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about halfway through their desired 50-year life spans. Because carriers can last so long before being retired, they are refueled and refurbished with an RCOH to extend their usable lifetime. At the same time a ship is refueled, it is given a complex overhaul in which broken, worn or obsolete parts
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have formed in the core, and the core has become highly radioactive. Refueling involves taking the expended core out of the reactor and putting in a new core with fresh nuclear fuel. Because it is so radioactive, removing a core with spent nuclear fuel from a reactor requires elaborate radiological
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with new fuel and a general maintenance fix-up, renovation, and often modernization of the entire ship. In theory, such process could simply involve only refueling or only an overhaul, but in practice, nuclear refueling is always combined with an overhaul. An ROH usually takes one to two years for
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and warfighting capabilities, its internal distribution systems are upgraded, and allowance is made for future upgrades over the ship’s remaining operational service life. Given the size of an aircraft carrier and the number of systems and subsystems it has, an RCOH is extremely complex, costly
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to bring it to desired temperatures, pressures, and other conditions. During the ROH, ship's Navy crew stand shutdown watches, and civilian shipyard workers do much of the repair, maintenance, and installation work. All personnel in an ROH maintenance work area are commonly required to wear a
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During an overhaul, an extensive testing program is conducted. Numerous test procedures that have been written are followed, data is recorded as required, and logs of the testing are kept. Tests that can be conducted include:
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and require special radiological handling and disposal precautions. In addition to radiological training and qualification required for working in radiation areas or with radioactive materials or contamination,
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aircraft carriers). For modern submarines and aircraft carriers, ROHs are typically carried out about midway through their operating lifespan. There are also shorter maintenance fix-ups called
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relief pressure setpoints. At the finish of the ROH, the testing data records are bound and retained as a permanent documentation record resulting from the ROH.
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prototype plants have also undergone similar refueling and overhauls, not at a shipyard but at whatever facility they are located.
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The overhaul commonly includes extensive maintenance and renovation work and checks of various systems and equipment aboard the
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for ships periodically at shipyards. A particularly lengthy refueling, maintenance, and modernization process for a nuclear
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and special operations force insertion platforms which can carry up to 66 special operations personnel. The first four
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handling precautions. All materials that came in contact with the critical core, including the internal surfaces and
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In a nuclear-powered ship, the nuclear fuel is essentially a solid inside a reactor core which is inside the ship's
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are repaired or replaced and systems are modernized. The modernization typically includes an upgrade of the ship’s
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submarines have undergone such conversions during their midlife refueling and overhauls. For more details, see
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As the ship is readied, toward the end of the ROH, the power plant is warmed or brought back up to the desired
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An example of renovation work done during refueling and overhauls of submarines is the conversion of a
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Unmanned
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and their silos out of the missile section in the submarine, and replacing them with 154
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To start ROH, operating procedures are used to shut down and cool down the propulsion
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submarines and up to almost three years for an aircraft carrier, performed at a naval
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well in advance and new equipment is obtained for any replacements or installations.
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Schank, John F.; Mark V. Arena; Denis
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to workers is monitored to ensure maximum exposure limits are not exceeded.
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equipment. The work for such overhauls is typically planned out by
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Extensive maintenance period for nuclear powered US Navy vessels
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can last up to almost three years and be referred to as a
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that power some aircraft carriers typically use up their
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USS Theodore
Roosevelt Headed Into Mid-Life Overhaul
464:(SSGN). Such a conversion consists of taking the 24
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481:Ohio-class submarine § SSBN/SSGN conversions
302:At a shipyard, a ship to undergo ROH goes into a
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368:(2001). (Note blocks, in dark shadow, under the
723:Nuclear-powered ships of the United States Navy
528:and pressure so it can be started when ready.
53:Learn how and when to remove these messages
667:Refueling and Complex Overhaul of the USS
563:is a process for refueling and upgrading
262:, which involves replacement of expended
230:Learn how and when to remove this message
212:Learn how and when to remove this message
110:Learn how and when to remove this message
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496:in drydock undergoing conversion to SSGN
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73:This article includes a list of general
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561:Refueling and Complex Overhaul (RCOH)
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150:adding citations to reliable sources
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613:CVN-68 Nimitz-class Modernization
565:nuclear-powered aircraft carriers
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445:equipment may be replaced by new
34:This article has multiple issues.
671:(CVN 68): Lessons for the Future
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546:Newport News Shipbuilding
275:) to up to 25 years (for
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470:Tomahawk cruise missiles
462:guided missile submarine
413:nuclear fission products
161:"Refueling and overhaul"
94:more precise citations.
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341:filled with seawater
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693:. Retrieved
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36:Please help
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503:radiography
410:radioactive
392:Land-based
382:power plant
360:in drydock
92:introducing
707:Categories
695:2010-12-04
646:2009-07-04
589:References
356:Greenville
273:submarines
172:newspapers
75:references
39:improve it
713:Shipyards
539:USS
491:USS
451:engineers
400:Refueling
358:(SSN-772)
252:refitting
202:June 2009
100:July 2009
45:talk page
433:Overhaul
387:hard hat
366:shipyard
333:Michigan
269:shipyard
658:Sources
569:US Navy
567:in the
551:in 1990
549:drydock
338:drydock
304:drydock
298:Process
242:In the
186:scholar
88:improve
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669:Nimitz
571:. The
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343:(2002)
280:-class
278:Nimitz
258:naval
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364:at a
325:(now
321:Then
260:ships
193:JSTOR
179:books
684:ISBN
493:Ohio
475:Ohio
439:ship
370:hull
354:USS
331:USS
327:SSGN
323:SSBN
308:hull
165:news
372:.)
336:in
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