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#781
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Once and for all...are humans or robots better for Mars?
On Feb 4, 9:10*pm, Fred J. McCall wrote:
Walter Bushell wrote: or a train. And just what do you think a 2.5 pound warhead does to a TRAIN, for God's sake? They're much better off using something like a TBG-7V. *Shorter range but a better warhead. *They also weigh much less, so more of them can be hauled around. Or just plant a couple of hundred pounds of explosives under the tracks and wait for the train, Hogan's Heroes style. Why use a missile at all on a train? No one's guarding all the miles of tracks. |
#782
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Once and for all...are humans or robots better for Mars?
On Feb 5, 4:47*pm, Quadibloc wrote:
On Feb 5, 2:26*pm, Pat Flannery wrote: Hey, wait a second here...we can put the reactors into the reservoirs behind the dams and use the water as radiation shielding, like a giant swimming pool reactor! Soon, the reservoirs will be so warm that you could go swimming in them in them, and new and exciting species of fish will begin to evolve in them. (Cut to scene of 20-foot-long Northern Pike with legs where the fins should be crawling out of water and attacking people on the beach.) ;-) Well, nuclear energy is expensive, while hydroelectricity is cheap, so places with hydroelectric dams don't need nuclear power plants. Actually, after the plant is built, nuclear energy is cheap too. Which is exactly the case for hydroelectric. They are very similar in that the bulk of the expense is a huge capital expenditure at the beginning and financing for that expenditure. Operating costs for nuclear power plants are tiny comparatively speaking. |
#783
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Once and for all...are humans or robots better for Mars?
On Feb 6, 10:38*pm, (William December Starr) wrote:
In article , "Sea Wasp (Ryk E. Spoor)" said: Walter Bushell wrote: "Sea Wasp (Ryk E. *wrote: Yep. There's a fair number of things like that; you absolutely need it to survive, and if you get too much, it kills you ugly. Oxygen for one. In fact hydrogen hydroxide is one of the leading causes of death among humans. You mean dihydrogen monoxide? DHMO is not even REGULATED! Man, if ever there was a perfect exemplar of Heinlein's concept of the "funny-once joke," it's the "dihydrogen monoxide" gag. (Yes, I said "Man" in the context of a THE MOON IS A HARSH MISTRESS reference. *No, I didn't even realize the potential double-meaning until I was proof-reading the post.) I've found that meme extremely useful when talking to my son. He reached an age where he would repeat the same thing over and over and over. I calmly explained that some jokes are only funny once or twice and now I just have to say "funny once" and he stops reusing a joke on me. |
#784
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Once and for all...are humans or robots better for Mars?
On Mon, 07 Feb 2011 08:03:01 -0700, Howard Brazee
wrote: On Mon, 07 Feb 2011 07:04:12 -0700, Fred J. McCall wrote: I wonder how many people don't fly anymore because of 9/11 versus how many people don't fly anymore because of the TSA's heavy handed search tactics. I know of a few people who are refusing to travel on airlines (even for business) because of TSA searches. These same people have flown after 9/11. Yep. People are likely to elect to drive longer distances. Not because of 9/11, but because it takes longer to get through airports so driving time that is acceptable goes up. I'm in your 2nd group - but there are significant numbers who claim that 9/11 is whey they don't fly. It is possible that they are conflating and mean the security measures that have gone into effect post-9/11. Sincerely, Gene Wirchenko |
#785
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Once and for all...are humans or robots better for Mars?
On Feb 7, 2:35*pm, trag wrote:
On Feb 5, 4:47*pm, Quadibloc wrote: On Feb 5, 2:26*pm, Pat Flannery wrote: Hey, wait a second here...we can put the reactors into the reservoirs behind the dams and use the water as radiation shielding, like a giant swimming pool reactor! Soon, the reservoirs will be so warm that you could go swimming in them in them, and new and exciting species of fish will begin to evolve in them. (Cut to scene of 20-foot-long Northern Pike with legs where the fins should be crawling out of water and attacking people on the beach.) ;-) Well, nuclear energy is expensive, while hydroelectricity is cheap, so places with hydroelectric dams don't need nuclear power plants. Actually, after the plant is built, nuclear energy is cheap too. Which is exactly the case for hydroelectric. * They are very similar in that the bulk of the expense is a huge capital expenditure at the beginning and financing for that expenditure. Operating costs for nuclear power plants are tiny comparatively speaking. except for waste disposal, the elephant in the room that nuclear suppoters always try to ignore |
#786
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Once and for all...are humans or robots better for Mars?
On Mon, 07 Feb 2011 07:49:12 -0700, Fred J. McCall
wrote: Yep. People are likely to elect to drive longer distances. Not because of 9/11, but because it takes longer to get through airports so driving time that is acceptable goes up. I'm in your 2nd group - but there are significant numbers who claim that 9/11 is whey they don't fly. Most of those people didn't fly before and are just making excuses. It could be. But not that's not evident in the small sample of people I know. -- "In no part of the constitution is more wisdom to be found, than in the clause which confides the question of war or peace to the legislature, and not to the executive department." - James Madison |
#787
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Once and for all...are humans or robots better for Mars?
Are nuclear power plants adequately protected?
The Sept. 11 terrorist attacks on the World Trade Center and the Pentagon illustrated the deadly intentions and abilities of modern terrorist groups. These attacks also brought to surface long-standing concerns about the vulnerability of U.S. nuclear installations to possible terrorist attacks. The United States is home to 103 nuclear power plants located in 31 states, generating about 20% the nation's electricity. There are an additional 14 decommissioned plants, some of which still contain radioactive material. Some of these plants are located near large urban population centers. Experts consider U.S. nuclear reactors to be “high-value targets” for a terrorist determined to inflict large-scale death and destruction in the country. Since the September 11 attacks, the Federal Bureau of Investigation (FBI), the Nuclear Regulatory Commission (NRC) and other federal and state offices have received a number of threats or scares concerning U.S. nuclear power plants. The Air National Guard has been scrambled at least a couple of times to keep low-flying aircraft away from nuclear power plants, including the Vermont Yankee plant in Vermont and the Oconee plant in South Carolina. On October 17, according to plant officials, the Three Mile Island nuclear power plant in Pennsylvania was put on the highest alert after receiving, as described by the plant officials, a “credible threat” against the installation. A day earlier, the city of Baltimore, MD, was put on high alert due to a threat received against a nearby nuclear power plant. The NRC, which is the agency responsible for monitoring the safety of U.S. nuclear installations, has acknowledged receiving serious threats against U.S. nuclear power plants even before September 11. In 1999, for example, the NRC admitted to Congress that it had received a credible threat of a terrorist attack against a nuclear power facility. How Safe are U.S. Nuclear Power Plants? Despite the recent media and public interest in the topic, concerns about the vulnerability of nuclear power plants against terrorist attack or sabotage are not new. As early as 1982, the Argonne National Laboratory, a Department of Energy (DOE) facility, conducted a study detailing the likely damage that a jetliner could inflict on the concrete containment walls protecting nuclear reactors. The study described possible scenarios where an accidental jetliner crash could compromise the safety of a nuclear power plant’s primary containment wall and interior structure. The report estimated that even if just 1% of a jetliner's fuel ignited after impact, it would create an explosion equivalent to 1,000 pounds of dynamite inside a reactor building. An explosion of this magnitude impacting on a containment structure that has already been weakened by the crash of a high-speed jetliner crash could potentially compromise the integrity of the power plant. While the report refrained from providing detail, in these accident scenarios, about how and when radioactivity might be released, it stated that “the breaching of some of the plant's concrete barriers may often be tantamount to a release of radioactivity.” The report further stressed that U.S. nuclear regulators might have underestimated the potential damage from such explosions. Following the 1993 World Trade Center (WTC) bombing and revelations that Ramzi Yousef, the convicted mastermind of this event, had also plotted similar attacks against nuclear power plants, the NRC put in place measures to protect the country’s nuclear reactors from attack scenarios using land vehicles filled with explosives. Under enhanced security provisions, which according to the NRC have been in place since 1996, nuclear power plant security personnel received advanced training, anti-sabotage procedures were implemented, and new plant- monitoring devices were installed at many of the country’s reactors. In 1998, the NRC completed enhanced security mechanisms for spent fuel rod storage facilities. Most of the existing NRC security regulations, critics claim, are intended to protect against internal fuel damage from a small group of well-armed intruders aided by one insider; a lone insider; or a 4- wheel-drive land vehicle bomb. Despite the enhanced safety mechanisms imposed by the NRC under the Operational Safeguards Response Evaluation program, U.S. nuclear reactors remain vulnerable to terrorist attack or insider sabotage. The NRC’s own tests have illustrated that safety firewalls at many U.S. nuclear power plants are penetrable by outside intruders as well as disgruntled employees on the inside. Since 1991, despite months of advanced warning and beefed up security, some 47% of U.S. nuclear power plants failed to repel small mock terrorist attacks conducted by the NRC. Immediately after the September 11 attacks, the NRC stated that American nuclear power plants could withstand the crash of a commercial jetliner like those used against the WTC and the Pentagon. Within days of this assertion, however, the agency spokesmen found themselves backpedaling and stating that before Sept. 11 the NRC had not considered and prepared for the danger of an aerial attack on U.S. nuclear reactors involving large commercial planes loaded with jet fuel. The agency had no serious contingency plans for such attack because, as the NRC spokesman Victor Dricks stated, “it was never considered credible that suicidal terrorists would hijack a large commercial airliner and deliberately crash it into a nuclear power plant.” The International Atomic Energy Agency (IAEA) has also confirmed that current nuclear power plants are structurally vulnerable against the September 11 attack scenario that destroyed the World Trade Center Buildings. According to IAEA Spokesman David Kyd, "[Nuclear] Reactors have the most robust engineering of any buildings in the civil sector — only missile silos and nuclear bunkers are built to be tougher. They are designed to be earthquake-proof, and our experiences in California and Japan have shown them to be so. They are also built to withstand impacts, but not that of a wide-bodied passenger jet full of fuel. A deliberate hit of that sort is something that was never in any scenario at the design stage. These are vulnerable targets and the consequences of a direct hit could be catastrophic." In an interview with CNN’s Moneyline program, Kyd asserted that successful use of a large passenger airliner to attack a nuclear power plant is a rather unlikely scenario. In the course of the same interview however, Kyd acknowledged that, if such an attack were successfully conducted, “the containment could be breached and the cooling system of the reactor could be impaired to the point where radioactivity might well be set free.” According to experts, if a large airliner were to hit a nuclear power plant’s containment structure, the jet engines could penetrate the structure, leading to the introduction within the building of jet fuel and most likely a severe explosion and fire similar to those witnessed at the WTC and the Pentagon on September 11. Nuclear power plants are not well equipped to deal with severe fires, known as “common-mode failures.” Such accidents could actually cause various safety systems to fail simultaneously, leading to a loss of coolant that cannot be mitigated and ultimately resulting in a meltdown of the nuclear fuel. According to Robert Alvarez, a Senior Policy Adviser to the Energy Secretary between 1993 and 1999, while an attack or internal sabotage in any part of a nuclear reactor could pose significant danger to human health and the environment, perhaps the most significant radiological consequences from acts of malice would come from commercial reactor spent fuel pools. Spent fuel pools at many U.S. nuclear reactors contain, on the average, about five times more radioactivity than in the reactor core and constitute collectively the largest concentration of radioactivity on the planet. With the exception of a handful of nuclear power stations where the spent fuel is stored in dry-casks, the vast preponderance of commercial spent fuel is stored in water. In these pools, there are some 40,000 tons of highly radioactive spent fuel in about 137,000 spent fuel rods. Many rods, in compacted storage, are only about 9 inches apart -- one inch more than fuel rod spacing in a reactor core. For safety reasons, most of the spent fuel pools at commercial nuclear reactors were never meant to hold this much-spent fuel. To get around this problem, the NRC has required many plant operators to install complicated equipment to maintain water chemistry and temperature and to prevent criticalities. All of these "engineering work-arounds," argues Dr. Alvarez, add to the fragility of the storage system at the country’s nuclear power plants. The spent fuel pools at commercial reactors are mostly encased in what the nuclear industry describes as "steel super-structures," otherwise known as corrugated buildings. The structures protecting commercial spent fuel pools are not as well built as primary containment structures designed to protect reactor cores and are unlikely to withstand a plane crash or a ground-launched missile. If a pool and its equipment are damaged and develop leaks as a result of an attack or internal sabotage, the fuel-cladding could undergo an exothermic reaction and spontaneously catch fire when the water level in the pool drops half-way, exposing the rods. This is a scenario roughly comparable to what took place after the explosion at the Chernobyl nuclear power plant in Ukraine on 26 April 1986, the worst nuclear reactor accident ever recorded. The human, environmental, and economic cost of a successful terrorist attack or internal sabotage could potentially be as devastating as, if not worse than, the nuclear nightmare witnessed at Chernobyl in 1986. While the true extent of the human and environmental damage caused by the accidental meltdown of the Chernobyl plant’s core in Ukraine is yet to be assessed, the initial experience provides a glimpse of what is at stake. According to one report: “The accident at the Chernobyl plant led to the deaths of 30 power plant employees and firemen within a few weeks, mostly from acute radiation effects, and to the evacuation of over 100 000 people from surrounding areas. Large parts of Belarus and Ukraine, plus parts of the Russian Federation, were contaminated and approximately five million people still live in areas of these countries with levels of Cs ground deposition of more than 37 kBq/[m.sup.2]. Other countries in the Northern Hemisphere –principally in northern and eastern Europe – were also affected by radioactive releases from the plant, although generally to a much lower extent than in the former Soviet Union. The most notable finding from health studies following the Chernobyl accident has been the excess of thyroid cancer among those exposed in childhood in the severely contaminated areas of Belarus, Ukraine, and the Russian Federation. About 1800 cases were reported during 1990 to 1998, with the risk appearing to be greatest for those exposed at very young ages.” The task of shutting down and sealing off the contaminated Chernobyl plant in the aftermath of the 1986 accident took two years, more than 5,000 tons of material and a workforce of over 600,000. In the United States, the destruction of the nuclear core at Three Mile Island Unit 2 on March 28, 1979, cost $1 billion to clean up, although little radiation leaked. Huge areas of contaminated land become unsuitable for crops, factories, and habitation. Nuclear facilities are often located near large bodies of water, to support water consumption or tailing ponds; they are therefore also vulnerable to threats that could come in the form of a boat landing or missiles or explosives lobbed from a ship. In addition to terrorist attacks, nuclear reactors are vulnerable to internal sabotage, which could result in devastating accidents. The Union of Concerned Scientists has documented over 120 acts of sabotage at US nuclear plants. In 1993, in one of these incidents, a deranged person drove his car through the gate and crashed it into the turbine building of the Three Mile Island nuclear plant. The person left his car and disappeared for four hours while the panicked plant officials, worried that the car contained explosive, evacuated the building. Perpetrated mostly by disgruntled workers at every level of employment, including control room operators and security guards, internal sabotage is a matter of serious concern for the security of U.S. nuclear power plants. Studies conducted by the Sandia National Laboratories have concluded "there is still virtually no protection from the sabotage acts of an insider.” Existing safeguards at U.S. nuclear power plants are based on a number of false assumptions. U.S. nuclear regulators have thus far operated under the assumption that an attack against a U.S. nuclear power plant, however unlikely, would be on the ground and involve a small number of low skilled, uncoordinated people (who would not be capable of disrupting complicated safety system at a nuclear power plant) unwilling to take a large number of casualties. The events of September 11 have, quite tragically, demonstrated that today’s terrorists could be highly skilled, well coordinated, suicidal, and determined to inflict immense death and destruction. The U.S. government will thus be prudent to prepare for all possible attack scenarios against the country’s 103 nuclear power plants. Preventing a nuclear nightmare will require comprehensive short-term and long-term solutions. In the short-term, state and federal government officials, the NRC, and the nuclear industry must work together to assure the security of all nuclear reactors in the country against any possible threat. Current ad hoc security measures, such as the stationing of U.S. National Guard members at nuclear reactors, should be replaced by a more permanent, nuclear industry-funded and NRC monitored security system. The Federal Aviation Administration (FAA) must require the same or comparable security for general and commercial aviation and determine the practicality of instituting effective no-fly-zones over commercial nuclear power plants. The NRC should also require every nuclear power plant currently operating under NRC license to provide a comprehensive risk assessment of its survivability from a terrorist attack on radiation containment and critical safety systems. The NRC must conduct Operational Safeguards Response Evaluation (OSRE) programs at all nuclear power plants in the country. This should include currently operating reactors as well as the reactors that have been shutdown but have onsite spent fuel pools that could be just as deadly weapons in terrorists’ hands as an operating nuclear reactor. Federal officials should conduct OSRE tests with regular frequency and any plant that fails to meet NRC’s OSRE test criteria should be immediately shutdown. The government should also consider stockpiling Potassium iodide, at least in the public health care facilities located near nuclear reactors. Although not a panacea, wide distribution of Potassium iodide in Poland in the aftermath of the Chernobyl accident is believed to have protected thousands of people from illness. On the other hand, an epidemic of preventable childhood thyroid cancer has ravaged children in the Chernobyl-affected regions of Ukraine, Belarus and western Russia where potassium iodide pills were not widely available |
#788
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Once and for all...are humans or robots better for Mars?
On Feb 7, 4:50*pm, Howard Brazee wrote:
On Mon, 07 Feb 2011 07:49:12 -0700, Fred J. McCall wrote: Yep. *People are likely to elect to drive longer distances. *Not because of 9/11, but because it takes longer to get through airports so driving time that is acceptable goes up. I'm in your 2nd group - but there are significant numbers who claim that 9/11 is whey they don't fly. Most of those people didn't fly before and are just making excuses. It could be. * But not that's not evident in the small sample of people I know. well airtravel is way down since 9 11, it fell a lot then began to recover, then the economic dump hurt air travel futher...... |
#789
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Once and for all...are humans or robots better for Mars?
Yeah robotic exploration just is well impossible, and certinally not
worth even attempting. just like auto drive vehicles its impossible....... except for this http://www.spaceref.com/news/viewpr.html?pid=32670 |
#790
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Once and for all...are humans or robots better for Mars?
In article
, " wrote: if your unlucky enough to need a connecting flight, the added TSA fees get to be expensive Huh? If you connect, you don't go through security again (except when connecting internationally, and at rare airports that are really poorly designed). It can actually be cheaper to get a connecting flight to another flight rather than simply buying a ticket for that second flight alone, as smaller airports often charge less for processing passengers. -- Mike Ash Radio Free Earth Broadcasting from our climate-controlled studios deep inside the Moon |
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