Title: Radiological analysis and transmutation calculation of representative castable nanostructured alloys

Abstract

In this work, radiological analysis regarding the waste management was performed on two current reduced-activation ferritic-martensitic (RAFM) steels Eurofer 97 and F82H and two castable nanostructured alloys (CNAs) CNA1 and CNA3 using the European DEMO first wall spectrum. CNA1 and CNA3 are a new generation of RAFM steels, which have increased amounts of nanoscale carbonitrides and carbides precipitates, respectively, via small composition modifications. Furthermore, the increased nitrogen in CNA1 leads to higher activity at ≥50 years, and thus to the disposal concern under the current NRC regulation. However, the calculation using Fetter’s evaluation leads to reduced waste disposal rating (WDR) of down to 0.25 depending on the damage dose from ~0.05 wt percent nitrogen in CNA1, and thus less concern on the waste disposal. Contact dose rate after 10 years from the first wall replacement primarily depends on the initial Co and Nb impurity levels. Other added elements, such as V and Si in CNA1 and Ti and Mn in CNA3, do not have significant effect on the specific activity, contact dose rate, or decay heat. Composition limits of CNAs are given based on the shallow burial disposal and materials recycling. In addition, composition evolution of typical precipitates in themore » CNAs was calculated using the DEMO first wall and the HFIR spectra. Larger transmutation-induced composition evolution occurs in the V/Ta-rich carbonitrides in CNA1 than that in the Ti-rich carbides in CNA3.« less

Authors:

Zhong, Weicheng  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-3158-9271"

Tan, Lizhen  ^[1]

• Search DOE PAGES for author "Tan, Lizhen"
• Search DOE PAGES for ORCID "0000-0002-3418-2450"

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:

Sun Nov 01 00:00:00 EDT 2020

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1651334

Alternate Identifier(s):

OSTI ID: 1775562

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Fusion Engineering and Design

Additional Journal Information:

Journal Volume: 160; Journal Issue: n/a; Journal ID: ISSN 0920-3796

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Fusion; waste management; reduced activation ferritic martensitic steels; composition limits