ML20092M293

Forwards Discussion of Differences Between Us Advanced BWR & K-6/7 Project.Advanced BWR Design Under Review for for Differences to K 6/7 & Addl Differences Will Be Included in Future Ssar Amend

ML20092M293
Person / Time
Site:	05000605
Issue date:	02/20/1992
From:	Marriott P GENERAL ELECTRIC CO.
To:	Pierson R NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
MFN-040-92, MFN-40-92, NUDOCS 9202270241
Download: ML20092M293 (9)

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, M N; &v Enugt February 20,1992 MFN No. 040 92 Docket No. STN 50-605 EEN-9226 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Robert C. Pierson, Director Standardization and Non-Power Reactor Project Directorate

Subject:

Comparison or U.S. ABWR and K 6/7 Enclosed are thirty four (34) copies of the differences between the U.S. ABWR and the K 6/7 project. The ABWR design is still being reviewed for differences to the K-6/7 design and any edditional differences will be included in the listing that will be incorporated in a future amendment to the ABWR SSAR.

Sincerely, P.W. M[rn tt, Manager Regulatory and Analysis Services M/C 382, (408) 925-6948 cc: F. A. Ross (DOE)

N. D. Fletcher (DOE)

C. Poslusny, Jr. (NRC)

R. C. Berglund (GE)

J. F. Quirk (GE) 2G0C52 .

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COMPARISON OF U.S. AllWR AND K 6/7 DIFFERENCES U.S. AHW11 K 6/7 REQUIREMENT /

COMMENTS

1. Gencral Design 1.1 Single unit plant Dual unit Some facilities shared between dual units and other site units 1.2 Scismic 03g SSE Scismic site specific ALWR all soils envelope 13 fo year plant life 40 year ALWR 1.4 Ultimate heat sink Maximum temperature of U.S. design supports maximum temperature of 85 F assumed generic site emtlope 95 F assumed 1.5 U.S. Codes and Stds MITI Codes and Stds NRC 1.6 ABWR Product Structure K-6/7 Product structure 1.7 Grid frequency 60 Hz 50 Hz 1.8 Radwaste system design Standard Hitachi/Toshiba customized for U.S. design 2, Plot Plan 2.1 Turbine building & tubrine Axis perpendicular to ALWR/ Japanese choose to axis in-line with reactor reactor building sddress turbine missile issue building entirely from a structural perspective to have a more compact site plot plan 2.2 Steam line volume less than 1000 cu. ft.

23 Controlbuildinglocated Located between dual between reactor building reactor buildings and turbine building

a. Control room HVAC Single air intake Dualintake design resultsin includes dual widely less dose to operator in U.S.

separated operator control room exposure analysis selectable air intakes l

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COMPARISON OF U.S. ABWR AND K 6/7 DIFFERENCES (ContingId)

b. RCW liX's located in Dedicated ilX building U.S. layout reconfigured to basement of control reflect different site plot plan building

c. RIP MG sets located in control building 2.4 Radwaste building designed Shared facilities on Japanese emphasis on for a single unit multi-unit site. K-6/7 efficiency and compact site (ABWR) share facilities layout with K 5 (BWR-5) 2.5 Technical support center NRC located in senice building 2.6 Condensate storage tank Storage pool kr.ated in in yard in radwaste building 2.7 Dual unit common switch. Common switchgear used gear deleated 1

3. Power Cycle System 3.1 Power cycle system Japanese emphasis is on ALWR design meets U.S. utility maximum heat rate and preference, with emphasis thermal efficiency on simplicity,

a. FW pumps driven by var- Steam driven pumps iable speed motor I

b. Condensate has 4x33 3/ % Condensate pumps plus pumps; no condensate booster pumps; 3x50%

booster pumps pumps at each stage

c. Iow pressure FW heater Pumped forward 1-tigh pressure heater drains drains cascaded back to pumped forward in both designs condenser

d. Moisture separator /re- 2 stage reheat heaters have 1 stage reheat

e. Condenser is multiple Single pressure pressure

f. Condenser tubing coo"ng Titanium ALWR requirements allow use water dependent of materials suitable for actual site cooling water conditions 2-r T - -

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COMPARISON OF U.S. ABWR AND K 6/7 DIFFERENCES (Continued)

g. Turbine gland sealing Dedicated system supplies steam extracted from clean steam main steam

h. Steam jet air ejectors 1100% train plus I startup has 2x100% trains train (driven by auxiliary steam)

1. Condenser heat s, ink site Seawater dependent J. TBCW system has 2x 3x50% pumps and IIxs 100% pumps and Hxs k, Condensate polishing Single stage - Meets water quality exposure is two stage & radwaste burial volume goals 3.2 Offgas system is GE N68 II/T design based on design earlier GE N62 design 33 Hydrogen v. ate / chemistry Not adopted Desirability still under study integral with design in Japan 3.4 Provision for Zine addition No Zinc addition Zine addition is optional to Feedwater 6

4. Electrical Design 4.1 Offsite/onsite AC power 7 unit site with multiple U.S. design reflects ALWR re-sources are the low vol- offsite AC power sources quirements (both designs tage generator output  : include normal compliment of j breaker plus one inde- emergency diesel generators) pendnent offsite source

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plus non safety onsite gas -

turbine 4.2 Onsite power distribution . No generator output . AC network interface designed -

network has generator breaker or gas turbine; for repsective site conditions output breaker and feed startup transformers used (switchinglogic alw modified from gas turbine added; to provide feed in convent _ accordingly) startup transformers ionalway -

deleted '

43 Isolation of 1E from non 1E loads on low voltage ac/de circuits -

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COMPARISON OF U.S. AHWR AND K 6/7 DIFFERENCES (Contlttutdl 4.4 DG fuel storage is 3a100% 2x200% divisionally cross- K 6/7 design emphasites divisionally separated tied tanks (per reactor compact site plot plan; cross tanks located underground unit) located above ground ties allowed byless rigorous divisional separation requirements 4.5 DG start capability incorp- Normal capability ALWR orates manual (no AC) start i capability 4.6 DG fire suppression is foam CO system ALWR 2

system 4.7 No PVC electricalinsulation Use of PVC OK ALWR allowed 4.8 Non-safety chillers and Gas turbine is not ALWR coolers connectable to required on-site gas turbine

5. Primary Containment 5.1 Severe accident design . Not part of design Subject of severe accident i features mitigation is still under study in Japan -

a. Containment overpres. Passive venting of wetwell airspace l

sure protection through two rupture disca in series in hardened path; containment integrity recoverable by:

l closing normally open AOW

b. Strengthened drywell Drywell head thickness increased head from 1" to 1.25'; Pressure -

capabilityincicased to near ultimate strength of balance of the containment structure j c. -Ilmestone concrete Reduces non-condensible gas prohibited in lower : generation from potential drywell area core-concrete interaction

d. Lower drywell flooder . - Utilizes fusible plugs on pipes .

- connecting suppression pool to lower drywell

c. ACindependent water Fire water system cross-tied addition capability into RHR with manually operated valves

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9 COMPARTSON OF U.S. ABWR AND K 6/7 D.lfflRENCES (Continued)

f. Onsite combustion ALWR turbine generator 5.2 Wetwell/Drywellvacuum No auto return logic, LOCA Vacuum breakers are air breakers with test during test mode considered testable check valves; auto circuit auto return to have sufficiently small return logic exhausts air from i normallogic on probability of occurrence test actuator on LOCA signal t.OCA signal as to be negligible to return valve to normal swing check mode 53 SRV discharge piping Specified as MITI Class 4 NRC in wetwell region so no ISI required specified as ASME Class 2 (MITI Class 3 equivalent) the cefore, ISI is required 5.4 RPV metal temperature K-6/7 to have extra monitor- ALWR/ Extra monitoring capa-sensor reduction ing capability bility not needed for follow-on plants 6 Secondary Containment 6.1 Redundant flammobility Portable skids one skid For K-6/7 redundancyis control system (hydrogen normallyinstalled in reactor provided by portability of skid recombiners) permanently building of each unit in other unit's reactor building installed 6.2 SGTS has 4000 scfm 1200 scfm capacity Less prescriptive require-capacity with auto ments for SGTS sizing in Japan; negative pressure control Increased capacity of U.S. system capability necessitates capability to control negative pressure to prevent excessive differential pressure on reactor building -

i 63 Steam and FWlines classi- Seismic out to turbine; no Seismically qualified turbine fled non-seismic outboard seismic interface restraint building is standard Japanese of seismic interface re- practice straint

a. leak before-break Conventionally analyzed Leak-before-break methodology methodology used to and supported still under studyin Japan eliminate pipe whip restraints 6.4 HPCF pumps discharge NRC/High pressure isolation check valve 5-

COMPARISON OF U.S. ABWR AND K 6/7 '  ;

DIFFERENCES (CQatinued) 6.5 ECCS injection valve . Subsection 19C.4(1) & (3) handwheel and improved position monitoring 6,6 CRD pump motor over. 20 % U.S. Codes and Standards speed 25%

6.7 Reactor building secondary Truck shipping access containment air lock

7. Control Room 7.1 ARBM logic enforces logic does not enforce ARBM enforcement of OLMCPR, even in Manual OLMCPR in manual mode; OLMCPR in all modes elim-mode, to prevent Rod RWE transient analyzed as inates RWE as credible Withdrawal Error transient acceptable transient in U.S.; thus, analysis is not required -

7.2 Automatie boron injection Manual NRC/ Recirculation run back and ARl/FMCRD run in initiated from scram -

7.3 Automatic suppression pool Manual cooling for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> -

7.4 Automatic ADS after additional Manual NRC 8 minutes without high drywell pressure-

a. ADS includes manualinhibit Inhibit switch not ADS inhibit switch required in switch on main control provided U.S. to help mitigate ATWS 4

panel i

i b. Monitor solenoid continuity - Subsection 19C.4(4) for ADS SRVs

, 7.5 RPS seismic trip is not an Trip on high ground Seismic scram trip is standard RPS input acceleration Japan practice i

l a. TCV solenoid position Trip on TCV solenoid ' Standard Japan practice j- tripis not an RPS input position switch input 1-

,' 7.6 RPV water levelinstrument- Reference zero at TAF for In Japan,it was decided that

} ation reference 2. o at: fuel zone range only; all least confusing solution is to TAF for allinstruments others use bottom of separ. - retain past BWR practice (U.S.

ator skirt for reference zero designed dictated by TMI Action Plan item) .

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.- COMPARISON OF U.S. ABWR AND K 6/7 DIFFERENCES (Continued 1.

7.7 Safety related RiiR lixs outlet Non IE NRC temperature monitor 7.8 Keylock switch on Ri!R discharge No keylock ALWR valve to radwaste y:-

8. Water /Alr 8.1 RCW has 3x50% ve.L. 2x100% horizontalIIXs Differing configurations llXs (per division) (per disision) reflective oflocational space constraints

a. Corrosion monitoring Not included ALWR subsystem included 8.2 Essential HVAC has cooling Division C uses forced air Division C has less heat load coils in all3 divisions; .

only for reactor building and cooling coils not needed at division C serves control loads and does not serve actual conditions of K-site; U.S.

rc.om control room design must support generic site envelope

a. IIVAC essential cooling Divisions A & B only water divisions A, B & C

b. Drain collection to Storm drains ALWR radwaste or recycle to RCW 8.3 liVAC normal cooling water Smaller size U.S. system has larger capacity system has increased size - to accommodate generic site envelope 8.4 RCIC room dedicated sump Shared sump with RHR 'A' Dedicated RCIC sump prosides considerable PRA benefit from flooding evaluation  !

8.5 Instrument air system has Auto-transfer to back up There is a cross-tie between manual cross-tie back-up nitrogen supply mode K 5, K 6 and K 7 to nitrogen supply 8.6 Breathing air is dedicated Supplied by service air system 8.7 Service air filters and No filters and dryers . ALWR dryers added 7

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COMPARISON OF U.S. AHWR AND K 6/7 DIFFERENCES (Continued)

9. Fire Protection .

9.1 Physical fire barricts with Some interdivisional equip- Japanese practice allows some 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> ratings used at all ment located in common areas areas that contain safety re-divisional boundaries out- designated as "non-fire zone". lated equipment (including of side containment high energy Penetrations do not require different divisions) to be piping penetrations also re- 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> ratings subject to less strict fire quire 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire ratings (or protection requirements if sup-appropriate justifiucation ported by analysis showing proba-otherwise) bility or size of fire to be low 9.2 US. design has dedicated No such mode is required US equires capability to exhaust smoke removal mode consisting moke, and prevent migration to of dampers and logic other divisions 93 Four SRVs controllable at 3 SRVs controllable per Addition of 4th SRV et RSP Remote Shutdown Panel (RSP) original design; US. design improves results of fire PRA change still under study by factor of 10 1

10. Radiation 10.1 Containment leakage 0.5%/ day 0.4%/ day assumed Japanese data shows consistent-assumed in dose analysis lyless leakage than in US.;

U.S. assumption reflects utility desire to retain margin for test 10.2 MSIV leakage 140 scfh total 45 scfh total assumed Historic Japanese data shows for alllines assumed in dose consistentlyless leqakage than analysis in US.; US. assumption reflects utility desire to retain margin for test 103 Reconfigure ARM & PRM systems- Site specific Accomodate plant arrangement to U.S. design and processes

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