ML20197J080

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Forwards Matls Engineering Branch SER Re Limiting Postulated Design Temp.Util Containment Pressure Boundary Matls in Compliance W/Gdc 51
ML20197J080
Person / Time
Site: Hope Creek PSEG icon.png
Issue date: 09/26/1984
From: Johnston W
Office of Nuclear Reactor Regulation
To: Novak J
Office of Nuclear Reactor Regulation
Shared Package
ML20197E062 List:
References
FOIA-86-280 NUDOCS 8410040256
Download: ML20197J080 (7)
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o UNITED STATES NUCLEAR REGULATORY COMMISSION  !

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Docket No: 50-354 MEMORANDUM FOR: Thomas M. Novak, Assistant Director for Operating Licensing Division of Licensing FROM: William V. Johnston, Assistant Director Materials, Chemical & Environmental Technololgy .

Division of Engineering .

SUBJECT:

GDC 51 COMPLIANCE REVIEW: PUBLIC SERVICE ELECTRIC ~"

AND GAS COMPANY - HOPE CREEK UNIT 1 t -

Plant Name: Hope Creek Generating Station, Unit 1 -

Suppliers: General Electric, Bechtel Licensing Stage: OL Docket Number: 50-354 .

Responsible Branch & Project Manager: LB#2; D. Wagner Reviewer: J. Halapatz Requested Completion Date: Open Description of Task: SER Re GDC 51 Compliance Review Status: Awaiting Confirmatory Information The Materials Engineering Branch, Division of Engineering, joint review of the containment pressure boundary materials of Hope Creek Generating Station, Unit 1, was conducted with General Electric at San Jose, CA on June 21, 1983 and with Bechtel at San Francisco, CA on June 23, 1983.

The review identified the limiting materials of the containment pressure ~

l boundary and the limiting environmental temperature placed on these '

materials under operating, maintenance, testing and postulated accident conditions cited by GDC 51, " Fracture Preve'ntion of Containment Pressure Boundary."

The applicant has submitted information intended to confirm that the limiting i postulated design temperatures will not violate the limiting temperatures '

identified by the review. We have reviewed the information and conclude, with l gwooprc V4 7 l- 1

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SEP 2 61564 Thomas M. Novak ,

one contingency, that the materials of the Hope Creek containment pressure boundary are in compliance with GDC 51. Our safety evaluation is presented in the attachment to this memorandum.

William V. Johnston, Assistant Director Materials, Chemical & Environmental Technology Division of Engineering ,

Attachment:

As Stated -

cc: R. Vollmer D. Eisenhut

- E. Sullivan

5. Pawlicki

. B. D. Liaw A. Schwencer W. Hazelton R. Klecker C. Cheng D. Wagner J. Halapatz

Contact:

J. Halapatz ~

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DISTRIBUTION:

DMB - Docket Files MTEB Reading Files MTEB Hope Creek Files DE: h>

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DE:MTEB DE:MTEB DE: . [E:MTEB J. Halapatz: tbjp W. Hazelton B. D. rfaw W. V. Johnston 9/10/84 9/11 /84 9/ /84 9/;i~/84 J

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ATTACHMENT PUBLIC SERVICE EL'ECTRIC & GAS COMPANY HOPE CREEK GENERATING STATION UNIT 1

Docket No. 50-354 MATERIALS ENGINEERING BRANCH MATERIALS APPLICATION SECTION 6.2.7 Fracture Prevention of Containment Pressure Boundary Our safety evaluation review assessed the ferritic materials in the -

Hope Creek Generating Station Unit 1 containment system that constitute ' '

the containment pressure boundary to determine if the material fracture toughness is in compliance with the requirements of General Design Criterion 51, " Fracture Prevention of Containment Pressure Boundary."

GDC 51 requires that under operating, maintenance, testing and postulated accident conditions, (1) the ferritic materials of the containment pressure boundary behave in a nonbrittle manner and (2) the probability of rapidly propagating fracture is minimized.

The Hope Creek Unit 1 primary containment includes a ferritic steel containment vessel (drywell), a ferritic steel suppression chamber (torus) and vent pipes providing the connection between the drywell and the torus. The ferritic materials of the containment pressure boundary, which were considered in our assessment, are those which have been applied in the fabrication of the drywell, drywell head, torus, vent pipes and primary containment equipment hatch, personnel 4

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lock and penetr'ation's and piping system componen~ts, including the valves required to-isolate the system. These components are the parts of the containment system which are not backed by concrete and must sustain loads under the conditions cited by GDC 51 and provide a pressure boundary during the performance of the containment function.

1 We have determined that the fracture toughness requirements contained -

in ASME Code editions and addenda typical of those used in the design "

. of the Hope Creek Unit I containment may not ensure compliance with GDC 51 for all areas of the containment pressure boundary. We have elected to apply in our licensing reviews of ferritic containment pres-sure boundary materials the criteria for Class 2 components identified in the Summer 1977 Addenda of Section III of the ASME Code. Because the fracture toughness criteria that have been applied in construction typically differ in Code classification and Code edition and addenda,.

we have chosen the criteria in the Summer 1977 Addenda of Section III of the Code to provide a uniform review, consistent with the safety function of the containment pressure boundary materials. Therefore, we reviewed the materials of the components of the Hope Creek Unit 1 containment pressure boundary according to the fracture toughness requirements of the Summer 1977 Addenda of Section III for Class 2 components.

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l Considered in our review were components of the containment system which are load bearing and provide a pressure boundary in the per-formance of the containment function under operating, maintenance, testing and postulated accident conditions as addressed in GDC 51.

These components are the containment vessel (drywell), torus, vent pipes, drywell head, equipment hatch, personnel airlocks, penetrations ,

and elements of specific containment penetrating systems. -

Our assessment of the fracture toughness of materials is based on the

. metallurgical characterization of these materials and fracture toughness data presented in NUREG-0577, " Potential for Low Fracture Toughness and Lamellar Tearing on PWR Steam Generator and Reactor Coolant Pump Supports," USNRC, October 1979,for comment, and ASME Code Section III, 9

Summer 1977 Addenda, Subsection NC.

The metallurgical characterization of these materials, with respect to their fracture toughness, was developed from a review of how these materials were fabricated and what thermal history they experienced during fabrication. The metallurgical characterization of these materials, when correlated with the data presented in NUREG-0577 and the Summer 1977 Addenda of the ASME Code Section III, provides the technical basis for our evaluation of compliance with the Code requirements.

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Based on our review 'of the available fracture to~ughness data and materials fabrication histories, and the use of correlations between metallurgical characteristics and materials ' racture f toughness, we conclude, with one condition, that the ferritic components in the Hope Creek Unit I containment pressure boundary meet the fracture toughness requirements that are specified for Class 2 components by .

the 1977 Addenda of Section III of the ASME Code. Compliance with -

these Code requirements provides reasonable assurance that the "

- Hope Creek Unit I reactor containment pressure boundary will behave i i

in a ncnbrittic ::nner, that the probability of rapidly propagating fracture will be minimized, and that the requirements of GDC 51 are satisfied. The contingency relates to the feedwater check valves (lF074 A&B).

c Our review identified 24-inch feedwater check valves (1 F074 A&B) as parts of the reactor containment pressure boundary. The cast bodies of these valves are known to contain shrinkage flaws, which have been known to propagate in l service. Because of the presence of these flaws and the uncertainty related l to their propagation in service, we were unable to conclude, relative to l

fracture toughness, that sufficient margin of safety existed under the limiting environmental condition to be experienced by these valves, VIZ.,

1180 psi at 40*F, postulated for HPCI, as identified by the applicant, when I

these valves are called upon to serve as a containment pressure boundary.

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We addressed th~e fra'cture toughness of the same 24-inch feedwater check valves (IF074 A&B: 2F074 A&B) with cast bodies also known to contain shrinkage flaws, in the review of Limerick Generating Station Units 1 & 2, (Docket Nos. 50-352/353). We concluded, in this case, based on the results of our own analysis and an augmented inservice inspection program acceptable to the staff, that reasonable assurance of compliance with GDC 51 would be provided. The augmented ISI would provide confirmation that the shrinkage <

flaws existing in the valve bodies on entering service have not propagated

. t6 either of the surfaces. Should the augmented ISI disclose, however, that tnese flaws nave propagated to the surface, the valves then are to be replaced by the licensee.

We request that the applicant in the matter of Hope Creek Unit 1 also consider f

i making a commitment to an augmented inservice inspection program, which will include inspection of the outer and inner valve body surfaces at the first refueling outage and at other times when the valve is disassembled for ,

maintenance. This condition is identified as a confirmatory item in our  !

safety evaluation.

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