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Federal Regulations, Codes, &
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ASME Section XI Users Group Bulletin Board |
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Welcome to the ASME Section XI Users Group Bulletin Board for the United States Nuclear Power Federal Regulations, Codes, & Standards Users Group. This bulletin board is for the use and benefit of all individuals and organizations that wish to post specific questions and replies that are relevant to the implementation and use of ASME Section XI. Questions and replies are posted below as they are received, and only identify the subject, date, and signature as provided, if any, to maintain individual privacy. Advertising and irrelevant material will not be posted. Please limit your postings to 100 words or less and do not include attachments. Send your questions and replies to bulletinboard@tech-tel.com. To search this bulletin board for key words and phrases, click on "Edit" on your web browser tool bar and then click "Find ... ". In the resulting dialog box, insert the desired key word or phrase and then click "Find ... ", repeatedly as necessary to locate multiple entries as you proceed through the page. |
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Note: All information provided on this bulletin board is provided "as is", without warranty of any kind, as stipulated in the Disclaimer and Conditions of Use for this web site. |
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Bulletin Board Postings: |
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Date:
Monday, 2 June 2008 Subject:
Implementing IWA-5244 For The Underground Diesel Fuel Oil Tanks Dear Group: I would like to post the following for
industry feedback: A lot of discussion
has circulated around the industry regarding buried portions of the Nuclear Service
Water system containing butterfly valves and the IWA-5244 requirements. I would like to know how those in the
industry are meeting the IWA-5244 requirements for the underground Diesel
Fuel Oil Storage tanks. If included in
the ISI program, these systems are generally classified as ISI Class 3. I would appreciate any information
regarding utility experience such as: 1. ISI classification or omission from ISI
based on Regulatory Guide 1.26. 2. Does anyone use American Petroleum
Institute (API) standards for testing? 3. Does the candy cane vent, which is open to
the atmosphere, constitute a nonisolable configuration? 4. Does anyone use a customized test
configuration such as a low pressure hose connected to the candy cane vent? Thanks in advance
for any information on this issue, Jim |
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Date:
Wednesday, 20 February 2008 Subject:
Activities That May Impact Inservice Inspection Plans Question #1: Do you perform any of the following activities
to identify changes to Class 1, 2, 3, MC/CC components that could impact your
current and future Inservice Inspection Plans (including pressure testing
plans)? 1. Review Repair/Replacement Plans for Code Repair/Replacement
Activities 2. Review repair/replacement work packages associated with
planned modifications prior to work being performed 3. Review completed NIS-2 Forms for Repair/Replacement
Activities 4. Perform periodic reviews of work packages associated with
plant maintenance activities 5. Perform periodic reviews of as-built drawings releases for
P&ID drawings to identify system classification and system boundary
changes Question #2: What
methods other than those described in Question #1 do you use to identify
changes to Class 1, 2, 3, MC/CC components so that personnel responsible for
your Inservice Inspection Program can evaluate what effect these changes have
on your Inservice Inspection Plans? Thanks, Mark |
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Date:
Friday, 11 January 2008 Subject:
Mid-Cycle Outage For Fuel Leak Dear Group: We’ve developed a fuel leak and have
performed suppression to minimize further degradation. Our site may still elect to perform a
mid-cycle outage to remove the leaking bundle to minimize future source term. After
reviewing Section XI (current code of record is 1995 Edition with 1996
Addenda) and also Interpretation XI-1-01-19 (attached), we’ve concluded that
Section XI doesn’t require a Category B-P pressure test for a mid-cycle
outage even if the RPV head is removed and reinstalled. For those plants that have
performed a
mid-cycle outage and removed/reinstalled the RPV head, what sort of inspection activity, if any, was performed to verify no
leakage after reassembly? What
edition/addenda of Section XI was in effect as their code of record at the time of the
mid-cycle outage? Thanks, Ric |
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Date:
Tuesday, 22 January 2008 Subject:
Mid-Cycle Outage For Fuel Leak Dear Ric: Please
see the responses below. Mike
Blew:
In this day and age, regardless what the ASME Code identifies (which are
minimum requirements) I think to perform the exam would be prudent, based on
the problems with boric acid. Roy
Blyde:
I fully agree with your Code interpretation, no Code examination is
required for a mid cycle outage as it is not a refueling outage. We have been in this situation during
forced outage (FO28), head off but no fuel removed. However, as a matter of good engineering
practice we performed a VT-2 examination of the disturbed pressure boundary
components. This is a practice we use
for all activities involving disassembly of pressure boundary components as
we believe it is prudent to check for leaks following such disturbance. However, these are not Code required
examinations as they are maintenance activities, e.g. disassembly and reassembly
of a valve bonnet or flanged joint. I would therefore recommend that a
non Code VT-2 examination is undertaken for the pressure boundary components
that have been disassembled. Jim
Boughman:
I do not recall any mid-cycle outages at Duke Energy plants where the
RPV head was removed and reinstalled.
In addition to Interpretation XI-1-01-19 that was referenced in the Hien
Do: We
do not require a Section XI pressure test after disassembly and reassembly of
RPV Head mid-cycle when there are no Section XI repair/replacement
activities. However, it is my
understanding that Ops would perform a walkdown at various pressure levels to
check for leaks. No VT-2 qualification
is required for this Ops walkdown. George
Fechter:
The first thing I was going to mention was the inquiry that Dan
Lamond:
I don't have much specific experience with this one other than the
interpretation you have already mentioned as clarifying that Section XI
pressure testing does not apply to this situation. Beyond that, I would think it would fall
under the plants maintenance program and that program would have requirements
for assuring structural/joint integrity after disassembly/reassembly
activities. Ken
Thomas:
When we had this condition, we performed the normal start-up walkdowns
for evidence of leakage. It was not a
VT-2 examination since there were no ASME XI repair/ replacements performed
during the mid-cycle outage. At that
time we were using the 1989 Edition of the Code. I have attached a white paper we
prepared for management. This should
help Russell
Turner:
I would agree that a category B-P VT-2 is not required, as Section XI
states it is for refueling outages. I
would consider that a maintenance outage.
However, there is probably some tech spec or maintenance requirement
to look at the head during restart to ensure no flange leakage, and it’s a
good idea to take a look. Rick
Wehry:
At Susquehanna, we came to the same conclusion (i.e., that Section XI doesn't
require a B-P pressure test for a mid-cycle outage). We performed mid-cycle fuel bundle
re-channeling outages in 2006 (Unit 2) and 2007 (Unit 1)). We did perform a non-VT-2 confidence leak
check following re-assembly (performed by Maintenance) in each instance. Our code of record is 1998 Edition through
2000 Addenda. |
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Date: Friday, 4 January 2008 Subject: Definition of Section XI Outage Dear Group: We are performing a repair on-line of one of our three
class 2 RHR pumps by taking a short RHR outage. We are planning to perform the
Code Category C-G pump casing welds during this time. They are only accessible from the ID. It will be the first pump in this group
that is being disassembled during this inspection interval. There are no definite plans to
disassemble another pump in this group before the end of the interval. If we find flaws that require additional
examinations (IWC-2420) does the code require the additional examinations be
performed during this repair evolution or can they be done at the next refuel
outage? IWC-2420 uses the term
"current outage" as to when the additional exams are to be
performed. A search of Section XI for
the word outage reveals that this term is only used with the time period that
the plant is shut down. It is not
associated with a system outage when the plant is on-line. A search of the interpretations did not
reveal any applicable to this situation.
I could interpret IWC-2420 that since we are not in an outage I don't
have to do additional examinations at this time. However nothing in the Code would require
me to do the additional exams at the next refuel outage. Thanks, Doug |
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Date: Tuesday, 15 January 2008 Subject: Definition of Section XI Outage Dear Doug: Please
see the responses below. Normally, in-service examinations
conducted during a scheduled refueling outage that reveal flaws exceeding the
acceptance criteria would require as a minimum the following actions/steps,
as applicable: 1. Supplemental examinations
(IWC-3200), comparison to preservice/previous in-service examination to aid
in characterization of flaw. 2. Repair/Replacement activity
(IWC-3122.2). Preparation of
Repair/Replacement Plan (IWA-4150) or 3. Analytical evaluation
(IWC-3122.3). Submittal to NRC. 4. Expanded sample (IWC-2430). Completed during outage. 5. Re-examinations (IWC-2420(b) and
(c) I am assuming that because they can only
perform these pump examinations from the ID surface, that they must have a
Relief Request that states they will perform these examinations only when the
pump is disassembled. In such a case,
expanded samples would be required during the current outage (scheduled or
not). In addition, regardless of Code,
their corrective action program should also require an extent of condition
evaluation, which normally would require some sort of expansion. As expansion would require the
disassembly of another pump and/or all pumps, they should have a contingency
plan in place. As a minimum they
should be prepared to perform an analytical evaluation based on the flaw,
that would justify conditional acceptance till the next scheduled refueling
outage. This evaluation should also
justify the need for not performing the expansion at this outage, considering
bringing the unit down. Provided the
analytical evaluation and extent of condition evaluation would justify this
action, and NRC acceptance is received prior to returning the pump to
service. Other considerations could include
Requests for Relief or Alternatives from Code requirements. Glenn Perkins: I agree with Ed’s input. Also consider the guidance provided by NRC
RIS 2005-20. Remember the on-line exam requirements
that some were trying to add into the code, they ran into roadblocks with
exactly this scenario. What do we do
when unacceptable flaws are identified? James
Boughman:
I am sorry, but I do not have enough experience with this scenario to
provide meaningful feedback, but I would like to offer a comment. The code does not currently have provisions
for online examinations. WG ISI
Optimization has an action to address online exams (reference WGISIO
#01-01). This item was assigned to WG
ISIO by Section XI Executive Committee during the February 2001 meeting. Establishing the appropriate scope and
applicability of the ASME Section XI Code for online exams has been
circulating through the code body since Tony Lentz was chairman of Water
Cooled Systems (a long time ago).
Those of us in the ISI Optimization working group have not been able
to reach a consensus on the action.
Coincidentally, the biggest issue for the working group is how to
address successive exams when performing online examinations. I am afraid that a formal inquiry to
ASME would not be useful unless it was worded in such a way the committee
could not say the code does not address online exams. Additionally, It might be best to submit an
Interpretation from the Section XI Code.
That way, it may lead to clarification of the code requirements in
subsequent editions/addenda. Another point I would like to add is
that in absence of Code requirements, the plants also need to follow their
CAP. If degraded conditions are
identified, the extended conditions needed to be addressed in a timely
manner. The Category C-G exams may be
performed from the internal or external surface of a component. I don’t see anything that would prohibit
performing the exam from the internal surface of one pump and from the
external surface of another pump. I
believe this is supported by the final sentence of IWC-2430(a), which
provides for selection of welds outside of the system that the one containing
the initially discovered flaws. I haven’t run into this situation
myself at Hatch since we only perform ISI during a refueling outage with the
exception of ISI pressure tests, which are primarily performed online and
which don’t have the scope expansion criteria of other categories. I’m not sure where WG-ISI Optimization is
with the on line ISI issue, or if it’s still an active issue being considered
within Section XI. If I were to provide an opinion, I’d
say that this plant is not in an outage and that the examination is being
performed “on-line”, even though the component or system in question is not
in service at the time. This issue
poses a dilemma for me in that, unless an adequate solution is found to the
licensee’s concern, a licensee in this position might choose not to perform
the Code examination simply to eliminate the risk that they might have to
perform additional examinations. If
they choose not to perform the code required examination at this time, but
find something of concern anyway, it is the plant’s Tech. Specs that would
govern how they would respond. I’ll think about this a bit more, but
I believe that the licensee would have no choice but to perform the required
additional examinations immediately if they find something in their C-G
exams, unless they file a Relief Request. Larry C. Keith: Mark, I think you are right, I think once
you find a reportable indication is found, the additional exams must be
performed before the unit is operational or don’t examine it unless you are
willing to take the risk of bringing the unit down. Dan
Lamond:
I don't think you are going to find a clear answer on this one. I believe the real question here goes to
the long standing item SCXI has been trying to address through WGISIOPT and
SGWCS regarding the scoping of the Code.
Mainly, does the Code apply to online or non-refueling examinations,
and if so, what are the requirements.
Since the Code does not specifically address this and has been
unsuccessful coming to consensus on rewrites addressing this specific topic,
the owners are left to perform these exams at risk and then interpret what is
required if a flaw is found.
Conservative, do the expansion in the same outage. Unconservative, do an evaluation to justify
some time out in the future. Perhaps
reasonable, do an evaluation that justifies getting to the next system outage
one of the other pumps in the group, assuming that next outage is not too far
out in the future. From a WGGR perspective,
we have tabled any work on these issues pending results from the Optimization
working group. My thoughts tend toward
performing the 'Additional Examinations' within some short time period after
discovery of the flaws. This would
mean during the same operating cycle.
I realize that this might be more conservative than what the author
proposes (next refueling outage), but it would satisfy the Code intent to
perform the additional scope within a month or so of discovery (i.e.: during
the current outage). But first, I would answer a few
questions. Why are you trying to avoid
sample expansion? Are you afraid of
the results? Are you just trying to
save money? If you find flaws that require
additional examinations, are you prepared to explain to the NRC and a
skeptical public why the plant is in service without those examinations
having been performed? If you can take
one RHR Pump off line, why can't you do the same with the other two? If any other pump later causes a plant
outage, are you prepared to explain why you didn't do the examinations when
you had an opportunity to do so? Worse
yet, if you haven't performed those examinations before the end of the next
refueling outage, can you explain why you should still have an operating
license? Currently, the code does not address
scope expansion for on-line exams. We
have an action at SGWCS to provide those rules (see attached). I would say you would have to discuss
deferring any additional exams with the regulator. One of the things ISI Optimization
was looking at was how to get the additional exams to be deferred until the
next outage. The NRC was having
difficulty accepting this idea, as they wanted us to look at other items as
soon as possible, even if it meant shutting down the plant. Another case of punishing us for doing the
right thing sooner than required. Here
are the latest minutes from that action.
Most of the issues seem to have been resolved. The title for this action is,
"Applicability of Section XI and On-Line Examinations". 10/30/06 Action.
Significant discussion took place pertaining to the revised information
provided in the agenda. Upon
conclusion of all the comments, it was determined that the following items
need to be considered for inclusion into the action: 1) addressing of supports (IWF), 2) risk informed implications with
scope expansions, 3) can a Code Case modify a Code Case
(Risk Informed), 4) time limit to performing
analytical evaluation (tech spec LCO?), 5) clarify intent of postulated flaw
analysis. In addition, in the last paragraph of
the inquiry reply, it was suggested to revise the last sentence to read
“beyond the next scheduled refueling outage”, to be consistent with the
response in (1). It was the general
consensus of the members and visitors present that the action needs to
continue. Although some support may
have dwindled slightly since the initiation of the action and implementation
of risk informed programs, the need to possibly address supports (IWF) may
enhance the benefits. The removal of
Class 1 components from the action significantly reduced the potential scope,
but was felt that may have increased the success possibility as the action
continues through the approval process.
Possible vote
in Jan 08. 01-29-07 Proposed
Code Case revised to address comments.
This case should not address Risk Informed because you can not use one
code case to modify another or to modify a relief request. At present, not considered necessary to
address component supports because the provisions of IWF-2430 and IWF-3122
are less stringent than the IWC/IWD requirements. A separate action will be brought forward
in May for supports. With minor
editorial changes, the Code Case passed 9-0-1. Item will be passed to WG ISC. At
WG-ISC at this time. I noticed there were no negatives on the last vote, and I assume the
NRC was the abstention. My take on reading the existing Code is the additional exams need to be
performed during the existing outage.
If performed on-line, then the definition of outage become vague. Many utilities have "system
outages" and used that as their "outage", but that link is
weak. There would be difficulty in
convincing the NRC that the additional exams should not be performed as soon
as possible as they tend to be very conservative. Not sure I can really answer
this. My advice is to be prepared for
the worst and hope for the best.
Understand what types of flaws are expected (casting flaws) or could
be found (cracks) and be ready to evaluate them. I think it may take a relief to not go into
another pump almost immediately. As
always, when you run into a difficult situation such as this, be prepared to
talk with the NRC and see if they will agree in writing to defer the exams
until the next refuel outage. Have
your evaluation ready. I have performed exams on-line in the
past, and will continue doing them in the future. Only one train at a time, usually only one
component at a time. That gives us
some breathing room if something is found.
Not always ALARA, and the NDE folks can get mad when they are
requested to do an exam next to the one they did yesterday. It is a risk we evaluate up front and we
thoroughly understand the potential consequences of our actions. As far as I am aware
Section XI does not address ISI examination requirements for NDE or visual
examinations other than at plant outages such as refueling shutdowns or
maintenance shutdowns. If you think
the intent was there with the current requirements, I would consider that to
be crafting the requirements ( i.e., the terminology that Gill Millman used
for many years) and that would be unacceptable. So, I believe that the situation that you
have described below fits into the on-line ISI examination arena. Since I believe this to be the case the
rules of Section XI do not apply in regards to additional examinations. However, there is no prohibition in
performing the examination to meet Section XI ISI requirements and taking
credit for the examination. Owners do
on-line ISI examinations for credit under their Section XI ISI programs all
the time, but at their own risk. What I mean by "at
their own risk" I know from my own experience. I found out many years ago that the
additional examination requirements of Section XI are not applicable because
doing this examination outside of a plant outage is the choice of the Owner. The Owner has to accept the risk in doing
this examination. Depending on the
severity of any indications or flaws identified by the Owner, the Owner must
handle those indications or flaws under their own corrective action
program. Section XI acceptance
criteria listed in Category C-G for your example pump welds can be used to
evaluate any indications or flaws that are identified, but the Owner will
also be required to perform an operability determination outside of Section
XI space under the plant's license requirements (i.e., Technical
Specifications or Technical Requirements Manual) and this operability
determination has to include an extent of condition evaluation. If it cannot be established by the Owner that
the extent of condition evaluation shows that the indications or flaws are
isolated to this particular pump, then the plant will have to disassemble
another pump or make it in-operable.
Time frames for meeting this criteria are all outside of Code requirements. This could result in entering an action
statement and limited condition for operation, or in a worst case situation
lead to shutting down the plant, thus as an Owner you have to be able to
accept the risk when you perform on-line ISI examinations. Now just so you are aware
the Code has been working on an action item at the Working Group on ISI
Optimization (WGISIO) to develop a Code case to provide rules for on-line ISI
examinations. The Code case passed the
WGISIO and then went to the Working Group on Inspection of Systems and Components
(WGISC). The WGISC also passed the
Code case during the November 2007 Code meetings. The Code case should be on the SGWCS agenda
for February and I have included a copy for your information. The Code case provides rules for additional
examinations to be performed when performing on-line ISI examinations. I
support this Code case and I have attached a copy for your information. I hope what I have given
you here helps. I believe that it would be good to
pursue an inquiry on what “current outage” means relative to system outage
not associated with a plant outage. A
second part or separate inquiry should address if it is the intent of the
code to cause a plant outage (if necessary) to perform the additional exams
if the examination causes an additional examination to be performed. And the response could include a revision
to these paragraphs to clarify that the additional examination can be
performed during the next regularly scheduled plant outage. I’m thinking that this is when the C-G
examination would have been performed to begin with. |
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Date: Thursday, 13 December 2007 Subject: Examination Category B-G-1 Bolting Dear
Group: Do most
licensees interpret Table IWB-2500-1, Examination Category B-G-1, footnote
(2) [1989 Edition through the 2004 Edition] to require that bushings and
threads in base material of flanges be examined when the connection is
disassembled, even if the bolting has already been examined during the
interval with the bolting in place under tension, as permitted by footnote
(1)? Thank you, |
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Date: Thursday, 20 December 2007 Subject: Examination Category B-G-1 Bolting Dear
Gary: Please
see the responses below. Southern Nuclear is performing
these examinations: (1) UT examination of the
RPV studs once per ISI Interval; (2) UT examination of the
RPV flange threads once per ISI Interval; (3) VT examination of the
RPV bushings once per ISI Interval. We believe the ASME Code only
requires a one-time examination per the ISI interval but a utility could
certainly look at the bushings to ensure that no damage has occurred. Steve
Brown:
The IWB experts I work with do not require another code exam to
be done on IWB B-G-1 items if they are disassembled once the initial
examination has been completed. We do not recall having been asked
this directly by any utilities, but our answer would be to examine. Based on my experience and
understanding of the Code requirements, the answer to the question in your
email below is YES, bushings
and threads in base material of
flanges require examinations stated in IWB-2500-1 B-G-1, even if the
bolting has been previously examined “in-place under tension” during the
Interval. The code Item Numbers for bushings and threads in flange would not have
been satisfied with an “in-place under tension” exam due to these items being
inaccessible when a bolted connection remains assembled. This same requirement would also be applicable
to the item number for flange
surface, when disassembled. Footnote 1 that you mentioned in your
email below applies to bolting; the
term bolting is a generic term which includes bolts, studs, nuts, bushings,
washers, and threads in base material and flange ligaments between threaded
stud holes. (Reference Interpretation XI-78-20). Footnote 2 goes on further to state
that bushings and threads in base
material of flanges are required to be examined only when the
connections are disassembled. Bushings
may be inspected in place. As shown in the IWB-2500-1 Table for
B-G-1, the bushings and threads in flange are permitted to be deferred to the
end of the Interval. Therefore, if the
bolted connection is not disassembled for the duration of the Interval, no
examination would be required for the applicable bolted connection. For the other “bolting” components
that were already examined “in-place under tension”, the examination would not
need to be re-performed, i.e. bolt/stud, nut, washer, even if the connection
is subsequently disassembled at a later time. Although they don’t change the
wording of the footnote requirements for bushings or threads in flanges, Code
Cases N-652 and N-652-1 provide for alternatives to the B-G-1, B-G-2
requirements for IWB-2500-1, and the C-D requirements of IWC-2500-1 that are
advantageous and more easily understood than those provided in IWX-2500-1
Tables. I would highly,
recommend an ISI Program Owner consider use of one of them as allowed (or
soon to be allowed) by 10CFR50.55a. ·
CC N-652 is acceptable
for use per Reg. Guide 1.147, Rev. 14.
RG 1.147, Rev.14 is acceptable for use per incorporation by reference
in the current 10CFR50.55a. o
Bushings and threads in
flange are discussed in footnote 3 of the B-G-1 Table of the Code Case o
N-652 was incorporated
into the 2002 Addenda. ·
CC N-652-1 is listed as
acceptable for use per Reg. Guide 1.147 Rev. 15 that was issued in Oct.
2007. However, it
should be noted that licensees cannot begin to use Rev.15 until incorporated
by reference in the upcoming revision to 10CFR50.55a which is supposedly due
for publication early in 2008. o
Bushings and threads in
flange are discussed in footnote 3 of the B-G-1 Table of the Code Case o
N-652-1 was
incorporated into the 2004 Addenda. George
Fechter:
I would understand the requirement to be that you would examine the
bushings/threads in base materials of flanges when the connection is
disassembled even if the bolting had previously been examined in place under
tension. In my opinion, the “in place
under tension” option is only applicable for the final outage in an interval,
and this is partially based upon the permissive to defer an examination to
the end of an interval. I would not
think it would be acceptable to examine in place at the beginning of an
interval without disassembly and then disassemble and not examine at a later
date in the same interval. For argument sake, let’s assume you
could credit examination of bushings in place with the bolting still
installed. You may then wish to
consider crediting the examination that allows the most access of the
area. This is similar to the requirements
of Footnote 2 of B-L-2 and B-M-2 which requires an examination at a later
time if subsequent disassembly for maintenance allows for a more extensive
examination. This is not an official
interpretation. It could certainly be
argued either for or against additional examinations. Based on this an Intent Inquiry would be
prudent. However, I think the argument
I outlined above would keep someone out of trouble with auditors and
regulators until the interpretation is addressed by the ASME Committees. | |||
