ML25316A023
| ML25316A023 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 10/02/2025 |
| From: | Dewhirst L Operations Branch IV, Nebraska Public Power District (NPPD) |
| To: | Kelly Clayton Operations Branch IV |
| References | |
| N1S2025057 | |
| Download: ML25316A023 (1) | |
Text
N Nebraska Public Power District Always there when you need us N1S2025057 October 2,2025 Kelly Clayton Chief Examiner U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 7601 1 -451 I
Subject:
lnitial Post-Examination Documentation Cooper Nuclear Station, Docket No. 50-298, Renewed License No. DPR-46 Reference NUREG 1021, Operator Licensing Examination Standards for Power Reactors, Revision 12 On September 16, 2025, Reactor Operator and Senior Reactor Operator written examinations were administered at Cooper Nuclear Station (CNS). On October 2,2025, the following post-examination documentation was transmitted electronically to your office as required by Section ES-4.4 8.7 of the reference:
the graded written examinations (i.e., each applicant's original answer and examination cover sheets) plus a clean copy of the applicant's answer sheet; the master written examinations and answer keys, annotated to indicate any changes made while administering and grading the examinations; any questions asked by the applicants and the answers given to the applicants during the written examination (ES-4.3);
all examination administration or post-examination review comments made by the facility licensee and the applicants after the written examination and operating tests (ES-4.3);
the seating chart for the written examination (ES-a.3);
documentation (through a cover letter or other correspondence) of facility licensee management or supervisor concurrence.
There were two substantive comments made by the facility licensee after the written examination. A performance analysis of the written examination was conducted; we request the Chief Examiner to consider two substantive changes to the written examination answer key.
The completion of Form 1.3-1, "Examination Security Agreement," is delayed due to issues associated with the collection of post-examination signatures; this form will be fonrvarded to you at a later date with your previous concurrence.
COOPER NUCLEAR STATION P,O. Box 98 / Brownville. NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd.com a
a t
a
N152025057 Page 2 of 2 The graded written examination and written examination performance analysis contain personally identifiable information. As such, we request the Nuclear Regulatory Commission (NRC) to withhold these documents from the public document room per 10 CFR 2.390.
We also request the NRC to withhold the master examination and answer key from the public document room for lwo years from the date of the exam.
This letter contains no new regulatory commitments. Should you have any questions or require add
, please contact me at (402) 825-5416 or Andrew Vaughn, Facility
, al(402) 825-5345 ly a
irst Regulatory Affairs and Compliance Manager ljo cc: Training Manager Cooper Nuclear Station Facility Representative Cooper Nuclear Station Operations Training Superintendent Cooper Nuclear Station CNS Records
- Exam item analysis not required for questions 82, 83, 85, 93, & 95-98 per NTP0.1, Rev. 17, Step 5.1.15.3.
Page 1 CN-2025-09 Exam Analysis - Copy Que #
Correct Ans Que Avg.
U1 I1 I2 R1 R2 R3 R4 "a"
RAW POINTS 68 71 62 63 71 66 64 1
b 14.3%
b b
b b
b c
b 0
2 b
14.3%
b b
b b
a b
b 1
3 c
0.0%
c c
c c
c c
c 0
4 c
0.0%
c c
c c
c c
c 0
5 c
0.0%
c c
c c
c c
c 0
6 a
42.9%
a a
a b
a c
b 4
7 c
0.0%
c c
c c
c c
c 0
8 a
0.0%
a a
a a
a a
a 7
9 d
0.0%
d d
d d
d d
d 0
10 b
0.0%
b b
b b
b b
b 0
11 c
0.0%
c c
c c
c c
c 0
12 c
57.1%
a a
c a
c a
c 4
13 c
71.4%
d c
d d
a c
d 1
14 b
0.0%
b b
b b
b b
b 0
15 b
57.1%
c b
a a
a b
b 3
16 d
14.3%
d d
c d
d d
d 0
17 d
0.0%
d d
d d
d d
d 0
18 b
0.0%
b b
b b
b b
b 0
19 b
0.0%
b b
b b
b b
b 0
20 d
14.3%
d d
d d
d d
b 0
21 c
14.3%
c c
c c
c c
d 0
22 b
14.3%
b b
b b
b b
a 1
23 a
0.0%
a a
a a
a a
a 7
24 c
0.0%
c c
c c
c c
c 0
25 d
0.0%
d d
d d
d d
d 0
26 a
0.0%
a a
a a
a a
a 7
27 d
0.0%
d d
d d
d d
d 0
28 a
42.9%
a b
a c
a a
c 4
29 b
14.3%
b b
a b
b b
b 1
30 a
28.6%
a a
a b
a a
b 5
31 a
0.0%
a a
a a
a a
a 7
32 c
14.3%
c c
c c
c a
c 1
33 d
0.0%
d d
d d
d d
d 0
34 a
0.0%
a a
a a
a a
a 7
35 d
0.0%
d d
d d
d d
d 0
36 d
14.3%
d d
d d
d b
d 0
37 b
14.3%
b b
b a
b b
b 1
38 d
0.0%
d d
d d
d d
d 0
39 a
0.0%
a a
a a
a a
a 7
40 a
14.3%
a a
c a
a a
a 6
41 b
0.0%
b b
b b
b b
b 0
42 c
14.3%
c c
a c
c c
c 1
43 d
14.3%
d d
d c
d d
d 0
44 a
71.4%
b a
d b
a b
c 2
45 d
0.0%
d d
d d
d d
d 0
46 a
0.0%
a a
a a
a a
a 7
47 c
0.0%
c c
c c
c c
c 0
48 c
42.9%
c c
b c
d c
d 0
49 c
14.3%
c c
b c
c c
c 0
50 a
0.0%
a a
a a
a a
a 7
51 c
14.3%
c c
c c
c c
d 0
52 b
0.0%
b b
b b
b b
b 0
53 b
14.3%
b a
b b
b b
b 1
54 b
14.3%
b b
b d
b b
b 0
55 d
14.3%
d d
d d
d b
d 0
56 a
14.3%
a a
c a
a a
a 6
57 d
0.0%
d d
d d
d d
d 0
58 a
0.0%
a a
a a
a a
a 7
59 b
0.0%
b b
b b
b b
b 0
60 a
14.3%
a a
b a
a a
a 6
61 c
71.4%
d d
d c
c d
d 0
62 b
28.6%
b b
b c
b a
b 1
63 d
14.3%
d d
d c
d d
d 0
64 d
0.0%
d d
d d
d d
d 0
65 c
14.3%
a c
c c
c c
c 1
66 a
14.3%
b a
a a
a a
a 6
67 d
0.0%
d d
d d
d d
d 0
68 d
0.0%
d d
d d
d d
d 0
69 b
14.3%
b b
d b
b b
b 0
70 b
0.0%
b b
b b
b b
b 0
71 c
0.0%
c c
c c
c c
c 0
72 c
0.0%
c c
c c
c c
c 0
73 a
0.0%
a a
a a
a a
a 7
74 b
0.0%
b b
b b
b b
b 0
75 b
0.0%
b b
b b
b b
b 0
RO 90.6 94.6 82.6 84.0 94.6 88.0 85.3 18 RAW POINTS 19 17 18 76 c
33.3%
c c
b 0
77 a
0.0%
a a
a 3
78 b
33.3%
b a
b 1
79 b
0.0%
b b
b 0
80 c
0.0%
c c
c 0
81 d
33.3%
b d
d 0
82 c
66.7%
a a
c 2
83 b
66.7%
d a
b 1
84 d
0.0%
d d
d 0
85 b
66.7%
b a
c 1
86 b
0.0%
b b
b 0
87 d
0.0%
d d
d 0
88 c
0.0%
c c
c 0
89 a
0.0%
a a
a 3
90 c
33.3%
c c
d 0
91 d
0.0%
d d
d 0
92 a
0.0%
a a
a 3
93 c
66.7%
b c
b 0
94 b
33.3%
b c
b 0
95 c
66.7%
c d
d 0
96 b
100.0%
a d
d 1
97 a
0.0%
a a
a 3
98 a
66.7%
c a
c 1
SCORE (%)
Page 1 of 1
Question #85 Executive Summary Cooper Nuclear Station Docket No. 50-298 (facility licensee and applicant) recommends that the answer key for Question #85 answer key be changed to accept two correct answers. The answer key identified Answer B as the correct answer. Answer A is also a correct answer.
Details providing a technical justification to support changing the answer key are provided below.
Applicants Statement The Applicant provided his thought process while answering this question.
With the conditions presented, the question directed me to determine where Maximum Safe Operating Water Level was required to be achieved to impact HPCI OPERABILITY.
While evaluating the potential solutions to this question, my understanding of the question was confirmed.
With HPCI equipment required for OPERABLE status located in the HPCI Room, water would be required to be retained in the HPCI room to threaten the OPERABLE status of HPCI. Based on the conditions and question stated above, Maximum Safe Operating Water Level in the HPCI Room is the correct answer to determine the OPERABILITY of HPCI.
Technical Justification Detail Facility/Applicant Comment Cooper Nuclear Station requests the NRC to consider an examination change to Question
- 85. During review of the procedure and justification in the answer key for Question #85, the site supports a change in the answer key.
Question #85, Part 2, requires the candidate to determine the operability of the HPCI system due to high water level. Operability determination is a Senior Reactor Operator (SRO) task and requires the analysis of various inputs. Parameters supporting Operability and values defined in the PSTGs do not necessarily meet the same requirements nor have the same desired outcome. Operability determination 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 student are plausible; therefore, Question #85 should be changed to accept Answers A and B.
Basis to change Question #85 Question #85 is a 2-part question concerning high water levels in the Reactor Building.
- 1. Per the PSTGs, what is the minimum level that Torus area water level will cause buoyance issues with the Torus?
- 2. Safe Shutdown HPCI equipment will be inoperable when level meets Maximum Safe Operating level in what area?
AMP-TBD00 Rev 13 includes the CNS PSTGs. Per page B.I-8-56, the Maximum Safe Operating value for the torus area is that water level which causes a buoyancy effect on the torus with suppression pool water level at the minimum LCO. Per page B.I-8-56, the torus area Maximum Safe Operating value is set to 4.5 feet. This addresses Part 1 of Question
- 85. The site has no challenges for Part 1 and agrees that it is correct.
To demonstrate that Part 2 has 2 correct answers, the following discussion will be broken down to defend the candidates Answer A and then support the answer keys Answer B.
Defense of Answer A Part 2 assesses when HPCI equipment will be inoperable based on reaching a Maximum Safe Operating level. The question states that a unisolable main steam line rupture occurred in the steam tunnel resulting in Sump Hi-Hi Level and Torus Area High Level alarms. To aid in developing the correct conclusion, EOP-5A (SECONDARY CONTAINMENT CONTROL (1-3)) was reviewed to assess plant status.
Part 2 of the question specifically asks about the operability of HPCI based on water level.
The Operability process consists of identifying a degraded or non-conforming condition that could call the operability of a system into question, performing a technical analysis of the effects of the condition on the equipment, and having an on-shift SRO evaluate the results. The determination of operability is based on having the Reasonable Expectation that that the identified condition will not erode belief in equipment being able to perform a required safety function. The Operability process answers to a high standard, requiring accurate information and data. While it is true that the HPCI room does not have an installed sump or level indication, and that the room communicates with the SW Quad via the floor drains and a large piping penetration, high water level indicated in the SW Quad
does not automatically render HPCI inoperable. Prior to declaring HPCI inoperable, the SRO would attempt to gather information about whether the water level is actually impacting HCPI operation. This information gathering could include looking at the health of HPCI from the Main Control Room indications, and/or dispatching personnel or using cameras to assess water level impact on the equipment. The assessment would require information on water level in the HPCI room, not the SW Quad.
Any Sump Hi-Hi Level or Torus Area High Level alarm is an EOP-5A entry condition. The WATER LEVEL leg requires operating available sump pumps to restore and maintain level below the associated Maximum Normal Operating (MNO) level (equal to the associated high-level alarm setpoint) [Step SC/L-2]. If water level cannot be restored and maintained below the MNO level [SC/L-3], the Control Room staff will attempt to isolate all systems discharging into the areas [SC-3]. The question states that this is an unisolable main steam line rupture. Based on plant design, this could either be a Main Steam system or a RCIC steam line rupture. In either case, this is a primary system discharging into secondary containment [SC-4], requiring entry into EOP-1A (RPV CONTROL (1-3)) [SC-5] to insert a scram and control RPV parameters from the EOP-1A flowchart. If multiple areas are exceeding the water level Maximum Safe Operating (MSO) value, Emergency Depressurization is required to bring the Reactor Pressure Vessel (RPV) to its lowest energy level [SC-6].
Alarm Response Procedure 2.3_S-1/A-3, REACTOR BLDG C SUMP HI-HI LEVEL, provides direction when high sump water level occurs:
2.4 IF level in area exceeds specified amount, THEN secure and de-energize electrical equipment not required by EOPs as follows:
2.4.1 At ~ 9' indicated level, perform following:
2.4.1.1 Open Breaker 2E on MCC-R for Sump Pump 1C-1.
2.4.1.2 Open Breaker 3D on MCC-S for Sump Pump 1C-2.
2.4.1.3 Open normal feeder to 125 VDC Starter Rack B (HPCI) breaker on 125 VDC Switchgear B.
2.4.1.4 Ensure emergency feeder to 125 VDC Starter Rack B (HPCI) breaker on 125 VDC Switchgear A is open.
2.4.1.5 Open normal feeder to 250 VDC Starter Rack B (HPCI) breaker on 250 VDC Switchgear B.
2.4.2 At ~ 10.5' indicated level, open Breaker 1C on MCC-S for HPCI fan coil unit.
The key statement in Step 2.4 pertaining to this exam comment is not required by EOPs.
Step 2.4 requires de-energizing sump pumps and HPCI control and motive power at 9. The sump pumps are required to support EOPs based on earlier actions in EOP-5A [SC/L-2],
Operate available sump pumps to restore and maintain level below its maximum normal operating water level. De-energizing the sump pumps would be contrary to the overall strategy of removing water from the area and would not be performed. Likewise, HPCI may be required to support EOPs based on the status of other plant systems. De-energizing HPCI if it was still operating correctly and needed would be contrary to the EOPs. As stated earlier, determining operability requires the assessment of equipment operation and condition. This assessment could include obtaining actual water level in the HPCI room.
Based on needing information on HPCI operation and local conditions to assess operability, Answer A is defensible.
Defense of Answer B CNS plant design has any water accumulating in the HPCI room draining to the SW quad sump (C Floor Drain Sump). This sump contains the Hi-Hi Level alarm and sump level transmitter circuitry. Additionally, the two rooms are connected via a large piping penetration. Assuming that no obstructions are present between the rooms, the water level in the SW Quad should be approximately the same as level in the HPCI Room. Based on the installed level instrumentation, the SRO may elect to declare HPCI inoperable when water level exceeds MSO water level in the SW Quad. The question does not provide details that HPCI is required for EOP actions. If HPCI is not required to support EOP actions, then actions per 2.3_S-1/A-3, REACTOR BLDG C SUMP HI-HI LEVEL Step 2.4 to de-energize HPCI control and motive power would be required. These actions would result in HPCI being declared inoperable due to loss of motive and control power to several HPCI motor operated valves, as shown on drawing 3058. Based on the likelihood of water levels being approximately the same in both rooms and carrying out alarm card actions, Answer B is defensible.
With Part 2 requiring an assessment of HPCI operability, the SRO may choose to base his decision on HPCI operation and indications, including water level in the HPCI room, or the SRO may choose to base his decision on indicated water level in the SW quad resulting in opening HPCI DC power feeder breakers to de-energize HPCI. Based on NUREG 1021, 4.4, Section C (3)(e), the site believes Question #85 meets the requirement to be an also-accept for both answers A and B.
Summary Operability requires an assessment of conditions potentially affecting the plant equipment.
The operability of HPCI due to high water level in the SW quad area cannot be determined with a reasonable level of accuracy. The impact of water level on HPCI requires knowledge of the water level in the HPCI area. A student strictly concerned about the operability of the HPCI system could focus on water level and its direct impact in the HPCI Room. A student considering the HPCI Room and SW Quad as connected rooms could focus on using available level indication, which is located at the SW Quad sump. Question #85 answer key should be changed to reflect that Answers A and B are both correct.
References AMP-TBD00, Accident Management Program Cooper Nuclear Station, EOP/SAG Technical Basis Document, Plant Specific Technical Guidelines, Severe Accident Technical Guidelines, Rev 13 EOP-5A, Secondary Containment Control (1-3), Rev 23 EOP-1A, RPV Control (1-3), Rev 26 Alarm Response Procedure 2.3_S-1, Rev 32 (C Sump Hi-Hi Level guidance)
Administrative Procedure 0.5.OPS, Operations Review of Condition Reports/Operability Determination, Rev 57 Drawing 3058, Cooper Nuclear Station DC One Line Diagram, highlighted for HPCI power
Question #97 Executive Summary Cooper Nuclear Station Docket No. 50-298 (facility licensee and applicant) recommends that the answer key for Question #97 be changed to accept two correct answers. The answer key identified Answer A as the correct answer. Answer B is also a correct answer.
Details providing a technical justification to support changing the answer key to accept Answers A and B are provided below.
Applicants Statement The Applicant provided his thought process while answering this question.
Regarding the IPTE question that I missed, I consider my answer of Shift Manager giving the brief should be considered as creditable for the following reasons. CNS-OP-116 states:
Step 5.1: The applicable Department Head ensures following:
Step 5.4.1: If IPTEs continue beyond one shift, the oncoming shift shall be briefed.
From Attachment 4: NOTE - This checklist is to be completed by the person performing the brief, or as designated by the responsible Department Head. The person completing the checklist will ensure the controls in the Controlling Document are adequate for the plant conditions that presently exist.
From Attachment 5: Ensure all controlling document issues and other concerns are immediately communicated to the IPTE Coordinator and IPTE Senior Line Manager prior to performing actions. Never proceed in the presence of doubt.
Question 7: IPTE Pre-Job Brief to be given by Test or Evolution Coordinator? (YES OR NO)
Consider the need for Test or Evolution Coordinator brief especially for the following:
Activities requiring multi-discipline involvement.
Activities of duration exceeding one shift.
If yes, specify:
The words If (Step 5.4.1) and consider (Question 7) allow 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, I 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 me under all conditions is the Shift Manager, and procedurally that is allowed.
Technical Justification Detail Facility/Applicant Comment Cooper Nuclear Station requests the NRC to consider an examination change to Question
- 97. During review of the procedure and justification in the answer key for Question #97, the site supports a change in the answer key.
Question #97, Part 2, requires the candidate 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.
Basis to change Question #97 Question #97 is a 2-part question concerning IPTEs (Infrequently Performed Tests or Evolutions) as covered in 0-CNS-OP-116, INFREQUENTLY PERFORMED TESTS OR EVOLUTIONS.
- 1. Per 0-CNS-OP-116, when is an IPTE required?
- 2. Per 0-CNS-OP-116, for evolutions involving multi-discipline teams, who will conduct the brief?
(Note: all procedure steps discussed below are included with this document for reference, as well as a copy of the procedure in its entirety.)
Per 0-CNS-OP-116 step 2.2.3, an IPTE is A test or evolution which if not properly conducted or for which if unexpected results are obtained has the potential to significantly reduce margins of safety, or introduce operational transients, or introduce reactor trips, and which may meet any of the following criteria:
-Is not covered by an existing approved procedure.
-Is a non-surveillance procedure that is performed less frequently than quarterly.
-Is a surveillance test that is performed less frequently than quarterly and which involves complicated sequencing or which places the plant in an unusual configuration (e.g., an Integrated Emergency Diesel Generator/Engineering Safety Features Test).
-Requires the use of special test procedures in conjunction with existing procedures.
Step 2.2.3 requires an IPTE for surveillances performed less frequently than quarterly, assuming the surveillance is sufficiently complicated or involves higher risk. This addresses Part 1 of Question #97. The site has no challenges for Part 1 of the question and agrees that it is correct.
Concerning Part 2 on who conducts the pre-job brief, 0-CNS-OP-116 provides information on responsibilities and content. Relevant steps are cited below:
Step 3.7.2: (The Senior Line Manager) (e)nsur(es) proper performance of the IPTE Pre-Job Brief and the Pre-Job Brief addresses Step 3.8: Test or Evolution Coordinator is responsible for the overall conduct of the test or evolution.
Step 5.3: An IPTE Pre-Job Brief shall be prepared using the Attachment 4.
Step 5.4: An IPTE Pre-Job Brief shall be presented using Attachment 5.
Step 6.1.3 (IPTE PRE-JOB BRIEF PREPARATION section): All items in (Attachment 4) may not apply to every task. It is the responsibility of the supervisor/brief leader and personnel involved in the task to determine the applicability of each of the items in this section., IPTE Supplemental Controls, NOTE: Supplemental controls are intended to provide a raised level of control, if necessary, in addition to those incorporated into the document governing the IPTE. The need for supplemental controls is at the discretion of the Responsible Department Head.
Att 3 Question 7: IPTE Pre-Job Brief to be given by Test or Evolution Coordinator? (YES OR NO)
Consider the need for Test or Evolution Coordinator brief especially for the following:
Activities requiring multi-discipline involvement.
Activities of duration exceeding one shift.
If yes, specify:, IPTE Pre-Job Brief Preparation Checklist, Question 9 asks:
Who should attend the IPTE Pre-Job Brief?
Senior Line Manager Yes; No Test or Evolution Coordinator Yes; No On-Shift Operations crew Yes; No
Shift Augmentation Yes; No Maintenance Yes; No Engineering Yes; No Radiological Protection Yes; No Chemistry Yes; No Vendor Representatives Yes; No Other (specify):
Yes; No (The format of Question 9 ensures that a Senior Line Manager and the Test or Evolution Coordinator attends the brief.)
Att 4, Question 10: Who will present the IPTE Pre-Job Brief?
(The format of Question 10 does not make it a requirement for the Test or Evolution Coordinator to conduct the brief.)
Review of the governing procedure finds no requirement for the Test or Evolution Coordinator to conduct the brief, nor prohibits the Shift Manager from leading the brief.
Based on NUREG 1021, 4.4, Section C (3)(e), the site believes Question #97 meets the requirement to be an also-accept for both answers since they do not conflict with each other nor with the procedural requirements.
Summary 0-CNS-OP-116 does not require the Test or Evolution Coordinator to lead the Pre-Job Brief in any case, including when using a multi-discipline team. The procedure only requires considering having the Test or Evolution Coordinator lead the brief. A Shift Manager is not prohibited from leading the brief and may elect to do so. Question #97 answer key should be changed to reflect that Answers A and B are both correct.
References 0-CNS-OP-116, INFREQUENTLY PERFORMED TESTS OR EVOLUTIONS (highlighted sections) 0-CNS-OP-116, INFREQUENTLY PERFORMED TESTS OR EVOLUTIONS (complete copy)