ML20059M519

Applicant Exhibit A-22,consisting of Responding to Violations Noted in Insp Repts 50-275/92-26 & 50-323/92-26

ML20059M519
Person / Time
Site:	Diablo Canyon
Issue date:	08/21/1993
From:	Rueger G PACIFIC GAS & ELECTRIC CO.
To:
References
OLA-2-A-022, OLA-2-A-22, NUDOCS 9311190139
Download: ML20059M519 (4)

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. Pacific 8m aml Ductric Company 17Beh Si'm oa SanFranesco N410d F~ 28 P26festkM Rue?*r Senior Vo Pre 9 dent ud Db m 415/973 4654 GeneralMenacer fivcMar Power Generation December 14, 1992 PGLE Letter No. DCL 92-275 U.S. Nuclear Regulatory Cunnission ATTN: Document Control Desk Washington, D.C. 20555 Re: Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Reply to Notice of Violation in NRC Inspection Report 50-275/92-26 and 50-323/92-26 Gentlemen:

NRC Inspection Report 50-275/92-26 and 50-323/92-26, dated November 13 ,

1992, cited one Severity Level IV violation regarding PG&E's radiation '

protection program. PG&E's response to the Notice of Violation is enclosed.

Sincerely, a

i)I m-Gregory H. Rueger cc: Ann P. Hudgdon John B. Martin Mary H. Miller Sheri R. Peterson .

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PG&E Letter No. DCL-92-275

^ ENCLOSURE REPLY TO NOTICE OF VIOLATION IN NRC INSPECTION REPORT 50-275/92-26 AND 50-323/92-26 On November 13, 1992, as part of NRC Inspection Report 50-275/92-26 and 50-323/92-26, NRC Region V issued a Notice of Violation (NOV) citing one Severity Level IV violation for Diablo Canyon Power Plant (DCPP) Units 1 and 2. The statement of violation and PG&E's response follow.

STATEMENT OF VIOLATION Technical Specification 6.8.1 requires that written procedures shall be established, implemented, and maintained cove,ing the applicable procedures re:onnended in Appendix A of Regulatory Guide (RG) 1.33, Revision 2, February 1978.

RG 1.33, Appendix A lists, in part, the following procedures:

7. Procedures for Control of Radioactivity (For limiting materials released to environment and limiting personnel exposure)

e. Radiation Protection Procedures (3) Airborne Radioactivity Monitoring

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(4) Contaminattun Control Licensee procedure MRS-2.4.2-GEN 38 (Steam Generator Shot Peening Procedure), Section 9.7.13,5.2, estaNished September 27, 1992, applied certain rules in order to-control airborne radioactivity and contamination. These rules required that, with ventilation interrupted to the steam generator cold leg for longer than 15 minutes, either:

1. Shot peening could be temporarily terminated, or

2. With ventilation switched from the cold leg to the hot leg, and dry air supply switched from the hot leg to the cold leg, shot peening could continue.

n Contrary to the above, on October 2, 1992, eddy current and shot peening operators failed to implement the provisions for control of radioactivity as given in MRS-2.4.2-GEN 38, Section 9.7.13.5.2, in that ventilation

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n was interrupted to the steam generator cold leg for one hour, and shot peening continued without. switching'of the  ;

ventilation and dry air supply as required. This failure ,

to implement the procedure resulted-in the unanticipated spread of airborne radioactivity.

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

REASON FOR THE VIOLATION PG&E agrees with the violation.  !

To provide humidity control-for shot peening work performed in the steam ,

generator (SG) hot leg, dry' air is blown into the hot leg manway. An additional source of pressurizing air is the shot peening equipment _ itself.

To maintain control of any loose contamination within the SG, .a~ negative pressure is maintained within. the SG by drawing air out from the cold ltes .

manway through a high efficiency particulate airborne (HEPA) filter. '

The personnel contracted to perform the shot- peening-work controlled the hot- l leg dry air supply for humidity control. Prior to beginning work, these '

individuals were trained on the significance of the ventilation-system in maintaining negative pressure in the SG. ,

^ However, the contract personnel responsible for eddy current testing and tube '

plugging on the cold leg side of the SG were accustomed _to HEPA suction on the opposite leg (hot leg) from their work. These individuals were not specifically trained on the new configuration of the SG ventilation for' shot peening (i.e., HEPA suction on the cold leg) prior to beginning work-in the cold leg.

The cover letter that transmitted the NOV and NRC Insoection Repm t- "",

50-275/92-26 and 50-323/92-26 noted that PG&E's overall control of )

radiological hazards encountered during SG work in the Unit I outage appeared. j to be exemplary. However, the Inspection Report identified a concern i

regarding recurrent unanticipated generation of airborne radioactivity,'since  !

two previous, related events occurred on September 25 and 26,1992.

i On September 25, 1992, there was an~ increase in contamination in the posted

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hot particle zone surrounding SG l-1. The cold leg manway door was opened for.

approximately one minute and it is postulated that loose contamination within the SG was blown onto the platform and down to the lower work areas.: Although contamination levels increased within the crane wall area, no increase in-activity occurred outside the crane wall. It.should be noted that.the discharge from the HEPA filters was' directed across a highly contaminated-trough, and it was not determined whether the spread ofccontamination was due-to the opening of the cold leg manway door' or the HEPA air ' discharge blowing-across the contaminated trough. Corrective actions were to reposition the HEPA discharge, provide. additional step-by-step . instructions - for removing cold

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leg ventilation, and review this information with the involved personnel.

l On September 26, 1992, the SG l-3 cold leg 'manway door was opened for eddy-current maintenance.- A dry. air supply valve to the hot leg was either not {

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a AUG 19 '93 12:51 F R 0f1 PG E-MRS To 910055414302 ' PACE.005e005

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- 4 e shut off all the way, or the valve was bumped open after it was shuth An airborne radiation monitor alarmed, and other airborne monitors inside containment were also reading upscale. The immediate corrective actions were to notify the control room and evacuate containment, formalize a checklist for . '

addy current personnel breaching the manway, and instruct shot peening '

personnel to stop shot peening if the cold leg manway door remained open for longer than 15 minutes. Personnel were tat 1 boarded prior to resuming work.

On October 2, 1992, the event that is the subject of the NOV occurred.

Personnel working in the cold leg opened the cold leg manway door andl stopped HEPA suction and dry air supply to.$C 1-4 for approximately,one hour without stopping shot peening in.the hot leg. as directed in the new guidance-added after the September 26, 1992 event. This caused an airborne radioactivity monitor to alarm.

PG&E agrees with the NRC that the corrective actions identified'for 'the' first two events were adequate and would have prevented the third event if. they had been effectively implemented. In additlun, PG&E's analysis of all three events enneluded that the root cause-of the cycnts was that na overall responsibility was established for proper nparation of the SC ventilation system to support (a)' shot peening activities in.-Lhe hot leg and (b) eddy .

current testing / tube plugging activities in the cold leg. A contributing .

factor was that the personnel working on the r.nid leg side were not well trained on the ventilation requirements. The corrective actions taken after.  !

i the first two events addressed only part of this overall prograssiatic root '

_ cause.

C0kRECTIVE STEPS TAKEN AND AESULTS ACHIEVED After the October 2,1992 event, shnt peening work was stopped'and a tailboard meeting was held to critique the event. The dry air supply-and HEPA suction were switched so that HEpA suction was new c,n the hot leg, thereby allowing i casier access to. work in the cold leg. The shot peening shift supervisor was i given overall responsibility for SG breaches and SG ventilation. This responsibility was added to the shot pcening procedure via a field change. -

Shot p%ening work continued with a tailhoara at each shift changt, and the work was completed with no further incidents.

CORitECTIVE STEPS THAT WILL BE TAKEN TO AYOID FURTHER VIOLATIONS Prior to the Unit 2 fifth refueling outage in the spring of 1993', the shot peening and oddy current testing procedures will be revised to permanently incorporate the field changes discussed above. personnel involved in $6 eddy i current testing will be trained on the operation of the ventilation system and j maintaining negative pressure.

DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED

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Based full on th'c completed field changes to the procedure PG&E is currently in-compliance. The' permanent procedure revisions and training of eddy l current personnel will be completed t:y March I,1993.

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