. There will be no impact on the overpower limit, departure from nucleate boiling ratio (DNBR) limits, heat flux hot channel factor, nuclear enthalpy rise hot channel factor, loss of coolant accident peak cladding temperature, peak local power density, or any other limit and associated margin
of safety. Required shutdown margins in the CORE OPERATING LIMITS REPORT will not be changed. The proposed change allows the continued operation for Cycle 20 with the instrument tunnel sump level transmitter inoperable until startup from a plant shutdown or startup from Refueling Outage 20. The containment normal sump level indication remains functional and the monitoring of the frequency of operation of the containment instrument tunnel sump pumps would provide indication of RCS leakage. Although not required by TS, additional diverse means of leakage detection capability are available as described in USAR Section 5.2.5. The TS will continue to require diverse means of leakage detection equipment, thus ensuring that leakage due to cracks would continue to be identified prior to propagating to the point of a pipe break and the plant shutdown accordingly. Therefore, the proposed change does not involve a significant reduction in margin of safety.
Following an initial review of this application, the requested amendments have been evaluated against the standards in 10 CFR 50.92 and the NRC staff has made a proposed (preliminary) determination that the requested amendments involve no significant hazards considerations. The changes do not significantly increase the probability or consequences of any accident previously considered, nor create the possibility of an accident of a different kind, nor significantly decrease any margin of safety.
If the proposed determination that the requested license amendment involves no significant hazards consideration becomes final, the staff will issue the amendments without first offering an opportunity for a public hearing. An opportunity for a hearing will be published in the Federal Register at a later date and any hearing request will not delay the effective date of the amendment.
If the staff decides in its final determination that the amendment does involve a significant hazards consideration, a notice of opportunity for a prior hearing will be published in the Federal Register and, if a hearing is granted, it will be held before the amendment is issued.
Comments on the proposed determination of no significant hazards consideration may be (1) telephoned to Eric R. Oesterle, Acting Chief, Plant Licensing Branch IV-1, by collect call to 301-415-1014, or by facsimile to 301-414-1222, (2) e-mailed to Eric.Oesterle@nrc.gov, or (3) submitted in writing to the Chief, Rules, Announcements and Directives Branch, Division of Administrative Services, Office of Administration, Mail Stop: 3WFN-06-A44MP, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. All comments received by close of business on September 26, 2014, from 7:30 a.m. to 4:15 p.m. Federal workdays will be considered in reaching a final determination. A copy of the application may be examined electronically through the NRCs Agencywide Documents Access and Management System (ADAMS) in the NRC Library at http://www.nrc.gov/reading-rm/adams.html at ADAMS Accession No. ML14254A129 and at the Commission's Public Document Room (PDR), located at One White Flint North, Public File Area O1 F21, 11555 Rockville Pike (first floor), Rockville, Maryland. Persons who do not have access to ADAMS or who encounter problems in accessing the documents located in ADAMS should contact the NRC PDR Reference staff by telephone at 1-800-397-4209, or 301-415-4737, or by e-mail to pdr.resource@nrc.gov.