ML20237H955

Responds to Notice of Violation & Proposed Imposition of Civil Penalty.Corrective Actions:Review Conducted of Health Physics Applications of Computer Programs & Addl Programs Subj to Independent Verification & Validation Procedures

ML20237H955
Person / Time
Site:	San Onofre
Issue date:	08/12/1987
From:	Baskin K SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), NRC OFFICE OF ENFORCEMENT (OE)
References
NUDOCS 8708170433
Download: ML20237H955 (16)

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yf"}f Southem Califomia Edison Company P. O. BOX 80 0 2244 WALNUT GROVE AVENUE ROSEM EAD. CALIFORNIA 91770 MENN ETH P BASMIN T E LE PHON E l VICE PRESIDENT s13 3026401 August 12, 1987

. Director,- Office of. Enforcement U. S. Nuclear Regulatory Commission Attention: Document Control Desk Hashington, D.C. 20555 Gentlemen:

Subject:

Docket No. 50-362 <

Reply to a Notice of Violation San Onofre Nuclear Generating Station Unit 3

Reference:

Letter, Mr. Kenneth P. Baskin to Director, Office of Enforcement; ,

Subject, scme as above; dated July 15, 1987 i By letter dated June 25, 1987, the Nuclear Regulatory Commission (NRC)

Region V Office issued a Notice of Violation (NOV) and Proposed Imposition of Civil Penalties for violations of NRC requirements regarding radiation safety matters. With respect to the two violations for which civil penalties were imposed, SCE in its letter referenced above, submitted a check in the amount proposed. The Southern California Edison (SCE) Company has thoroughly I examined the incidents described in the NOV and, in accordance with the requirements of 10 CFR 2.201, is providing the response as an enclosure to this letter.

Should you have any questions, please do not hesitate to call.

Very truly yours,

&n Enclosure cc: H. Rood, NRR Senior Project Manager, San Onofre Units 2 and 3 i J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 8708170433 870812 PDR ADOCK 05000362 \

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ENCLOSURE Response to the Notice of Violation and Proposed Imposition of Civil Penalties contained in the enclosure to Mr. J. B. Martin's letter dated June 25, 1987. The following references are cited in the reply:

(1) Letter, R. A. Scarano (NRC) to Kenneth P. Baskin (SCE),

USNRC Inspection Report 50-362/86-37, dated' April 13, 1987 (2) Letter, R. A. Scarano (NRC) to Kenneth P. Baskin (SCE), USNRC Inspection Report 50-362/87-13, dated May 28, 1987 (3) Letter, John B. Martin (NRC) to Kenneth P. Baskin (SCE), dated June 25, 1987 (4) Letter, Harold B. Ray (SCE) to USNRC, Licensee Event Report No. 86-15 Revision 2,. Docket No. 50-362, dated May 7, 1987 (5) USNRC, Office of Inspection.and Enforcement, Information Notice No. 86-23, dated April 9, 1986 (6) "A Health Physics Program for Operation with Failed Fuel",

R.: V. Harnock et al, Radiation Protection Manaaement, Vol . 4, No. 4, (July / August 1987), pp. 21-30.

(7) Letter, H. E. Morgan (SCE) to USNRC, Licensee Event Report No. 87-03, Docket No. 50-362, dated March 24, 1987.

ITEM I The enclosure to Mr. Martin's letter states in part:

"10 CFR 20.101(a) limits the total occupational radiation exposure to the hands of an individual-in a restricted area to 18.75 rem per calendar quarter.

t~ " Contrary to the above, during the fourth calendar quarter of 1986, a maintenance worker received a cumulative exposure to the right hand on the order of 512 rem while performing maintenance activities in a restricted area of the San Onofre Nuclear Generating Station (SONGS).

"This is a Severity Level III violation (Supplement IV)."

RESPONSI

1. Admission or denial of the alleaed violation SCE admits that a finger-ring thermoluminescent dosimeter (TLD) indicated that a maintenance worker may have received a cumulative dose to a portion of the right hand on the order of 512 rad l

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b while performing maintenance activities in a restricted area during October 1986. SCE acknowledges that the dose equivalent resulting from such an exposure when calculated in accordance with Reference

(5) exceeds the above cited quarterly occupational exposure limit.

As indicated in References (2) through (4), such a dose represents a l

limited health hazard, based on its very localized character.

SCE believes that the dose equivalent resulting from such an exposure should be' consistent with the limited health hazard which it represents. SCE believes that the principles established by the International Commission on Radiological Protection (ICRP) provide the appropriate basis for determining the dose equivalent. These principles are endorsed in a memorandum of recommendations, " Federal Radiation Protection Guidance.for Occupational Exposure," which was approved for implementation by Federal agencies on January 20, 1987 by President Reagan.

Using these principles, SCE has determined that the dose equivalent for this exposure would not exceed 10 CFR 20.101(a) limits.

However, notwithstanding this, SCE has responded to the event with.

corrective steps to minimize the potential for exposures of this type as described in Reference (4) and discussed further below.

These corrective steps have been developed and implemented as though a 512 rem dose occurred and that it was a consequence of the circumstances described in References (1) through (3).

2. Reassns for the violation The most likely cause of dose of this magnitude is direct contact of the worker's hand with a small irradiated fuel particle (IFP), as indicated in Referenct (1). SCE did not anticipate the possibility '

that an IFP of the size required to yield a significant exposure could have been present at the locations whnre the work was performed, and have remained undetected by the radiation survey measures being used. Nevertheless, as discussed in Reference (1),

this possibility did exist.

IFPs can be released to the Reactor Coolant System (RCS) in substantial quantities from certain kinds of fuel clad defects during power operations. Most IFPs present in the San Onofre Units 2 and 3 RCS and connected systems were released in this manner. IFPs may also be released to the Spent Fuel Pool (SFP) area during fuel inspection and repair activities.

At the time of the'first refueling of Unit 3 in late 1985, Combustion Engineering (C-E), the fuel manufacturer, performed necessary fuel inspection and repair in the SFP area using procedures and radiological protection measures which had previously been used elsewhere with no apparent problems. Work of this type previously had not been performed at San Onofre and SCE established a planning group to support the effort. Measures which were known J

at the time to SCE personnel for the definition of, and for protection against, the radiological hazard associated with this ,

work were included in the controls applied. l i

SCE first recognized that a significant radiological hazard associated with IFPs existed when one was detected on the modesty garment of a radiation worker at a step-off pad serving the SFP area late in the fuel inspection and repair process. Following the initial IFP discovery, more IFPs were detected on the floor of the SFP area. The initial SCE response to the identification of IFPs is described in Reference (6).

As indicated in Reference (1), SCE took action to identify the systems connected to the RCS and SFP into which IFPs may have been released. These connected systems were recognized as having tne possibility of being contaminated by IFPs. However, based on the information then available, SCE did not anticipate that very large IFPs (i.e., IFPs large enough to result in an overexposure in accordance with Reference (5) methods in a brief period of direct contact) would likely exist in these connected systems. Measures to control the work, therefore, were not developed with the expectation that such very large IFPs would be present.

3. Corrective steos that have been taken and the results achieved

> Hith respect to the maintenance worker who received the exposure to ,

his right hand, our corrective steps and results achieved are  !

described in Reference (4).

Reference (4) describes a number of corrective steps taken, in particular those associated with the ube and processing of finger-ring TLDs. During the investigation of this event, a number of deficiencies were identified in this area which contributed to l

uncertainty concerning the dose reported.

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Although very large IFPs have not been found outside the area surrounding the SFP area since the presence of IFPs was identified in late 1985, all work involving the systems identified earlier as possibly contaminated by IFPs is now controlled on the basis that such IFPs may be present.

In planning for repair of the fuel in the SFP by C-E in 1985, no l

special containment methods were considered necessary or were known to have been used before. Anticipating the need to perform similar work during the upcoming Unit 2 refueling outage, SCE conducted a '

comprehensive review of industry experience in this area. This review did not identify any effective methods which have been developed or used elsewhere for confinement of IFPs during fuel '

inspection. Our efforts to develop such methods have not been entirely successful. Consequently, diligent effort will be made to 1

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l avoid inspection and repair of defective fuel in the SFP.

l- Nevertheless, SCE will seek to implement measures to reduce the I release of. IFPs to. the SFP should inspection and repair of defective fuel be necessary.

Early consideration was given to the possibility of removing IFPs from the RCS and connected systems, once they had been liberated from the fuel defects. No practical means of doing this were identified at the time. In 1986 a task force was created to evaluate further this possibility. The task force has reviewed input from several NSSS vendors familiar with the consequences of fuel failure and the technology that might be employed to remove the IFPs. No practical means for achieving any significant removal of IFPs from the RCS, the SFP or the connected systems has yet been identified.

In certain situations, although there is essentially no risk of overexposure using the dose determination methods which SCE  :

considers applicable for IFPs, as discussed in Reference (4),

radiological surveys cannot preclude such risk using the dose determination methods of Reference (5). These situations involve i circumstances when maintenance work is required on complax mechanical devices in areas of high background radiation. This is discussed further in the response to Item II.C.(1).

4. Corrective steos that will be taken to avoid further violations From the time when the fuel failures were first det:ected, SCE has worked with C-E to identify the cause and the corret.tive actions required. One cause of failure, which was identified following the inspections performed at Unit 3 in late 1985, and subsequently confirmed by the NRC in inspections performed at the manufacturing facility, has been addressed by improved quality measures during fuel fabrication.

Fuel failure has been experienced in Unit 2 fuel. Since we have not been able to identify methods for preventing IFP releases to the SFP l area during inspection and repair of defective fuel, we have not i determined how to proceed with such work during the upcoming Unit 2 refueling. Disassembly of the fuel may be necessary for inspection and repair. However, such work, if necessary, will be minimized.  ;

SCE will continue to search for methods to confine the spread of IFPs, and to remove them from systems where they exist currently.

As no practical methods have as yet been identified, measures to reduce the possibility of significant exposure from IFPs will continue to emphasize protection of the worker against the hazards involved.

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5. Date when full comoliance will be achieved As discussed under 1. above, SCE believes that the appropriate dose equivalent determination method is that described in Reference (4) and if applied, this exposure would not exceed the quarterly extremity dose limit of 10 CFR 20.101(a). Recognizing that this method is not consistent with that described in Reference (5), SCE will seek a prompt resolution of this matter through appropriate technical discussions with the NRC.

ITEM II.C.(1)

The enclosure to Mr. Martin's letter states in part:

"C. 10 CFR 20.201(b) requires that each licensee shall make such surveys as may be necessary to comply with the regulations in Part 20 and are reasonable to evaluate the extent of radiation hazards that may be present. 10 CFR 20.201(1) defines ' survey' as an evaluation of the radiation hazards incident to the production, use, release, disposal, and presence of radioactive materials.

"(1) Contrary to the above, during October 1986, individuals were permitted to engage in maintenance activities involving the reactor coolant and crud tank pumps without making a survey as necessary to comply with the hand dose limit expressed in 10 CFR 20.101(a), as evidenced by a worker receiving a dose to one hand on the order of 512 rem."

RESPONSE

1. Admission or denial of the alleaed violation SCE admits that individuals were permitted to engage in maintenance activities involving the reactor coolant and crud tank pumps without assuring that the surveys which were conducted would detect an IFP that could cause an extremity exposure in excess of the limits expressed in 10 CFR 20.101(a) when determined in accordance with Reference (5).

2. Reasons for the violation As discussed in Licensee Event Report No 86-015, Revision 1, SCE expected that the surveys conducted would be adequate to detect any unanticipated, large exposure sources. These surveys included continuous coverage by a Health Physics technician of both the reactor coolant and crud tank pump work. However, the survey methods used, and the other limits established for the work, did not exclude the possibility that a very large IFP might have been present and remained undetected.

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3. -Corrective steos that have been taken and the results achieved Detection of IFPs does require the use of extraordinary survey methods, as noted in Reference (1). Therefore,-a major element of the corrective steps taken involves.the use of time limitations which are based on the possible presence of IFPs that could remain undetected by the survey methods being used.

As noted in Reference (4), time limitations were used in connection with the maintenance activities involving the reactor coolant and crud tank pumps. Much shorter time limitations are'now considered for certain jobs where even extraordinary. survey methods cannot assure the absence of large IFPs. As there is a practical lower bound for such time limitations in order to accomplish a necessary task, it may not be possible for surveys to assure in every case the absence of IFPs. capable of producing an exposure exceeding the limits when doses are calculated in accordance with Reference (5).

Accordingly, additional steps are being taken, as discussed in i Section 4. below and in response to Item II.A.

Steps have been and are continuing to be taken to improve the survey methods used by the technicians in order to increase their I sensitivity.to the detection of IFPs. These st rvey methods were included as enhancements to the technician training for performing IFP surveys, hs discussed in Reference (4).

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4. Corrective steos that will be taken to avoid further violations In.the same manner in which improved monitoring equipment has greatly increased detection sensitivity at the exit from the radiologically controlled areas (i.e., use of the PBM-200s), SCE concludes that it is essential to identify and use improved monitot ing equipment in certain work locations where IFPs may be present. This is discussed in the response to Item II.A.(1).

Accordingly, SCE intends to make every effort to provide monitoring i equipment that has increased sensitivity to the presence of IFPs in j areas of high background activity.

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5. Date when full comoliance will be achieved Full compliance with survey requirements of 10 CFR 20.201 was achieved on January 1, 1987, when enhancements to technician training for performing IFP surveys were fully integrated into the HP program.

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ITEMS II.A.(1) and II.C.(2)

The enclosure to Mr. J. B. Martin's letter states in part:

"A. 10 CFR 20.105(b) requires that no licensee shall possess, use'or transfer licensed byproduct material, except as authorized, in such a manner as to create radiation levels in any unrestricted area which, if an individual were continuously present, could result in his receiving a dose in excess of two millirem in any one hour.

" Contrary to the above, byproduct material was transferred such that radiation levels in an unrestricted area would have exceeded two millirem in any one hour, if an individual were continuously present.

Specifically:

"(1) On February 2, 1987, a worker at SONGS was surveyed by a whole body contamination monitor, PMB-200, and found to apparently be contaminated. Repeated hand frisking of the suspect area with an E-140 type detector did not identify the source of contamination. The worker was released to the unrestricted area. The next day, an HP technician performed a full body frisk and located a radioactive particle on the jacket sleeve of the worker. The carticle was found to be a 0.08 microcurie irradiated fuel fragment which was capable of producing a calculated contact dose rate of approximately 400 mrem /hr...

"C. 10 CFR 20.201(b) requires that each licensee shall make such surveys as may be necessary to comply with.the regulations in Part 20 and are reasonable to evaluate the extent of radiation hazards that may be present. 10 CFR 20.201(a) defines ' survey' as an evaluation of the radiation hazards incident to the production, use, release, disposal, and presence of radioactive materials...

"(2) Contrary to the above requirement, on February 2, 1987, repeated personnel monitoring booth alarms indicated radioactive material in or on a worker's body and a survey necessary to prevent the unauthorized release of radioactive material and reasonable to evaluate the extent of radiation hazard to the worker was not made prior to allowing him to go j home."

RESPONSE

1. Admission or denial of the alleged violation SCE admits that, on February 2,1987, even though an exit radiation monitor continued to indicate the presence of radioactive contamination, a worker was permitted to leave the restricted area with byproduct material on his person that could have resulted in a radiation exposure level in excess of 2 mrem in any one hour. In addition, surveys adequate to evaluate the extent of the radiation

.- . 1 hazard were not performed at the time the worker was' permitted to leave, or at the time when radioactive contamination was first l

detected on his protective clothing.

2. Reasons for the violation-A survey adequate to evaluate the extent of the radiation hazard was not performed at the time contamination was first detected on the worker's protective clothing because the responsible Health Physics itechnician failed to consider the possibility that IFPs might- be present in the contaminated area.  !

The worker removed his protective clothing and, during the exit process, was counted in several PBM-200 personnel monitors. In each instance, the monitor alarmed and indicated that contamination existed on the worker's chest or other torso locations. The responsible Health Physics-technician failed to consider that the PBM-200's indication of chest contamination could have been produced by an IFP.on the upper arm. Instead, the technician attributed the alarm to noble gas decay products and the very sensitive setting of the newly installed PBM-200 monitors. Satisfied that no significant radioactive contamination actually existed, based on a survey of the worker's chest, the technician authorized the worker to leave.

In summary, the Health Physics technician was not sufficiently .

sensitive in this case to the need for performing surveys adequate to evaluate the extent of the hazard that could be represented by an IFP when the PBM-200 indicated the presence of contamination.

3. Corrective steos that have been taken and the results achityrd Regarding the failure to perform a survey adequate to evaluate the extent of the radiation hazard at the time contamination was first detected on the worker's protective clothing, the critical importance of conducting adequate radiation surveys, including instances where protective clothing is found to be contaminated,-has been reinforced to all personnel. The hazard associated with IFPs, and the fact that they have a relatively small gamma component which makes their detection especially difficult, has been reviewed in detail.

Regarding the final worker release, since the Health Physics technician's actions were contrary to both his training and experience level, he was disqualified from continuing to perform these duties and is no longer at San Onofre.

The PBM-200 represents a major improvement over the use of manual survey methods. Additional training has been provided to all Health Physics technicians concerning the use of this equipment. Release of any person experiencing continuing PBM-200 alarms must be approved by a General Foreman or above. When additional contractor

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technicians come to San Onofre for.the upcoming Unit 2 Cycle 4 -4 refueling outage, they will be required to successfully complete this training prior to participating in IFP-related activities. ]

4. Corrective stens that will be taken to avoid further violations Standard manual survey instrumentation only views an area of 15 to 20 square centimeters and must be moved slowly in order to have adequate sensitivity for IFPs. A typical adult has a surface area roughly 1,000 times the detector viewing area. The PBM-200s have an  ;

eff3ctive viewing area of approximately 14,000 square centimeters, 1 whi(n is one reason why the PBM-200 automatic survey monitors are much more effective than manual survey techniques in detecting IFPs.

Based on our experience with the PBM-200 monitors, and the SCE developed laundry monitors which are described in Reference (6), SCE is obtaining for evaluation automatic monitors for hand-carried articles which cannot be surveyed by the PBM-200. They will be procured and installed if they prove to be effective. In addition, SCE is taking similar action to obtain specialized survey meters I which have increased sensitivity to IFPs. If necessary, SCE will-

- participate with the manufacturer in the development of effective monitors, as was done in the case of the PBM-200s.

SCE has been aware of and concerned with the possible ingestion of IFPs. In order to minimize the potential for facial skin exposures, SCE requires the use of a respirator for work in IFP zones. In response to a recent NRC inquiry, SCE and the whole body counter manufacturer are jointly reflu g the whole body counter's software to further improve our ability to detect an ingested IFP.

Initial efforts indicate that significant software changes are necessary to increase our ability to detect an IFP which might be present. It is estimated that modification to software and machine settings will be completed by October 1, 1987.

5. Date when full como11ance will be achieved Full compliance was achieved on February 3, i987, when the IFP was identified and removed from the individual.

ITEM II.A.(2)

The enclosure to Mr. J. B. Martin's letter states in part:

"A. 10 CFR 20.105(b) requires that no licensee shall possess, use or transfer licensed byproduct material, except as authorized, in such a  ;

manner as to create radiation levels in any unrestricted area which, if an individual were continuously present, could result in his receiving a dose in excess of two millirem in any one hour.

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" Contrary to the above, byproduct material was transferred such that radiation levels in an unrestricted area would have exceeded two millirem in any one hour, if an individual were continuously present.

' Speci fically: ...

"(2) On February 21, 1987, a HP technician discovered a 0.2 microcurie irradiated fuel fragment in the carpet of his residence. The fuel fragment was transferred.to the techr.ician's~ residence, an unrestricted area, by the technician following his involvement in health physics activities at SONGS. The contact dose rate of this particle was calculated to be approximately 1200 mrem /hr."

RESPONSE

1. Admission or denial of the alleaed violation SCE admits that on February 21, 1987, an IFP which caused a dose rate in excess of 2 mrem per hour was identified in an unrestricted  :

area.

2. Reasons for the violation Based on SCE's experience with the sensitivity and operation of the PBM-200 exit monitors currently in use, the IFP identified by the Health Physics technician in the carpet of his residence must have been transported there by some means other than having been carried through such a monitor on the person of the technician. This may have occurred prior to the widespread use of such monitors, or it may have involved transport on a hand -carried article not monitored by the PBM-200s.

One hand-carried article where this would have been likely was the portable survey instrument which the technician removed without authorization to conduct the survey of his residence. The instrument had not been released as free of contamination and the technician did not evaluate it for the presence of contamination.

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3. Corrective steos that have been taken and the results achieved l The technician's residence, its grounds and his automobile were i extensively surveyed, and no other contamination was found.

PBM-200 automatic monitoring equipment has been installed at the I three units in sufficient quantity that they are available to all I personnel exiting the controlled area. This equipment provides assurance that IFPs will not be removed on the person of workers  ;

using the equipment.

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The need to very carefully monitor hand-carried items being removed.

from the controlled area for the presence of IFPs has been E

emphasized to Health Physics personnel.

As noted in Reference (1), IFPs are very difficult to detect by manual survey methods. As beta emitters with only a low gamma component, IFPs are ear,ily shielded from detection using manual survey methods. Highly sensitive, automatic monitoring equipment is i required to provide assurance that any IFPs present will be consistently detected.

4. Corrective stens that will be taken to avoid further violations SCE has considered the need to perform additional surveys in unrestricted areas to determine if other IFPs might also be found.

Such surveys will be performed for persons who request them, and who have worked extensively in IFP areas as in the case of this technician.

As discussed in the response to Items II.A.(1) and II.C.(2), SCE is I proceeding to obtain additional, sensitive monitoring equipment for use with hand-carried articles and for use in detecting IFPs within the controlled area itself. This equipment is intended to have a greatly increased sensitivity to the beta emissions characteristic of IFPs.

5. Date when full comoliance will be achieved Full compliance was achieved on February 21, 1987, when the IFP was identified and removed.

ITEM II.B The enclosure to Mr. J. B. Martin's letter states in part:

"B. 10 CFR 30.41 requires that no licensee shall transfer byproduct material except as authorized pursuant to this section.

" Contrary to the above, on February 19, 1987, a HP technician was found, upon entering SONGS, to have the outside of his shoe contaminated with an i irradiated fuel fragment. The particle was embedded in the technician's shoe and thus may have been removed from SONGS on more than one occasion.

The removal of the particle from SONGS constitutes an unauthorized transfer of byproduct material."

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L RESPONSE

1. Admission or denial of the alleaed violation SCE admits that on February 19, 1987, a Health Physics technician was found to have a radioactive particle embedded on the outside of his shoe. As inditated in Reference (7), the contamination was detected by a Beta Booth at the entry to the Units 2 and 3 locker room which is located well within the radiologically controlled area'.. The Health Physics technician was seeking to leave a radiologically controlled area in order to gain access to a locker room which is maintained contamination free when the particle was discovered. The technician recalled a similar PBM-200 alarm about a month earlier when he might have been wearing the same shoes. Thus, the particle may have been removed from SONGS during that period.

Reference (7) also indicated that this incident would continue under investigation. Based on an isotopic analysis of the particle on February 19,.1987, it contained 7.2 E-3 microcuries of cerium 144 and 5.7 E-4 microcuries of cesium 137. A comparison of this isotopic analysis to isotopic analyses for " typical SONGS IFP's",

indicates that the analysis does not match the expected isotopic pattern.

A revision to Reference (7) will be submitted by August 31, 1987 to document the completion of the investigation of this event.

2. Reasons for the violation As discussed above, a radioactive particle was discovered embedded in the outside of a Health Physics technician's shoe. It is believed that the particle may have been transported outside the restricted area. If so, the cause of this event was evidently lack of thoroughness in personnel monitoring.

3. Corrective steos that have been taken and the results achieved Corrective steps taken to minimize the likelihood that radioactive particles will be removed from SONGS are described in the responses to Items II.A.(1) and II.A.(2).

4. Corrective steos that will be taken to avoid further violations Corrective steps being taken to avoid the removal of radioactive particles from the SONGS site are described in the responses to Items II.A.(i) and II.A.(2).

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5. Date when full comoliance will be achieved >

Full compliance was achieved when the particle was removed from the Health Physics technician's shoe.

ITEM III The enclosure to Mr. J. B. Martin's letter states in part:

"10 CFR 20.403(a)(1) requires that ear.h licensee shall immediately report any event involving by-product, source, or special nuclear material possessed by the licensee that may have caused or threatens to cause exposure to the hand of any individual to 375 rem or more of radiation.

" Contrary to the above, having been informed by electronic data transmission and followup written report on or before November 17, 1986 of a significant overexposure, the licensee had sufficient information available to recognize, yet did not report until 11:30 a.m., December 12, 1986, an event involving licensed material that may have caused an exposure to the hand of greater than 375 rem.

"This is a Severity Level III Violation (Supplement IV)."

RESPONSE

1. Admission or denial of the alleaed violation SCE admits that on or about November 17, 1986, information was electronically transmitted to SCE from its thermoluminescent dosimetry (TLD) vendor which included data indicating that a finger-ring TLD had received a radiation exposure in excess of 1 375 rad. This information was subsequently also contained in a written document forwarded by the vendor to SCE. SCE did not report to the NRC until December 12, 1986, that this indicated TLD exposure might reflect an exposure in excess of regulatory limits to the hand of a worker, i

2. Rftasons for the violation As noted in Reference (1), the TLD vendor's procedures require that SCE receive telephone notification immediately when processing of '

the TLD indicates a potential high radiation exposure, as in this case. In addition, SCE had informally requested that the vendor provide this notification at a lower exposure value than required by the vendor's procedures. The investigation discussed in Reference (4) concluded that this failure to immediately notify SCE was due to personnel error.

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r SCE initially receives the results of the TLD processing from the vendor by electronic transmission. SCE Health Physics personnel developed a computer program for the receipt and processing of q'+actronically transmitted data from the TLD vendor. The program hcludes a feature to alert SCE to the receipt of data indicating an i exposure in excess of 3.8 rad. A software error caused the program to truncate data to the left of the one's column. Thus, the 511.99 rad data was read by the program as 1.99 rad and the 3.8 rad alert feature was not activated in this case. Although SCE has applied the independent validation and verification requirements of ANSI /IEEE Standard 730-1981 to computer programs designated as safety-related, these requirements had not been imposed on the SCE computer programs developed by Health Physics personnel for the receipt and processing of data transmitted electronically from the TLD vendor.

Health Physics personnel did not immediately review the written report from the TLD vendor when it arrived because SCE would have expected to receive immediate telephone notification from the vendor of any TLD indicating high exposure and be alerted by the computer feature described above. Review was delayed until December 11, 1986, when the report of a high exposure was first identified by SCE Health Phytics personnel. Following confirmation of the data with the TLD vendor, a report was provided to the NRC on December 12, 1987.

3. Corrective steos that have been taken and the results achieved SCE has emphasized to the TLD vendor the importance of complying with its requirements, and those of SCE, in providing immediate telephone notification to SCE of indicated high radiation exposures. This importance has been stressed in a modification to the SCE contract with the vendor.

All written TLD vendor reports that are associated with electronic receipt of data have been reviewed, and it has been confirmed that there are no other differences between these reports and the computer records. The computer programs associated with transmission of dosimetry results have been independently verified and validated by the Nuclear Information Systems Division at San Onofre. Requirements have been established for these programs to be maintained in accordance with the administrative controls of that division. ,

4. Corrective steos that will be taken to avoid further violations A review has been conducted of all Health Physics applications of computer programs. Additional programs will be subject to independent verification and validation procedures. This work will be completed by June 1988. Until independent verification and validation is completed for each program, supplementary means will be used to provide assurance of the data quality, where necessary.

5. Date when fulLcomoliance will be achieved Full compliance was achieved on December 12, 1986, when SCE made the required telephone notification.

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