nuclear critics charge reactors\' o ring seals pose a threat to safety

Stuart DIAMONDSEPT.
1986 this is a digital version of an article from The Times Print Archive, before it starts online in 1996.
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Thousands of O-rings similar to those that caused the shuttle disaster were used as seals for nuclear power plants.
Although the problem is not serious in the reactor, it has raised concerns among nuclear critics, regulators and operators.
In a report released today, scientists critical of nuclear industry safety projects say seals have failed hundreds of times in nuclear power plants over the past decade.
None of these failures caused a serious accident, but it is reported that such an accident may occur, or that serious accidents caused by other reasons may deteriorate due to O-ring failure.
It says that ordinary industrial O-rings cannot withstand the high temperatures and radiation of some serious nuclear accidents, just as the O-rings of the Challenger shuttle cannot withstand low temperatures.
They failed to seal the belt in January.
Seven crew members were killed in the disaster.
The report said no orders were made for systematic remedial action at the nuclear power plant. The report was written by current and former engineers from the Washington Association of relevant scientists.
An advertising spokesman for the industry and the government said they were working on the issue, which they said was not as serious as the report said.
The AdvertisementO ring is an exact engineering version of the gasket that prevents leakage of the faucet, the gasket that seals the fluid in the car engine, or the rubber ring that seals the jelly tank.
They are mainly used to isolate materials.
Oil, water or gas.
Internal parts that are connected and released from time to time.
The diameter of the O-ring can range from less than 1 inch to more than a dozen feet.
The waterproof watch also has an O-ring to seal.
Unlike conventional washers, the O-ring is designed to close any escape passage through deformation as the pressure increases to form a tighter seal.
In the space shuttle, the O-ring is designed to prevent gas from leaking from the solid
Fuel Booster Rocket
But the cold temperatures apparently cost the seals flexibility.
In nuclear power plants, O-rings are used to separate fluids in pumps, valves and switches.
They are also part of a system to prevent leakage of radioactive materials in accidents, acting as seals for dozens of hatches, wires or other equipment that penetrate concrete and steel reactor containment buildings. The 65-
The page report, funded by public citizens of groups critical of nuclear energy, lists dozens of cases of nuclear power plant failures from 1975 to June.
For example, on June, the O-ring at the LaSalle nuclear power plant in Senica failed.
The company was accused of a failure of an automatic shutdown system and an emergency cooling system, the report said.
On August 1985, two main emergency cooling pumps of reactor No. 1 of Biver Valley, Port Pa Shiping.
The report said they were declared unable to operate after a leak in the O-ring was found.
In various factories, O-rings that leak oil can damage the function of shock avoidance devices that protect pipes and other equipment during an earthquake.
O-ring problems were also found to affect diesel generators used for backup power supplies in emergency situations.
\"This is a serious problem,\" Robert D.
Pollard, the author of the report and a nuclear safety engineer at the relevant league of scientists, said in an interview.
\"I don\'t know if it will cause an accident tomorrow, as NASA knew before January, and its O-ring will cause a disaster for the Challenger shuttle.
However, there are known safety defects in the operation of the nuclear power plant, and the Nuclear Regulatory Commission has not taken systematic actions to correct these defects.
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Pollard, a former commission staff member, said that the nuclear O-ring problem was not serious with the shuttle problem, which prompted the study because the loss of the O-ring would not result in the loss of the nuclear power plant.
But he pointed out that many O-rings in nuclear power plants usually can only withstand temperatures of 500 degrees Fahrenheit, and if the nuclear fuel melts, it is less than half the possible temperature in the containment.
High radiation, he said, further damages O-rings, thereby damaging the emergency system.
Victor Stello, executive director of the operations of the regulatory commission and top staff, said in an interview yesterday that the O-ring was a long-standing problem, but not serious.
Pollard argued.
He said his experts and the nuclear industry are fully addressing the problem.
\"There are thousands of O-rings in the nuclear power plant, and you will see a lot of O-rings malfunction . \"Stello said.
\"We are making announcements to address these issues.
However, there is no O-ring collection anywhere in the nuclear power plant that can cause major safety issues.
There is no basis for any comparison with the challenger.
However, he does say that in the case of some Westinghouse pumps circulating cooling water to the reactor, the regulator sees the O-ring leakage as \"a major problem \".
If all the AC power is lost, the four pumps may heat to the extent that the O-ring is degraded, causing the leakage of 80 gallons of cooling water per minute, he said.
But he said that before the reactor core is in danger of melting, the loss of power to flood the reactor must last 16 hours. Loring E.
Mills, vice president of nuclear activities at the Edison Electric Power Institute of the utility industry trade association, said reactor operators were aware of potential problems involving O-rings and were taking corrective measures. E.
Preston Lach, nuclear safety manager at Westinghouse power company, said last night that Westinghouse plant had more than 0. 14 billion hours of experience in the \"no catastrophic failure\" of the reactor coolant pump o-ring.
But he said the company is completing the development of an advanced O-ring material to further improve safety. Mr.
Stello of the regulatory commission said that if there were other O-ring problems, there was a backup system, adding that the additional amount of radiation leaked from the failed containment seal was relatively small.
However, he said the regulator was very concerned about this and issued a series of announcements on the matter, most recently in July 11.
He added that in the case of some serious accidents, O-rings in some reactor equipment were not eligible for temperature and radiation.
\"This is an area that we are looking at right now,\" he said . \". Mr.
Mills at the Edison Institute, a nuclear engineer, said the reactor operator was taking corrective actions in regular maintenance projects and special studies.
While O-rings may fail in some cases, it is not a catastrophic thing, he said.
\"A version of this article appears on the national edition C00003 page of September 16, 1986, titled: nuclear critics accuse the O-ring seal of the reactor of posing a threat to safety.