ML061800029

Handout for June 28, 2006, Meeting with Representatives of Wolf Creek Nuclear Operating Corporation for Wolf Creek Generating Station on the Main Steam and Feedwater Isolation System (Msfis) Controls Replacement Project

ML061800029
Person / Time
Site:	Wolf Creek
Issue date:	06/28/2006
From:	Hooper D Wolf Creek
To:	Office of Nuclear Reactor Regulation
Donohew J N, NRR/DLPM,415-1307
References
Download: ML061800029 (21)

Text

MEETING WITH WOLF CREEK NUCLEAR OPERATING CORPORATION (LICENSEE)

RELATED TO WOLF CREEK GENERATING STATION MAIN STEAM AND FEEDWATER ISOLATION SYSTEM (MSFIS) REPLACEMENT PROJECT MEETING HELD JUNE 28, 2006 DOCKET NO. 50-482 Attached is the 20-page handout from the licensee for the meeting.

Main Steam & Feedwater Isolation System (MSFIS)

Controls Replacement Project 28 June 2006 Wolf Creek Generating Station 1

Agenda

• Main Steam & Feedwater Isolation Replacement Project

• Current MSFIS Controls

• Replacement MSFIS Controls

• Advanced Logic System (ALS)

• Development Team and Development Process

• Regulatory Process

• Questions 28 June 20oo my W *W Iv my Vv Wolf Creek Generatina Station 2

Project Overview

• Replace existing hydraulically operated MSIV and MFIV actuators with actuators operated by process fluids

• Replace MSIV and MFIV bodies

• Replace existing MSFIS Controls

• Installation of MSIV/MFIVs and controls is schedule for RF16, April 2008 28 June 2006 Wolf Creek Generating Station 3

Current MSFIS Controls 28 June 2006 Wolf Creek Generating Station 4

Current MSFIS Controls Current MSFIS Controls are a digital control system

- Boards are based on discrete logic IC's along with common analog signal conditioning components for interfacing with field I/O

- Valve Control Module, which is the key module, is custom to the application

- Board interconnection is custom to the application

- Test Panel provides limited test capability

° Issues with current MSFIS controls

- Becoming less reliable

" Plant Trip due to circuit card failure

" Recent circuit failures have caused valves to stroke partially closed

- Troubleshooting requires a significant effort

- Multiple single point vulnerabilities which can cause plant transients

- Obsolete components

- Current Valve Control Module logic will not operate the replacement actuators 28 June 2006 Wolf Creek Generatinc Station w

5

Current MSFIS Controls Architecture Field Input:

MCB Hand Field Outputs:

Switches Solenoids ESFAS, Relay Driver Status Panel Valve Limit Safeguards Test Switches I I I I 28 June 2006 Wolf Creek Generating Station 6

Replacement MSFIS Controls 28 June 2006 Wolf Creek Generating Station 7

Replacement MSFIS Controls Goals of the Replacement MSFIS Controls

- Operate replacement actuators

- Eliminate single point vulnerabilities within the control system

- Improve testability to both improve test coverage and reduce manpower required for maintaining the system

- Improved diagnostics to enhance troubleshooting capabilities

- Mitigate future obsolescence issues

- Implement a scalable architecture to allow future systems to be replaced with a common platform

- Retain existing safety system architecture, maintain a low level of complexity 28 June 2006 Wolf Creek Generating Station 8

Advanced Logic System (ALS)

CORE LOGIC BOARD

- Deterministic - The system behaves the same all the time, it's fully predictable

- Single Failure Proof - System architecture is designed such that no single failure will cause a false actuation INPUT BOARD OUTPUT BOARD

'HAN E C= L

- Fault Tolerant - Detects a fault and JRLS ON i-places system in a safe state and notifies

'HANNELý-- - SIGNAL OUT #32 the control operators ýTRI,.SENSE-, CONDITION INPUT BOARD

- Modular - Boards are autonomous, a OUTPUT BOARD IANEL OUT #1 failure of one board does not cause failures in other boards IWO ANNEL SIGL OUT #32 RL!.SENSE CODTN

-Scalable - The system is built from standard modules, no module is designed specific to a particular application

- Advanced Diagnostics - Plant personnel can interface with the system for SERVICE & TEST BOARD troubleshooting and other diagnostics activities 28 June 2006 Wolf Creek Generating Station 9

Advanced Logic System (ALS) Overview

- Logic Based Architecture

" Standard logic implemented in field programmable gate array (FPGAs)

• Logic elements are pre-built, FLASH cells 'wire' the logic elements together similar to discrete logic on a printed circuit board

• Logic and test vectors are portable, providing protection to future obsolescence

- Testable

" System allows for thorough testing during the development process

" Deterministic testing - same behavior every time

" Run-Time testing - applied to continually verify system integrity

" FPGA logic incorporates Built-In Self Test (BIST) engines

- Reliable

" Simple and stable architecture

- No Stack/Heap/Interrupt overflow/underflow/overwrite

" Only deploys digital flip-flop's and protected FLASH cells' for storage

- No SRAM or program FLASH issues

" Boards are a simple design with a small number of components (as compared to current discrete system or a microprocessor based system),

which means there are less components to fail 28 June 2006 Wolf Creek Generating Station 10

"Advanced Logic System (ALS) FPGA's

- FPGA Types

" FLASH - rad tolerant, highly reliable, reprogrammable

• Anti-FUSE - rad hard, highly reliable, one time programmable

" SRAM - complex system-on-chip high speed, commercial applications

- ALS utilizes the Actel FLASH FPGAs

• Application is low gate count implementing only standard logic

• Implements simple design practices 9 High radiation survivability is not critical, as in Space applications Actel FPGA's

" Products focused on high reliability applications

" Widely used in Military, Avionics, and Aerospace Industry's

" Proven development tools with qualifications meeting Military, Avionics, and Aerospace requirements 28 June 2006 Wolf Creek Generating Station 11

ALS Rack for MSIV I]

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(,,)PAN OPAL O PAL

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0 28 June 2006 Wolf Creek Generating Station 12

Train A: Train B:

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4 FWOPEN 4 MS('LOV 4 MS EAISE I MSA: L(I.W; I MSAL(TO)S IV A M51(1.055 N SSPS 4 MS W-SAS -SP AAS 4

4 F5W EFAS TpwA F .SA ¶mE WENA ALARM BYPASS A,B,C A,B,C FWIV AEFV39 AEFV40 AEFV4I AEFV42 VFO.VFC A.B.C V 1- i . I vru.vr ji, A.B,C "A,B.C MSIV / 'BHVh7 ABHVI4ABHV2O ARHYII VFOVFC T VFOVFC 28 June 2006 Wolf Creek Generating Station 13

Development Process 28 June 2006 Wolf Creek Generating Station 14

MSFIS Controls Project Team 28 June 2006 Wolf Creek Generating Station 15

Development Life Cycle Concept Requirements Design System Installation Phase Phase Phase Phase Integration Phase And Test I I I Phase Validation Verification Validation Testing Verification Verification Verification Vedficabon 28 June 2006 Wolf Creek Generating Station 16

Project Milestones Customer Requirements Jun-06 MSFIS System Specification Jul-06 ALS Design Specifications Sep-06 Qualification Testing Oct-06 Qualification Test Report Jan-07 V&V Report Jan-07 LAR Submittal Mar-07 Factory Acceptance Test Jul-07 Site Acceptance Test Sep-07 Installation Apr-08 28 June 2006 Wolf Creek Generating Station 17

Regulatory Process 28 June 2006 Wolf Creek Generating Station 18

b Regulatory Process License Amendment Request

- TS 3.3.2, Function 4, Steam Line Isolation, and Function 5, Turbine Trip and Feedwater Isolation

• Add new sub-Functions for MSFIS Automatic Actuation Logic and Actuation Relays

- TS 3.7.2/TS 3.7.3 - MSIV/FWIV Closure Times (SR 3.7.2.1/SR 3.7.3.1)

• Limits will be moved to the TS Bases based on TSTF-491, Rev. 2

- TS 3.7.3 - Addition of Main Feedwater Regulating Valves and Bypass Valves (consistent with NUREG-1431, _W Standard TS)

- TS 3.7.3 - Extend Completion Time for one or more MFIVs inoperable from 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (consistent with NUREG-1431, W Standard TS) 28 June 2006 Wolf Creek Generating Station 19

b Questions?

28 June 2006 Wolf Creek Generating Station 20