ML20057A550
| ML20057A550 | |
| Person / Time | |
|---|---|
| Issue date: | 09/01/1993 |
| From: | Alexander Adams Office of Nuclear Reactor Regulation |
| To: | Laraia M INTERNATIONAL ATOMIC ENERGY AGENCY |
| References | |
| NUDOCS 9309140386 | |
| Download: ML20057A550 (4) | |
Text
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September 1, 1993 Mr. Michele Laraia Waste Management Section Division of Nuclear Fuel Cycle and Waste Management International Atomic Energy Agency
'l Wagramerstrasse 5 j
P.O. Box 100 A-1400 Vienna, Austria
Dear Mr. Laraia:
SUBJECT:
DECOMMISSIONING TECHNIQUES FOR RESEARCH REACTORS As requested in your letter of June 30, 1993, we have reviewed the o
June 1993 draft of Decommissioning Techniques for Research Reactors.
. provides comments which we have on the draft.
I have also f
enclosed an appendix from our Non-Power Reactor Technology Course that i
contains drawings of several types of research reactors.
These may be of j
some use to you.
I enjoyed the opportunity to meet you and to contribute to the development of this document.
If I can provide any further information, i
please call me at 301-504-1127.
Sincerely, AlYxa*nher[dEm"s,N.,SeniorProjectManager Non-Power Reactors and Decommissioning Project Directorate l
Division of Operating Reactor Support i
Office of Nuclear Reactor Regulation
Enclosures:
l As stated 4
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E UNITED STATES 5;i[
NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 205 %-0001 September 1, 1993 i
Mr. Michele Laraia Waste Management Section Division of Nuclear Fuel Cycle and Waste Management International Atomic Energy Agency Wagramerstrasse 5 P.O. Box 100 A-1400 Vienna, Austria
Dear Mr. Laraia:
SUBJECT:
DECOMMISSIONING TECHNIOUES FOR RESEARCH REACTORS l
As requested in your letter of June 30, 1993, we have reviewed the June 1993 draft of Decommissioning Techniques for Research Reactors.
Enclosure I provides comments which we have on the draft.
I have also enclosed an appendix from our Non-Power Reactor Technology Course that contains drawings of several types of research reactors. These may be of some use to you.
I enjoyed the opportunity to meet you and to contribute to i
the development of this document.
If I can provide any further information, please call me at 301-504-1127.
Sincerely, 68{an& b Alexander Adams, Jr., Sen or Project Manager Non-Power Reactors and Dec mmissioning Project Directorate Division of Operating Reactor Support Office of Nuclear Reactor Regulation
Enclosures:
As stated i
i i
ENCLOSURE 1 USNRC STAFF COMMENTS ON DECOMMISSIONING TECHNIQUES 3
FOR RESEARCH REACTORS JUNE 1993 VERSION 1.
Page 3, line 14.
If it is possible to determine how many of the l
l reactors listed under miscellaneous are prototype power reactors, delete this number from the category and drop the reference in the text to prototype power reactors.
g 3
1 2.
Page 13, tables VI and VII. The costs in these tables, which were taken from a NRC report, do not consider future dollars discounted back to present value. Discount rates should be used to properly consider the present value of future dollars. The discount rate should be 2 to 3 percent above the rate of inflation.
Because the table is in constant dollars, the cost of the deferring dismantling is overstated. This l
l should be pointed out to the reader. All readers may not be able to i
appreciate footnote "a" to the tables.
l1 3.
Page 20, section 6.2.1.
Two additional conditions of fuel storage l
should be considered. They are the ability to remove decay heat from l
the fuel storage area, if necessary, and maintaining water quality if j
the fuel is stored in water.
Poor water chemistry could lead to fuel 1
l clad failure which could complicate fuel shipment and storage area i
decommissioning.
4.
Page 24, note.
In response to your note, operations monitoring system is assumed to be the original radiation monitoring system for the reactor facility. This would include the area radiation monitors that measure radiation fields and the effluent monitoring system that measure l
airborne, and in some cases, waterborne radionuclide concentrations.
5.
Page 26, note.
In response to your note, forced air breathing systems would include self contained air packs.
6.
Page 29, table X.
This table is confusing because it mixes two t
i concepts. One concept is proceeding systematically from stage 1 to
)
stage 2 to stage 3.
The other concept is operators who wish to decommission without delay and proceed directly to stage 3.
This leads to internal inconsistencies in the table such as draining the reactor pool in stage 1 but using the pool to cut items underwater in stage 3.
l This table should be modified to be applicable only to operators that want to decommission using all three stages.
A separate table should be considered for operators that go directly to stage 3.
7.
Page 33, line 4.
Consider adding high density concrete as a particular aspect to be considered.
The type of concrete needs to be considered to have the correct equipment available for decommissioning.
Cutting methods that work for regular concrete such as diamond saws may not work on high density concrete.
f
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i 8.
Page 38, section 7.1.1, line 5.
Add pool floor to areas that are activated in a pool type reactor. The floor activation is normally greater than the pool walls.
i 9.
Various places in document. The TRIGA reactor type is normally all
~,
capital letters because it is an acronym for training reactor, isotopes production, General Atomic.
p 10.
Reactor figures.
Please give reference to the type of reactor to which the figure refers.
For example, Figure 5 should state that the DIDO reactor is a heavy water type.
11.
Figure 9.
The figure is for the core region of an AGN-201 reactor, not the complete reactor.
12.
Page 56, line 6.
Change " moderator systems" to " heavy water systems" to i
reflect the fact that some reactors use heavy water as a moderator, reflector, and coolant.
l 13.
Page 56, second line from bottom. What is the "WWR" reactor design?
l' Please define.
14.
Page 57, section 7.4.4, line 8.
Consider pointing out that the use of nitrogen or other inert gases to reduce explosion hazard creates another potential hazard in the form of oxygen deficient environments.
15.
Page 59, section 7.6.
Consider moving.this information to section 7.1 or 7.4.
The information would make a good introduction to either of t
those sections.
16.
Page 64, note. This section should be deleted or reduced to just state that numerical risk analysis is not required for decommissioning safety analyses but may provide additional insight if used.
Deterministic analysis should be required.
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