ML17363A269

Korea Hydro & Nuclear Power Co., Ltd - Revised Response to RAI 463-8570 for the Question 10.03-5

ML17363A269
Person / Time
Site:	05200046
Issue date:	12/29/2017
From:	Korea Hydro & Nuclear Power Co, Ltd
To:	Office of New Reactors
Shared Package
ML17363A267	List: ML17363A268 ML17363A269
References
MKD/NW-17-0382L
Download: ML17363A269 (4)

Text

10.03-5_Rev.1 - 1 / 2 KEPCO/KHNP REVISED RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION APR1400 Design Certification Korea Electric Power Corporation / Korea Hydro & Nuclear Power Co., LTD Docket No.52-046 RAI No.: 463-8570 SRP Section: 10.3 - Main Steam Supply System Application Section: 10.3 Date of RAI Issue: 04/19/2016 Question No. 10.03-5 GDC 4 requires that SSCs important to safety are designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents. GDC 34 requires the portions of the main steam system (MSS) associated with residual heat removal function to transfer heat from the reactor core at a rate such that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are not exceeded. SRP 10.3 provides guidance and acceptance criteria to meet relevant requirements associated with the MSS.

The staff reviewed DCD Tier 2, Section 10.3, for a description of all flowpaths that branch off the main steamlines between the main steam isolation valves (MSIVs) and turbine stop valves as specified in SRP 10.3,Section III.5.E. The staff determined that this information is either incomplete or missing from the application.

The applicant is requested to include in the DCD a complete tabulation and description of all flowpaths between the MSIVs and turbine stop valves, including shutoff valves in connected piping, and bypass valves. The type of information and level of detail needed for the staff to complete its review is listed in item i through ix of SRP 10.3,Section III.5.E.

Response - (Rev. 1)

A new table including information required in SRP 10.3,Section III.5.E had been added in the DCD Tier 2, Subsection 10.3.2.2.1.

That table format was based on the similar table provided in other DCDs. The changes that were proposed in the original response to this RAI have been incorporated into Revision 1 of the DCD; however, changes to Tier 2 DCD, Table 10.3.2-6 were identified resulting from a self-assessment necessitating a revised response to this RAI are included in the Attachment.

10.03-5_Rev.1 - 2 / 2 KEPCO/KHNP Impact on DCD DCD Tier 2, Table 10.3.2-6 will be revised as indicated in the attachment markup.

Impact on PRA There is no impact on the PRA.

Impact on Technical Specifications There is no impact on Technical Specifications.

Impact on Technical/Topical/Environmental Reports There is no impact on any Technical, Topical, or Environmental Report.

RAI 463-8570 - Question 10.03-5_Rev.1 Attachment (1/2)

APR1400 DCD TIER 2 RAI 463-8570 - Question 10.03-5_Rev.1 Table 10.3.2-6 Main Steam Branch Piping (2.5 Inches and Larger), Between the MSIVs and the Turbine Stop Valves Max. Steam Description Flow Shutoff Valve Valve Closure Time Actuator Comments Turbine bypass 1,292,000 lb/hr 16 in (406.4 mm) globe within 5 sec when the Air operated ; Fail close Valves are normally closed during power lines to condenser ; (162.79 kg/s), (turbine bypass valve) permissive signal from the operation 8 lines total each lines SBCS Reheating steam 2nd 413,500 lb/hr 12 in (304. 8mm) Gate (( Max. 49 sec ))1) Motor operated ; Jogging/Fail-As-Is Flow to reheater ceases following turbine stage to MSRs ; (52.1 kg/s), (isolation valve) trip flow ceases following valve closure on a 2 lines total each lines main steam isolation signal Main steam supply 476,000 lb/hr 10 in (254 mm) globe (( Max. 60 sec ))1) Motor operated ; This line is normally open during power to auxiliary steam (59.975 kg/s) (isolation valve) Fail-As-Is operation.

system. ;

1 line High pressure 4,504,000 lb/hr 32 in (812.8 mm) gate 0.3 sec Electro-Hydraulic operated, Fail close Main steam flow to high pressure turbine turbine steam (567.49 kg/s), (HP turbine stop valve) ceases following stop valve closure on a supply lines ; each lines turbine trip 4 lines total Main steam supply 38,987 lb/hr 4 in (101.6 mm) gate (( - ))1) Motor operated ; Fail-As-Is This line is normally open during power for turbine steam (4.91 kg/s) (isolation valve) operation.

seal ;

1 line Main steam supply 146,287 lb/hr 6 in gate (( - ))1) Electro-Hydraulic operated, Fail close Flow ceases after receipt of main steam to feedwater pump (18.43 kg/s), (H.P. steam inlet stop valve) isolation signal turbine , 3 lines each lines

1) Value determined by valve supplier Replace with "A" 10.3-35 Rev. 1

RAI 463-8570 - Question 10.03-5_Rev.1 Attachment (2/2)

RAI 463-8570 - Question 10.03-5_Rev.1 Table 10.3.2-6 Main Steam Branch Piping (2.5 Inches and Larger), Between the MSIVs and the Turbine Stop Valves Description Max. Steam Flow Shutoff Valve Valve Closure Time Actuator Comments Turbine bypass lines 1,292,000 lb/hr 16 in (406.4 mm) within 5 sec when Air operated ; Valves are normally closed to condenser ; 8 lines (162.79 kg/s), each globe (turbine the permissive Fail close during power operation.

total lines bypass valve) signal from the SBCS Reheating steam 2nd 413,500 lb/hr (52.1 12 in (304. 8mm) (( Max. 49 sec ))1) Motor operated ; Flow to reheater ceases stage to MSRs ; 2 kg/s), each lines Gate (isolation Jogging/Fail-As- following valve closure due to lines total valve) Is turbine trip or main steam isolation signal.

Main steam supply to 476,000 lb/hr 10 in (254 mm) (( Max. 60 sec ))1) Motor operated ; There is no flow to this line auxiliary steam (59.975 kg/s) globe (isolation Fail-As-Is during power operation. Valve system. ; 1 line valve) is automatically closed by MSIV close fail signal.

High pressure turbine 4,504,000 lb/hr 32 in (812.8 mm) 0.3 sec Electro- Main steam flow to high steam supply lines ; 4 (567.49 kg/s), each gate (HP turbine Hydraulic pressure turbine ceases lines total lines stop valve) operated, Fail following stop valve closure close on a turbine trip.

Main steam supply for 38,987 lb/hr (4.91 4 in (101.6 mm) (( - ))1) Motor operated ; Valve is normally closed turbine steam seal ; 1 kg/s) gate (isolation Fail-As-Is during power operation.

line valve)

Main steam supply to 146,287 lb/hr 6 in gate (H.P. (( - ))1) Electro- There is no flow to this line feedwater pump (18.43 kg/s), each steam inlet stop Hydraulic during power operation.

turbine , 3 lines lines valve) operated, Fail Valves are closed after close receipt of main steam isolation signal.

1)

Value determined by valve supplier A