IR 05000298/2025301

NRC Examination Report 05000298/2025301

ML25316A173
Person / Time
Site:	Cooper
Issue date:	11/13/2025
From:	Patricia Vossmar NRC/RGN-IV/DORS/OB
To:	Dia K Nebraska Public Power District (NPPD)
References
50-298/25-301 50-298/OL-25
Download: ML25316A173 (1)

Text

November 13, 2025

SUBJECT:

COOPER NUCLEAR STATION - NRC EXAMINATION REPORT 05000298/2025301

Dear Mr. Dia:

On September 11, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an initial operator license examination at Cooper Nuclear Station. The enclosed report documents the examination results and licensing decisions. The preliminary examination results were discussed on September 11, 2025, with Mr. B. Chapin, General Manager, Plant Operations, and other members of your staff. A telephonic exit meeting was conducted on October 31, 2025, with Mr. A. Vaughn, Superintendent, Simulator & Training Support, who was provided the NRC licensing decisions.

The examination included the evaluation of four applicants for reactor operator licenses, two applicants for instant senior reactor operator licenses and one applicant for an upgrade senior reactor operator license. The license examiners determined that six of the seven 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, Patricia J. Vossmar, Chief Operations Branch Division of Operating Reactor Safety Docket No. 05000298 License No. DPR-46 Enclosures:

1.

Examination Report 05000298/2025301 2.

NRC Post-Examination Comment Resolution

Electronic distribution via LISTSERV Signed by Vossmar, Patricia on 11/13/25

ML25316A173 SUNSI Review:

ADAMS:

Non-Publicly Available Non-Sensitive Keyword:

By: KDC1 Yes No Publicly Available Sensitive NRR-079 OFFICE OB:SOE OB:OE OB:OE C:OB NAME KClayton KMurphy PBreidenbach PVossmar SIGNATURE

/RA/

/RA/

/RA/

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DATE 11/13/25 11/13/25 11/13/25 11/13/25

Enclosure 1 U.S. NUCLEAR REGULATORY COMMISSION Examination Report Docket Number:

05000298 License Number:

DPR-46 Report Number:

05000298/2025301 Enterprise Identifier:

L-2025-OLL-0036 Licensee:

Nebraska Public Power District Facility:

Cooper Nuclear Station Location:

Brownville, Nebraska Inspection Dates:

August 4, 2025, to September 11, 2025 Examiners:

K. Clayton, Senior Operations Engineer (Chief Examiner)

K. Murphy, Operations Engineer P. Breidenbach, Operations Engineer Approved By:

Patricia Vossmar, Chief Operations Branch Division of Operating Reactor Safety

Enclosure 1 SUMMARY Examination Report 05000298/2025301; August 4 - September 11, 2025; Cooper Nuclear Station; Initial Operator Licensing Examination Report The NRC examiners evaluated the competency of four applicants for reactor operator licenses, two applicants for instant senior reactor operator licenses, and one applicant for an upgrade senior reactor operator license at Cooper Nuclear Station.

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 September 16, 2025. The NRC examiners administered the operating tests on September 8 - 11, 2025.

The NRC examiners determined that six 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.

Enclosure 1 REPORT DETAILS OTHER ACTIVITIES - INITIAL LICENSE EXAMINATION

.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 developed the written outline. The license developed the operating test outlines, operating tests, and written examinations using the requirements of NUREG-1021, Revision 12. The NRC examiners conducted onsite validation of the operating tests the week of August 4, 2025.

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.

.3 Operator Knowledge and Performance a.

Scope On September 16, 2025, 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 to the NRC on October 7, 2025.

The NRC examination team administered the various portions of the operating tests to all applicants on September 8 - 11, 2025.

b.

Findings No findings were identified.

Six of seven applicants passed the written examination, and all applicants passed all parts of the operating tests. The final written examinations and post-examination

Enclosure 1 analysis may be accessed in the ADAMS system under the accession numbers noted in the attachment. There were no post-examination comments as indicated in the licensee submittal.

The examination team noted two generic weaknesses associated with applicant performance on the operating tests (scenarios). The weaknesses were associated with failure and subsequent bypass of local power range monitors and shifting to manual (MDEM) mode on the reactor feed pump controllers. These deficiencies were captured in the licensees corrective action program as Condition Reports CR-CNS-2025-04405 and CR-CNS-2025-04406. Post-examination analysis revealed five generic weaknesses associated with applicant performance on the written examination. The weaknesses were associated with tripping the main turbine outside of the control room; assessing temperatures during a partial loss of reactor equipment cooling; concerns with loss of shutdown cooling and thermal stratification; instrument failure effects on reactor vessel level controls; and indications of an uncoupled control rod in the control rod drive system. These deficiencies were captured in the licensees corrective action program as Condition Report CR-CNS-2025-04404. 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 examination security and applicant control were reviewed and discussed with licensee personnel.

b. Findings No findings were identified.

EXIT MEETINGS AND DEBRIEFS Exit Meeting Summary The chief examiner presented the preliminary examination results to Mr. B. Chapin, General Manager, Plant Operations, and other members of the staff on September 11, 2025. A

Enclosure 1 telephonic exit was conducted on October 31, 2025, between K. Clayton, chief examiner, and Mr. A. Vaughn, Superintendent, Simulator & Training Support. The licensee did not identify any information or materials used during the examination as proprietary.

ADAMS DOCUMENTS REFERENCED Accession No. ML25316A007 - FINAL WRITTEN EXAMS Accession No. ML25316A019 - FINAL OPERATING TEST Accession No. ML25316A023 - POST-EXAMINATION ANALYSIS

Enclosure 2 NRC Resolution to Cooper Nuclear Station Post-Examination Comments A complete text of the licensee's post-examination analysis and comments can be found in ADAMS under Accession Number ML25316A023.

Questions 85 and 97 have post examination comments with requested changes and appear below in numerical order. It is noted that one of the two applicants below asked a question during exam administration for Question 85. He asked the proctor Can you read the question to me? There were no questions asked during administration on Question 97. During the post-grade review with the class, one of the two applicants below made a comment for Question 97.

He commented to the proctor Procedure directs consider having IPTE brief done by coordinator. I picked the Shift Manager because one is always present.

SRO QUESTION # 85 The plant was operating at 100% power when an unisolable main steam line rupture occurred in the steam tunnel causing the following alarms:

S-1/A-1 REACTOR BLDG A SUMP HI-HI LEVEL

S-1/A-2 REACTOR BLDG B SUMP HI-HI LEVEL

S-1/A-3 REACTOR BLDG C SUMP HI-HI LEVEL

S-1/A-4 REACTOR BLDG D SUMP HI-HI LEVEL

S-1/B-4 TORUS AREA HIGH LEVEL (1) Per the PSTGs, at what minimum level will the Torus area water level cause a buoyancy effect of the Torus with Torus level at 12 feet 7 inches?

AND The safe shutdown HPCI equipment will be inoperable when level meets the Maximum Safe Operating level in ____(2)_____.

A.

(1) 4.5 feet (2) HPCI room B.

(1) 4.5 feet (2) Southwest Quad RHR room C.

(1) 9.5 feet (2) HPCI room D.

(1) 9.5 feet (2) Southwest Quad RHR room Answer:

D

Enclosure 2 Answer Explanation-A -

Is wrong. Part 1 is correct. Part 2 is plausible because the applicant could believe that the High Pressure Core Injection (HPCI) equipment safe shutdown is in the HPCI room not within a specific quad. It is wrong because the HPCI room drains flow to the RHR room and it is measured in the RHR room (SW Quad in table 11).

B -

Is Correct. Per Plant Specific Technical Guidelines (PSTGs) Page B.I-8-56 Secondary Containment water levels and water areas were determined assuming:

• Any standing water on elevations above 859 El. does not submerge equipment located on the upper elevations but rather flows to the Reactor Building basement or floor drain sumps.

• The flow capacity of the HPCI room drains permit sensing an abnormal southwest quadrant sump level before any HPCI equipment necessary for safe shutdown becomes inoperable.

• The Maximum Safe Operating value for the torus area is that water level (4.5 feet) which causes a buoyancy effect on the torus with suppression pool water level at the minimum LCO.

Table 11 from EOP-5A C-Is wrong. Part 1 is plausible because the quad levels are associated with 9.5 feet and the applicant could choose this choice. It is wrong because the question is asking about the torus area. Part 2 is plausible for the reasons stated in Choice A.

D -

Is wrong. Part 1 is plausible for the reasons stated in Choice C. Part 2 is correct.

LICENSEE COMMENTS: The facility licensee and one applicant recommend that the answer key for Question #85 be changed to accept two correct answers. The answer key identified Answer B as the correct answer. They contend that Answer A is also a correct answer.

Enclosure 2 Part 2 of this question requires the applicant to determine the operability of the HPCI system due to high water level. Operability determinations are Senior Reactor Operator (SRO) tasks and require the analysis of various inputs. Parameters supporting operability and values defined in the Plant Specific Technical Guidelines (PSTG) do not necessarily meet the same requirements nor have the same desired outcome. Operability determinations may require information that is not readily obtained from installed instrumentation and requires an assessment from an SRO on equipment impact. Since the question asks about the operability of HPCI, the necessary information could be obtained from the HPCI Room via camera or Operator report. Alternatively, the information could be inferred from installed level instrumentation in the Southwest Quad RHR room (SW Quad), since the HPCI Room and SW Quad are connected by floor drains and a piping penetration. Both choices given to the applicant are plausible; therefore, Question #85 should be changed to accept Answers A and B.

NRC RESOLUTION: The NRC disagrees with the licensees recommendation and will maintain the key with only B as the correct answer to this question.

Question 85 was constructed in a two-by-two question format. In the approved key, the following is the question justification for distractor A being an incorrect answer:

Distractor A: Is wrong. Part 1 is correct. Part 2 is plausible because the examinee could believe that the HPCI equipment safe shutdown is in the HPCI room and not within a specific quad. It is wrong because the HPCI room drains flow to the RHR room, and it is measured in the RHR room (SW Quad).

The licensees contention is part 1 of distracter A and answer B are the same (A1 and B1),

therefore their challenge is to accept answers A2 and B2 as both correct. With the focus on part two of the question, the licensees focus is on the operability of HPCI with a high-water level condition. The following is part two of question 85:

The safe shutdown HPCI equipment will be inoperable when level meets the Maximum Safe Operating level in ____(2)_____.

The NRC will maintain the key with only B as the correct answer based on the following points:

Distractor A2 specifies HPCI Room. The HPCI Room does not have a Maximum Safe Operating level specified in Table 11 SECONDARY CONTAINMENT WATER LEVELS. The five different areas specified in Table 11 include NW Quad (Sump A), NE Quad (Sump B), SW Quad (Sump C), SE Quad (Sump D),

and Torus Area. The HPCI room design, including the walls and floor drains, does not have a Maximum Safe Operating level. The HPCI room is designed so that any water from a design basis event (steam rupture in this case) will drain to the area in the SW quad of the RHR room where it has installed instrumentation to measure operating levels of water within both the SW Quad and the HPCI room. This is why there is no Maximum Safe Operating Level for HPCI defined in Table 11 of the emergency procedures. Since the HPCI room/area is NOT one of those areas, this makes distractor A2 incorrect.

• The NRC reviewed flooding and design documents related to these two areas (HPCI and SW Quad) as well as the PSTGs for the emergency operating procedures and found nothing to support this challenge to the question. As water is coming up in the SW Quad, it appears here well before any water collects in

Enclosure 2 the HPCI room (by design as mentioned above) and therefore HPCI operability based on flooding concerns from a design basis steam break is bounded per the design basis documents by the Maximum Safe Operating Level for the SW Quad as listed above in Table 11.

• The applicant and licensees focus on HPCI operability in the post exam comments is misplaced because the question is asking for the Maximum Safe Operating level in a particular area, which is a defined emergency procedure term. The question was not an operability evaluation.

Because this part of the question is not asking for inoperability of HPCI based on anything other than the Maximum Safe Operating Level in the SW Quad, the NRC disagrees with the licensees recommendation that distracter A is a second correct answer for question 85. The key will be maintained with only B as the correct answer.

Enclosure 2 SRO QUESTION # 97 Per 0-CNS-OP-116, INFREQUENTLY PERFORMED TESTS OR EVOLUTIONS, Attachment 2, IPTE Screening Checklist, An IPTE brief is required for a test which at a minimum would require that it would be performed less frequently than a _____(1)____.

AND The ____(2)_____ is responsible for CONDUCTING the IPTE Pre-Job Brief for the test for activities requiring multi-discipline involvement.

A.

(1) quarter (2) Test Coordinator B.

(1) quarter (2) Shift Manager C.

(1) month (2) Test Coordinator D.

(1) month (2) Shift Manager Answer:

A Answer Explanation-A -

Is Correct. Per Procedure 0-CNS-OP-116, Definitions, Step 2.2.3, an IPTE is a non-surveillance procedure (or surveillance) performed less frequently than a quarter. Also, per that procedure, Attachment 3, Step 7, Test Coordinator leads briefs for multi-discipline involvement, not the Shift Manager.

B -

Is wrong. Part 1 is correct. Part 2 is plausible because the Shift Manager is available 24/7 and could plausibly fill that role. It is wrong because 0-CNS-OP-116 states that the Test Coordinator leads the IPTE brief.

C -

Is wrong. Part 1 is plausible because a month is a reasonable length of time to cause a loss of proficiency in performing an evolution. Part 2 is correct.

D-Is wrong. Part 1 is plausible for the reasons stated in Choice C. Part 2 is plausible for the reasons stated in Choice B.

Enclosure 2 LICENSEE COMMENTS: The facility licensee and one applicant recommend that the answer key for Question #97 be changed to accept two correct answers. The answer key identified Answer A as the correct answer. They contend that distracter B is also a correct answer.

After the exam was reviewed with the class, the applicant identified that the IPTE procedure uses the words If (Step 5.4.1) and consider (Question 7) in this procedure, which allows for operational flexibility in determining who performs the brief. There is no written requirement in this procedure that designates that the coordinator SHALL give the brief in the conditions given.

Based on IPTEs being able to go multiple shifts, with each shift requiring a briefing, the applicant determined that with the generic conditions given it would be unreasonable in every situation for the coordinator to be present under all conditions to give the brief. A Shift Manager, however, IS required to be physically present 24/7. With the 2 options given, the only option that generically made sense to the applicant under all conditions is the Shift Manager, and procedurally that is allowed.

The facility review of this issue for Question #97, Part 2, requires the applicant to determine who will conduct the pre-job brief as dictated by an administrative procedure. Based on the wording in the procedure, there is no absolute requirement regarding who is assigned as the brief leader. Both choices given to the student are plausible; therefore, Question #97 should be changed to accept Answers A and B.

The facility review of the governing procedure found no requirement for the Test or Evolution Coordinator to conduct the brief, nor prohibit the Shift Manager from leading the brief. Based on NUREG 1021, 4.4, Section C (3)(e), the facility believes this question meets the requirement to accept two answers as correct (A and B) since they do not conflict with each other nor with the procedural requirements.

NRC RESOLUTION: The NRC agrees with the applicant and licensees recommendation. The key has been changed to accept both answer A and distracter B as correct.

During post-exam comment reviews, the NRC requested an IPTE qualification card, training on IPTE, and any OJT training (if performed). The facility submitted training on IPTE but there was nothing in the training on who was required to conduct the brief for these evolutions. There was also no qualification card and no OJT training on IPTE at Cooper Nuclear Station. The facility found and submitted several IPTE packages from the station where the Shift Manager performed the brief.