(May 6, 1994) Northern States Power (NSP) is refusing to fully remove and replace a faulty fire barrier at its controversial two-unit Prairie Island nuclear power plant, despite years of evidence that the material does not work and may even contribute to fires, and despite NSP's voluntary removal of the material from its Monticello reactor.
(411.4074) WISE Amsterdam - The material in question is called Thermo-Lag, and it is used to protect vital electrical cables - necessary to operate reactor safety systems - from fire and water damage. Thermo-Lag has failed virtually every test conducted both by the federal Nuclear Regulatory Commission and by independent testing agencies. A federal grand jury is currently investigating Thermo-Lag's manufacturer, Thermal Science, Inc. of St. Louis, for possible fraud and misrepresentation.
Instead of having an operable fire barrier as required by NRC regulations, NSP - like many other utilities - is paying plant employees to circulate around the plant every hour, 24 hours/day, to check for fire. These 'fire watchers" are not issued protective clothing, even though, when burning, Thermo-Lag releases large amounts of highly toxic gases. Obviously, "fire watchers" are not capable of serving as fire barriers, Thermo-Lag's intended mission and a federal requirement.
In a virtual admission of Thermo-Lag's failures, NSP already has re-moved and replaced all Thermo-Lag used at its Monticello reactor, according to reliable sources, and more than half that used at Prairie Island. But in a February 10, 1994 letter to the NRC, recently obtained by NIRS, NSP states that removal of its remaining Thermo-Lag is the fifth of six possible options. The utility's first option is to simply declare that the material is sound. If that doesn't work, the utility hopes to seek an exemption from federal fire protection regulations. Other preferred options include repairing or upgrading the material, and/or rerouting the electrical cable. The only option considered by NSP to be inferior to removing and replacing the material is to actually test to ensure that its safety cables can withstand fire. Even under its preferred options, NSP does not contemplate resolving the issue until December 31, 19%.
At Detroit Edison's Fermi-2 reactor, which has a similar amount of Thermo-Lag as Prairie Island, removing and replacing the material with an effective fire barrier is costing only $325,000 - less than NSP is spending per week to attempt to convince the legislature to keep the plant open.
Background
Following a two-year investigation, in July 1992 NIRS submitted a petition to the NRC demanding that the River Bend reactor in Louisiana (upon which the most Thermo-Lag testing had been conducted) be prohibited from restart until its Thermo-Lag had been removed and replaced. In August 1992, NIRS amended its petition to demand the shutdown of several other nuclear reactors using large amounts of Thermo-Lag. A few days later, the NRC's own Inspector General issued a report charging Thermal Science, Inc. with conducting improper and possibly fraudulent tests of the material. In December 1992, NIRS further amended its petition to demand that every reactor using Thermo-Lag (79 in all) be forced to remove and replace the material during its next refueling outage. The NRC denied all NIRS petitions, but has yet to rule on most of the underlying issues involved.
On March 3, 1993, the House Energy Subcommittee on Investigations, chaired by Rep. John Dingell held a hearing at which the Subcommittee charged that Thermo-Lag is no more effective than gypsum board as a fire barrier material. The federal grand jury was convened around the same time.
Beginning shortly before NIRS' original petition, the NRC began testing Thermo-Lag. The material has failed all but one of the dozens of tests conducted. Testing criteria require that the material contain temperatures to no more than 325 degrees for either one or three hours, depending on the usage. Thermo-Lag has never passed a three-hour test, and even on one-hour tests has failed - often dramatically - within minutes. Temperatures in some tests have reached more than 1700 degrees. NIRS has color photos available of tests in which Thermo-Lag itself caught fire and burned.
The NRC acknowledges that Thermo-Lag is combustible itself, a violation of NRC regulations which require no combustible materials near electrical cables. In addition, Thermo-Lag has been unable to pass seismicity and other tests.
Despite this record, the NRC so far has refused to order Thermo-Lag's removal and replacement. NIRS has filed a formal complaint with the NRC's Inspector General charging the NRC staff with favoritism on this issue. Several utilities already have begun voluntarily removing their Thermo-Lag.
Meanwhile, the nuclear industry, through its trade association "NUMARC" (now part of the Nuclear Energy Institute) has been attempting to circumvent the fire protection rules. However, Thermo-Lag has failed even NUMARC's own tests, leading the industry to propose massive exemptions from the regulations or eliminating the regulations entirely.
The NRC's fire protection regulations were promulgated following a near-catastrophic fire at TVA's Browns Ferry reactor in 1975. As early as 1982, NRC staffers recognized that Thermo-Lag's effectiveness was suspect, but the agency did not act on the concerns for another ten years.
NRC reactor safety studies (for example, NUREG-1150) predict that each reactor can expect to experience 3 or 4 significant fires during its operating lifetime, and that, if there is a core meltdown, chances are as high as 50% that it will be caused by fire, even with an effective fire barrier.
Source & Contact: Michael Mariotte, Nuclear Information and Resource Service, 1424 16th Street NW, #601, Washington, DC 20036, Phone: +1 202-328-0002; Fax: + 1 202-462-2183; e-mail: nirsnet@aol.com.
