ML19329B161
| ML19329B161 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/29/1972 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Sampson G TOLEDO EDISON CO. |
| References | |
| NUDOCS 8001300732 | |
| Download: ML19329B161 (3) | |
Text
O e
UNITED STATES I
ATOMIC ENERGY COMMISSION 4 C-y DIRECTORATE OF REGULATORY OPERATIONS REGION lli Q #'8 fit l' p 799 ROOSEVELT ROAD TurPHONE GLEN ELLYN, ILLINOIS 60137 (J12) 858-2660 June 29, 1972 Toledo Edison Company Docket No. 50-346 ATTN: Mr. Glenn J. Sampson Vice President, Power 420 Madison Avenue Toledo, Ohio 43601 Centlemens Information obtained during inspections conducted by the Directorate of Regulatory Operations, has disclosed that a number of facilities have been equipped with valves with wall thicknesses below the minimum requirements specified by the applicable codes, standards and procurement specifications. In other instances, licensees have not been able to dociament whether or not their valves met minimum wall thickness require-ments. Our survey of this subject has disclosed that the matter is not limited to any class of licensee or valve supplier.
In light of the above information, you are requested to verify, through manufacturing records or other suitable means, that valves important to mielmar safety installed or to be installed at your facility meet the minimum wall thickness requirements of the specified codes or standards. To the extent that verification records are es.rrently available, you are requested to promptly accumulate those records at the plant site, and to advise this office within thirty (30) days of the date of this letter, of what records are available and when our inspector may examine them at the plant site.
In the event that records are not currently available, you are requested to advise this office within thirty (30) days, of your plans and sch=Ai1=s for demonstrating by suitable alternate means, that valves important to nuelaar safety installed or to be installed at your facility are acceptable with respect to wall thickness. Records of conformance
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shall be maintained current with inspections performed.
O 8001300 fM
Toledo Edison Company.fune 29, 1972 The valves which require descuatration of acceptable wall thickness are the following:
Each valve within the reactor coolant pressure boundary, as defined in subsection 50.55(a) (Codes and Standards) of 10 CFR 50, where the valve ist (a) over 1-inah naminal pipe size for pressurized water reactors; (b) over lle-inch -i==1 pipe size in water lines for boiling water reactors; (c) over 24-inch naminmi pipe size in steam lines for bofling water reactors.
The following techniques are considered to be a sufficient demonstration of acceptable wall thickness. Alternate techniques may be offered, but there is no assurance that they will be found acceptable:
O (1) Documented direct physical measurement of actual wall thicloness, with comparison to specified minimiss vall this'assa.
(2) Documented results of ultrasonic measurement of wall thickness, with comparison to specified minimum wall thich====, and doctmentation that the ultra'nonic measure-ment technique is demonstrated to have a maximum error
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in repeatability and accuracy, of not more than 2% of the well thickness.
(3) Wall thicknesses, verified by either of the above techniques, to be not less than 90% of specified minimma t
l wall thickness will be acceptable, provided that the documented mechanical characteristics of the material exceed the specification minimum by an amount sufficient to compensate for the measured reduction in wall thickness.
(4) "Specified Min 4==== Wall Thickness" as used above, means the wall thickness required by the relevant codes and standards (e.g., ASA B31.1 (1955); USAS B31.1.0 (1967);
USAS B16.5; MSS-SF-66) in effect on the date of the purchase order.
I Toledo Edison Company June 29, 1972 (5) Certain of your valves may have, for procurement convenience, been ordered. to ratings higher than actually required by service conditions. In such instances, you may, if you wish, provide for our review, en engineering justification for accepting valves which j
do not conform to procurement specifications, but do in your opinion, satisfy service requirements. Such justification should be promptly transmitted to this office, in ten (10) copies.
(6) In certain instanees, you may wish to repair valves found i
l to have well thicknese below the specified minimum. In such instances you are requested to provide this office for our review, the proposed repair procedure, including a description of techniques to be used to verify the acceptability of the repaired components. Such a proposed procedure should also be submitted in ten (10) copies.
Acceptable documentation of conformance with the above requirements must be i
j completed within three (3) years of the date of this letter.
Yery truly yours, Boyce H. Grier Regional Director bec: RO Files DR Central Files PDR Local PDR
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