ML20235H220
| ML20235H220 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/16/1987 |
| From: | Drey K DREY, K. |
| To: | Shotkin L NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| References | |
| NUDOCS 8707150059 | |
| Download: ML20235H220 (2) | |
Text
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' Mrs.Mo Drey 515 West Point Avenue y
. University City, MO 63130 i
l June 16, 1987 Mr. Louis Shotkin, Chief Reactor Systems Branch Division -of Reactor and Plant Systems Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission -
Washington, DC - 20555 Dear Mr. Shotkins Last November when investigating the announcement by the NRC of two Level IV violations which had been issued.to Union
= Electric involving a primary coolant ' leak in August 1986 at the Callaway nuclear power plant, and the related radia-tion exposure of ten workers, a St. Louis Post-Dispatch reporter.was told by Union Electric that as of that time an estimated;100 fuel rods out of the 50,000+ in the reactor were probably defective -- causing levels of radioactivity in the reactor coolant above technical' specification limits.
The UE spokesman sought to assure. the public that this unex-n pectedly elevated level of radioactivity was to be only tempo-ary (that is, for. only about another year): "'We're checking with Westinghouse to see if we got a bad batch....We don't like it, but it's well within our ab,ility to clean up.>
The defective rods will be replaced next September [1987]
when the plant refuels for the second time."
(St. Louis Post Dispatch; November 7,1986).
I was reminded of the impending September refueling when I read the enclosed Fulton Sun article concerning a June 8 accident during the shipment of some of Callaway's replacement fuel. According to the article, a truck bearing seven casks containing perhaps two fuel assemblies each ' *urned over on a highway exit ramp near Knoxville, Tennessee.
I am sending this letter to you to ask several questions about that accident:
1.
Would you please tell me if the NRC has called for an investigation of these thin-walled fuel rods to see whether the-impacts received during the accident caused any. ruptures due to bending or sheer stresses not antici-pated in design?
Since the zirconium-alloy tubing or cladding is only 2 hundreds of an inch. thick, it would appear to me that any weakening of the thin-walled fuel rods from excessive stresses could lead to accelerated corrosion and higher leakage rates of the fuel rods' fission products into 4
the reactor cooling water.
0 pmme p Wa*
gi
p Mr. Louis Shotkin, Chief Page 2 June 16, 1987 2.
Am I correct in assuming that the rods being transported were the new Westinghouse Vantage-5 fuel rods designed for the higher burnup levels currently being allowed by the NRC? If not, would you please tell me the type of rods -- and the thickness and type of cladding?
3.
Is there enough time for an adequate investigation and inspection of the rods prior to the refueling scheduled to start in September, or will the NRC require Union Electric / Westinghouse to replace these structurally questionable fuel rods and assemblies?
f Your response to the above request for information will be greatly appreciated.
I Sinc erely, f
p.s.
Also, may I please trouble you for a copy of the NRC's Environ-mental Impact Appraisal on the generic use of high-burnup nuclear i
fuel in the United States? I would be happy to pay for photocopying and postage, l
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