Overview of FRAP-K1 And Status of Major Modifications GOOD PRACTICES IN OUTAGE MANAGEMENT AT KANUPP Penned By: Shahid Mahmood Malik Pakistan Atomic Energy Commission
PAEC operates one CANDU & two PWR units. KANUPP (CANDU unit) is operational from 1972. CHASMA-1 (PWR Unit) is operational from 2000. CHASMA-2 (PWR Unit) is operational from 2011. Two PWR units are under construction.
Planning and Scheduling for Outage Outages are necessary for safe & reliable plant operation and installation of modification & improvement projects. Single group can not handle the outages in isolation effectively. High level of coordination required for successful outages. Pre-outage preparation, careful execution, well developed plan for radiation and industrial safety is the key for best performance during outages.
Types of Outages at KANUPP There are three types of outages at KANUPP Poison out shutdown: Planning & preparation starts at the beginning of next cycle. Short Shutdown: Planning & preparation starts at the beginning of next cycle. Long Shutdown: Planning & preparation starts at least 6 months in advance. Initially once in month, then fortnightly & weekly in the end
Preliminary Meeting Set tasks that have to be completed before outage Some of the important tasks are: Finalize list of jobs. Defining each maintenance activity in terms of time/ man hrs number of groups and expected radiation dose. Decide and schedule critical path using best estimate planning i.e. realistic estimate of task duration. Arrangement of Spares and Tools.
Preliminary Meeting Identification of jobs which are prone for high radiation exposure, D2O spill, challenge core cooling. Special emphasis on availability of common amenities like Lighting, Crane Telephone, decontamination facilities and power supply for equipment used for LSD. Refresher training of Plant personnel on Industrial Safety precaution, Foreign Material exclusion and radiation protection prior to outage enable the completion of outage within time and without incident.
Preliminary Meeting Preparation of related plans, OTOs and tags for isolation & normalization of major equipments prior to LSD helped in issuing the permits on schedule. Incorporation of Lesson learn in outage work plan from internal and external OEF related to outage. Identification of outage coordinator from each section. Preventive Fire Protection plan during outage.
Equipment performance Monitoring Group Select & Monitor the important equipments performance using vibration analysis, bearing temperature trend, oil analysis, infrared thermography and acoustic monitoring. Issue health reports of selected equipments monthly. These reports help in selecting the jobs for LSD work plan. Make the work plan a good blend of condition base maintenance and preventive maintenance jobs. Rationalize the outage duration and reduce the maintenance cost.
Conflict Management Meeting During outages many plant divisions/sections and individuals work together. Conflict/disputes are common to develop during outages among divisions/sections. It causes delay in Authorization of work permit and upset the outage. Daily Evening Meeting to resolve these issues. Operation & Maintenance coordinators are the key participants. This helps in keeping the outage on track.
Prevention of D2O Spill D2O spill delayed outage and increase dose. Identify Jobs prone to D2O spill during preliminary meeting. Isolation & draining of hold up water in the equipment by using Helium pressure helps in reducing spillage of D2O while opening the equipment.
Prevention of D2O Spill Sending both operation & Maintenance personnel for opening of equipments containing heavy water reduces chances of accidents spillage of D2O and reduces communication gap. Arrangement of D2O collection equipments like Vacumax, Carboys, Buckets, Cotton rolls at work location prior to job.
Break up of Maintenance Jobs Many maintenance jobs required assistance from other division/section. These jobs are break up in to many associated jobs required to prepare the equipment for maintenance. These associated jobs are reflected in the work plan of responsible section for early planning and in time scheduling.
Break up of Maintenance Jobs For example Overhauling of Primary Coolant Pump/Motor are break up into a. Removal of Insulation. (Workshop unit) b. Removal of computer & control connection. (I&C unit). c. Removal of Electrical Connection. (EM unit) d. Disconnection of process cooling water lines. (MM unit) This helps in start and finish the job as per schedule of outage.
Use of Mock-up and other Practices to reduce Worker dose Typically 60-65% of plant radiation exposure occurs during outages. Following practices are used to keep the Dose within set target: a. Special radiological protection & precaution are exercised during shutdown. b. Mock-ups are used for the jobs likely to give high radiation exposure e.g. Boiler tube plugging, cuting/welding job on stand by cooling system.
Use of Mock-up and other Practices to reduce Worker dose c. Good Work control like: o o o Minimizing the number of workers assigned to a particular job. Determination of what tools are necessary for the job to avoid delay. Establishment of 2 nd work station in very low dose area to provide quick assistance to working group. d. Test facility is used to qualify the components/equipments prior to installation in the system to avoid repeat maintenance.
Use of Mock-up and other Practices to reduce Worker dose e. Monitoring of individual dose daily to minimize the chances of over exposure. f. Special ventilation arrangement for specific work location to minimize tritium uptake. g. Use of alarm dosimeters to avoid inadvertently high radiation exposure during maintenance of hot equipment.
Post Outage Analysis Outage analysis carried out after each LSD to identify a. What worked well b. Procedural or equipment failure which i. Delayed duration of LSD ii. iii. iv. Lead to spread of contamination D2O spillage Caused problems after start up
Post Outage Analysis v. High radiation exposure vi. Incidents causing degradation of safety of plant personnel or equipments. Identify lessons to be learnt for preventing recurrence in future. Post outage report for systematic gathering of OEF from outages.