ML050480250

12-2003 - Licensee Written Exam Performance Analysis

ML050480250
Person / Time
Site:	San Onofre
Issue date:	12/30/2003
From:	Gody A Operations Branch IV
To:	Ray H Southern California Edison Co
References
50-361/03-301, 50-362/03-301 50-361/03-301, 50-362/03-301
Download: ML050480250 (11)

Text

RO EXAM Question Percentage Question Percentage Question Percentage Question Percentage missed missed missed missed 1 33 26 0 51 0 76 17 2 16 27 33 52 0 77 0 3 17 28 17 53 33 78 67 4 0 29 17 54 17 79 50 5 0 30 17 55 33 80 1 6 17 31 0 56 0 81 0 7 17 32 0 57 0 82 17 8 0 33 0 58 0 83 0 9 0 34 0 59 17 84 0 10 33 35 0 60 0 85 33 11 0 36 17 61 33 86 17 12 0 37 17 62 0 87 0 13 100 38 17 63 0 88 17 14 0 39 17 64 17 89 0 15 33 40 33 65 33 90 0 16 17 41 0 66 0 91 17 17 50 42 33 67 0 92 50 18 0 43 0 68 0 93 0 19 33 44 0 69 50 94 33 20 0 45 83 70 0 95 0 21 0 46 17 71 100 96 0 22 33 47 17 72 100 97 0 23 0 48 67 73 17 98 0 24 0 49 17 74 0 99 0 25 17 50 0 75 0 100 0

SRO EXAM Question Percentage Question Percentage Question Percentage Question Percentage missed missed missed missed 1 0 26 0 51 0 76 0 2 0 27 50 52 0 77 0 3 0 28 0 53 0 78 100 4 0 29 0 54 0 79 0 5 0 30 0 55 0 80 0 6 0 31 0 56 0 81 0 7 0 32 0 57 0 82 50 8 0 33 0 58 0 83 0 9 0 34 0 59 0 84 0 10 0 35 0 60 0 85 50 11 0 36 50 61 0 86 50 12 0 37 0 62 0 87 0 13 100 38 0 63 0 88 0 14 0 39 50 64 0 89 0 15 0 40 0 65 0 90 0 16 0 41 0 66 0 91 0 17 0 42 0 67 0 92 0 18 0 43 0 68 0 93 0 19 0 44 0 69 0 94 0 20 0 45 50 70 0 95 0 21 0 46 0 71 0 96 0 22 0 47 0 72 0 97 0 23 50 48 0 73 0 98 50 24 0 49 0 74 0 99 0 25 0 50 0 75 0 100 0

The San Onofre Training Staff conducted a detailed examination analysis on the Initial RO and SRO License Written examination administered on December 19, 2003. The questions that were missed by more than 60% of the students were reviewed as were a few additional questions as identified during post exam debrief. The questions identified and reviewed are provided below including the % missed, the determination of question validity, any required actions for San Onofre, and the reference used.

RO & SRO Question 1:

Question was missed by 6 of 8 students. (75% wrong answers)

Valid question. The distractor chosen by the 6 students was a valid answer, just not to the particular question being asked. No further action required.

Reference:

Abnormal Operating Instruction, SO23-13-13, Misaligned CEA Question 1:

Given the following conditions:

• Reactor Power 100%

• Group 6 CEA 23 LEL is lit

• Core mimic light for CEA 23 is lit

• Tcold is 535ºF and lowering Which ONE (1) of the following actions should be taken in accordance with SO23-13-13, Misaligned Control Element Assembly?

Within 15 minutes of discovery initiate Rx Power reduction of 5% by A. inserting Part Length CEAs.

B. inserting Group 6 CEAs.

C. commencing RCS boration.

D. reducing turbine load using CVOL.

Answer: C.

Reference:

SO23-13-13, Misaligned or immovable Control Element Assembly

RO & SRO Question 13:

Question was missed by 8 of 8 students. (100% wrong answers)

Valid question. The training materials need to be updated to include this information.

Reference:

Lesson Plan 2XAR07, Emergency Core Cooling, Containment Spray, and Containment Isolation Systems Question 13 Given the following plant conditions:

• The reactor is tripped on Steam Generator low level due to a feed line break inside containment.

• 186 Lockout relay is dropped on normal supply breaker for bus 2A04.

• SIAS/CIAS were manually initiated.

Which ONE (1) of the following statements is correct concerning the remaining design capacity for reducing temperature and pressure in containment, and design capacity for Iodine removal?

A. Temperature and pressure reducing capability 50%, Iodine removal capability 50%

B. Temperature and pressure reducing capability 100%, Iodine removal capability 100%

C. Temperature and pressure reducing capability 150%, Iodine removal capability 200%

D. Temperature and pressure reducing capability 100%, Iodine removal capability 50%

Answer: B

Reference:

SO23-740

RO & SRO Question 45:

Question was missed by 5 of 8 students. (62.5% wrong answers)

Poor question. The question was testing the student knowledge of the actual labels on the switches on the Excore Instrumentation Drawers for distractors C and D versus the understanding of the function of the switches. No further action required.

Reference:

Lesson Plan: 2XCR08, Excore Nuclear Instrumentation Question 45 Given the following conditions:

• Unit 3 is operating at 85% power.

• Surveillance testing is in progress on the Excore Nuclear Instruments

• The following channel trips are received:

o High LPD and Low DNBR Which ONE (1) of the following Excore Nuclear Instrumentation switch manipulations would cause this?

A. Placing the Linear Calibrate Switch to "Zero" B. Placing the Rate Calibrate Switch to "Zero" C. Placing the Log Calibrate Switch to "Zero" D. Placing the Linear Calibrate Switch to "125%"

Answer: B

RO & SRO Question 48:

Question was missed by 4 of 8 students. (50% wrong answers)

Valid question. The training materials contain the correct information. No further action required.

Reference:

Lesson Plan 2XCR06, Accident Monitoring System Question 48 Given the following conditions:

• Unit 2 is at 100% power.

• ONE (1) Core Exit Thermocouple failed to ZERO (0) output.

Which ONE (1) of the following describes the effect of this failure on the Qualified Safety Parameter Display System (QSPDS) Representative CET (REPCET) reading?

A. Indicates lower; 0 temp indication is averaged into calculation.

B. Does not change; input not used in calculation.

C. Indicates lower; flagged as invalid.

D. Indication will flash indicating failure of input; Operator can manually delete failed input to restore display.

Answer: B

RO & SRO Question 71:

Question was missed by 6 of 8 students. (75% wrong answers)

Poor question. Although technically correct, the differentiation between correct and incorrect answer is only a difference of 5% power. The component being discussed is one that is infrequently to not at all removed from service while at power. The answer selected by the students was correct except for the power level, which was only 5%

different from the correct answer. No further action required.

Reference:

SO23-5-1.7, Power Operation Procedure Question 71 Bled Steam and Live Steam tube bundles have been isolated on the Moisture Separator Reheaters due to leakage.

What is the MAXIMUM plant power level that can be maintained and the basis for this precaution.

A. 90%, Reduced Rankine cycle efficiency.

B. 85%, Increase in LP Turbine windage due to greater quantity of steam going through the turbine.

C. 90%, reduced preheating of the feedwater.

D. 85%, Increased moisture in the steam going to the LP Turbine.

Answer: A

Reference:

SO23-160, SO23-9-1

RO & SRO Question 72:

Question was missed by 6 of 8 students. (75% wrong answers)

The question is poorly worded. The correct answer does not contain information on the Vacuum Pump while two of the distractors do list the Vacuum pump status. This lead to confusion since the students knew the Vacuum Pump would start, they selected an answer containing this statement. The training materials are correct as written and no further action is required.

Reference:

Lesson Plan, 2XP103, Condenser Air Removal Question 72 Given the following plant conditions:

• The plant is at 100% power.

• Condenser Vacuum Pump hand switch HS-3331A (CR-53) is in AUTO.

• Condenser Vacuum starts to degrade slowly and is at approximately 4 in Hg absolute pressure.

Which ONE (1) of the following describes the design of the Condenser Vacuum System that will prevent continued degradation of Condenser vacuum?

A. PV3335B will OPEN and PV3335A will CLOSE placing the Air Assisted Air Ejectors in service.

B. Condenser Vacuum Pump will shift to the "Hogging" mode of operation and prevent further loss of vacuum.

C. Condenser Vacuum Pump will startup and will be operating in the "Hogging" mode after the inlet diaphragm valves are opened.

D. PV3335A will OPEN and PV3335B will CLOSE placing the Air Assisted Air Ejectors in service.

Answer: A.

References:

SO23-190

RO & SRO Question 78:

Question was missed by 7 of 8 students. (87.5% wrong answers)

Question is poorly worded. The training material and procedures address the use of RSAS as a back up for Instrument Air. The question is asking for which is NOT a function and the inclusion of the for the safe shutdown of the plant in the correct answer is the bases for the answer being correct is confusing as the RSAS is designed to allow continued operation of the plant.

Reference:

Lesson Plan 2XQ107, Compressed Air System Question 78 The purpose/function of the Respiratory/Service Air System (RSAS) includes all of the following EXCEPT:

A. To provide compressed air to service outlets throughout the plant and Make-up Demineralizer area for operation of pneumatic tools and other service requirements.

B. To inflate and maintain the spent fuel pool seals.

C. To provide compressed air at a normal pressure of 115 psig and meet OSHA Class D breathing air requirements.

D. To provide a backup source of compressed air for the safe shutdown of the plant in the event of a failure of the Instrument air system.

Answer: D

Reference:

SO23-570

1. The NRC does not concurr with San Onofre comments and justification on RO question 61 to accept both answers B and D as correct. Based on SO23-12-11, B not D would be the only correct answer.

Since operators are required by procedure to operate CHARGING and SI systems as necessary to maintain Throttle/Stop criteria. SO23-740, Safety Injection, Containment Spray, And Shutdown Cooling System states that Shutoff head for the HPSI pumps is 1500Psig. The SI pumps would be at shutoff head so failing to start HPSI P019 and the third charging pump would not be meeting the intent of SO23-12-11 FS-7b.

2. The NRC does not concurr with San Onofre comments and justification on RO and SRO question 73 to accept both answers A and D as correct. A is the correct answer. The stem of the question specifies FIRST action taken by the crew. Both the foldout page and the main procedure SO23-12-8 list Initiate S)23-12-11 Attachment 8 Restoration of Offsite Power as the first step. The Station Blackout foldout page Step 3 Monitor Electrical Power reads:

a) If at least one 220KV Switchyard section is NOT energized to the Unit via Reserve Auxiliary or Unit Auxiliary transformers, THEN initiate SO23-12-11, Attachment 8, Restoration of Offsite Power.

b) If 4KV bus A04 or A06 remains de-energized, THEN evaluate 4KV bus cross tie per SO23-12-11, Attachmnet 6, Diesel Generator Failure followup Actions.

c) SO23-12-11, Attachmnet 6, Diesel Generator Failure followup Actions states in step 9: verify 1E4KV bus A04 or A06 energized. The Response Not Obtained action states: IF AC power restoration is NOT imminent, THEN initiate Attachmnet 24, Supplying 1E4KV Bus with Opposite Unit Diesel.

To determine if restoration of AC power is imminent or not, the crew would need to initiate SO23-12-11, Attachment 8, Restoration of Offsite.

3. The NRC does not concurr with San Onofre comments and justification on RO and SRO question 82 to accept both answers A and D as correct. D is not a correct answer based on the following execrpt from San Onofre Technical Specifications.

B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)

B 3.5.5 Trisodium Phosphate (TSP)

Trisodium phosphate (TSP) dodecahydrate (with 12 hydrates) crystals are placed in baskets on the floor of the containment building to ensure that iodine, which may be dissolved in the recirculated reactor cooling water following a loss of coolant accident (LOCA), remains in solution. TSP also helps inhibit stress corrosion cracking (SCC) of austenitic stainless steel components in containment during the recirculation phase following an accident.

After a LOCA, the components of the core cooling and containment spray systems will be exposed to high temperature borated water. Prolonged exposure to the core cooling water combined with stresses imposed on the components can cause SCC. The SCC is a function of stress, oxygen and chloride concentrations, pH, temperature, and alloy composition of the components. High temperatures and low pH, which would be present

after a LOCA, tend to promote SCC. This can lead to the failure of necessary safety systems or components.

Adjusting the pH of the recirculation solution to levels above 7.0 prevents a significant fraction of the dissolved iodine from converting to a volatile form. The higher pH thus decreases the level of airborne iodine in containment and reduces the radiological consequences from containment.

The LOCA radiological consequences analysis takes credit for iodine retention in the sump solution based on the recirculation water pH being $ 7.0. The radionuclide releases from the containment atmosphere and the consequences of a LOCA would be increased if the pH of the recirculation water were not adjusted to 7.0 or above.

The TSP is required to adjust the pH of the recirculation water to > 7.0 after a LOCA. A pH > 7.0 is necessary to prevent significant amounts of iodine released from fuel failures and dissolved in the recirculation water from converting to a volatile form and evolving into the containment atmosphere. Higher levels of airborne iodine in containment may increase the release of radionuclides and the consequences of the accident. A pH > 7.0 is also necessary to prevent SCC of austenitic stainless steel components in containment.

SCC increases the probability of failure of components.

The required amount of TSP is based upon the extreme cases of water volume and pH possible in the containment sump after a large break LOCA. The minimum required volume is the volume of TSP that will achieve a sump solution pH of $ 7.0 when taking into consideration the maximum possible sump water volume and the minimum possible pH. The amount of TSP needed in the containment building is based on the mass of TSP required to achieve the desired pH. However, a required volume is specified, rather than mass, since it is not feasible to weigh the entire amount of TSP in containment. The minimum required volume is based on the manufactured density of TSP dodecahydrate.

Since TSP can have a tendency to settle or to agglomerate from high humidity in the containment building, the density may increase and the volume decrease during normal plant operation. Due to possible agglomeration and increase in density, estimating the minimum volume of TSP in containment is conservative with respect to achieving a minimum required pH.

Therefore not having any TSP in the recirculation sump would result in a pH of < 7.0 and by your justification in DBD-SO23-TR-PL, Design Bases: Plant Level Topical Report excessive hydrogen generation would not be a consequence.