3F0997-04, Documents Resolution of Potential USQ Re Atmospheric Dump Valve Design Capacity
| ML20216B219 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 09/02/1997 |
| From: | Grazio R FLORIDA POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 3F0997-04, 3F997-4, NUDOCS 9709050255 | |
| Download: ML20216B219 (3) | |
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September 2,1997 3F0997-04 U.S. Nuclear ReOulatory Commission Attention: Document Control Desk Washington, DC 20555-0001
Subject:
Resolution of a Potential Unreviewed Safety Question Regarding Atmospheric Dump Valve Design Capacity
References:
A.
FPC Meetings with NRC
- July 20 and 21,1997 B.
NRC Memorandum to File, dated July 30,1997 " Transmittal of Attachment D to the Minutes of Restart Panel Meeting for Crystal River"
Dear Sir:
The purpose of this letter is to document the resolution of a potential Unresolved Safety Question (USO) identified by Florida Power Corporation (FPC).
/
On July 20 and 21,1997, FPC met with the Nuclear Regulatory Commission (NRC) to [
review progress on resolution of technical issues and progress toward restart of Crystal River Unit 3.
During technical presentations, FPC advised the NRC that a potential concern regarding Atmospheric Dump Valve (ADV) relief capacity was !.
undergoing 10 CFR 50.59 review and may result in an USQ, requiring NRC review.
FPC rietermined the changes do not constitute an USQ.
This potential USQ is identified as the first portion of item 24 in Attachment D of Reference B.
Earlier changes were rnade to the ADVs and the Final Safety Analysis Report (FSAR) pursuant to 10 CFR 50.59. The ADV discussion on pages 10-6 and 10-7 of section 10.2.1.4 of the FSAR now requires clarification to ensure all sections provide an CRYSTAL RIVER ENERGY COMPLEX: 1s7eo w Pow.e un at. cmi.i m.<. Fioeid. 3442e e70s. tas2 -
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U. S. Nuclear Regulatory Commission 3F0997 04 Page 2 adequate description of the ADV relief capacity. In 1994 changes were incorporated into the FSAR stating. the actual ADV relief capacity.
However, due to an administrative oversight, FPC failed to revise all required FSAR areas when the section was changed.
FPC.has completed the safety essessment and has concluded that since this change is a clarification of existing information, it does not require an additional 10 CFR 50.59 evaluation, therefore, it does not result in an USO. FPC has also reviewed the assumptions for ADV capacity used or credited in accident analyses l
-and determined that the actual capacity is consistent with the analyses. A summary of the safety assessment is provided in Attachment 1. The complete safety assessment for this FSAR text clarification is available on site for NRC review.
Additionally, item 24 in Attachment D of Reference B also refers to " local operator
. action for opening." This issue refers to the potential requirement to access the ADVs locally for manual operation during a post fire cooldown and is currently being
= addressed as part of Appendix R resolution under restart item D 11.
Iflyou have any questions regarding this letter, please contact D. F. Kunsemiller, Manager, Nuclear Licensing at (352) 563-4566.
Sincerely, f
R.E. Graklo Director, Nuclear Regulatory Affairs REG /Irm-Attachment xc:
Regional' Administrator, Region 11 Senior Resident inspector NRR Project Manager l
t U. S. Nuclear Regulatory Commission 3F0997-04 Page 3 ATTACHMENT 1
SUMMARY
OF FSAR REVISION TO DESCRIBE i
ATMOSPHERIC DUMP VALVE DESIGN FLOW CAPACITY lanum The proposed changes in the. Final Safety Analysis Report (FSAR) reflect clarifications of relief capacities of the Atmospheric Dump Valves-(ADVs), MSV-25 & MSV-26.
The clarification to pages 10-6 and 10-7 of FSAR section 10.2.1.4 is required to correct the inconsistencies within this section discussing the ADV relief capacity, i-
Background
Prior to 1980, the configuration of the ADVs was modified to correct problems with excessive leakage across the valve seat. The modification of the ADV changed the necessary spring load to prevent seat leakage, the limited size of the actuator only allows the valve stem to stroke 1-1/8 inches,45% of the normal full stroke resulting in the ADVs* current relief capability. In 1994, changes were made to the FSAR and Enhanced Design Basis Document (EDBD) to state the actual ADV relief capacity, a Safety Evaluation was performed, and the results provided to the NRC in the annual update. However, portions of section 10.2.1.4 were inadvertently not revised during 4
this change.
Assessment The required changes to the FSAR are simply clarifications to bring consistency between all sections concerning ADV relief capacity. The safety assessment provides a discussion of the functional aspect of the ADVs. This discussion is provided for information purposes only, since these changes are to bring all ADV relief capacity discussions in line with the changes in 1994. These changes are clarifications to -
reflect past changes to the ADVs and FSAR made pursuant to 10 CFR 50.59, and as such, do not require an additional 10 CFR 50.59 review.
Summary The proposed changes to FSAR text are clarifications related to the ADVs' flow j
capacity. The existing capacity and operating characteristics of the ADVs are already described in the FSAR and EDBD.
The proposed FSAR changes are considered clarifications to bring FSAR 10.2.1.4 consistent with portions previously corrected.
The actual ADV relief capacity has been previously evaluated, reported and determined to be acceptable.
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