ML20091L325
| ML20091L325 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 08/22/1995 |
| From: | Pelletier J VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BVY-95-91, NUDOCS 9508290142 | |
| Download: ML20091L325 (4) | |
Text
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3, 2 VERMONT YANKEE-
' NUCLEAR POWER CORPORATION r
Ferry Road, Brattlebdro, VT 05301-7002.
- AkM YTO ENGINEERING OFFICE 580 MAIN STREET BOLTON, MA 01740 (508) 779-6711 August 22, 1995 BVY 95-91 United States' Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555
Reference:
(a)
License No. DPR-28 (Docket'No. 50-271)
'I
Subject:
Vermont Yankee Nuclear Power Corporation, 10 CFR 50 Appendix "R"
Isr,ues This letter is. submitted to transmit a Status Report related to the 10 CFR 50 Appendix "R"
issues recently discovered at Vermont
. The report describes the issues and provides informatior.
Yankee.
regarding corrective actions presently underway.
The subject was discussed with the NRC during telephone conversations on 7/26/95 and 8/3/95 at which time it was requested by Mr. William Ruland that a letter be submitted.
Should you require additional information, please contact us.
Sincerely, Vermont Yankee Nuclear Power Corp.
- v)nW ames P. Pelletier Vice President, Engineering USNRC Regic-
'ministrator cca.
USNRC Resid spector-VYNPS USNRC Projo anger-VYNPS 230123.
oh 9508290142 9tiO922 i
3 PDR ADOCK 05000271 ij
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VERMONT YANXFE NUCLEAR POWER CORPORATION Vermont Yankee Summary Report I
Appendix "R" Issues j
Descriotion of Condition and Events On 7/25/95 it was datermined that the " Hot Short" concern as described in NRC IE Notice 92-18 was applicable to Vermont Yankee and " hat the operation of Motor Operated Valves, from Alternate Shutdown Panels, could be impacted.
The condition involves response to a fire in the Control Room, Cable Vault, or two Reactor Building areas. Compensatory measures (fire watches) were promptly implemented to ensure that the intent of 10 CFR 50 Appendix "R"
is shtisfied.
On 7/27/95, as a result of follow-up to a question which originated during Plant Operating Review Committee (PORC) review of the " Hot Short" concern, it was identified that a problem existed in the Vermont Yankee Safe Shutdown Capability Analysis (SSCA) in the specific response to a fire on the North side of ele /ation 252 of
'the Reactor Building.
The analysis credits use of Reactor Core Isolation Cooling (RCIC) and a Safety Relief Valve (SRV) in the Alternate Shutdown mode; yet, cabling needed to support operation of the SRV system is located in the area and could potentially be damaged by the fire.
Compensatory measures were' implemented to satisfy the intent of Appendix "R" requirements.
Subsequent to this discovery, additional vulnerabilities were identified in the same plant areas.
Under certain scenarios, loss of RCIC function in the Alternate Shutdown mode or inadvertent primary system depressurization could occur from fire damage to SRV or RCIC cabling.
Compensatory measures were adjusted for the additional findings.
No other vulnerable plant areas have been identified.
Corrective Actions The following corrective actions have been initiated:
i Compensatory measures consisting of fire watches, equipment monitoring, administrative controls and enhanced awareness of 4
potential vulnerabilities have been implemented.
An Operations Standing Order has been issued to provide details of the conditions and provide operator actions for response to particular fire scenarios. These measures will be adjusted as necessary upon identification of any additional concerns.
These compensatory measures are being used to ensure that the intent of 10 CFR 50 Appendix "R"
is satisfied.
A Self Assessment Team has been assembled which will ensure that.any additional vulnerabilities are promptly identified.
'The team is reviewing the SSCA to ensure present assumptions and conclusions for each fire zone are acceptable.
This includes design,. procedural, licensing, staf fing and training 1
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7 VERMONT YANKEE NUCLEAR POWER CORPORATION -
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aspects' The team consists of five senior personnel, with
= diverse backgrounds, from Vermont Yankee, Yankee Atomic and
_ f external organizations, none of. whom 'had significant i
-involvement in the original program development.
The Self H
Assessment began on 8/7/95 and is scheduled to be completed by 8/25/95.
l An Evaluation Team has been established for evaluation of
- concerns, both initial and those identified : by the Self 4
I Assessment Team, operability considerations, compensatory measures, procedures'and analytical solutions.
The team was established on 7/28/95 and ' will remain = in place for the i
duration. necessary to evaluate any findings of the Self Assessment.
.A Repair Team was established on 7/28/95 to evaluate conceptual designs that may be required for resolution of identified concerns previously assessed by the Evaluation Team.
A fourth team is planned to investigate the root cause of the l
events.
The results of the root cause evaluation will be reported via a Licensee Event Report.
This team is scheduled to be fully assembled by 8/28/95.
h Schedule Full compliance with Appendix "R"
requirements, without the need for the above compensatory measures, will be achieved no later than the startup from the next refueling outage, currently scheduled for Fall ~1996.
Additional Information TSI Thermo-Lag fire wrap material was originally used in the plant to achieve fire separation for compliance to " Appendix R".
Vermont Yankee-had Thermo-Lag installed in small amounts in three j
locations.
Subsequent modifications were made in the plant which eliminated reliance on TSI Thermo-Lag.
Some Thermo-Lag was abandoned in place, in two locations.
Vermont Yankee review of the generic TSI Thermo-Lag issue, IN 92-i 82, included a combustibility assessment of the three affected plant ' locations.
The results of the assessment, utilizing the NUMARC developed screening guide, indicated no combustibility concern with the anandoned Thermo-Lag configurations.
A re-review of the remaining Thermo-Lag at VY, in response to concerns indicated in IN 95-27, confirmed TSI Thermo-Lag is not relied upon to maintain Appendix R compliance.
Of'the original'three locations, one configuration was previously removed.
LA second
- location, as~ indicated by the previous 2-
.p VERMONT YANKEE NUCLEAR POWER CORPORATION assessment, increased 'the' " combustibles" in the zone by an insigriificant amount.
This increase has been included in the most 1
recent~ draft revision to the Fire Hazards Analysis.
The third location, within.the combustible Free Zone in the Reactor Building-
' Torus Area, was previously analyzed to be a "non-combustible" based on-installed configuration.
In response,to the concerns in IN 95-27, Vermont. Yankee is planning on removing the Thermo-Lag from this
? location.
.0oerability Determination i
No equipment or systems have been rendered inoperable as a result of the identified conditions.
However, the conditions identified do-involve deficiencies in some of the features credited for providing compliance with the specific requirements of 10 CFR 50 i
' Appendix "R".
As stated above, a combination of compensatory measures are currently in place, including:
Continuous and roving fire watches in affected areas More stringent control of combustibles More stringent control of " hot-work" Based on these actions, plus the normal fire detection and protection features, a fire event that could negatively impact safe operation and shutdown of the facility is concluded to be of very
. low probability.
As a result of Vermont Yankee's actions regarding the NRC concerns with TSI Thermo-Lag, the plant no longer relies on this material to meet Appendix'"R" Safe Shutdown requirements.
Therefore, the TSI
'Thermo-Lag issue does not compound the recently identified Appendix "R"
issues at the plant.
Manacement Awareness It is recognized that the events of this report are of concern when considered in conjunction with previous weaknesses in the fire protection and Appendix "R"
areas.
As a result of the combined
- Triennial / Annual Fire Protection Program Audit, recently completed, a Fire Protection Program Improvement Team has been formed to assess the overall program and review the Fire Protection Program base documents against the current regulatory documents.
In
-addition, considerable improvement efforts were already underway in the.SSCA l as a result of the corrective actions from previously identified fire barrier and Appendix "R"
lighting issues.
The findings'of the. currently active Assessment Team and the planned
- Root'Cause Analysis Team will be considered in conjunction with the
'other ongoing efforts in determining the actions required to ensure
.a robust fire protection program.
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