GARDEL: Recent developments

Néstor Patiño and Claudio Oña 2011 International Users Group Meeting , | May 24-25, 2011 GARDEL

• On-line core monitoring system. – Supervision of thermal margins and other operational limits with the

methods of CASMO and SIMULATE, usually combined with adaption.

• Core analysis and simulation functions to support reactor operation. – All information, since BOL, stored in the database: operation data (every ~30s) and core tracking results (scalars and distributions, to the pin level). – Analysis tools. Planning of maneuvers and recalculation of past events. • All functions made available to users through a graphical user interface. – Multi-user system, each configured according to his functions. All languages supported.

Stockholm, May 2011 International Users Group Meeting GARDEL applications

• Official on-line core monitoring system.

• Parallel on-line core monitoring system: A second, independent opinion. • Operational support (CMSOps): – Installed on-site. – As a hosted solution on Studsvik’s data center, for remote access. • Training operators, installed with GARDEL-SIM. • Training simulator support: – To provide JITT: Cycle-specific, updated core model with the actual operation history.

Stockholm, May 2011 International Users Group Meeting New installations (completed or in progress)

• 4 BWRs: – Mühleberg (Switzerland) – Perry ()

– TVO units 1 and 2 (Finland) • 3 PWRs: – Ascó units 1 and 2 (Spain) – Vandellòs-2 (Spain) • 2 BWR GARDEL-SIM installations: – Gundremmingen () – Mühleberg (Switzerland) • Update and installation in control room: – Ringhals units 2, 3 and 4 (Sweden) + Vattenfall Nuclear Fuel AB

Stockholm, May 2011 International Users Group Meeting GARDEL installations

• GARDEL is currently used, or being installed, in 42 reactors/installations worldwide.

• Official core monitoring system: – 19 PWRs – 9 BWRs • Operational support: – 8 PWRs – 6 BWRs • Also used with GARDEL-SIM to train operators of 6 plants.

Stockholm, May 2011 International Users Group Meeting New functions: Decay heat module (on- and off-line) (I) • Uses Studsvik’s SNF program for the calculations.

• On-line use: – Determine the decay heat if a shutdown occurs “now”. – Profits from the 3D, detailed power history built by GARDEL. – Maintains an updated detailed power history during the last 3 days. – Power history updating triggered automatically or at user’s request.

Stockholm, May 2011 International Users Group Meeting Decay heat module (on- and off-line) (II)

• Off-line decay heat analysis: – Calculation domains: • Reactor core

• Spent fuel pool • Coupled core-pool (“reload” mode, connection between core and pool is open). – Include the entire core/pool or individual assemblies only. – Calculations may apply to current core, or any predicted state in the future. – Results obtained: • Decay heat. • Activity [Bq]. • “Reference times” (time to reach a reference temperature).

Stockholm, May 2011 International Users Group Meeting Decay heat module (on- and off-line) (III)

– Answers questions like: • What is the decay heat of the core after “n” days of power, possibly followed by a shut down period?

• For how long can be part of the cooling system switched off before reaching certain reference temperature? • How many pumps must be in operation to ensure sufficient heat removal? • Long term planning of spent fuel cask loading.

Stockholm, May 2011 International Users Group Meeting Cycle condensation (I)

• Function to generate SIMULATE input decks suitable for core-follow calculations, from the “fine-grain” automated

on-line core-tracking operation of GARDEL: – Few cases that capture the most relevant operating events. • Several new case “triggering” criteria exist: – Max. change of power, flow, CRs, burnup, etc. – Detector calibrations are executed with their exact operating conditions. • Plus a number of “exclusion” criteria. • Implemented as a pre-defined calculation: It is steered from a graphical interface.

Stockholm, May 2011 International Users Group Meeting Cycle condensation (II) • Condensed parameters and position of detector calibration superimposed to the “fine” data source, to analyze

the quality of the condensation.

Stockholm, May 2011 International Users Group Meeting Custom mimics displays in BWRs

Stockholm, May 2011 International Users Group Meeting HERMES – Extended Data Base Size

• Motivation: Increasing demands on HERMES database storage capacity: – Longer cycles.

– Higher frequency of “snapshots”. – More information saved in each snapshot. Pin-wise distributions. – More elaborate PCI models (e.g. with soak time modeling). • Solution: – Changed HERMES addressing to 64-bit representation. – Virtually unlimited storage capacity. – Can be used in 32- and 64-bit operating systems. – Backwards compatible: Existing files can be used directly. – Easy deployment: HERMES client programs only need to be re-linked.

Stockholm, May 2011 International Users Group Meeting PWR “pre-defined” calculations

• New “Boration to reduce power” calculation: – Determine the boration volume required to reach the specified power

levels and CR insertions from the current operating conditions. – Then determine the boron concentration and CR bank positions necessary to maintain criticality and ∆I during a user-specified time span.

• Required boration/dilution volumes and rates displayed in all PWR calculations of boron concentration (Predictions, Recalculations, ECC’s, SDM).

Stockholm, May 2011 International Users Group Meeting Archiving of process data files

• GDGATE background process implemented.

• All process data files arriving to GARDEL are compressed and stored in a HERMES data base. • The incoming data files are indexed with the corresponding time stamp and power level. • Gives full reproducibility of past operation. • Facilitates replaying events.

Stockholm, May 2011 International Users Group Meeting Documentation

• Extend and improve the GUI manuals and the documentation of GARDEL functions available to the

user via the GUI.

Stockholm, May 2011 International Users Group Meeting

International Users Group September 2009 Meeting