ML13002A134

License Amendment Request on Purification of the Borated Water Storage Tanks, Acceptance Review, ME9877

ML13002A134
Person / Time
Site:	Oconee
Issue date:	12/21/2012
From:	Boska J Plant Licensing Branch II
To:	Alter K Duke Energy Carolinas
Boska J
References
TAC ME9877, TAC ME9878, TAC ME9879
Download: ML13002A134 (2)

Text

From: Boska, John Sent: Friday, December 21, 2012 4:08 PM To: Alter, Kent R Cc: 'Meixell, Bob'; Bartley, Jonathan; 'Shingleton, Boyd'

Subject:

ME9877 BWST purification using a non-seismic system (RO), acceptance review Importance: High Kent, after discussion with the reviewers we have decided there are information insufficiencies in your license amendment request (LAR) to use a non-seismic purification system on the borated water storage tanks (BWSTs) during power operation. We intend to reject the LAR per NRR office instruction LIC-109, acceptance reviews, ML091810088, with an opportunity to supplement. We are offering an opportunity for a phone discussion on the insufficiencies if you wish, as stated in LIC-109. I am on vacation next week, so the next opportunity is the first week of January. If you wish to have a call, let me know what days you are available. Per LIC-109, if you decide to supplement we will need your supplement within 13 days of the call. You may also withdraw the LAR, and resubmit later when you have all the necessary information.

The following are the information insufficiencies we have identified:

SUBJECT:

Acceptance review of proposed license amendment request (LAR) 2012-05

[ADAMS Accession No. ML12307A219] to allow Oconee Nuclear Station (ONS) to operate a reverse osmosis (RO) system to remove silica from the BWSTs and spent fuel pools (SFPs) during unit operation, including associated proposed Technical Specifications (TS) and bases, dated October 30, 2012.

BACKGROUND: The proposed change would allow non-seismically qualified piping in the RO system to be connected to the BWST during unit operation. The LAR states that the RO system supply piping will be connected to the spent fuel purification system (SFPS) through a new manually operated safety related seismic boundary valve and flow limiting orifice. The LAR also states that the RO system return piping will be connected to the SFPS through a new safety related seismic check valve and non-seismic isolation valve. The remainder of the RO system is non-safety related and non-seismic.

REVIEW: The NRC approved an Alternate Source Term (AST) analysis by license amendments 338, 339, and 339, ML041540097. The licensees design basis AST analysis for a large break loss of coolant accident (LOCA) assumes back leakage of sump water into the BWST during recirculation and leakage from the emergency core cooling systems (ECCS) outside the containment during recirculation. The AST analysis does not assume there is any back leakage of post-LOCA fluids into the SFPS or RO systems or any leakage to the environment from the SFPS or RO systems. Since the RO system takes suction from the BWST, through the SFPS, using piping that may be exposed to post-LOCA fluids during recirculation, the proposed change introduces an unanalyzed release path for post-LOCA fluids during recirculation. ONS proposes a manual operator action to ensure the RO system boundary valve is closed before recirculation is initiated to prevent release of post-LOCA fluids. However, the proposed change does not include sufficient information for the staff to determine the impact of leakage through the single seismic boundary valve, on the licensees AST LOCA analysis. Specifically, the LAR does not include sufficient information regarding how leakage past the single boundary valve will be quantified and controlled, an analysis of the impact of any acceptable leakage past the

boundary valve after isolation, or how failure to close the boundary valve impacts the analysis of the limiting single active component failure assumed in the AST analysis.

The following items are required in order for the staff to perform its review:

- An analysis of the impact of a failure to close the boundary valve on the analysis of the limiting single active component failure assumed in the AST analysis.

- Limitations and controls for the amount of acceptable leakage past the single boundary valve after closure (perhaps a Technical Specification surveillance on the leak rate).

- An analysis of the impact of any acceptable leakage past the boundary valve after isolation on the AST LOCA analysis.

- Further timing analysis with different operators, to get an average time to close the valve starting from the furthest location the dedicated operator would be allowed to be located.

John Boska Oconee Project Manager, NRR/DORL U.S. Nuclear Regulatory Commission 301-415-2901 email: john.boska@nrc.gov