Presentation on theme: "Liquid Effluents Optimization Plan at IPEC. EPRI document The recent EPRI report suggests a side-wide optimization plan for liquid effluents. Good place."— Presentation transcript:
EPRI document The recent EPRI report suggests a side-wide optimization plan for liquid effluents. Good place to lock down ideas and policies that might otherwise escape with VSP. Offers a place for historical perspective and bases discussions, as a learning tool. Can be used as a starting point for building station procedures or updates to the ODCM.
Why was this important at IPEC? Integration: –New and unexpected source terms –Inexperienced people Needed a means to implement new ideas Long Term commitment tracking Simplifies compliance during inspection Gets key contributors to think together
Typical Source Terms Unit 3: –Co-58 during and after outages –Otherwise, Co, Mn, Cs, Ag, and Sb –Generally well removed during processing Unit 2: –Similar to unit 3, with a little more total volume –Aggressive cleanup kept Ci’s released approx = U3 Unit 1: –Completely separate issues, involving Sr, Ni, etc, plus the typical long-lived isotopes like Cs-137.
Optimization Plan 1.0INTRODUCTION 1.1Methodology 1.2Arrangement of Document 2.0BACKGROUND 2.1General Plant Information 2.2History of Liquid Effluent Reduction and the Move to “Zero Release” 2.3Initial Plant Design of Liquid Effluent Cleanup Systems 2.4Modifications 2.5Effluent History, Milestones and Initiatives 3.0SITE EVALUATION AND TECHNICAL BASES 3.1Evaluation of current systems 3.2Evaluation of Effluent Processing Stream Contaminants 4.0LIQUID EFFLUENT OPTIMIZATION PLAN 4.1Goals 4.2Responsibilities 4.3Procedures 4.4Processes and Controls 4.5Action Levels 4.6Contaminant Introduction Methods 4.7Contaminant Removal Methods 4.8Sampling Points and Decision-Making from Chemistry Data 4.9Contributions to Liquid Effluents from Refueling Operation 4.10Technical Bases 5.0REFERENCES
New challenges : Unit 1 A continuous – intermittent release pathway from the containment curtain drain (mostly rainwater with slight contamination, including some PCBs from old oil spills. Legacy issues with solid waste and pool water with high levels of Sr-89, Sr-90, Ni- 63, and Cs-137. Connections to “IPEC” waste processing
Gamma Spec is only part of the story In early Feb 2004, a weakness was identified in the new Optimization Plan. Beta lab results for batch liquid effluent tanks indicated a ten-fold increase in Sr-90 for Dec 03. After verification, January’s Sr-90 values were rushed and returned with a verified five-fold increase over December’s data. The investigation started. Two staff members independently discovered the cause was ineffective processing of unit 1 “legacy” water.
What NOT to do with Unit 1 Pool Water In Sep 2003, an inspection of the East side of the unit 1 pool was scheduled. It was widely known that this water had been NOT been aggressively demineralized like most operating reactor SFPs, and had accumulated continuous activity bled from the old fuel rods into the pool. Some water needed to be drained out in order for a better inspection. Approx 10000 gallons was drained to the Cask Wash Pit, then to a collection tank for processing.
Personnel in charge of the inspection were confident that the pool was filled with rain-water and could easily be cleaned up (there was no fuel stored in the pool at the time). During transfer, Waste Management personnel recognized some sludge was being sent to the processing system and terminated the transfer. Since there was every intention to process this water, no samples were taken at the time. The water was moved from the wash pit to a Waste Collection Tank to await processing.
As yet, there was still no direct communication with Effluents Management (Chemistry) regarding the Unit One Project Team’s plans and the movement of this sludge and water. In Nov 2003, processing began. Typical gamma spectroscopy sample were obtained during the processing, in Nov and Dec 2003.
Gamma Spec results showed high Cs-137 on inlet (as expected with 20-20 hindsight). Waste processors wanted to use a cation and mixed bed to cleanup, but were instructed by senior team members to use the Cs Specific bed. This train was intended for processing rain water with very slight contamination from environmental Cs-137 only. There was still no discussion with Chemistry. Cs-137 in the outlet was indeed below admin levels, and the team initially thought they were successful in processing this waste efficiently.
The bulk water in the east pool was indeed rain water, with trace levels of Cs-137. Removal of the Cs eliminated the gamma indicator for evaluation, but did not reduce the activity of Sr-89/90 (approx 1E-2 uCi/gm or higher). Some sludge was transferred to the collection tank without communication to Effluents (Chem). Elevated Sr-90 ensued on subsequent batch liquid waste tank releases, not discovered till Jan 04 due to turn-around time from Beta lab on composites.
Impact from Dec 2003 to Mar 2004: Curies Released: Sr-89:Approx 0.003 Sr-90: Approx 0.028 vice routine levels of < 0.0001 Ci/Qtr Dose Impact: WB0.0077 mrem Bone0.0321 mrem (Critical Organ) increased typical quarterly critical organ dose by factor of 10
Lessons Learned People on site cannot assume adequate knowledge of new source term or new operating guidelines or goals. Good communication is vital during site consolidation or whenever there is a significant change in roles and responsibilities. Despite knowledge and ability available on site, it was neither sought nor utilized. Significance of Chemistry’s involvement in Waste Management and Effluent Control continues to be discussed in open forum. Unit 1 source term challenges and liabilities were added to Revision One of IPEC’s Liquid Effluent Optimization Plan.
Follow-up Actions SOPs and WM procedures were updated to require Chem Superintendent concurrence when processing unit 1 “legacy” water. Chem Superintendent’s permission is needed any time the Cs-specific bed is used in favor of the Cation and Mixed bed train. –Cs specific was valuable when unit 1 NCD overflow resulted in need to process rainwater. This pathway should no longer be needed with the new continuous-intermittent system, so this should NOT be an operational restriction.
Timely Effluent Training This event occurred DURING the effluent training that was provided to Chemistry, Operations, REMP personnel, and WM. Follow-up briefings were conducted with WM, the Unit 1 Project Team, Chemistry and Ops. Recently completed effluents training documentation was updated to also focus on the unit 1 source term issues.
Elements of the Optimization Plan Methods of establishing liquid effluent goals each year, both curie and dose. A study of potential contaminants harmful to the processing system, including careful control of floor- cleaning compounds. Risk and Cost basis analyses comparing liquid effluent with solid waste. Discussions of some of the new isotope-specific resins available to the industry Chemical Injection: what, when, how much? pH control – for optimum processing efficiency, need pH and conductivity of source
Site Consolidation Merging together the talents and knowledge of all possible resources for an improved site performance. Not possible without aggressive pursuit of these talents and knowledge, through pre-job briefings, and other standard techniques of communication. Cannot afford to operate in silo mode due to rapidly changing roles/responsibilities, which can occur anywhere, anytime.