ML20203L735
| ML20203L735 | |
| Person / Time | |
|---|---|
| Issue date: | 08/22/1986 |
| From: | Jonathan Montgomery NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Levin A HAWAII, STATE OF |
| References | |
| NUDOCS 8608290120 | |
| Download: ML20203L735 (3) | |
Text
_
AUG 2 2 586 The Honorable Andrew Levin Representative First District'of Hawaii llouse of Representatives State Capitol Honolulu, llawaii 96813
Dear Representative Levin:
In response to your letter of July 9,1986, in which you requested information concerning food irradiation, the enclosed information is respectfully submitted.
The NRC is responsible for the licensing and inspecting of irradiators in the State of flawaii. The health physicists in our Region V office in Walnut Creek, California review and evaluate any applications for an irradiator license. If the applicant meets all of our requirements which are designed to ensure the safe use of the radioactive material at the irradiator facility, the license would be granted. As you know an immobile irradiator source license is in effect for the University of ifawaii at Manoa. We have inspected this irradiator routinely. All NRC inspections are coordinated with the llawall Department of IIealth, and their personnel have accompanied us on past inspections at the University.
To provide a comprehensive and concise answer to your concerns I will first respond to questions 9, 10 and 11 as you requested. Additional information regarding the irradiator sources will complete our response in enclosure 1.
To provide information on your remaining questions I have enclosed a copy of the April 18,1986, Federal Register containing the proposed 21 CFR Part 179 regulations governing food irradiation (enclosure 2).
If you have additional questions concerning the NRC's licensing and inspection activlties for irradiators please contact this office or telephone me at 415-943-3778.
Sincerely, s
t's
~_J James
. Montgomery, Chief Nuclear Materials Safety and Safeguards Branch
Enclosure:
As stated bec w/ enclosures G. Cooks B. Faulkenberryl J. Marting RSB/ Document Control Desk (RIDS); State of llawail Reg!
V
\\ yk JHon gomery/ dot 8/2*/86 0600290120 860022 19 dg e
eDn steno escuteDR j
(
Response To Items of Concern: June 18, 1986 Letter to Dr. James Moy from Representative Andrew Levin Item 9: Low level exposure:
"The effect of exposure to low levels of ionizing radiation to people living near or working in radiation jndustries are now being shown in studies to be at least ten times greater than current protection standards assume. Your comments please."
NRC inspections and measurements at commercial irradiators indicate that the radiation levels associated with normal operation are quite low and significantly below NRC limitations. The radiation levels around the edge and above the shielding pool (a restricted area within the confines of the irradiator facility), range from 1-2 millf roentgens per hour when the sources are in the fully shielded configuration. These levels of radiation exposure are below the current NRC radiation protection standards for restricted areas which are based on years of extensive research by recognized experts in the field of health physics and radiation protection. Unrestricted areas around the outside of the irradiator butiding with the source in the exposed position would be limited to radiation icvels at or below 0.6 mil 11 roentgen per hour for any seven consecutive day period. Again, this level is consistent with NRC regulations.
Item 10: Contamination:
"Is there a potential for surface or ground water contamination due to leaky or ruptured jackets which contain the radjoactive source?"
With intact radiation sources, the potential for surface or ground water contamination is extremely remote. The cooling water in the shielding pool is continuously filtered to remove any contamination present. Sensitive instru-mentation is used to monitor the water processing system for contamination.
In the most severe earthquake, any contamination, if present, should remain within the stainless steel ifned tank or the irradiator building and not affect the offsite environment. Even if, in an extreme worst case (where the cource is not damaged), the water were to escape the structure and enter the ground water tabic, the radioactivity concentration in the pool would be below NRC regulatory limits for unrestricted areas and would pose no health hazard.
Item 11: Worst case situation:
" Finally, and most important, if everything goes wrong, what is the affect on the facility, the workers, and the surrounding area? I know we touched on this in your office and that you indicated that the evacuation of an area a few hundred feet in diameter would be enough. Can you indicate for me how long such an area would be contaminated and what the maximum evacuation area would be? Could you give me separate figures for both cobalt and ceslum?"
s..
2
?
4 l'
i 1
L There are two credible situations that could be classified as the worst cases.
One, if-the source"were "to get stuck in the exposed position due for example to a mechanical malfunction; and two, the loss of the shielding water from the l-pool. In neither case would there be a problem or concern for the surrounding i
environs. Contamination (if any) and radiation exposure would not exceed NRC regulatory limits outside the confines of the irradiator facility, i
If however, an extremely unifkely catastrophic event should occur.which ruptures the source (s), the contamination and radioactivity within the irradiator i
structure could be high and significantly exceed the NRC regulatory limits. If the catastrophic event also breached the pool liner and irradiator structure I
in addition to the sources, the contamination and radioactivity could escape into the environment and ground water and significantly exceed NRC regulatory limits. The off-site area which should be evacuated or controlled in such a major catastrophe would be dependent on many variables including source type and strength, type of accident, size of facility, and weather conditions.
i j
Additional Information:
f All high energy gamma radiation emitting sources with activities in the r
millions of curies generate a significant amount of heat in addition to gamma l
radiation. Depending on the type and strength of irradiator source, cooling j
to adequately dissipate. heat may be essential. The large irradiators are also
[
required to meet stringent fire safety standards, i
i Cesium 137 has a physical half life of approximately 30 years.
In ten half j
ifves (i.e. 300 years) a cesium source which was initially 1,000,000 curies would have decayed to about 1000 curies.
i i
r l
l l
{
i I
1 i
l
[
i i
I i
i
,