ML20058K132
| ML20058K132 | |
| Person / Time | |
|---|---|
| Issue date: | 12/11/1989 |
| From: | Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | |
| References | |
| TASK-PINC, TASK-SE SECY-89-370, NUDOCS 8912200253 | |
| Download: ML20058K132 (11) | |
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POLICVISSUE December 11, 1989 pHmo (NEGATIVE CONSENT)
For:
The Commissioners From:
James H. Taylor Executive Director for Operations
Subject:
MODIFIED ENFORCEMENT POLICY FOR HOT i
PARTICLE EXPOSURES
Purpose:
To inform the Commission of the staff's plans to implement a modification of the NRC Enforcement Policy addressing exercise-of enforcement discretion in cases involving occupational dose -
to the skin from exposure to radiation from radioactive particles, which are called hot particles in the modified policy and in this paper.
Discussion:
The staff intends to.use the enclosed policy (Enclosure 1) in exercising en arcement discretion in cases involving occupa-tional dose to the skin from_ hot particle exposures.
(Note:
The enclosed policy was called an " interim standard" in earlier draf ts. ) In this policy, and in. this paper, such exposure means an occupational dose to the-skin resulting from exposure to radiation emitted from the radionuclides in a hot particle on the body (including hair) or clothing of the exposed indi-vidual.
(The modified policy does not change existing criteria applied to whole body exposures that may result from hot-particles.)
l The dose limits of Section 20.101 of 10 CFR Part 20 for occupa--
tional exposure of the~ skin are 7.5 rem per quarter, except for the skin of the hands and forearms, and feet and ankles for which L
the Ifmit is 18.75 rem per quarter. Considering currently avais-l able scientific data, the staff believes that these limits for the skin are overly restrictive-when applied to hot particle exposures.
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James Lieberman, OE 492-0741 000001 Q/
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The Commissioners i For the past several years, the NRC; staff has exercised enforcement discretion in cases associated with such exposures that resulted in doses to small areas of the skin in excess of the current' limits ofJ10 CFR Part 20. As n' result of the staff's exercise of such discretion, the severity level in the Enforce-ment Policy (Supplement IV to Appendix C of 10' CFR Part 2) for such overexposures has been lower than for similar exposure levels where larger skin areas (and volumes of tissue) are exposed to radiation. - (See Statements of Consideration' for
- October 13, 1988 revision to the Enforcement Policy, 53 FR 40021.)
l The enclosed policy will extend the exercise of enforcement discretion by:providing that, for a hot particle exposure ofi an individual above the limits of 10 CFR 20.101, the NRC will use a dose criterion of 100 rads to the skin averaged over 1 cmr at a depth of 7 mg/cm2 A notice of. violationwill not' be -
issued for a hot particle exposure of an individual below 100 rads.
However, other violations, such as' failure to survey, l
may result in enforcement action regardless of the exposure l
levels, consistent with current enforcement practice.
The l
interim standard provides that for a hot particle exposure above the 100-rad criterion, but less than 1000 rads, the l
severity level of the violation will be Severity Level IV.
For hot particle exposures resulting in skin doses of 1000 rads or more, the severity level of the violation'will be Severity Level III.
The staff has determined that establishment of numerical criteria for Severity, Levels I and II in this policy is not warranted.
In addition -to the enforcement l discretion related to the skin dose, enforcement discretion also'will be-exercised in considering'the severity levels for failure to notify or report to the NRC violations of-10'CFR Part 20 limits for doses to the skin in cases of hot particle exposures.
The basis for enforcement discretion in these cases is that failure to notify or' report a violation should not be categorized at a higher severity level than the underlying violation. This change is reflected in the enclosed policy.
The enforcement discretion provided in the enclosed policy applies to all licensees. NRR and NMSS licensees will be informed of the policy in generic cossiunications to licensees.
To date, hot particle exposures have been a problem for NRR licensees but have not been a problem for NMSS licensees.
The policy will be used until rulemaking can be completed to l
change the 10 CFR Par,t 20 licits for hot-particle exposures.
(The major revision of 10 CFR Part 20 that is now awaiting Comission decision does not address-the hot particle issue.)
This rulemaking will take two years or more to complete. The
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The Commissioners -
Office of Nuclear Regulatory Research (RES) is now proceeding with the development of an advance notice of proposed rule-making on-the subject of a limit for occupational doses.to the skin resulting from hot particle exposures.
This advance notice-will request public comment on specific issues, but will not propose a specific-limit.
In establishing a regulatory limit for hot particle exposures r
through rulemaking, a major issue'on which public coment will be requested is the ' question of which nonstochastic effects c
I should be prevented.
(Nonstochasticeffectsareeffects.for-which the severity of the effect in affected. individuals varies l
-with the dose, and for-which a threshold usually exists.) Acute ulceration is generally agreed to. be the nonstochastic effect' of greatest concern for hot particle exposures; however, there is not general agreement as to whether all ulcers of the skin i
or only: larger ulcers should be prevented.' A subcomittee of the National Council on Radiation Protection and Measurements (NCRP) and a task group of the International Cosmission on Radio-logical Protection (ICRP) have considered this question but, to date, have.not agreed on an answer.- The dates-on'which final NCRP and ICRP reconnendations will be available have not -
yet been determined.
(Enclosure 2 is the most recent-letter.
from the NCRP concerning its report on hot particles.)
The staff has developed the enclosed policy after considerations of:
(1) draf t NCRP recommendations-(report of NCRP 80-1, draf t of June 8,1988/Rev. 3), (2) information on draft ICRP recom-mendations providt.d informally by members of the ICRP task group developing limits for hot particle exposures, (3)-available 1
i scientific data and analysis of these data by scientists at Brookhaven National Laboratory (BNL) in work sponsored by the NRC, (4) comments by the Nuclear Management and Resources Council (NUMARC) during meetings with the NRC staff and the Advisory l
Committee on Reactor Safeguards (ACRS),~ (5)- connents mace by the ACRS (in a letter from Forrest J. Remick to~ Chairman Zech, dated May 9,1989) on an earlier draft of an interim standard,-
I and (6) connents made by the Committee to Review Generic-Requirements (CRGR) on an earlier draft of an interim standard (in a memorandum from E. L. Jordan to-V. Stello, dated March 20, 1989).
1 l
The staff has selected a dose criterion for the enclosed policy that provides adequate protection against both nonstochastic effects (skin ulcers, as discussed above) and stochastic effects.
(Stochastic effects are effects, the probability of which,.
rather than their severity,:is a function of radiation dose withoutthreshold.) Skin cancer is the stochastic effect of-concern in hot particle exposures.
There is general agreement that a dose limit that provides adequate protection against skin ulcers (nonstochastic effects) will provide adequate
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The Commissioners 4-protection against stochastic effects.
The~ reason for this is that a dose limit established to prevent skin ulcers cor-responds to a risk of fatal skin cancer that is well below the-risk of fatal skin cancer that is useJ-to establish stochastic limits for occupational radiation' exposure.
~ The 100-rad dose criterion in the policy was selected because it is the lower of two values being considered by the NCRP and i
ICRP subgroups as limits for hot particle exposures. This selection was influenced by the current uncertainty regarding the value of the threshold for ulceration, which-is discussed i
below. The June 1988 draft NCRP recommendations included a.
limit of 75 microcurie hours, which corresponds to a. dose of 400-500 rads (at a depth-of 7 mg/cm._ averaged over an area of r
I cm ) for.a typical fuel particle. The ICRP task group is e
considering a' limit of 100 rads (at' a depth of 10-15 mg/cma-averaged over an area of 1 cm ).
(Note: Because the 100-rad e
criterion in the policy is the dose at 7 mg/cm2, rather than-at 10-15 mg/cm', it is slightly more conservative than the limit being considered by the ICRP task group. The 7-mg/cm2 depth is currently used by NRC and its licensees and is being retained in the policy to avoid.a need to change existing.
computationalpractices.) As stated above, acute ulceration of the skin is generally agreed to be the nonstochastic effect of greatest concern for hot particle exposures. Both the NCRP and ICRP draft limits are based on preventing acute ulceration of minute areas of the skin.
The draft NCRP limit is based primarily on an evaluation of unpublished data from research by two U.S. scientists in the 1960s.
The limit being con-
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sidered by the ICRP task group is based primarily on published and unpublished work by a group of English scientists'during the 1980s. Two of these scientists are members of the ICRP task group; the chairman of the NCRP scientific coastittee that prepared the NCRP draft report is also a member of the ICRP task group. Representatives of the NCRP and ICRP-subgroups are continuing to discuss their differences but have not resolved them to date.
The NCRP June 1988 draft report indicates that the recossended limit of 75-microcurie hours (corresponding to a 400-500 rad.
dose for a typical fuel particle) was set at the threshold for ulceration. This threshold value was determined by extrapola-tion-of a set of data for which the experimental doses were all above the threshold. The 100-rad limit being considered by the ICRP task group was set at a value believed to be below the threshold for ulceration based on an analysis of a set;of data from the work of English scientists.
This set of English data included doses:that ranged from doses below to doses above i
the threshold.
In NRC-sponsored research, scientists at Brook-haven National Laboratory (BNL), in consultation with the English scientists, have determined that there is an uncertainty-in the value for the ulceration threshold cbtained from the
p The Commissioners 5-q English data. The range of this uncertainty now appears to be i
from roughly 100 rads.to roughly'300 rads.
In a continuation of the NRC-sponsored research, scientists at BNL are working with the English scientists and with scientists at the National.
Institute of Standards and Technology (formerly the National Bureau of Standards) to narrow the range of the uncertainty in the ulceration threshold.
Based'on the preceding considerations, it appears that the range of uncertainty for the ulceration j
threshold now extends from: roughly 100 rads to roughly 500 r
l rads. Therefore, there is a possibility that the 100-rad I
dose criterion in the enclosed policy corresponds to the threshold for ulceration; on the other hand, if the threshold actually is 500-rads,'the 100-rad criterion is clearly con-servative.
The enclosed policy differs from an earlier draft that was-discussed with the CRGR and ACRS. :The enclosed policy pro-vides a dose criterion of 100' rads' rather than the 50-rad value that was included in the earlier draft. This. change is~ based on the consideration of additional information that was not previously available..In addition, the enclosed version does i
not adopt some CRGR and ACRS recommendations that were based on their reviews of the' earlier version.
Before meeting with the ACRS, the staff had responded to a CRGR comment by provid-ing that application of the policy would be limited to just one hot particle exposure of an> individual in a calendar quarter that was above the limits of 10 CFR Part 20.. Reasons given by CRGR for wanting to maintain a quarterly limit were consistency with current limits in Part 20 and concern for multiple exposures of an individual during a year. The ACRS disagreed with this "per quarter" provision. The staff has not included this limitation in the enclosed policy because the effects are non-3 stochastic and multiple exposures of'the same small area are
- extremely unlikely. The ACRS also recommended that the staff develop an " interim standard" based on' final NCRP recommenda-tions; however, these final recommendations are not yet avail-able. The ACRS further recommended that the definition of a hot particle be clarified with respect to particle size. The-ACRS apparently believed.an upper limit on particle size was needed. Considering what.is known of the effects of hot part-icles as a function of their size, the staff does not believe that a numerical upper limit on particle size is needed in the policy. A " particle" is commonly understood to be very small, a " speck," and the question of an upper limit to particle size has not arisen in hot particle exposure cases to date.
In the versions of the colicy reviewed by both the CRGR and ACRS, enforcement examples for Severity Levels'I through IV were included. The enclosed policy includes. examples only for Severity Levels III and IV as discussed earlier in this paper.
Because of our desire to proceed expeditiously neither the CRGR nor the ACRS has reviewed the enclosed policy. However, N
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'Thel Commissioners l we believe we understand their views on these issues based on previous interaction. The staff will offer to brief botn Comittees following Comission review.
Because this policy in effect modifies the existing dose limits of 10 CFR Part 20, it falls within the definition of onckfit-ting as defined in.10 CFR 50.109(a)(1). However, in modifying-the limits, in effect, thin policy involves redefining the, level of adequate protectiw. of the public health and safety for occupational exposures that result from hot particles..
Therefore, this poli falls within:the exemption, provided
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in10CFR50.109(a)(
(iii), from~the provisions of 10 CFR 50.109(a)(2) and (a) 3).. The provisions of:10 CFR 50.109(a)(2) and (a)(3) require a systematic and documented analysis, which isdescribedin10CFR50.109(c),. leading.toadetermination-l that there is a substantial increase in the overall public health and safety or common defense and security to be derived-from the backfit and that the. direct and indirect. costs-of implementation for the backfit are justified in view of the increased protection.
However, as was made clear in the State-ments of Consideration for revising the backfitting rule l
(53 FR 20603; June 6,1988), the Commission will not and can-l not take economic costs'into consideration in defining or l
redefining what level of protection for the public health and l
safety or comon defense and security should be regarded as adequate.
The NRC staff does not intend that the implementation of this-l policy will significantly alter programs established to mini-mize personnel contamination'and exposure or degrade controls needed to contain hot particles within each plant and prevent them from being transported off site inadvertently.
Notifica--
tion and reporting requirements for licensees are not changed-by this policy because they are administrative requirements-and are not essential for redefining the level of adequate pro-tection of public health and safety for exposure of the skin resulting from hot particles.
(Although severity levels for-failures to notify and report are changed.) The staff will continue to monitor reports of hot particle contamination, hot particle exposures, and inadvertent offsite rcleases of hot particles for-indications of licensee program degradation.
The Office of the General Counsel has reviewed this' paper and has no legal objections.
Recomendations: That the Comission:
1.
Note that the staff plans to implement the enclosed modification of the enforcement policy. The staff intends to implement this policy within 10 working days of the date of this paper unless otherwise instructed by the Commission.
The Commissioners !
2.
Note that the staff intends to place this paper in the TJb" Tic Document Room unless otherwise--instructed by the Con;;ission within 10 working days of the date of the 1
pa per.
W[
l ames M. T lor i
Executive Director i
for Operations
Enclosures:
I 1.
" Modified Enforcement Policy l
for Cases of Occupational j.
Doses to the Skin from Radiation Emitted from Hot Particles" 2.
Ltr fm W. K. Sinclair, President, NCRP, to 8. M. Morris, NRC/RES, q
dta October 26, 1989 SECY NOTE:
In the absence.of instructions to the contrary, SECY will notify the staff on Tuesday, December 26, 1989,.
that the, Commission, by-negative consent, assents to the action proposed in this paper..
DISTRIBUTION:
Commissioners i
)
OIG LSS GPA REGIONAL OFFICES EDC ACRS ACNW-ASLBP ASLAP SECY l
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ENCLOSURE 1 Modified Enforcement Policy for
~
Cases of Occupational Doses to the Skin from Radiation Emitted from Hot Particles-
'1.
Purpose 4
This policy modifies the'NRC Enforcement Policy in 10 CFR Part 2, Appendix C to provide for the exercise of enforcement discretion.in.-
cases that involve an occupational dose to the skin resulting from exposure to radiation' emitted from a hot particle on or near the skin.
The provisions of this policy will be followed by the NRC staff until a new limit applicable to such cases'is established by revision of 10 CFR Part 20, 2.
Sccpe This policy applies only to occupational doses to the skin that are above the liniits of 10 CFR 20.101 for the " hands and forearms,. feet and ankles" or the " skin of the.whole body" and that are the result of radiation emitted from a hot particle on the body or clothing-of the exposed individual.
This policy does not change criteria for -
whole-body doses.
3.
Definitions As used in.this policy --
" Hot particle" neans a radioactive particle.
I
" Hot. particle exposure" means an occupational dose to the skin l
resulting from exposure to radiation emitted from.the radionuclides in a hot particle on the body or clothing of the exposed individual.
" Occupational dose" includes ex (a) in a restricted area or (b)posure of an individual to radiation in the course of employment in which the individual's duties involve exposure to. radiation, provided, that
" occupational dose" shall not be deemed to include any exposure of an 1
individual to radiation for the purpose of medical diagnosis or medical-therapy of such individual.
(Note:
This is the. definition of this-term given in 10 CFR Part 20).
i 4.
Occupational Exposure Limit The limits on occupational dose specified in the table in paragraph.
(a) of 10 CFR 20.101 for the hands and forearms, feet and ankles, and the skin-of the whole boQ apply to'all exposures ~, including hot -
particle exposures. However, because of the nature of the principal radiation (beta) involved, the extremely localized effects, and the j
lower biological risk, the staff believes a different limit for hot i
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2 particle exposures should be established through rulemaking and that enforcement discretion should be applied until a new limit for hot i
particle exposures is established by rule.
For a hot particle exposure of an individual above the limits of 10 CFR 20.101, the NRC will not issue a notice of violation for a dose to the skin of less than 100 rads calculated at a depth of 7 mg/cm' averaged over an area of 1 ca, including the region of highest dose This value r
will be used for each hot particle exposure; there are no quarterly or annual limitations. A notice of violation will be issued tin cases in which an individual receives a hot particle exposure in excess of 100 rads. Also, a notice of violation may be issued for violations of other regulatory requirements associated with an event involving hot particle exposures (e.g., violation of 10 CFR 20.201, " Surveys")
regardless of the magnitude of the hot particle exposure.
For purposes of comparison with either the limits of 10 CFR 20.101 i
or the 100-rad standard, hot ) article exposures will not be added to skin doses from sources ot1er than hot particles nor will hot particle typosures from different particles be summed unless the different particles result in doses to the same area (location) of skin.
5.
Records. Notifications, and Reports Nothing in this policy should be construed as changing, or in effect l
changing, other requirements of 10 CFR Parts 19 and 20.
In partic-l ular, the requirements of 10 CFR 20.401 (records),10 CFR 20.403 (notifications of incidents),10 CFR 20.405 (reports of overex 10 CFR 20.408 (reports of personnel monitoring on termination)posures),
, and 10 CFR 20.409 and 10 CFR 19.13 (notifications and reports to indi-viduals) remain in effJct and are related to the current dose limits in 10 CFR 20.101.
For example, a hot particle exposure resulting in a skin dose of 75 rads to the feet, ankles, hands, or foreams must be reported tc the NRC within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
6.
Entorcement Examples:
10 CFR Part 2. Appendix C. Supplement IV in addition to the enforcement discretion with respect to issuing f
notices of violations, enforcement discretion also will be exercised with respect to the severity levels of violations.
For a dose to l
the skin from hot particle exposures, the following examples will be used for determining severity levels:
(a) Severity Level III - Violations involving, for example --
1.
Hot particle exposures for which the dose to the skin exceeds 1000 rads.
2.
Failure to make a notification (required by 10 CFR 20.403) or a report (required by 10 CFR 20.405) for a hot particle exposure that results in a skin dose that exceeds 1000 rads, t
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(b) Severity Level IV - Violations involving, for example --
1.
Hot particle exposures.for which the dose to the skin
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exceeos 100 rads but oces not exceed 1000 raos.
2.
Failure to make a notification (required by 10 CFR 20.403) or a report (required by 10 CFR 20.405) f or a hot particle exposure thot results in a skin dose that exceeds 100 raos but cows not exceed 1000 rads.
Note: lio numerical criteria (skin doses) have been established as exaniples f or Severity Levels 1 and 11.
7.
Ettective Date This po) icy is effective ineediately, i
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ENCLOSURE 2 l
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National Council on Radiation Protection and Measurements 7910 WOODuoNT AVENUE, SUITE s00. BETHESDA. MARYLAND 20814 Ms5 AREA Co0E (301) 657 2652 WARAEN K SINCLAIR. Ph D., Prescem S JAMES ADELETEIN W 0.. vee Prescem W ROGE R NEY, J D., (seevhe GreeNw Fax Numbers (301) 907-8768 October 26, 1989 Dr. Bi". A M. Morris, Director Di"*sion of Regulatory Applications Of1 ice of Nuclear Regulatory Commission Washington, D.C.
20555
Dear Dr. Morris:
1 refer to Mr. Beckner's letter of October 16, concerning the progress of the NCRP's report on hot particles.
While this letter correctly describes the anticipated schedule for the NCRP report, 1 should emphasise that there are some te chnical issues still outstanding concerning the hot particle l
question. We hope that some of these can be resolved when some of the the parties involved meet at a scheduled November 16th meeting and that soon j
thereaf ter it may be possible to discuss further where the technical matters i
stand and the appropriateness of the schedule we have outlined.
If the conclusion of these discussions is favorable, 1 expect to complete my final review of the report very soon. Af ter this the docuesnt can be made available to you. Should the discussions evidence the need for further action, we will, of course, have to modify the schedule.
I am sure you appreciate that there are some complex issues involved and that the NCRP is anxious to resolve these in a scientifically responsible manner at a time when not all the scientific evidence that is really needed is available.
Thank you for your consideration.
We look forward to our continued cooperation.
Sincerely yours,
/
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,h U4r Warren K. Sinclair President WKS/mc 1
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