ML20236X776

Responds to 870807 Ltr Re Violations Noted in Insp Rept 50-395/86-22.Violation Occurred as Stated in Notice of Violation for Reasons Presented in Encl.Nrc Will Continue to Assess Skin Exposures in Accordance W/Existing Policy

ML20236X776
Person / Time
Site:	Summer
Issue date:	12/03/1987
From:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Nauman D SOUTH CAROLINA ELECTRIC & GAS CO.
References
EA-87-007, EA-87-7, NUDOCS 8712100258
Download: ML20236X776 (7)

See also: IR 05000395/1986022

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DEC 0 31987

Docket No.: 50-395

License No.: NPF-12

EA 87-07

South Carolina Electric and Gas Company

ATTN: Mr. D. A. Nauman, Vice President

Nuclear Operations

P. O. Box 764 (167)

Columbia, SC 29218

Gentlemen: 1

SUBJECT: NRC INSPECTION REPORT NO. 50-395/86-22

Our letter dated July 13, 1987, in response to your letter of April 9,1987,

stated that with regard to violation A, we concluded for the reasons presented

in the Enclosure to our letter, the violction occurred as stated in the Notice

of V M ation (NOV) transmitted with NRC Inspection Report No. 50-395/86-22.

With regard to your letter of August 7,1987, after careful review of the bases

for your denial, we continue to conclude, for the reasons presented in the

Enclosure to this letter, that the violation occurrer: as stated in the NOV. We

again have also considered your view that the proposed severity level for both

violations is not warranted and again concluded that the violations were

appropriately categorized as a Severity Level III problem.

Since you provided corrsctive actions for the violation durira the Enforcement

Conference held on December 16, 1986, as documented in NRC Inspection Report

No. 50-395/86-22 sent to you on March 12, 1987, no further response is

requi red. If your understanding of corrective actions has changed since this

meeting, you should provide the NRC an update of the corrective actions.

The NRC recognizes that the calculated dose of 420 rems is a quite conservative

value and that the safety implications of the dose may be significantly reduced

because of the extremely limited area of exposure. Because of the lessened

safety significance of this dose, as opposed to a similar dose to a large area

of skin, the NRC categorized the violation as a Severity Level III rather than

a Severity Level I, which is that listed in our Enforcement Policy in

10 CFR Part 2 for skin doses in excess of 375 rems. We recognize the unique j

circumstances of high doses to very small areas of the skin. We also agree ]

with your consultant's recommendation that the individual's cose record should i

contain a notation of the circumstances of this dose to put the dose in proper {

perspective. j

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South Carolina Electric -2- DEC 0 31987

and Gas Company

As we have indicated previously, the NRC recognizes the general need for a

reevaluation of the basis for dose assignment due to very small, highly

radioactive particles on the skin. The NRC formally requested the National

Council on Radiation Protection and Measurements to review and provide guidance

on the issue. We will keep you informed of any changes to our regulations and

criteria that may result from this review. In the interim, and unless there

are changes forthcoming, however, the agency will continue to' assess skin

exposures in accordance with the existing policy.

In accordance with Section .2.790 of the NRC's " Rules of Practice," Part 2,

Title 10, Code of Federal Regulations, a copy of this letter and its enclosure

will be placed in the NRC Public Document Room.

We appreciate your cooperation in this matter.

Sincerely,

OF3GRiAL W !E0 U"

lie 1SDilCR!,

J. Nelson Grace i

Regional Administrator

Enclosure:

Staff Assessment of Licensee i

Response to Notice of Violation with

Attachment

cc w/ encl:

0. S. Bradham, Director, Nuclear Plant

Operations

J. L. Skolds, Deputy Director

Operations and Maintenance

J. B. Knotts, Jr. 1

Debevoise and Liberman

W. A. Williams, Jr., Special

Assistant, Nuclear Operations -

Santee Cooper

A. M. Paglia, Jr., Manager

Nuclear Licensing

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and Gas Company

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ENCLOSURE

STAFF ASSESSMENT OF LICENSEE RESPONSE TO

NOTICE OF VIOLATION

Violation A (50-395/86-22-02) involved the failure to control licensed material

in such a manner as to limit the occupational dose to an individual's

extremities to less than 18.75 rems per calendar quarter as required by

10 CFR 20.101(a).

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Licensee Comment: 1

10 CFR Part 20 does not prescribe a method of calculating non-uniform doses

resulting from a " hot particle" on the skin of an extremity, and NRC IEN 86-23

is not a regulatory requirement which can be made the basis for a Notice of

Violation.

NRC Response:

As stated previously in the Enclosure to our letter dated July 13, 1987, NRC

regulations are based on recommendations such as those in ICRP 26, Radiation

Protection Guidances to Federal Agencies (developed by EPA), NBS handbooks,

current research by recognized experts, and comments received during the public

comment period for proposed rule changes. The current 10 CFR Part 20 is based,

in substantial part, on the recommendations of NBS Handbook 59. Where there is

a need to clarify the intent of NRC regulations, the preferred approach is to 1

obtain clarification from the base document, in this case NBS 59. Thus in this

case, where specific implementation details on how to do assessments are not

included in 10 CFR Part 20, the source documents were used to define the methods

used.

With regard to IEN 86-23, it should be noted that the main purpose of this ~

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Notice was to inform licensees of occurrences of skin contamination by small

particles of radioactivity. Licensees were expected to review the information

in the Notice for applicability to their specific program. In addition, the

Notice reminded licensees of the long-standing NRC policy regarding assessments

of dose to the skin. The Notice did not create a regulatory requirement; it

did provide information on events and remind licensees of techniques for skin

dose calculation.

The NRC recognizes that significant advances have been achieveo in the field of

Health Physics as noted in your response. The proposed 10 CFR Part 20 has been

out for comment, and comments received are being reviewed. The general points

made by SCE&G and those provided by other sources regarding the advancements in

health physics will be considered during the review. Nonetheless, the current

regulations remain valid and in effect.

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Licensee Comment:

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Calculational methods consistent.with current good practice in the field of

' health physics, such as the method employed by SCE&G, should be accepted'in the

absence of a method prescribed, or incorporated by reference, in the

regulations.

The thirty year old method on which NRC guidance and regulatory interpretation

is based (NBS Handbook No. 59) results in significant over estimation of

biolcgical effects of such an exoosure which is inconsistent with the l

philosophy of current recommendations, such as International Commission on

Radiological Protection (ICRP) Publication 26 and the principles of ALARA.

Based on recommendations of the ICRP and previous guidance provided by the NRC,

SCE&G contends that guidance given in IEN 86-23 is inappropriate for

determining dose equivalent due to hot particle contamination. Furthermore,

ICRP-26 states in Paragraph 183, "... if the dose . distribution is extremely

non-uniform, as that from very small particles in contact with the skin, the

local absorbed dose (rads due to beta and gamma components) should be assessed

and used to predict possible local skin reactions." SCE&G implemented this

recommendation to determine the potential for non-stochastic effects (cosmetic

changes) and retained professional medical assistance to assure there were no

local skin reactions. The ICRP goes on to say that "It is inappropriate,

however, to relate such localized absorbed doses to the absorbed doses

corresponding to the dose-equivalent limit." Regulatory interpretation as

reflected in IEN 86-23 contradicts previous staff guidance, Regulatory

Guide 8.23, while ignoring both current state-of-the-art and ICRP recommenda-

tions.

NRC Response:

NRC recognizes the need for a reevaluation of the basis for dose assignment due

to very small, highly radioactive particles. Recently the NRC formally

requested the National Council on Radiation Protection and Measurements (NCRP)

to review and provide guidance on this issue. As appropriate, when this

guidance is received, the NRC will re-evaluate the current basis of

10 CFR 20.101(a). However, until, and unless, the basis of 10 CFR 20.101(a) is

changed, the guidance in NBS Handbook 59 and IE Notice 86-23 is to be used in

determining compliance with the current regulations. IEN 86-23, rather than l

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being contrary to the regulations, as you indicated, represents the NRC

position on how licensees should calculate the dose to the skin from

radioactive contamination. This guidance is considered most appropriate at

this time. It is not at all clear, as suggested by SCE&G, that the basis of

10 CFR 20.101(a) should be changed. Recent scientific publications (see

Attachment) have indicated that the ICRP-26 guidance is inadequate,

particularly for non-uniform exposures, and have suggested the continued use,

as an interim measure, of the current practice of determining skin dose at the

basal layer of the epidermis (7 mg/cm2) averaged over an area of one square

centimeter.

Licensee Comment:

Regulatory Guide 8.23 (in a footnote to Table 2) states that for the hands,

averaging over the whole area of the hands is acceptable, nominally 300 cm2,

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NRC Response:

i The NRC had noted the need for a change in this portion of Regulatory

Guide 8.23 since it implied a method of calculation different from that upon

which the regulations were based. Action has been initiated to revise this

Regulatory Guide to make it clearly consistent with NRC policy.

Licensee Comment:

! ICRP-26 does not, as pointed out by your response, support the omission of the

beta component; however, paragraph 17 states that the absorbed dose is

insufficient by itself to predict either the severity (non-stochastic) or the

probability (stochastic) of the deleterious effects on health resulting from

irradiation under unspecified conditions. The dose equivalent unit, rem, was

developed to correlate delayed stochastic effects with radiation exposure.

SCE&G has therefore assigned a dose equivalent which more appropriately

correlates the probability of future stochastic effects due to the skin

irradiation by this highly localized contamination. That dose equivalent which

reflects current understanding of the 1.tochastic risks associated with skin

dose, has been recorded as 0.43 rem and does not exceed the limits of

10 CFR 20.101(a).

NRC Response:

As stated in our letter of March 10, 1987, it is the NRC's position that the

methodology SCE&G used was inappropriate. The beta component cannot be

ignored, nor is it appropriate to average the dose over 100 cm2 Furthermore,

ICRP-26 does not suggest that the dose from the accidental contamination of

individuals from small particles should be averaged over any area larger than

one square centimeter. As stated above, the NRC does have under evaluation

consideration of changes in skin dose assessment methodology that might result

in a different factor for converison from a rad to a rem for doses to very small

areas of the skin. Until a decision is made on whether such a change is appro-

priate,10 CFR Part 20 specifies that for beta doses, one rad equals one rem.

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ATTACHMENT

NUREG/CR-4418, " Dose Calculation for Contamination of the Skin ,

Using the Computer Code VARSKIN," PNL 5610, August 1987.

Reece, W. D., et al., " Extremity Monitoring: Considerations for

Use, Dosimeter Placement and Evaluation," NUREG/CR-4297,

December 1985.

Charles, M. W. and J. Wells, "The Development of Criteria for

Limiting the Non-Stochastic Effects of Non-Uniform Skin Exposure,"

Proceedings of the 5th Congress of the International Radiation  !

Protection Society, Jerusalem, March 1980.

' Rohlof, F. and M. Heinzelmann, " Calculation of Dose Rates for Skin

Contamination by Beta Radiation," Radiation Protection

~

Dosimetry 14 (4), 279-287 (1986).

Strather, J. W., " Radiation Damage to Skin," Report of a Workshop

on Radiation Damage to Skin, Fundamental and Practical Aspects,

Saclay, France, 9-11 October, 1985, NRPB Bulletin, No. 70,

(March 1986).

Francis, T. M. , " Dosimetry of Beta Particles and Low-Energy

X-Rays" Report of a Workshop held at the Nuclear Research Centre

(CEA),Sacla

(March 1986)y, France, 7-9 October, 1985, NRPB Bulletin, No. 70,

.

Charles, M. W. , " Skin, Eye, and Testis: Current Exposure Problems

and Recent Advances in Radiobiology," J. Soc. Radiol. Prot. 6, (2),

69-81 (1986).

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