Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 41

Get Book Here

Book Description
The purpose of this testing and evaluation plan (TEP) is to provide the high level guidance on testing requirements for ensuring that the equipment and systems to be implemented for remediation of the SY-101 waste level rise USQ are effective.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 98

Get Book Here

Book Description
The tank 241-SY-101 transfer system was conceived and designed to address the immediate needs presented by rapidly changing waste conditions in tank 241-SY-101. Within the last year or so, the waste in this tank has exhibited unexpected behavior (Rassat et al. 1999) in the form of rapidly increasing crust growth. This growth has been brought about by a rapidly increasing rate of gas entrapment within the crust. It has been conceived that the lack of crust agitation beginning upon the advent of mixer pump operations may have set-up a more consolidated, gas impermeable barrier when compared to a crust regularly broken up by the prior buoyant displacement events within the tank. As a result, a series of level-growth remediation activities have been developed for tank 241-SY-101. The initial activities are also known as near-term crust mitigation. The first activity of near-term mitigation is to perform the small transfer of convective waste from tank 241-SY-101 into tank 241-SY-102. A 100 kgal transfer represents about a 10% volume reduction allowing a 10% water in-tank dilution. Current thinking holds that this should be enough to dissolve nitrite solids in the crust and perhaps largely eliminate gas retention problem in the crust (Raymond 1999).

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 67

Get Book Here

Book Description
This document shows compliance with DOE order 6430.1A of the 241-SY-101 RAPID Mitigation system. The purpose of this document is to record the design attributes of the RAPID Mitigation System which fulfill the pertinent requirements specified in DOE Order 6430.1A-General Design Criteria. Those pertinent Order requirements which are not met by the project at the time of the release of this document are recorded and noted as open items in Section 4.0-Conclusions.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

Get Book Here

Book Description
An Unreviewed Safety Question was declared related to the unexplained waste surface level growth in high-level radioactive waste storage Tank 241-SY-101 at the Hanford Site in Richland, Washington. Because the waste surface level in Tank 241-SY-101 was growing in a manner inconsistent with previous behavior, the following issues of concern were recognized: (1) The continually rising surface level had the potential to reach physical encumbrances or limits within the tank (e.g., instrumentation, cameras, established Authorization Basis limits, and the double containment boundary) and the potential to significantly change the consequences of previously analyzed accidents (e.g., flammable gas deflagrations). (2) The presence of new hazards because of significant quantities of flammable gas retained in the crust (e.g., crust collapse gas-release events). (3) The potential to inhibit information gathering related to the existing hazards in the tank (e.g., unable to determine surface level to assess the potential for large gas releases). In response to this situation, a Contractor Project Team, which included Department of Energy representation, was formed to constructively address the issue. The team was responsible for developing and evaluating remediation options and executing the chosen option for remediating the surface level rise issue for Tank 241-SY-101. From an Authorization Basis perspective, the following important aspects will be discussed in this paper: (1) The integrated nature of the Project Team. The team consisted of all the organizations necessary to ensure that the time available to remediate Tank 241-SY-101 was effectively used. Most notable is the connectivity of the Nuclear Safety & Licensing organization with the Engineering, Design, and Operations organizations. (2) The ability of the safety analysis support to adjust to and address evolving Project Team goals and dynamic tank conditions. (3) Due to the urgency to mitigate this developing issue, supplemental controls to ensure safety during remediation operations and activities were developed and approved at the Contractor level with DOE cognizance through their participation as an integral part of the Project Team. This approach was selected as the most expedient to meet the aggressive project schedule and changing tank conditions. This project has been successful in meeting established goals because of the effectiveness of an integrated project team that included Nuclear Safety & Licensing at the start, the integral involvement of DOE during each phase of the project, and the ability of the Contractor to develop, approve, and implement the supplemental controls necessary to safely perform operations and activities.

Author: United States. Department of Energy. Environmental Restoration Conference
Publisher:
ISBN:
Category : Environmental protection
Languages : en
Pages : 980

Get Book Here

Book Description

Author: Chuck Stewart
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 550

Get Book Here

Book Description
The nuclear reactors and separation plants at the Hanford Site in Washington State made the plutonium for the bombs dropped on Japan in 1945. Plutonium production expanded during the Cold War and continued into the late 1980s leaving Hanford with a majority of the national inventory of high-level radioactive waste stored in its underground tanks. This book tells the story of one specific tank, the million-gallon double-shell tank 241-SY-101 in Hanford's 200-West Area. SY-101 was a dominating element in DOE waste management for the last decade of the 20th century. The possibility of a flammable gas burn in SY-101 was acknowledged as the safety issue of highest priority in the entire DOE complex during the early 1990s. Uncontrolled crust growth demanded another large-scale emergency effort in the late 1990s that finally allowed the tank to return to service in September 2001. It received its first waste as an "active" tank in November 2002. The experience spawned a legacy of inspired engineering, tight project discipline, and supportive teamwork that still affects the Hanford culture today. This narrative presents the whole SY-101 story from the viewpoint of those who lived through it. If it makes people who work in nuclear waste management pause and worry a little when funding, scheduling, or political pressures curtail creativity and prudence, the book will have served its purpose.

Author: Yasuo Onishi
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 36

Get Book Here

Book Description
The mixer pump installed in Hanford Tank 241-SY-101 (SY-101) in July 1993 has prevented the large buoyant displacement gas release events (BD GRE) it has historically exhibited. But the absence of periodic disruption from GREs and the action of mixing have allowed the crust to grow. The accelerated gas retention has resulted in over 30 inches of waste level growth and the flammable gas volume stored in the crust has become a hazard. To remediate gas retention in the crust and the potential for buoyant displacement gas releases from below the crust, SY-101 will be diluted in the fall of 1999 to dissolve a large fraction of the solids in the tank. The plan is to transfer waste out and back-dilute with water in several steps of about 100,000 gallons each. Back-dilution water may be added at the transfer pump inlet, the base of the mixer pump, and on top of the crust. The mixer pump will continue to be required to prevent formation of a deep nonconnective layer and resumption of BD GREs. Therefore, it is vital to ensure that the transfer and back-dilution processes do not significantly degrade the pump's effectiveness. Part of the strategy to avoid mixer pump degradation is to keep the base of the crust layer well above the pump inlet, which is 236 inches above the tank bottom. The maximum transfer for which an equal back-dilution is possible without sinking the crust is 90 kgal if water is injected at the 96-inch transfer pump inlet and 120 kgal for injection at the 9-inch mixer pump burrowing ring. To keep the crust base above the lowest observed elevation of 295 inches, transfer and back-dilution must be limited to 143 kgal and 80 kgal, respectively, for the 96-inch back-dilution and 175 kgal with a 112 kgal back-dilution using the 9-inch back-dilution elevation. These limits can be avoided by adding water to the top of the crust to dissolve the negatively buoyant layers. If 20 kgal of water is placed on top of the crust and the rest of the back-dilution is placed under the crust, back-dilution becomes limited by crust sinking at a 128 kgal transfer using the 96-inch injection point and at 160 kgal at 9 inches. The crust base remains well above the 295-inch minimum, and crust base elevation does not limit transfer volume. This result shows that top dilution is very beneficial in providing operational flexibility to the transfer and back-dilution process.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

Get Book Here

Book Description
This Criticality Safety Evaluation Report (CSER) documents a review of the criticality safety implications of a process test to be performed in tank 241-AZ-101 (101-AZ). The process test will determine the effectiveness of the retrieval system for mobilization of solids and the practicality of the system for future use in the underground storage tanks at Hanford. The scope of the CSER extends only to the testing and operation of the mixer pumps and does not include the transfer of waste from the tank. Justification is provided that a nuclear criticality is extremely unlikely, if not impossible, in this tank.