ML20198A431
| ML20198A431 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/24/1997 |
| From: | Nunn D SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-361-97-21, 50-362-97-21, NUDOCS 9801050370 | |
| Download: ML20198A431 (4) | |
Text
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A,, unsov nmvmont cm, December 24,1997
- e U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
' Gentleman:
Subject:
Docket Nos. 50-361 and 50-362 Reply to an Inspec6cn Weakness San Onofre Nuclear Generating Station, Units 2 and 3
Reference:
Letter, Mr. Arthur T. Howell lil, (USNRC) to Mr. Harold B. Ray (SCE),
dated November 25,1997 The referenced letter transmitted the results of NRC Inspection Report No. 50-361/
G7-21 and 50-362/97-21, conducted October 27-31,1997, at the San Onofre Nuclear Generating Station, Units 2 and 3. The enclosure to the referenced letter contained an exercise weakness (9721-01), involving improper performance of air sampling for the Operations Support Center (OSC) habitability surveys. The enclosure to this letter provides Southern California Edison's (SCE) reply to the weakness, as requested.
?! you ha /e any further questions, please contact me.
Sincerely, u
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Enclosure:
As stated cc:
E. W. Merschoff, Regional Administrator, NRC Region IV K. E. Perkins, Director, Walnut Creek Field Office, NRC Region IV
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,,0 *7 M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3 J. A. Sloan, NRC Senior Resident inspector, San Onofre Units 2 and 3
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9801050370 971224 PDR ADOCK 05000361 O
POR l'. O. Ilox 128 San Clemente. CA 92674-0128 I.l. ll.!Illl!!lill!- lII.
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s ENCLOSURE 4
The enclosure to Mr. Howell's letter dated November 25,1997, states, in part:
Description of Weakness:
"The inspector determined that air sampling was not performed at a frequency required by the licensee's procedure and those samples that were performed were not valid due to the missing o-rinc.' Since this information would be used to assess the need to evacuate the OSC, protection of personnel within the OSC was not adequately demonstrated. The improper performance of air sampling for OSC habitability surveys was identified as an exercise weakness (50-361; -362/9721-01)."
1.
Response
SCE agrees the air sampling was not performed at the half-hourly frequency required by the Emergency Plan Implementing Procedure (EPIP). The reason for the procedural oversight was isolated personnel error.
Also, SCE agrees tho air sempler head should have had an O-ring properly installed.
The reason for the oversight was inadequate attention to detail during the installation of the filter cartridge in the sample head.
2.
Additional Information:
The intent of the EPIP was to ensure that quantitative airborne radioactivity surveys are performed when necessary. The procedure was also intended to give the Operations Support Center (OSC) Health Physics (HP) Coordinator the flexibility to determine the appropriate airborne sampling frequency. The current wording of this procedure requires SCE to monitor airborne activity "Every 1/2 hour or as requested by the TSC HP Leader.' After the initial air sample was taken, personnel mistakenly believed the procedure permitted them to await the TSC HP Leader's instruction to take the next sample; they did not appreciate the specific wording of the procedure.
3.
Safety Significance:
The OSC emergency kit contained three additional air samplers, two of which had all the necessary O-rings. One sampler was missing aa inner 0-rin0, with the outer O-ring being intact. Had an airborne problem developed in or around the OSC, multiple samplers would likely have been used to tako additional, simultaneous air samples in the surrounding areas where alarming friskers were located. In such an instance, all sample results would be evaluated. The evaluation would have shown discrepancies between the samples, which would likely have led to identification of the samplers with missing O-rings.
ENCLOSUPF. -
Similar to HP practices in use at other facilities, San Onofre uses friskers to provide continuous monitoring of radiation and airborne conditions. Friskers are well suited to provide an indicatior, of increasing ambient radiation or airborne radioactivity levels.
The alerm setpoint of those friskers is sufficiently low (typically 100 cpm ebove background) to provide an early warning of an ambient radiation or an airborne radioactive material level change, and to trigger the need for additional surveys to quantify levels. Friskers are able to sense a change in airborne radioactivity at a level well beluw the point where protective action is required. Friskers will become less useful and air sampling will become more important for detecting changes in airborne levels as those levels increase.
In addition to the frisker located in the OSC, two others were positioned at the step-off pads in the hallway on either side of that facility. There were also several friskers and whole body contamination monitors located at the radiologically controlled area (RCA) entry point down the hall from the OSC. Had radiological conditions worsened, many of those instruments would likely have alarmed and indicated the need for confirmatory airborne and radiation measurements.
If a person were to have a radioactive material uptake, any dose associated with the uptake wou'd be assessed from bioassay (typically whole body counts) results rather than from an individual air sample, in summary, SCE believes that there was no safety significance to the identified exercise weakness.
4.
Corrective Measures Completed:
a.
Following the exercise, a survey of the five emergency kit locations, containing a total of 16 air samplers, was performed to determine if there were additional air Fam? e heads with missing O-rings. Five additional air l
samplers were found with one of the four required 0-rings missing.
These deficiencies were promptly corrected.
b.
Health Physics Technicians were counseled on the need to thoroughly check all survey equipment before use. When received, relevant sections of the NRC inspection report were given to all HP personnel for review of the air sampling problem.
c.
HP Policy Statement 1-2,"HP Division Guidance for Emergency Response," was modified to formalize the quarterly survey of cmergency kit instrumentation, including air sampler O-rings.
2-
V ENCLOSURE d.
'HP Procedures SO123-Vil-5.6.5, "Radeco Model 809V1 High Volume Air Sampler," and SO123-Vil-5.G.12, "Ametek Model P4L Personal Air Sampler," were modified to require verification that the O-rings are in place before the sampler is used.
5.
Corrective Measures Remaining to be Completed:
EPIPs SO123-Vill-40, "TSC HP leader Duties," and SO123-Vill-40.1, "OSC HP Coord;nator Duties," will be revised: 1) to ensure that necessary radiological surveys are made, and 2) to provide flexibility in establishing the frequency of quantitative airborne surveys.
6.
Schedule for Completing these Actions:
All corrective measures will be completed on or before Februare 13,1998.
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