ML20028F874
| ML20028F874 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 03/16/1982 |
| From: | Halapatz J Office of Nuclear Reactor Regulation |
| To: | Vollmer R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20027A667 | List: |
| References | |
| NUDOCS 8302040551 | |
| Download: ML20028F874 (2) | |
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MEMORANDUM FOR: Richard H. Vollmer, Director Division of Engineering FROM:
Joseph Halapatz Division of Engineering
SUBJECT:
DIFFERING PROFESSIONAL OPINION This memorandum responds to the memorandum, Vollmer to Halapatz, dated March 8,1982, subject, " DIFFERING PROFESSIONAL OPINION," which addressed my visit to the General Electric Office at San Jose to review documenta-tion related to my concern. The memorandum requested that you be informed, of (1) the dates.of my trip and (2) of any difficulty in arranging a meeting with the appropriate people.
The memorandum also directed that I provide you a report of my findings and recommended actions within thirtf.
days after my trip.
By this memorandum you are provided an update of the current status of my OPO.
In a telecon with GE* on March 10, 1982, it was learned that GE objected to my visit, based on concern that my review would develop into an expanded scope review requiring an extensive GE manpower commitment.
GE provided information on plans to perform, under GE and utility sponsor-ship, a first time comprehensive metallurgical examination of type 304 stainless steel core structurals and internals of a long operating history BWR reactor, the West German KRB reactor, which has been shut down and decommissioned. TMse components will be removed from the reactor vessel and examined by procedures including dye penetrant inspection.
GE stated that plans for the examination are incomplete, but that the examinatign would be done before the end of the year.
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Given GE's objection to my visit to review fabrication procedures (in order to reach resolution of my DP0 I submit alternatives:
y 1.
Ongoing reviews of BWR reactor internals (SRP Section 4.5.2, " Reactor Internal Materials") should request that fabrication procedures, including welding and in-process and final heat treatment, begrovided S
for reactor internals.
GE: D. Robare & H. Watanabe (Licensing), Dr. Gordon &
Participants:
J. Cass (Metallurgy), W. Walker & P. Higgins (Services)
NRC: J. Halapatz & E. Sullivan l
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- Richard H. Vollmer
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It is inferred from our telecon with GE that high heat input weld'ing was used on some core internals. Given the design of some of the components, such as the core plate, in-process stress relief heat treatments would be required for dimensional stability purposes prior to final machining.
Such stress relief normally involves a tempera-ture of about 1650'F or higher to avoid the sensitization range.
Paradoxically, however, while a slow cool from the stress relief temperature would favor dimensional stability in such structures, it would likely seriously sensitize the material. On the other hand, if such structures were cooled rapidly from the stress relief tempera-ture in order to minimize sensitization, the structuras would likely i
distort dimensionally. Thus, the assessment of the propensity to IGSCC of material must be based also on its metallurgical heat treat-ment history.
Such history is available to the NRC through SRP 4.5.2.
SRP 4.5.2,III.4, "Austenitic Stainless Steel," commits the reviewer:
"The materials and fabrication procedures used for reactor internals Within this context, the metallurgical histories, pertinent to my DPO,can-be made<;-
are reviewed."
involving welding ~ and heat treatment available through ongoing OL reviews.
2.
GE's planned comprehensive metallurgical examination of the West German KRB reactor core structurals and internals at end of life deprecates the through-life assessments of integrity invoked by Section XI of the ASME Code.
In order for GE to perform its examination, the KRB reactor core structurals and internals will be removed from the reactor vessel.
Section XI Examination Category B-N-2, however, demands only that undefined " accessible surfaces" of in-place components be examined visually to acceptance standards, which are yet to be developed. There is some question then,related to the efficacy of Section XI require-ments in providing assurances of component integrity. A review of inservice inspection records of an operating plant should characterize the assurances of component integrity provided by Section XI ISI.
Within this context I propose the review of the ISI records of.
Monticello, a Mark I BWR, which completed its 10 year ISI during tts 1981 Fall maintenance outage. A review of these records would entail?
a two day trip to the Monticello site, located approximately thfity miles from Minneapolis, MN.
I will be prepared to propose recommended actions to reach the point of resolution of my DP0 within thirty days after implementation of the alter-natives I have identified.
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s ph Halapat cc: W. Johnston, DE l
W. Hazelton, DE C. Mohrwinkel, OP J. Thomas, NTEU
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