ML18153C468
| ML18153C468 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 11/21/1990 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 90-705, IEIN-88-004, IEIN-88-4, NUDOCS 9012130250 | |
| Download: ML18153C468 (7) | |
Text
e e
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 November 21, 1990 United States Nuclear Regulatory Commission
~-U N~i~ N~~' : 09~-705 Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Gentlemen:
- VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 CONTROL ROOM PRESSURE BOUNDARY ELECTRICAL PENETRATION INSPECTION RESULTS NO/ETS R4 Docket Nos.
50-280 50-281 License Nos. DPR-32 DPR-37 The Control Room pressure boundary electrical penetrations were inspected to evaluate the condition of the penetrations as a follow-up to NRC Information Notice 88-
. 04.
The inspection effort identified deficiencies in the current 'as-installed' configurations for the electrical penetrations.
The results of the electrical penetration inspections were discussed. with your staff on October 23, 1990. In accordance with the staff's request, Virginia Electric and Power Company is p*roviding the results of the inspections.
The inspection results are provided in the Attachment. In addition, a discussion of the safety impact and planned corrective actions are included.
The Control Room electrical penetration inspections results and the evaluation of the
- remaining plant fire barrier were reviewed and approved by the Station Nuclear Safety
- and Operating Committee.
At the completion of the fire penetration seal evaluation program a summary report-will be provide for your information.
If you have additional questions, please contact us.
Very truly yours, JlS~
W. L. Stewart Senior Vice President - Nuclear Attachment 9012130250 901121 PDR ADOCK 05000280 Q
cc:
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Mr. W. E. Holland
- NRC Senior Resident Inspector Surry Power Station
ATTACHMENT INADEQUATE FIRE RATING OF ELECTRICAL PENETRATION SEALS CONTROL ROOM PRESSURE BOUNDARY SURRY POWER STATION UNITS 1 & 2
e ELECTRICAL' PENETRATION SEAL INSPECTION IN THE CONTROL ROOM PRESSURE BOUNDARY In response to NRC Information Notice 88-04 and NRC Information Notice 88-04, Supplement 1, Virginia Electric and Power Company developed a Fire Penetration Seal Evaluation Program for Surry Power Station. Implementation of this program was begun this past July when a walkdown of the Cantrel Room (CR) Pressure Boundary electrical penetrations was conducted. The purpose of the walkdown was to inspect and document the condition of each individual CR Pressure Boundary seal and fire door. By October 23, 1990, 725 electrical penetrations had been evaluated and classified as follows:
293 seals qualified for a three hour rating.
289 seals needed repairs to qualified as a three hour seal.
143 seals could not be fully evaluated. These seals were accessible from one side only and adequate information could not be obtained to fully evaluate the seal.
The 289 seals needing repair were either empty sleeves with a single cap, or sleeves with inadequate depth of Dux Seal/Flamemastic or Silicone foam. The inspection acceptance criteria were very conservative in that there was no allowance for Engineering Evaluations that may have qualified a number of the seals that were not strictly in accordance with specifications. Therefore, the nonconforming penetrations were determined to be not in compliance with 10 CFR 50 Appendix "R" Section 111.G.2.a., which requires separation of cables and equipment and associated non-safety circuits of redundant trains by a fire barrier having a three hour fire rating.
Compensatory action was taken as required by Technical Specifications when a non-compliance was identified during the inspection.
There are approximately 4900 electrical penetrations in the plant (both Units 1 and 2).
The penetrations are in barriers that define fire areas. Fire areas containing safe.
shutdown equipment are listed in Table 1. Only ten of the fire areas in the station have a calculated fire duration of greater than 90 minutes and these areas have detection and fire suppression systems. Those areas with a duration of greater than one hour and no suppression system have automatic detection systems. The remaining fire areas have a fire duration of less than sixty minutes. For the remaining penetrations not evaluated in the control room study, some seals are expected not to qualify for a three hour rating using the same inspection program acceptance criteria. However, based on results of the CR penetration inspection, seals that do not qualify are expected to provide at least a one hour fire rating. The number of seals that do not qualify is expected to be a significantly lower percentage based on the fact that the single cap seal is expected to be found only in reinforced concrete walls and that a full 10 inch depth of foam, as required in the inspection acceptance criteria, is not required for a three hour fire rating.
page 1 of 3
e Evaluation of tlie CR Pressure Boundary and the remaining seals indicates that the integrity of the station's fire barriers is functionally adequate and special compensatory actions are not required.
The existing se~ls will provide an acceptable level of protection based on the following:
- a.
Fire detection and suppression systems *are provided in fire areas where the expected fire duration is 90 minutes or greater.
- b.
Automatic fire detection is provided in fire areas where the expected fire duration is one hour or greater and no suppression is provided.
c..
Based on the results of the CR pressure boundary seal inspection, seals in the remainder of the plant which do not meet the three hour fire rating are expected to provide at least a one hour fire rating. and therefore provide adequate protection in the fire areas where the expected combustible loading duration is one hour or less.
- d.
Fire watches are posted in those areas identified by inspection as having fire seals which are not qualified for a three hour rating based on the consrevative inspection criteria of this porgram. Additional fire watches will be posted as necessary.
The condition of the station fire area barriers which now exists does not constitute a condition where the health and safety of the public are affected.
The observed condition is believed to have been caused by improper installation of the penetration seal material(s) during station construction and was not detected.
earlier because of inadequate post-construction inspection procedures. A review of*
the station drawings and test reports for three hour fire rated configurations indicates installation of the end caps and Dux Seal material was not in accordance with drawings and tested configurations. Repair procedures have been developed which provide station personnel with the correct repair method based on the type of seal material present. The surveillance procedure for fire barriers does not require an inspection acceptance criterion that evaluates the fire rating of the seals. Only the physical condition of the seal is verified.
Approximately 70o/~ of the penetration* seals that have been identified as not meeting the inspection acceptance criteria for a three hou_r seal have been repaired to date, and repair efforts are continuing.
An inspection of the remaining CR pressure
- boundary penetrations and the remainder of the plant fire barrier penetrations will be
- initiated to locate and repair seals that do not meet the requirements for a three hour fire rating. There are approximately 4300 fire barrier penetrations remaining to be inspected. Initial attention will be directed toward inspecting for empty sleeves with single caps. It is our intention to programmatically inspect seals that do not fall into the empty sleeve configuration over a three year period factoring inspection results into the determination of program scope and schedule, with approximately one-third of the remaining penetrations inspected each year beginning in the second quarter of 1991.
page 2 of 3
The surveillance and maintenance procedures used to inspect, repair and seal fire barrier penetrations will be reviewed and revised as necessary to reflect the various configurations identified in the station.
During future inspections, seals which do not qualify as-a three hour barrier will be identified, documented and repaired in accordance with the station's corrective action program. At the completion of the inspection program for the remaning fire barriers a summary report will be provided for your information page 3 of 3
- l
TABLE 1 SURRY POWER STATION SAFE SHUTDOWN FIRE AREAS FIRE AIREA PROTECTION 01 Cable Vault and Tunnel -1 Detection, CO2, Manual Sprinklers 02 Cable Vault and Tunnel -2 Detection, CO2, Manual Sprinklers 03 Emergency Switchgear Room -1 Detection, Manual Halon 04 Emergency Switchgear Room -2 Detection, Manual Halon 05 Control Room Detection 06 Emergency Diesel Generator -1 Detection, Manual CO2 07 Emergency Diesel Generator -2 Detection, Manual CO2 08 Emergency Diesel Generator -3 Detection, Manual CO2 15 Reactor Containment -1 Detection 16 Reactor Containment -2 Detection 17 Auxiliary Building Detection, Note 2 18A Fuel Oil Pump House -1 Detection, CO2 188 Fuel Oil Pump House.,2 Detection, CO2 19 Safeguards -1 Detection 20 Safeguards -2 Detection 28 Intake Structure Detection, Note 2 31 Turbine Building Limited Det. and/or Supp.
45 Mechanical Equipment Room -3 Detection 54 Charging Pump Service Water Pump Room Detection 55 Technical Support Center Detection NOTES:
- 1.
- 2.
Separate plant structure; fire rating not required.
Fire area includes fire suppression system(s) for special hazards (eg:
CO2 for charcoal filters, deluge for oil reservoir, etc.).
.t BARRIER Fl~E DURATION RATING (hr) 3
>180 3
>180 e
3
>180 3
>180 3
35 3
149 3
149 3
149 3
71 3
71 3
18 3
100 3
100 3
<10 3
<10 Note 1
>180 3
89 3
34 e
3
<10 3
28