IR 05000445/2024301
| ML25014A202 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/15/2025 |
| From: | Heather Gepford NRC/RGN-IV/DORS/OB |
| To: | Peters K Vistra Operations Company |
| References | |
| 50-445/24-301, 50-446/24-301 50-445/OL-24, 50-446/OL-24 | |
| Download: ML25014A202 (12) | |
Text
January 15, 2025
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT, UNITS 1 AND 2 - NRC EXAMINATION REPORT 05000445/2024301 AND 05000446/2024301
Dear Mr. Peters:
On December 5, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an initial operator license examination at Comanche Peak Nuclear Power Plant, Units 1 and 2. The enclosed report documents the examination results and licensing decisions. The preliminary examination results were discussed on October 25, 2024, with Mr. S. Sewell, Site Vice President, and other members of your staff. A telephonic exit meeting was conducted on December 25, 2025, with Mr. B. Simpson, Director, Nuclear Training, who was provided the NRC licensing decisions.
The examination included the evaluation of six applicants for reactor operator licenses and eight applicants for instant senior reactor operator licenses. The license examiners determined that eleven of the fourteen applicants satisfied the requirements of 10 CFR Part 55, and the appropriate licenses have been issued. There were two post-examination comments submitted by your staff. Enclosure 1 contains details of this report and Enclosure 2 summarizes post-examination comment resolution.
No findings were identified during this examination. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Heather J. Gepford, Ph.D., Chief Operations Branch Division of Operating Reactor Safety Docket Nos. 50-445; 50-446 License Nos. NPF-87; NPF-89 Enclosures:
1.
Examination Report 05000445/2024301 and 05000446/2024301 2.
NRC Post-Examination Comment Resolution Electronic distribution via LISTSERV Signed by Gepford, Heather J.
on 01/15/25
ML25014A202 SUNSI Review:
ADAMS:
Non-Publicly Available Non-Sensitive Keyword:
By: JCK Yes No Publicly Available Sensitive NRR-079 OFFICE SOE:DORS:OB SOE:DORS:OB SOE:DORS:OB OE:DORS:OB SOE:DORS:OB C:DORS:OB NAME JKirkland KClayton NHernandez CHarrington DYou HGepford SIGNATURE
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DATE 01/14/25 01/15/25 01/14/25 01/14/25 01/14/25 01/15/25
Enclosure U.S. NUCLEAR REGULATORY COMMISSION Examination Report Docket Numbers:
05000445, 05000446 License Numbers:
NPF-87, NPF-89 Report Numbers:
05000445/2024301 and 05000446/2024301 Enterprise Identifier:
L-2024-OLL-0045 Licensee:
Vistra Operations Company, LLC Facility:
Comanche Peak Nuclear Power Plant, Units 1 and 2 Location:
Glen Rose, Texas Inspection Dates:
October 21, 2024, to December 5, 2024 Inspectors:
J. Kirkland, Senior Operations Engineer (Chief Examiner)
K. Clayton, Senior Operations Engineer N. Hernandez, Senior Operations Engineer C. Harrington, Operations Engineer D. You, Operations Engineer Approved By:
Heather J. Gepford, Ph.D., Chief Operations Branch Division of Operating Reactor Safety
SUMMARY Examination Report 05000445/2024301 and 05000446/2024301; October 21, 2024 -
December 5, 2024; Comanche Peak Nuclear Power Plant, Units 1 and 2; Initial Operator Licensing Examination Report The NRC examiners evaluated the competency of six applicants for reactor operator licenses and eight applicants for instant senior reactor operator licenses at Comanche Peak Nuclear Power Plant, Units 1 and 2.
The licensee developed the examinations using NUREG-1021, "Operator Licensing Examination Standards for Power Reactors," Revision 12. The written examination was administered by the licensee on October 31, 2024. The NRC examiners administered the operating tests on October 21 - 25, 2024.
The NRC examiners determined that eleven of the fourteen applicants satisfied the requirements of 10 CFR Part 55, and the appropriate licenses have been issued.
A.
NRC-Identified and Self-Revealing Findings None.
B.
Licensee-Identified Violations None.
REPORT DETAILS OTHER ACTIVITIES - INITIAL LICENSE EXAM
.1 License Applications a.
Scope The NRC examiners reviewed all license applications submitted to ensure each applicant satisfied relevant license eligibility requirements. The NRC examiners also audited three of the license applications in detail to confirm that they accurately reflected the subject applicants qualifications. This audit focused on the applicants experience and on-the-job training, including control manipulations that provided significant reactivity changes.
b.
Findings No findings were identified.
.2 Examination Development a.
Scope The NRC examiners reviewed integrated examination outlines and draft examinations submitted by the licensee against the requirements of NUREG-1021. The NRC examiners conducted an onsite validation of the operating tests.
b.
Findings The NRC examiners provided outline, draft examination and post-validation comments to the licensee. The licensee satisfactorily completed comment resolution prior to examination administration.
The NRC examiners determined the written examinations and operating tests initially submitted by the licensee were within the range of acceptability expected for a proposed examination.
.3 Operator Knowledge and Performance a.
Scope On October 31, 2024, the licensee proctored the administration of the written examinations to all applicants. The licensee staff graded the written examinations, analyzed the results, and presented their analysis and post-examination comments to the NRC on November 7, 2024.
The NRC examination team administered the various portions of the operating tests to all applicants from October 21 - 25, 2024.
b.
Findings No findings were identified.
Eleven applicants passed the written examination and all parts of the operating test.
Two reactor operator applicants did not pass the written examination, and one instant senior reactor operator applicant did not pass all parts of the operating test. The final examinations and post-examination analysis and comments may be accessed in the ADAMS system under the accession numbers noted in the attachment.
Post-examination analysis revealed three generic weaknesses associated with applicant performance on the written examination. The applicants displayed weaknesses associated with actions on a loss of ventilation chill water, technical specifications associated with an inoperable station service water valve, and procedure selection during a natural circulation cooldown. These weaknesses were captured in the licensees corrective action program as tracking report TR-2024-006816. Copies of all individual examination reports were sent to the facility training manager for evaluation and determination of appropriate remedial training.
.4 Simulation Facility Performance a.
Scope The NRC examiners observed simulator performance with regard to plant fidelity during examination validation and administration.
b.
Findings No findings were identified.
.5 Examination Security a.
Scope The NRC examiners reviewed examination security for examination development during both the onsite preparation week and examination administration week for compliance with 10 CFR 55.49 and NUREG-1021. Plans for simulator security and applicant control were reviewed and discussed with licensee personnel.
Findings No findings were identified.
EXIT MEETINGS AND DEBRIEFS Exit Meeting Summary The chief examiner presented the preliminary examination results to Mr. S. Sewell, Site Vice President, and other members of the staff on October 25, 2024. A telephonic exit was conducted on December 5, 2024, between J. Kirkland, Chief Examiner, and Mr. B. Simpson, Director, Nuclear Training.
The licensee did not identify any information or materials used during the examination as proprietary.
ADAMS DOCUMENTS REFERENCED Accession No. ML25013A024 - FINAL WRITTEN EXAMS Accession No. ML25013A023 - FINAL OPERATING TEST Accession No. ML25013A028 - POST-EXAMINATION ANALYSIS-COMMENTS
Enclosure 2 NRC Resolution to the Comanche Peak Nuclear Power Plant Post-Examination Comments A complete text of the licensee's post-examination analysis and comments can be found in ADAMS under Accession Number ML25013A028.
QUESTION # 50 COMMENT: The licensee recommended changing the correct answer for question #50 from D to C. This question involved the status of the charging system following ECCS termination. The applicant was asked after ECCS termination, how many charging pumps would be running (one or two) and discharging to the RCS through which valves (injection line isolation or charging line isolation).
The question begins at step 21 of ECA-1.1A, Loss of Emergency Coolant Recirculation, Check if ECCS can be terminated. Step 23 places all SI and RHR pumps in standby, and all but one charging pump. Step 24 closes the injection line isolation valves, and step 25 opens the charging line isolation valves.
The licensee is not recommending a change to Part 1 of the question, with the correct answer being one charging pump running, i.e., answer choices C and D. Part 2 was intended to ask for the final alignment of charging after ECCS was terminated, which would result in the correct response to Part 2 being through the charging line isolation valves, answer choice D.
In their post-exam comments, the licensee stated that ECCS termination refers to placing ECCS pumps in standby, thus Part 2 was technically asking where the CCP is discharging immediately upon placing the ECCS pumps in standby, i.e., after completion of step 23. As a result, they concluded that the one running charging pump would be discharging to the RCS through the injection line isolation valves, answer choice C.
The licensee concluded that question #50 was affected by information not considered during the original exam review and approval, and therefore the correct answer to the as-written question was C and not D.
NRC RESOLUTION: The NRC disagrees with the licensee's recommendation to change the correct answer from D to C for question #50. Answer choice D remains the only correct answer.
The evaluation of this question was complicated by the fact that additional information was provided to the applicants during administration of the written examination; however, that information was not received by all applicants. An applicant asked the question, What is meant by ECCS termination? Is it just terminating pumps or including realignment of charging. After consulting with the NRC, the licensee provided the following information to the class to drive the correct answer to be D: The question is asking about ECA-1.1A major action category. That firmly establishes answer choice D as the correct answer. Three individuals had already completed the exam when the additional information was provided.
Normally the NRC would not consider changes to an answer key based on applicants not receiving additional information provided to others; however, the licensees contention that the as-written question was flawed allows the NRC to consider answer key changes.
Prior to completing step 23, all available SI, RHR, and charging pumps are in injection phase.
After completing step 23, only one charging pump remains running, and it is still in injection phase. However, the NRC disagrees with the licensees statement that ECCS termination refers to placing the pumps in standby at step 23 because not all ECCS pumps are placed in standby.
According to training material LO21SYSSI1, Emergency Core Cooling, the Comanche Peak ECCS system consists of high head injection pumps (charging pumps), intermediate head injection pumps (SI pumps) and low head injection pumps (RHR pumps). Therefore, all three types of pumps are considered ECCS pumps.
Therefore, ECCS cannot be considered terminated until either all ECCS pumps are secured or the charging pump injection line isolation valves are closed at step 24.c. Furthermore, the RNO for step 21 (Check if ECCS can be terminated) is to go to step 26. That indicates that terminating ECCS is accomplished by performing steps 22 through 25, which includes closing the injection valves and opening the isolation valves.
The NRC also evaluated whether there were no correct answers to this question since initially after placing pumps in standby discharge flow from the one running charging pump is through the miniflow valves. However, the NRC concluded that the question is not asking for charging pump flow to the RCS when ECCS is terminated, but explicitly asks for the flow after ECCS is terminated and discharging to the RCS. Additionally, once the miniflow valves open, water does not discharge to the RCS until the charging line isolation valves are open.
In hindsight, the clarifying information provided to most of the class was unnecessary, as the question is correct as written.
Based on the above analysis, answer choice D remains the only correct answer.
QUESTION # 66 COMMENT: The licensee recommended removing question #66 from the exam due to an unclear stem. This question involved prioritizing alarms while performing actions of an abnormal operating procedure.
The question has the applicant responding to a plant transient with ABN-302, Feedwater, Condensate, Heater Drain System Malfunction. After a runback has completed and the immediate actions of ABN-302 are complete, two alarms are received: one associated with performance ABN-302 and one not associated. The question asks if Unit Supervisor permission is required to use the master silence button during the transient condition and which alarm should be prioritized.
The licensee is not recommending a change to Part 1, with the correct answer being Unit Supervisor permission is required, answer choices C and D. Part 2 was intended to test the statement in ODA-102, Conduct of Operations, alarm announcements not associated with the flow of ABN/ERG communications should be prioritized. When conditions permit, those alarms not previously announced but which are operationally significant should be addressed."
This would result in the correct response to part 2 being the alarm not associated with ABN-302, answer choice D.
The licensee stated that the information in the question stem does not allow the candidate to analyze or determine whether the alarm associated with ABN-302 requires entry into additional
ABNs / ERGs. If the alarm had required entry into an ABN / ERG, then this alarm would be the priority. The licensee also stated that there was additional confusion to part 2 of the question because ABN-302 also states, "a trip of a condensate pump at high power has a high probability of losing both Main Feed Water Pumps resulting in a Plant Trip."
The licensee thus believes that question #66 had an unclear stem that confused the applicants and resulted in not enough information to determine the correct answer.
NRC RESOLUTION: The NRC disagrees with the licensee's recommendation to remove question #66 from the exam. Answer choice D remains the only correct answer.
The NRC evaluated this question from two different perspectives. First, NUREG 1021, ES-4.4.C.3.c states, The NRC will consider examination changesif a question with an unclear stem that confused the applicants or did not provide all the necessary information (to assist in determining whether an unclear stem confused the applicants, closely evaluate any applicant questions asked during the examination; also evaluate the question stem to determine whether the information provided could reasonably result in the applicant misunderstanding the intent of the question or the validity of the answer choices).
[emphasis added]
No questions were asked during administration of the exam, and eight of fourteen applicants answered the question correctly as keyed.
The licensee stated that the information in the question stem did not allow the applicants to analyze or determine if the alarm associated with ABN-302 required entry into additional ABNs/ERGs. The NRC determined, in retrospect, the question was more likely a tier 1 (emergency and abnormal evolutions) question than the intended tier 3 (generic knowledge and abilities) question. The licensee also provided information as such, by indicating the question required specific knowledge of the AOP. NUREG 1021, ES-4.4.C.3.d, states the NRC will not accept examination changes when a question does not exactly match the K/A statement (which the NRC believes includes not matching the correct tier). As a result, the question cannot be deleted based on the tier mismatch.
The NRC further evaluated whether the question contained enough information to elicit a correct answer from a tier 1 standpoint. Specifically, the NRC evaluated ABN-302 to determine if an alarm associated with ABN-302 could require entry into additional ABNs / ERGs. The NRC found no indication that any other ABN / ERG entry would be required; the only plausible entry would be due to a loss of both main feed water pumps, and as discussed below, the stem of the question indicates that this was not feasible.
The NRC also evaluated the licensees statement that the stem was confusing because ABN-302 states, a trip of a condensate pump at high power has a high probability of losing both Main Feed Water Pumps resulting in a Plant Trip. The NRC noted that the stem of the question stated that the runback to 60% was complete, indicating that at that point, the feed water pumps had not tripped. As a result, the statement from the procedure regarding the potential to lose both main feedwater pumps would not have led to confusion of the applicants since the status of the feed water pumps could be determined based on the information in the stem.
The NRC closely evaluated the stem and concluded that it would reasonably result in the applicant fully understanding the intent of the question and the validity of the answer choices.
Additionally, when evaluating the question from both tier 1 and tier 3 perspectives, the NRC determined that answer choice D remains the only correct answer.