ML102930470
| ML102930470 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 10/19/2010 |
| From: | NRC/RGN-II |
| To: | |
| References | |
| Download: ML102930470 (3) | |
Text
Differences Review The differences between Unit 1 and Unit 2 are not so significant that they would affect the operators ability to operate each unit safely and competently. Many of the Unit 2 modifications involve fault tolerant changes or one-for-one controller replacements. The fault tolerant changes preclude the need for operator action due to instrument malfunctions based on a median select feature for the controlling instruments. The controller replacements are simply a one-for-one change out on many of the systems for valves and master controllers. The new controllers will be demonstrated during classroom and mockup training and operate in a more straightforward manner.
However, based on the differences training plan provided by the licensee, the following Unit 2 differences could challenge the operators because of the lack of simulation capabilities on the Unit 1 simulator; therefore, these differences warrant special attention by the licensee and/or inspection follow-up actions.
Steam Generators (SGs): Unit 2 will install the D3 model, which requires both forward and back flush operations. The Watts Bar simulator training will be limited because the new Unit 2 switches and controllers associated with the SGs will not be installed on the Unit 1 plant reference simulator. Even though the licensee is temporarily changing the simulator software to replicate the D3 steam generators (for training purposes) the operators will not be able to operate the new Unit 2 controls and switches on the same simulator that models the D3 SG during training scenarios.
Moisture Separator Reheaters (MSRs): Unit 2 will install new MSRs that have different drain and vent flow rates. Additionally, the Unit 2 feedpumps will be connected to different MSRs than the Unit 1 feed pumps and some of the MSR valve locations are different. The licensee is providing classroom training; however, the operators will not be able to experience the thermodynamic differences on the simulator because this change will not be implemented on the Unit 1 simulator.
Source Range and Intermediate Range Monitors: Unit 2 will replace the radiation monitors with digital monitors. These monitors have different knobs and different scales (i.e.,
decades per minute versus counts per second). The training plan did not identify that the operators will have an opportunity to operate this equipment before starting up Unit 2. The classroom training will probably discuss these instruments; however, the operators will not have an opportunity to startup the simulator using these new instruments in concert with the new procedures.
In-Core Monitoring: Unit 2 will install new displays for Core Exit Thermocouples (CETs) and for the Reactor Vessel Level Indication System (RVLIS). The CETs and RVLIS are used extensively during dynamic scenarios to determine the required functional restoration procedure(s) and/or contingency procedures in the emergency procedures network. The classroom training will probably discuss these instruments; however, the operators will not
have an opportunity to interpret the displays during an accident scenario on the simulator using the new procedures.
Additionally, Unit 2 will install fixed incore instrument thimbles that each house 5 neutron detectors; whereas Unit 1 has movable in-core detectors. The in-core flux mapping displays and controls will be different than Unit 1. The classroom training will probably discuss these instruments; however, the operators will not have an opportunity to use the flux mapping displays and/or indications to obtain and interpret the thermal limits.
Boric Acid Controls: Unit 2 will install two digital displays instead of using the 3 batch counters on Unit 1. The classroom training will probably discuss these instruments; however, the operators will not have an opportunity to use the controllers and digital displays on the simulator before the Unit 2 startup.
Comments on the licensees Differences Training Plan The Unit 2 fuel cycle one core design and criticality procedures training is scheduled to begin in LOR Cycle 11 on 10/3/11 even though the licensee plans to submit the Form 398 applications for the Unit 2 licenses on 9/19/11. The training on the Unit 2 core and criticality procedures is a requisite to the NRC issuance of licenses to the currently licensed operators.
The licensee proposes that BOTH Initial License Classes (ILT 11-6 and ILT 11-10) be exempted from having Unit 2 differences on their NRC written and JPM examinations even though this training content will be delivered to LOR during the same time frame as the NRC exams. The licensee has stated that the reason why BOTH classes should not be exposed to written and JPM evaluations on Unit 2 differences is that there isnt enough time in their training program to deliver this training. It may not be appropriate for the agency to issue the applicants a license on Unit 1 and then immediately issue a license on Unit 2 during the subsequent two weeks (after theyve completed the differences training) without including Unit 2 differences test items in their NRC exam.
Normally, newly licensed operators are excused from taking the annual LOR operating exam and/or biennial written exam when it is scheduled to be administered during the first requal training cycle in which the newly licensed operator participates (Refer to NUREG 1021, ES-605, Section C.1.b). The ILT 11-10 class may be excused from taking the annual operating and biennial written exams scheduled for LOR Cycle 12 (Beginning on 11/21/11) since their NRC Initial License exam is scheduled for October 2011. However, the ILT 11-6 class will take their NRC Initial License exam in June 2011 and these applicants are expected to promptly enter the requalification training program. Since these applicants will be able to attend LOR Cycle 10 and Cycle 11, they are required to take the annual operating and biennial written exams during LOR Cycle 12.
The licensees training plan describes the LOR Cycle 10 content as being an overview of Unit 2 procedures. Typically, an overview is not sufficient to allow the operators to safely operate the unit. It is not clear whether the licensees procedures for Unit 2 will be ready to allow the training staff time to develop and conduct the training on the Unit 2 procedures to permit detailed test items on the comprehensive written differences examination during this cycle. If the procedure training is simply an overview, then the licensee may not be able to adequately evaluate the operators knowledge of the procedure changes before the Unit 2 startup.
The licensee will administer a comprehensive differences exam (consisting of written exam items and JPMs) during the LOR Cycle 10, which is scheduled to begin on 8/15/11. In the licensees 8/27/10 training plan submittal, they indicated (page E2-28) that the unit differences comprehensive exam will be modeled after the Watts Bar biennial exam process for licensed operators. It is anticipated that the licensee will administer an open book examination to test the licensed operators knowledge of the new Unit 2. The following items need to be clarified:
o The differences exam (written and JPMs) will only include Unit 2 systems, indications, controls, and logic that are different from Unit 1.
o The licensee should employ the same qualitative and quantitative criteria for the written portion of the differences exam, including the required sample plan methodology, as used for the biennial LOR written exam.
o The licensee should ensure that all multiple choice written items adhere to the standards for plausible distracters and psychometrics.
o The JPMs used on the differences exam should include all of the attributes for JPMs administered to initial license applicants, i.e., clear pass/fail criteria for critical steps, tolerance bands where appropriate, etc.