ML19270H021

Interim Deficiency Rept 1 from 790226-0301 Audit:Nine Pipe Spools Failed to Meet ASME Physical Impact Requirements. Caused by Failure to Follow ASME Charpy Impact Procedures. Next Interim Rept Scheduled for 790715

ML19270H021
Person / Time
Site:	Midland
Issue date:	06/13/1979
From:	James Anderson BECHTEL GROUP, INC., BECHTEL POWER CORP.
To:
Shared Package
ML19270H018	List: ML19270H017 ML19270H021
References
NUDOCS 7906220377
Download: ML19270H021 (3)

Text

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Bechtel Associates Professional Corporation Attac! rent to BLC-7767 s

SUBJECT:

MCAR 29 INTERIM REPORT 1 DATE: June 13, 1979 PROJECT: Consumers Power Company Midland Plant Units 1&2 Bechtel Job 7220 Description of Discrepancy Nine pipe spools, fabricated from ASME SA106, Gr B pipe,11 eat N32762, failed to meet the physical impact requirements for the material in accordance with ASME Section III code criteria. The NRC identified these spools during a review of Grinnell documentation. Crinnell subsequently notified Ecchtel of the potentially reportable problem.

Potenttal Safety Implication A potential safety problem would exist if inadequate material impact toughness properties at low feedwater temperatures resulted in, or contribute to, a main feedwater line break.

Investigation During an NRC audit of Grinnell on February 26, 1979 through March 1, 1979, it was discovered that ASME Charpy impact test procedures were not followed for Heat N32762 and, therefore, the results are not acceptabic.

The specific code requirements are as follows:

In accordance with NB 2332(1) of ASME Section III, test three Cv specimens at a temperature lower or equal to the lowest service temperature. All three specimens shall meet the requirements of Table NB 2332-1.

According to Table NB 2332-1, the required Cv (Charpy V notch test) values for piping are as follows:

Nominal wall thickness Lateral expansion (mils) 5/8" or les<, No test required Over S/8" to 3/4" (inclusive) 20 over 3/4" to 1-1/2" (inclusive) 25 Ove r 1-1/2" to 2-1/2" (inclusive) 40 2347 318 7900220 377 f

. w Bechtel Associates ProfessionalCorporation Attachrent to BIC-7767 MCAR 29 Interim Report 1 June 13, 1979 Page 2 of 3 Subarticle NB-2350 of ASME Section III pernits one Charpy V-notch impact retest (consisting of two additional specimens taken as near as practicable to the failed specimens) at the same temperature to be conducted, provided the following.

a) The average value of the test meets the minimum requirements, b) Not more than one specimen per test is below minimum.

c) The specimen not meeting the requirement is not lower than 10 ft-lb or 5 mils below specification requirements.

Contrary to the above, for IIcat 32762, Grinnell had performed four separate tests as identified below:

a) 19151: Test voided because specimen oriented incorrectly b) 19676-1 Results: 21, 40, and 45 mils (The minimum requirement is 25 mils for a material with a nominal wall thickness of 0.937 inches.)

c) 19676-3 Results: 21, 40, 45, 25, and 18. The last two were not noted as a retest, which was permissible, though Test l';676-1 indicated that only three samples were tested.

The failing 18 mils valee precludes a further test at the same temperature, d) A subsequent test was performed by the ITT Grinnell test laboratory with passing values at 29, 30, and 32 mils. This was a third test of the heat which is not allowed by the Code. This test was accepted by ITT Grinnell Industrial Pipe Inc.

Corrective Action

'Ih e follouing actions have been initiated or completed to resolve this situation.

1) l'echtel and CPCo vill revicu all impact tented material documentation at Grinnell ca June 14, 1979.

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. Bechtel Associates ProfessionalCorporation Attadrent to BIC-7767 MCAR 29 Interin Rc oort 1 June 13, 1979 Page 3 of 3

2) In response to the recommended action item, Grinnell stated at a meeting with Bechtel and CPCo on May 31, 1979, that it would recommend SA333 in lieu of SA106B for services that require low impact terperature material in all future orders.

3) Additional data obtained by Grinnell indicate that there may be regions of heat-effected zone on hot-bend sections of the pipe which will not meet the minimum Charpy test requirements. This spool has not been shipped from Grinnell. Grinnell has tested samples removed from the bend area itself during qualifications of the hot bend procedure which exceeded our minimum Charpy test requirements. Bechtel is pursuing this natter wi-b Grinnell and will provide an update in the next interim report.

4) Ecchtel originally specified that the feedwater pipe be supplied with a minimum Charpy test temperature of 30F. Bechtel has reviewed the minimum Charpy test temperature required for the specific heat-related spools. In accordance with Code definitions of ir.inimum service temperature and the operating criteria for the applicable portion of the system, a minimum service temperature of 70F is required. A minimum service temperature of 30F was originally specified, based on the minimum expected service temperature for any fluid piping system within the plant. Tl'is conservat ive value was specified for feedwater piping for case and consistency in contract administration.

Based on additional test data available at Grinnell for these specific heats, the material uould exceed Charpy test requirements except for hot bend sections. Therefore, we believe that the reportable condition of the pipe is indeterminate at this time because the acceptability of the hot bend sections is uncertain.

Forecast Data for Investy,ation and Corrective Action Our next interim report is scheduled for July 15, 1979.

Subnitted by:  ;

&y Approved by- /JMG -k dQ Concurrence by: -g y (_.

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