Cracks in Concrete at HEUMF Being Monitored by Y-12 Officials
NS&D Monitor
2/6/2015
Cracks in the Highly Enriched Uranium Materials Facility apparently haven’t worsened—at least not significantly—over the past year-and-a-half, but studies are still underway to determine how to address the situation at the Y-12 facility that houses the nation’s principal supply of bomb-grade uranium. “An evaluation of the cracks was made in 2014 by two independent concrete experts,” federal spokesman Steven Wyatt said this week in response to questions. “They concluded the cracks are due to normally expected shrinkage of the concrete,” Wyatt added. “The cracks do not pose any threat to the structural integrity of the building in the short term, but over many years they could create problems if not addressed.”
In 2013, officials confirmed that cracks had formed in the exterior of HEUMF. At the time, there were some mixed reports about the cracks. “As stated in 2013, the cracks are monitored on a regular basis,” Wyatt said this week. He said Y-12 is “evaluating several repair recommendations by concrete industry and concrete engineering experts” and expects to begin repairs within the next few years.
New Y-12 Fire Station Back on the Table
NS&D Monitor
2/6/2015
A new Fire Station at the Y-12 nuclear weapons plant has been identified as a need for a number of years, and while the project has faced difficulties in moving forward, it now appears to once again be in the works, though some uncertainty remains. “We are in the pre-conceptual stages of planning for replacement for the existing fire house,” Steven Wyatt, a spokesman for the National Nuclear Security Administration’s Production Office, said in response to questions. “Part of this process is defining the mission need and program requirements.” Wyatt said he could not provide a preliminary cost estimate or schedule for the project because that has not been approved.
Some parts of the current Y-12 fire station date back to the World War II Manhattan Project. According to Wyatt, the original wooden fire hall was built in July 1945. Since then, there have been a couple of additions, both in 1980. A few years ago, plans for a new Fire Station were folded into the overall proposal for a $50 million Complex Command and Control Center at Y-12. However, that project, which was to be privately financed and built and then leased back to the government contractor, got scrapped because of a lack of support from the White House Office of Management and Budget and certain programs at DOE.
Spallation Neutron Source Operating at Conservative Level Because of Target Failures
NS&D Monitor
2/6/2015
The Spallation Neutron Source, perhaps the world’s leading source of neutrons for research experiments, is operating again following a short winter maintenance period, but the power level is being maintained at a conservative level in order to better protect the target vessel, which has proved vulnerable with multiple failures that have occurred prematurely over the past year. Kevin Jones, the director of the Research Accelerator Division at Oak Ridge National Laboratory, said the SNS is operating well and open to researchers at the same time that investigations are continuing into several target failures last fall.
The winter maintenance outage at the Spallation Neutron Source was shortened by two weeks in order to help recover some of the research time that was lost last fall. Operations resumed Jan. 23. Since then, the availability to users has been about 92.5 percent, Jones said, noting that’s above the goal. Jones said the SNS beam is operating at a reduced power level of 850 kW, which he characterized as a “target conservation mode.” Currently, the lab only has one backup target vessel and so there’s some extra caution being taken until some additional spares arrives on the Oak Ridge campus.
The stainless-steel target vessel holds and circulates about 20 tons of mercury, which produces neutrons by the trillions as it is struck a powerful proton beam. The vessel currently in use at SNS is the 12th in the research center’s history since operations began in 2006. Jones indicated that the investigation team is trying to determine with some precision what caused Target 10 and Target 11 to fail unexpectedly. The team has identified the location of the failure on both target vessels, but the actual cause is a still a matter of review and conjecture.
A second spare target vessel is expected to arrive in late March, and the SNS team is planning a one-week maintenance period beginning April 13. Neutron production for experiments is due to resume on April 21. If everything goes well between now and then, the plan is to boost the beam power to 1.2 megawatts or even beyond at that restart point, the ORNL official said.
Detailed Evaluations Ongoing
The ORNL official provided some detailed descriptions of the evaluations to date on Target 10 and Target 11. There are detailed evaluations taking place on the failed pressure vessel to better understand what may have been material weaknesses. Jones said analysis and modeling of the target design and the stresses experienced during operations are ongoing as well. “We will have an external group of experts visit us in the last week of February to review our analyses of the failures and the analytical modeling we are doing, and we expect that this group will provide us with both a critical review of the work we have done and valuable advice on other possible avenues of assessment to improve our understanding,” he said.
ORNL Director Thom Mason said the lab is still in the planning stages for a second Target Station that would essentially double the number of research instruments and greatly boost the experimental capability at the Oak Ridge facility. Another Target Station is expected to cost $1 billion or more. The lab had hoped to get a little extra funding in Fiscal Year 2015 to carry out some improvements at SNS instruments but that now that been shifted into the 2016 timeframe.
