Nuclear - ASME Section III N-Stamp - Requirements over and above AS9100 and ISO 9001



My company is currently registered to ISO 9001-2000 and AS9100. We are looking at expanding our product line into the nuclear power industry. I understand from our potential customers that they would require us to obtain an ASME Section III N-Stamp. I have started to research this on the internet, but have found very little information. I am interested in determining what the requirements are over and above AS9100 / ISO. Since my searched didn't locate any posts regarding the N-stamp, I have started a new thread.
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Quite Involved in Discussions


Do a google search for Appendix B to Part 50- Quality Assurance Criteria for Nuclear Power Plant and Fuel Reprocessing Plan
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Al Rosen

Staff member
Super Moderator
I don't have first hand knowledge about this, but I did find the attached Quality System Checklist. Hope it helps give you an idea of what's required. Of course the bottom line is purchase the standard(s) associated with the product(s) you intend to get certification for.


Al Rosen

Staff member
Super Moderator
BadgerMan said:
I saw that ASME has it available for a mere $375.00

Or you can buy the following:
III - Rules for Construction of Nuclear Power Plant Components (11-volume set) $3,940
The Complete ASME Code $10,600
The Complete ASME Code, with 32 Special Binders $11,240



You must first have a QA program that complies with 10CFR21, 10CFR50 Appendix B, ASME NQA-1, ANSI N45.2, and ASME NCA-3800. My company is in compliance with these and has researched the N-stamp angle. Too expensive for our business. As stated earlier, just the cost of the the B&PV code books will set you back quite a bit.


Hi gnesslar,

I work for a Canadian nuclear power plant operator. Nuclear items are designed and fabricated to CSA N285.0 which adopts many sections of the ASME III code. The ASME III is a design code that tells you how to design, fabricate and inspect things, complete with required calculations and material strengths. It requires complete traceability of items from raw material to finished product to installation. The joke in nuclear is that the paper-work can cost more than the item!

ASME III NCA-4110 (b) requires a quality assurance program to meet the requirements of NQA-1 1989 edition with 1989, 1991 and 1992 addenda. You can buy old copies of the code from I have a 1996 (outdated) checklist which might help you to decide how close your current program is to meeting ASME III requirements. The quality assurance is the REAL big cost of the program, not the code books.

Yes, the code books are expensive (they’re massive), BUT unlike ISO, you aren’t continually forced to buy the newest code. You pick a code revision "date" that works for you and your customers, and you use all the code for that date. Nuclear customers prefer to purchase items to the code-effective date of their station (i.e. older codes).

It’s not an easy field to jump into and understand. An introductory course from ASME or ANRIC Enterprises would be well worth the money to get a good over-view, ensure you don’t miss something and make a good business decision. Also recommended is a couple of hours browsing through a copy of the code at a nearby university library.

An interesting twist worth exploring is the Canadian regulations. An N stamp is NOT required. You must build to the ASME code and register the design with a province. In the case of Ontario that's the the TSSA

It’s true that the number of nuclear suppliers has declined since new plants are not being built. However operators of existing nuclear plants are willing to pay high prices to the dwindling number of suppliers for replacement items and parts that meet code requirements. Don’t shy away from the business because the apparent price of the product appears too high! From my perspective it’s frequently cheaper than designing a modification or shutting a nuclear station down.

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