IR 05000312/1988020

Insp Rept 50-312/88-20 on 880617.Violations Noted.Major Areas Inspected:Status of Unresolved Item 50-312/88-07-01 Re Skin Exposure of Worker Reported by Licensee on 880204

ML20150D734
Person / Time
Site:	Rancho Seco
Issue date:	06/23/1988
From:	Cillis M, Yuhas G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
Shared Package
ML20150D728	List: IR 05000312/1988020 ML20150D726
References
50-312-88-20, NUDOCS 8807140121
Download: ML20150D734 (9)

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V. S. NUCLEAR REGULATORY COMMISSION

REGION V

Report No. 50-312/88-20

     : Docket.No. 50-312 License No. DPR-54 Licensee: Sacramento Municipal Utility District 14440 Twin Cities Road Herald, California 95638-9799 Facility Name:        Rancho Seco Nuclear Generating Statien Inspection at: _ Clay Station, California Inspection Conducted: June 17, 1988 Inspector:          -         S [[

M. Cillis, Senior Radiation Specialist Date Signed Approved By: $h - P. Y Nh _ , Chief 6/13/ W Date Signed Faciliti adialogical Protection Section Summary: Inspection on June 17, 1988 (Report No. 50-312/88-20) __ Areas Inspected: Special unannounced inspection by a regionally based inspecter to review the status of unresolved item 50-312/88-07-01 related to a skin exposure of a worker reported by the licensee on February 4,198 The inspection included review of the SMUD letter, dated June 9, 1988 and referenced evaluation. Inspection procedures addressed were 30703, 90712 and 9370 Results: In the one area inspected, two apparent violations were identified involving a failure to control licensed raterial to maintain the dose to_the skin of a worker within the regulatory limits (paragraph 2.0) and failure to provide an individual a report on his exposure data pursuant to 10 CFR 20.409(b) (paragraph 2.D).

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DETAILS

1. Persons Contacted '

 (a). Licensee
 *R. G. Croley, Assistant General Manager, Technical and Administrative Services
 *D. Keuter, Director, Operations and-Maintenance
 *J.-Shetler, Director, Plant Support Services-
 *R. Harris, Radiation _ Protection Manager-
 "J. Delezenski, Assistant Licensing Manager
 *J. Meyer, Quality Assurance-Supervisor
 *R. Orthen, Manager, Health Physics and Chemistry Support
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 *R. Little, Technical and Administrative Services Engineer
 *D. Price, Supervisor Nuclear Training
 * Borter, Supervisor, Health Physics and Chemistry Support
 * Giomi, AGM Technical Assistant
 * Wierjorek, Instructor, Nuclear Training
 *P. Murphy, Health Physicist, Health Physics and Chemistry Support (b). Contractor Personnel
 *R. Jones, Licensing Engineer (IMPELL)
 *E. D. Scalsky, Health Physicist (QCI)'
 (c). U. S. Nuclear Regulatory Commission
 *A. Johnson, Enforcement Officer, Region V
 *P. Qualls, Resident Inspector
 * Denotes; attendance at the exit interview held on June 17, 196 The inspector also met.with and held discussions with other nembers of the licensee's and contractor staf . Followup Item Unresolved Item 50-312/88-07-01:  This item.is associated with the radiation exposure of a Rancho Seco worker to a highly radioactive particle of material which resulted in a dose that was reported to be in excess of the regulatory limit. The licensee's immediate notification of the potential overexposure was made on February 4, 1998. Subsequently, the 30 day Licenser Event Report (LER) 88-03 describing the event was submitted to the 'iRC pursuant to 10 CFR Part 20.405(a)(1)(iv) on March 8,

1988.

! Unresolved items are matters about which more information is required in order-to ascertain whether they are acceptable items, violations or deviations. An unresolved item involving the determination of a workers extremity exposure is discussed herein.

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. . 2 Background Additional developed information on the reported 523 rem exposure to-the left leg of a Rancho Seco worker, including the licensee's
 . initial investigation, are contained in NRC Inspection Reports 50-312/88-07 and 50-312/88-08, and LER 88-03. NRC inspection 50-312/88-07:was conducted on February'E,1988 and February 8,1988 and inspection 50-312/88-08 was conducted during the period of March 7-22,.198 This event was classified as an unresolved item pending the completion of the. licensee's investigatio During the Management Meeting held on March 16, 1988,- the licensee informed the Region V staff that their investigation ~would be completed on or about June 2, 198 Subsequently, two apparent violations related to the event were identified in Region V Inspection Report 50-312/88-0 The licensee's final: investigation report, HOT PARTICLE EXPOSURE OF FEBRUARY 4,-1988 dated June 9, 1988, was received in the Region V Office on June 10, 1988. , The June 9, 1988, letter provides the licensee's final analysis of the event and postulates the licensee's
 "Worst Case" and "Best Engineering Estimate" scenario A "Worst Case" exposure of 278 rem and a "Best Engineering Estimate" occupational exposure of 19 rem skin dose to the extremity were calculate It should be noted that 10 CFR Part 20.101(a) requires that no licensee possess, use or transfer licensed material in such a manner as to cause an individual to receive in any one calendar quarter from radioactive material and other sources of radiation, a total occupational dose in excess of 7.5 rem to the skin of the whole bod CFR 20.101(a) 2 also limits the quarterly dose to "Hands and forearrs; feet and ankles" to 18.75 rem. The term "extremity" is not currently used in the regulatinn. At this time, any area of skin not on the hands, forearms, feet or ankles is considered to be
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part of the skin of the whole bod In-Office Review An in-office review of the information provided in the licensee's June 9, 1988, letter was conducte Informatioa referenced in this letter includes: Updated report of skin dose assessment "Worst Case" assumptions Evaluation of small particle by Battelle Pacific Northwest Laboratories Incident time line Medical report of exposed individual I m

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. Biological effects evaluation of the exposure Executive summary The letter stated that the "Hot Particle" from the event was sent to Battelle Pacific Northwest Laboratories for analysi The Battelle analysis consisted of (1) initial identification, (2) gamma spectral analysis, (3) bcta spectral analysis, (4) extrapolation chamber measurements, (5) activity determination, (6) instrument response, (7) scanning electron microscopy and energy dispersive spectroscopy, (8) determination of potential skin dose rate, and (9) estimate of actual dose received by the workcr. The Battelle report stated that a gamma spectrum of the particle was obtained using a portable intrinsic germanium detector with associate electronic The Battelle report stated that the spectrum revealed the particle consisted of essentially 100% Cobalt-60 as indicated by the photopeaks seen at 1173 key and 1332 ke The teta spectroscopy was performed using a prototype instrument developed by the Kansas State University under contract with the Department of Energy and modified by Battelle Pacific Northwest Laboratorie The results of the beta spectroscopy analysis supported the findings from the gamma analysis. It indicated that the particle did not include pure beta-emitting radionuclides which could not have been identified by the gamma spectral analysis. Battelle determined the activity of the particle to be 23.8 microcuries of Cobalt-6 A reassessment of the worker's dose was performed by the licensee's staff upon completion of Battelle's analysi The licensee stated that due to the uncertainty regarding the duration of the exposure and the distance between the particle and skin, a skin dose was

, determined using the two scenarios. The "Worst Case" analysis calculated the beta dose rate by using the NRC accepted VARSKIN computer code while the beta dose rate used in the "Best Engineering Estimate" was based on an excelectron dosimeter measurement. Other assumptions described in the licensee's evaluations were as follows:

"Worst Case"- The particle was deposited on the worker's skin innediately aft *r the worker donned his protective clothing and remained there until the time that the clothing was removed. The total exposure time used in this case was 2.6 hour "Best Engineering Estimate"- The worker was exposed to the "Hot Particle" shortly after the work evolution began ard it migrated over an area of 10 square centimeters during the work evolutio It was also assumed that, due to vigorous contact between the clothing and skin characteristic of the region behind the knee, the particle transferred back and forth continuously until the worker removed his clothin No correction was made for shielding and distance for the time the particle was away from the ski The total time used for this calculation was 2.33 hour The inspector noted that, while either scenario is possible, it cannot be determined with any certainty what the duration of the exposure was and what the actua' enavior of the particle was during

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the exposure perio It would seem reasonable that the worker ' received an exposure to the skin that did not exceed 278 rem The inspector concluded that the "Best Engineering Estimate" evaluation, while possible, was not supported by facts to positively conclude that the particle had not bee 1 lodged directly on one area of skin for greater than one tenth the exposure time. The inspector noted that the. licensee's evaluation did not include an evaluation of the gamma dose to the end of the thigh bone (i.e. whole body).

Discussions with the licensee's staff disclosed that they felt the gamma dose to the end of the femur would be negligibl However, they stated that an evaluation of the gamma dose to the femur would be conducte . The licensee concluded that the maximum conservative dose to the skin of the extremity of the worker was 278 rem. The inspector was informed that this extremity dose was assigned to the worker. The workers prior accumulative whole body dose for the first quarter of 1988 was 0.136 re Therefore, his total accumulative extremity dose for the first quarter of 1988 has been assigned as 278.136 rems. As noted in A above, the regulations currently require that this dose be assigned to the skin of the whole body rather than the skin of the extremit The medical reports stated that the worker was informed that there would be no biological effects from the exposure insofar as skin erythema rarely occurs below doses of 600-800 rems and typically only following an exposure to a larger area than was assumed. The medical report added that no clinically determinal effects would be expected from the maximum postulated dos C. On-site Inspection An on-site inspection was conducted to verify that the licensee's correctives actions for preventing a recurrence of the event had been implemented as described in Region V Inspection Reports 50-312/88-07 and 50-312/88-08. The inspection included a review of the worker's occupational records, applicable procedures, training records, audit and surveillance records, and discussions with the licensee's staf Exposure Record Review 10 CFR part 20.409(b) states:

 "When a licensee is required pursuant to paragraphs 20.405 or 20.408 to report to the Commission any exposure of an individual to radiation or radioactive material, the licensee shall also notify the individua Such notice shall be transmitted at a time not later than the transmittal to the Commission, and shall comply with the provisions of paragraph 19.13(a)."

A review of the worker's occupational exposure records disclosed that the licensee had assigned 278 rem to the l

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5 ~ extremity as indicated in the licensee's June 9, 1988, lette However no notice had been sent to the individual pursuant to 10 CFR.20.409 even though LER 88-03 had been submitted to the ' ' ' Commission pursuant-to 10 CFR 20.405. The licensee's staff 1 informed the inspector that the individual had been verbally .

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 ' informed on more then one occasion of the initial dose estimate of 523 rem and the-f nal dose estimate of 278 rem that was subsequently. assigned to him. The licensee's staff added that

, they thought they had sent the worker a copy of the earlier estimate but they were unable to locate a copy of the repor The inspector verified through a discussion held with the worker that he had not received any written notification of his exposure as of June 17,1988. The worker confirmed that the licensee had verbally informed him of his exposure on several occasions since February 4, 1988. The staff added that.they

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had intended to send the worker a copy of his exposure after the revision to the initial LER 88-03 was approved and submitted to the NRC. The licensee stated that the revised LER 88-03 would be ready for issue on or about June 27, 198 . Hot Particle Program Implementation The inspector found the licensee's "Hot Particle Program" that was developed in accordance with their corrective Action Plan had been implemented in a timely manner. The following documents were reviewed: Phase I Hot Particle Program Action Plan closeout

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Environmental Protection Guide 700 entitled, Skin dose calculations for Hot Particle Contaminations Training records for Hot Particle Program training provided.to:

 (1) Non-radiation workers (2) Radiation workers (3) Radiation. Protection Staff (4) ALARA Coordinators (5) QA/QC personnel The following procedures that are related to the licensee's
 "Hot Particle Program" were reviewed:

Procedure N Title Date RSAP-1104 Hot Particle Control Program 3/21/88 RP.30 Radiation Work Permits 3/21/88 RP.30 Protective Clothing and 3/21/88 Equipment Use

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, RP.30 Area Definitions, Postings, and 5/23/88 Requirements RP.30 Contamination Limits and Control 5/23/88

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for Plant Surfaces RP.305.9A Removal of Tools an'd Equipment 5/23/88 from Controlled Areas RP.305.9B Personnel Contaminatior. Monitoring 6/10/88 RP.305.9C Decontamination Procedures 5/23/88 RP.305.90 Personnel and Clothing 3/21/88 Decontamination Reports RP.305.9E Hot Particle Controls 3/21/88 RP.305.12 OTSG Radiation Protection Coverage 5/16/88 RP.305.16 Receipt of Radioactive Material 3/21/88 AP.309 I-4 Protective Clothing Shipment 5/5/88 and Receipt AP.309 II-6 Contaminated Protective Clothing 5/5/88 Handlirg The inspector also held discussions with plant workers and the radiation protection staff to determine their awareness of the Rancho Seco "Hot Particle Program".

The inspector concluded that the licensee had met their objectives for implementing an effective "Hot Particle Program" in accordance with their commitments made at the March 16, 1988, Management Meetin . Other Actions The' inspector verified through the review of appropriate records that the licensee had taken action to implement their Management Action Plan as presented at the Management Meetin The purpose of-the Management Action Plan was to make workers aware of management's expectations for maintaining a quality health and safety program for the protection of Rancho Seco workers and the general publi The plan emphasizes the need for:

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Procedure adherence Attention to details

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Improved supervision

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Improved planning

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Improved work control' Holding people accountable

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Team work =, Sel f-critical - appraisal s

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Safety' responsibilities Effective communication

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_ Adequate shift _ turnovers

  ' Adherence to Radiation Work Permit (RWP) requirements
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Importance for quality work and a quality Radiation Protection program The Master Action Plans assigned to Plant Operations and Maintenance Departments were reviewed and were found to be consistent with the licensee's-March 16, 1988, commitment The inspector also held discussions with the Quality Assurance supervisor to determine if steps were taken to enhance Quality

 . Assurance's involvement in-radiation protection. The inspector verified through'the discussion and a review of Quality Assurance records that Quality Assurance activities had been enhanced in the area of radiation protection.

! The' Quality Assurance supervisor informed the inspector that his staff had received the specialized training related to the >

 ; plants' Hot Particle Progra The inspector reviewed a checklist that was developed for the Quality Assurance staff ,

assigned to examine the adequacy of the plants Hot Particle Program. Surveillance report EP 88-1172 Hot Particle program _

 - Activities, dated May 5,1988, and the Quality Assurance surveillance reports 88-S-331 of May 5, 1988, and 88-S-380 of June 2, 1988, related to radiological control activities, were reviewed. .The inspector concluded that Quality Assurance activities in the area of radiological controls had been enhanced since the February 4,1988, even D. Conclusion The inspector concluded that the approach taken by the licensee in deter 91ning the worker's final exposure was reasonable and that their corrective actions in.plemented for preventing recurrence of similar events were timely and consistent with the industry standards. To be consistent with 10 CFR 20.101(a) the licensee should correct the individual's dose records (NRC Form 5) to identify the dose as being to the skin of the whole body rather than to an extremit The inspector brought the above observations to the attention of the licensee at the exit interview held on June 17, 198 The licensee was informed that unresolved item 50-312/88-97-01 was closed. The inspector added that the failure to maintain the involved worker's occupational exposure to the skin of his leg to less than 7.5 rem in the first quarter of 1988 is an apparent violation of 10 CFR 20.101(a) (50-312/88-20-01).

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The inspector also informed the licensee that the failure to provide on March 8, 1988, a written statement to the worker of his exposure was an apparent violation of 10 CFR 20.409(b) (50-312/88-20-02). Exit Interview The inspector met with the licensee representatives (denoted in paragraph 1) at the conclusion of the inspection on June 17, 198 The scope and-findings of the inspection were summarize The two apparent violations discussed in paragraph 2.0. were brought to the licensee's et.tention. The licensee informed the inspector that the worker had been verbally informed of his exposure even though a written report had not been sent to the individual as required by 10 CFR 20.409 and 10 CFR Part 19.13(a). The licensee acknowledged both violation The inspector informed the licensee that enforcement action related to the apparent violations discussed in paragraph 2.D. of this report and the apparent violations discussed in Inspection Report 50-312/88-08, paragraph 5(d), and the findings of Inspection Report 50-312/88-07 would be addressed in separate correspondenc \

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