ML20049G853
| ML20049G853 | |
| Person / Time | |
|---|---|
| Issue date: | 12/31/1975 |
| From: | NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20049G843 | List: |
| References | |
| PROC-751231, NUDOCS 8110020457 | |
| Download: ML20049G853 (4) | |
Text
-
I DREI GUIDELINES FOR DECONTAMINATIe'! 0F FACILITIES AND EQUIPMENT PRIOR TO RELEASE FOR UNRESTRICTED USE OR TERMINATION OF LICENSES FOR BYPRODUCT, SOURCE, OR SPECIAL NUCLEAR MAT'ERIAL U.S. Nuclear Regulatory Comission Division of Fuel Cycle and Material Safety Washington, D.'C. 20555 DECEMBER, 1975
~
l 8110020457 810924
-NMS LIC30 08-14043-01 PDR
.,. m.._
...~._-._.. _. _ -, _, _... _... _. _,..,
The instructions in this guide in conjunction with Table I specify tha radioactivity and radiation exposure rate limits which should be used in accomplishing the oecontamination and survey of surfaces or premises and equipment prior to abandonment or release for unrestricted use.
The limits in Table I do not apply to premises, equipment, or scrap containing induced radioactivity for which the radiolegical considerations pertinent to their -
use may be different.
The release of such facilities or items from regula-tory control will be considered on a case-by-case basis.
1.
The licensee shall make a reasonable effort to eliminate residual contamination.
2.
Radioactivity on equipment or surfaces shall not be covered by paint, plating, or other covering matrial unless contamination levels, as determined by a survey and documented, are below the limits specified in Tables I prior to applying the covering.
A reasonable effort must be made to ninimize the contamination prior to use of any covering.
3.
The radioactivity on the interior surfaces of pipes, drain lines, or ductwork shall be determined by making measurements at all traps, and other appropriate access points, provided that contamination at these locations is likely to be representative of contamination on the in-terior of the pipes, drain lines, or ductwork.
Surfaces of premises, 6quipment, or scrap which are likely to be contaminated but are of such size, constructicn, or location as to make the surface inacces-sible for purposes of measurement shall be presumed to be contaminated in excess of the limits.
4.
Upon request, the Commission mey authorize a licensee to relinquish possession or control of premises, equipment, or scrap having surfaces contaminated with materials in excess of the limits specified.
This may include, but would not be limited to, special circumstances such as razing of buildings, transfer of premises to another organization continuing work with radioactive materials, or conversion of facilities to a long-term storage or standby status.
Such requests must:
Provide detailed, specific information describing the.. premises,.
a.
equipment or scrap, radioactive contaminants, and the nature, extent, and degree of residual surface contamination.
b.
Provide a detailed health and safety analysis which re'lects that the residual amounts of materials on surface areas, together with other considerations such as prospective use of the premises, equipment or scrap, are unlikely to result 'in an unreasonable risk to the health and safety of the public.
5.
Prior to release of premines for unrestricted use, the licensee shall make a comprehensive radiation survey which establishes that contam-ination is within the limits specified in Table. I.
A copy of the survey report shall be filed with the Chief, Materials Branch, Division
( -
-a g
.i 7
g f
.-,,,.g y - - -
-w 3m
~
~
"of'Fdel Cycle and Material Safety, USNRC, Washington, D.C. 20555, and also the Director of the Regional Office of the Offica of Inspection and Enforce-i ment, USNRC, having jurisdiction.
The report should be filed at least 30 days prior to the planned date of abandonment.
The survey report shall:
I a.
Identify the premises, b.
Show that reasonable effort has been made to eliminate residual contamination.
c.
Describe the scope of the survey and general procedures followed.
d.
State the findings of the survey in units specified in the
]
instruction.
Following review of the report, the NRC will consider visiting the facili-ties to confirm the survey.
l t
I l
! (
t t
I L
n 1
TABLE I ACCEPTABLE SURFACE CONTAMINATION LEVELS a
bcf bdf bef l'
NUCLIDES AVERAGE MAXIMUM REMOVABLE U-nat, U-235, U-238, and associated decay products 5,000 dpm a/100 cm2 15,000 dpm a/100 cm2 1,000 dpm a/100 cm2 j
Traasuranics, Ra-226, Ra-228, j
Th-230, Th-228, Pa-231, 100 dpm/100 cm2 300 dpm/100 cm2 20 dpm/100 cm2 Ac-227, I-125, I-129 i
Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U-232, I-126, 1000 dom /100 cm2 3000 dpm/100 cm2 200 dpm/100 cm2 1-13), 1-133 f
i Beta-gamma emitters (nuclides with decay modes other.than~
5000 dpm sy/100 cm 15,000 dpm By/100 cm2 2
1000 dpm sy/lco cm2 l
alpha emicsion or-spontaneous fission) except/ sri 90 and others noted above.
"Where surface contamination by both alpha-and beta-gamma-emitting nuclides exists, the limits established for alpha-and beta-gamma-emitting nuclides should apply independently.
b j
Ac used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as determined l
by correcting the counts per minute observed by an appropriate detector for background, efficiency, and geometric factors i
associated with the instrumentation.
" Measurements of average contatainant should not be averaged over more than 1 square meter. For objects of less surface l
area, the average should be derived for each such object.
1 The maximum contamination level applies to an area of not more than 100 cm,
2 9
"The amount of removable radioactive material per 100 cm 2 of surface area should be determined by wiping that arer,with 2
dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the L
j wipe with an appropriate instrument of known efciciency. When removable contamination on objects of less surface area is determined, the pertinent levels should be reduced proportionally and the entire surface should be wiped.
IThe average and maximum radiction levels associated with surfce contamination resulting from beta-gaiana emitters should nc exceed 0.2 mrnd/hr at I cm and 1.0 mrad /hr at I cm', resp.ct.ively, measured through not more than 7 milligrams per square centimeter of total ab.-
'Ser.