ML20077S022
| ML20077S022 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 01/12/1995 |
| From: | Saccomando D COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9501230232 | |
| Download: ML20077S022 (4) | |
Text
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N Commonwealth Edison l
) 1400 Opus Place
( ~ J Downers Grova. Ilknois 60515 Januaiy12,1995 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Document Control Desk
Subject:
Supplement to Application for Amendment to Facility Operating Licenses-Main Control Room Ventilation System:
Braidwood Station Units 1 and 2 NPF-72/77: NRC Docket Nos. 50-456/457
References:
1.
D. Saccomando letter to Dr. Murley dated January 5,1994, transmitting amendment request for Main Control Room Ventilation System 2.
D. Saccomando letter to W. Russell dated April 26,1994, transmitting Supplement to Amendment Request for Main Control Room Ventilation System 3.
D. Saccomando letter to W. Russell dated September 30,1994, transmitting Additional Information Regarding Amendment Request for Main Control Room Ventilation System Reference 1 transmitted Commonwealth Edison Company's (Comed) request for amending the Braidwood Technical Specification to delete the surveillance which verifies that the Main Control Room ventilation system can be manually isolated in response to a report of a chlorine accident in the vicinity of Braidwood. In addition to amending the Technical Specifications, Reference 1 also requested the Nuclear Regulatory Commission Staff to reconsider the additional SER commitment made by Comed to demonstrate control room integrity on a periodic basis. This amendment request was supplemented via Reference 2.
Reference 3 transmitted additional information regrading this amendment request and committed Braidwood Station to performing surveys every three years and to perform associated evaluations to ensure that the protection of the control room personnel from risk due to any potential chlorine accident is maintained sufficiently small. This information has been incorporated into an Evaluation of Significant Hazards Considerations and in included in the Attachment. This evaluation will supersedes that transmitted in Reference 2.
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9501230232 950112 PDR ADOCK 05000456 P
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URC Document Control January 12,1995 Please address any further comments or questions regarding this matter to this office.
i Sincerely, h
Denise M. Saccomando Nuclear Licensing Administrator Attachment cc:
R. R. Assa, Braidwood Project Manager - NRR S. G. Dupont, Senior Resident Inspector - Braidwood J. B. Martin, Regional III Administrator OfIice of Nuclear Facility Safety - IDNS i
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ATTACHMENT EVhLUATION OF SIGNIFICANT IIAZARDS CONSIDERATIONS FOR PROPOSED CHANGES TO APPENDIX A TECHNICAL SPECIFICATIONS OF FACILITY OPERATING LICENSES NPF-72 AND NPF-77 Commonwealth Edison Company (Comed) has evaluated this proposed amendment and determined that it involves no significant hazards considerations. According to Title 10 Code of Federal Regulations Part 50 Paragraph 92 Subparagraph c (10 CFR 50.92(c)), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed amendment would not:
1.
Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2.
Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3.
Involve a significant reduction in a margin of safety.
This proposed change will delete Technical Specification Surveillance Requirement (TSSR) 4.7.6.e.6; the requirement to test control room ventilation manual isolation capability every 18 months based on the potential for a rail-borne chlorine accident near Braidwood.
A.
The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
Elimination of the requirement to test control room ventilation manual isolation capability does not involve a significant increase in the probability or consequences of an accident previously evaluated. This requirement had been previously necessary because of the potential of a rail borne chlorine accident. Since that time of the imposed surveillance, the Norfolk and Western railroad line which transported chlorine near Braidwood has been removed. In addition, a study has concluded that there are no potential stationary chlorine release sources within a 10 mile radius that could pose a threat to control room habitability. The i
evaluation concluded that the realistic probability of a transported source of i
chlorine passing within the critical distance of 4900 feet of Braidwood Station is practically zero. Even using the very conservative assumption that all transported I
sources of chlorine use IL 53 or IL 129, the occurrence of an accidental release i
4 from these shipments was calculated to be only 2x10 events per year. Thus the probability of a chlorine release is within the requirements of NUREG-0800, Standard Review Plan (SRP), July 1981 Section 2.2.3, and removal of the requirement to conduct Control Room ventilation isolation tests every 18 months does not involve a significant increase in the probability or consequences of an accident previously evaluated.
To ensure that no potential stationary chlorine release source is introduced within a ten mile radius of Braidwood Station, the station will perform a survey every three years to ensure that the protection of the control room personnel from risk due to any potential chlorine accident is maintained sufficiently small.
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B. -
Tha proposed chinga doe 2 n:t create the pos:ibility cf a nsw or different l
kind of accident from any accident previously evaluated.
The probability of a chlorine accident that could impact the control room
' environment has been shown to be within the requirements of SitP Section 2.2.3.
Control room isolation capability testing was performed only to address a chlorine accident. Therefore, removal of this requirement does not create the possibility of a new or different kind of accident from any accident previously evaluated.
C.
The proposed change does not involve a significant reduction in a margin of safety.
Control room ventilation isolation testing was performed as a result of the possibility of a chlorine accident in the vicinity of I3raidwood. As demonstrated by a recent study, the probability of this event occurring has been reduced to practically zero within the acceptable limits of SItP Section 2.2.3 for transportable chlorine. Survey of the ten mile radius around Ilraidwood found no stationary chlorine sources with large enough quantities to pose a hazard to control room personnel. Thus, the removal of the requirement to perform Control Itoom ventilation isolation tests every 18 months does not involve a significant reduction in a margin of safety.
Ilased upon the above evaluation, Comed has concluded that this change involves no significant hazards considerations.
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