ML20095D065
| ML20095D065 | |
| Person / Time | |
|---|---|
| Site: | 05000447 |
| Issue date: | 08/20/1984 |
| From: | Sherwood G GENERAL ELECTRIC CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| MFN-122-84, NUDOCS 8408230209 | |
| Download: ML20095D065 (10) | |
Text
~.
GENERAL $ ELECTRIC ~
NUCLEAR POWER SYSTEMS DMslON GENERAL ELECTRIC COMPANY
- 175 CURTNER AVENUE o SAN JOSE, CAUFORNIA 95125 August 20, 1984 MFN-122-84 U.S. Nuclear Regulatory Comission Office of Nuclear Reactor Regulation Washington, D.C.
20555 Attention:
Mr. D.G. Eisenhut Division of Licensing
SUBJECT:
IN THE MATTER OF 238 NUCLEAR ISLAND GENERAL ELECTRIC STANDARD SAFETY ANALYSIS REPORT (GESSAR II) DOCKET N0. STN 50-447 DRAFT AMENDMENT TO GESSAR II SECTIONS 1G.12 AND 1G.21
~ Attached please find a draft amendment to GESSAR II Sections 1G.12 and 1G.21. Section 1G.12 responds to 10CFR50.34 (f) Item (1)(xii) pertaining to the evaluation of alternate Hydrogen Control Systems.
Section 1G.21 responds to 10CFR50.3? (f) Item (2)(ix) pertaining to Hydrogen Control System preliminary design.
The utility Applicant is required to provide an igniter Hydrogen Control System capable of handling hydrogen generated as required by the proposed Interim Requirements Related to Hydrogen Control (December 23, 198146FRG2281). This Hydrogen Control System will be based on the NRC approved results of the BWR Hydrogen Control Owners Group (HC0G) tests and analyses. Although the hydrogen generation required by 10CFR50.3+
(f) Item (2)(ix) is higher than required by the proposed Interim Requirements Related to Hydrogen Control, utilization of the HC0G results are acceptable because the GESSAR II design, utilizing the Ultimate Plant Protection System (UPPS), reduces the overall risk of core damage of an order of magnitude.
If there are any questions on the information provided herein, please contact me or J.F. Quirk (408) 925-2606.
Very truly yours, c (8pi d n G1 nn G. Sherwood, Manager Nuclear Safety & Licensing Operation Attachment cc:
D.M. Crutchfield (NRC)
L.S. Gifford (GE-Bethesda)
D.C. Scaletti (NRC)
R. Villa (GE)
C.0. Thomas (NRC)
J.F. Quirk (GE)
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ATTACHMENT DRAFT AMENDMENT TO GESSAR II SECTIONS 1G.12 AND 1G.21
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P Table 1.9-1 CHAPTER 1 GESSAR II/FSAR INTERFACES (CONTINUED)
ITEM
~
NO.
SUBJECT DESCRIPTION INTERFACE PAGE SUBSECTION CATEGORY 1.127 Hydrogen Con-Provide design descriptions of equip-1G.12-1 1G.12 -
3 trol System ment, function and layout of ignition Evaluation Hydrogen Control System based on the results of the BWR HC0G sponsored tests and analyses.
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- s 1.128 Long-Term Establish a training program which 1G.13-1 1G.13 3
og CO i
Training addresses the. concerns related Ncn 7
Upgrade to Item I.A.4.2 of NUREG 0718.
1.129 Long-Tern Establish a program for integrating 1G.14-1 1G.14 3
$U w
Program of and expanding current efforts to Upgrading of improve plant procedures.
C Procedures 5:
U 1.130 Hydrogen Provide an igniter Hydrogen Control 1G.21-2 1G.21
~
control 3
System capable of handling. hydrogen-System generated as required by the proposed Interim Requirements. Related. to.
Hydrogen Control (December 23,1981, 46 F.R. 62281) l.131 Purging Provide performance information of 1G27.1 1G.27 3
purge valves my my e
8 g
1
GESSAR II 22A7007 238 NUCLEAR ISLAND Rev.
1G.12 EVALUATION OF ALTERNATIVE HYDROGEN CONTROL SYSTEMS j
[ Item (1) (xii)]
NRC Position Perform an evaluation of alternative hydrogen control systems that would satisfy the requirements of paragraph (f) (2) (ix) of 10CFR50. 34 ( f).
As a minimum include consideration of a hydrogen ignition and post-accident inerting system.
The evaluation shall include:
(A)
A comparison of costs and benefits of the alternative systems considered.
(B)
For the selected system, analyses and test data to verify compliance with the requirements of (f) (2) (ix) of 10CFR50.34.
(C)
For the selected system, preliminary design descrip-tions of equipment, function, and layout.
Response
(A)
GE has conducted evaluations of the various hydrogen control concepts for the GESSAR II design.
These con-cepts included distributed ignition, catalytic burners and post-accident inerting with carbon-dioxide or halon.
Of the concepts considered, only distributed ignition (igniters) and carbon-dioxide post-accident inerting appear to be viable alternatives.
The costs and bene-fits of these two alternatives are summarized in Table 1G.12-1.
Neither igniters or post-accident inerting exhibit overriding benefits.
However, from a cost standpoint, igniters should be an order of magnitude less expensive than post-accident inerting provided the first GESSAR II Applicant is not required to incur the cost of an equipment qua.b qualification program. Assuming that the first Applicant referencing GESSAR II can fully utilize the results of the BWR Hydrogen Control Owners Group (HCOG) sponsored tests, igniters are clearly more cost-
. effective than post-accident inerting.
Hence, the Applicant shall comit to a igniter Hydrogen Control System.
L G.12 -1
The resu\\f3 of 4k swr HCoG 4esks owd oralg saa will be.
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(B) to ccr;g sa hs iY pre.-y :;;elic..g; with the requirements of v s e.N 10CFR50. 34 (f) (2) (ix).
(C)
The Applicant will provide the design descriptions of equipment, function, and layout 7 based on M nault.s of 4k BwR H CO G S P o"3 0 W cI de 5+1 and awa lgscs.
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1 G. t 2.- 2.
GESSARLII 22A7007 238 NUCLEAR ISLAND Rev.,)(
Table 1G.12-1 COMPARISON OF HYDROGEN CONTROL ALTERNATIVES Item Igniters Post-Accident Inerting Description Distributed ignition systems. Liquid CO2 discharged controlled burn at low H2 into containment air-concentration space (prevents combustion)
Cost (Order
$1 Million*
$10 Million*
of Magnitude)
R&D Concerns Flammability, mixing,. pres-Possible partial sure response inerting flammability characteristics.
Mixing, effects on electronic equipment
- W R&D Programs Underway EPRI/NRC/BWR WCOG None planned Pros e Minor impact of inadver-e No heat loads tent operation e No dependence on H2 e Low cost generation rate e Minimum design impact e Minor impact on e Lower containment existing equipment pressures e AC power not required for inerting' Cons e Potential for large equip-e Inadvertent actua-ment qualification program tion has potential e Assurance of combustion at adverse impact on low concentrations plant operation e Sensitize to hydrogen e High containment generation rate and con-pressure tainment entry point e High cost e Requires active heat e Some redesign of a
l removal containment piping l
to accommodate e Potential adverse effects from low l
temperatures during l
injection l
- These costs do not in61ude the cost of corresponding equipment qualification programs.
Inclusicn,of equipment qualification costs could result in nearly equal total costs for the first Applicant referencing GESSAR II.
R d v a g s v-Conke.\\ S3 s+% 4e sbS b 4k
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SWR H u dvo3cn -Cowheel Owwer. Grou p ( H C 0 G).
s' 1G.12-3/lG.12-4 w
GESSAR II 22A7007 238 NUCLEAR ISLAND Rev. 17 1G.21 HYDROGEN CdNTROL SYSTEM PRELIMINARY DESIGN [ Item (2) (ix)]
NRC Position Provide a system for hydrogen control that can safely accommodate hydrogen. generated by the equivalent of a 100% fuel-clad metal water reaction.
Preliminary design information on the. tentatively preferred system option of those being evaluated in paragraph (1) (xii) of 10CFR50.34(f) is sufficient at the construction per-mit stage.
The hydrogen control system and associated systems shall provide, with reasonable assurance, that:
(II.B.8)
(A)
Uniformly distributed hydrogen concentrations in the containment do not exceed 10% during and following an accident that releases an equivalent amount of hydrogen as would be generated from a 100% fuel clad metal-water reaction, or that the post-accident atmosphere will not m
support hydrogen. combustion.
(B)
Combustible concentrations of hydrogen will not collect in areas where unintended combustion ' cur detonation could cause loss of containment integrity or loss of appro-priate mitigating features.
(C)
Equipment necessary for achieving and maintaining safe shutdown of the plant an'd maintaining containment integrity will perform its safety function during and after being exposed to the environmental conditions attendant with the release of hydrogen generated by the.
equivalent of a 100% fuel-clad metal water reaction including the environmental conditions created by activation of the hydrogen control system.
1G.21-1
3 GESSAR II.
22A7007 I
238 NUCLEAR ISLAND' Rnv.
1G.21 HYDRO' GEN CONTROL SYSTEM PRELIMINARY DESIGN (Item (2) (ix)]
(Continued)
(D)
If the method chosen for hydrogen control is a post-accident inerting system, inadvertent actuation o'f the system can be' safely accommodated during plant operation.
Response
The Applicant will provide an igniter Hydrogen Control System capable o'f handling hydrogen generated as required by the proposed Interim Requirements Related to Hydrogen Control (December 23,1981, 46 F.R. 62281). This Hydrogen Control System will be based on NRC approved results of the BWR Hydrogen Control Owners Group (HCOG) tests and analyses. Although the hydrogen generation required by Item (2)(ix) is higher than required by the proposed Interim Requirement: Related to Hydrogen. Control, utilization of the HC0G results are accep, table because the GESSAR II design, utilizing the Ultimate Plant Protection System (UPPS), reduces the overall risk ~ of core damage an order of magnitude.
The Applicant shall demonstrate that the BWR HC0G results are applicable to iis igniter Hydrogen Control System. This will constitute reasonable,
assurance that:
(1) Uniformly distributed hydroge'n concentrations in the containment do not exceed 10% during and following an accident that releases hydrogen as required by the proposed Interim Requirements Related to Hydrogen Control.
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GESSAR II 22A70 R v. [07 238 NUCLEAR ISLAND 1G.2L HYDROGEN CONTROL SYSTEM PRELIMINARY DESIGN [ Item (2) (ix)]
(Continued)
Response (Continued)
(2)
Combustible concentrations of hydrogen will not collect in areas where unintended combustion or detonation could cause loss of containment integrity or loss of appropriate mitigating features.
(3)
Equipment necessary for achieving and maintaining safe shutdown of the plant and maintaining containment integ-rity will perform its safety function during and after:
being exposed to the environmental conditions attendant with the release of hydrogen generated b; the r;tifrient as t-e-Qu\\etd h3 th pv o a g a m b ex W 4 d +=4 d Tnke.n m e
M An &
3 Cow 4rel.
t 1G.21-2a
GESSAR II 22A7007 238 NUCLEAR ISLAND Rev.
1G.21 ' HYDROGEN CONTROL SYSTEM PRELIMINARY DESIGN [ Item (2) (ix))
(Continued) of ; 1000 fu:1 sind m;t:1 ;;t r rc;; tic.., including the environmental conditions created by activation of the hydrogen control system.
The following criteria will be used to design the Hydrogen Control System:
(1)
The system will be single active failure proof.
(2)
Operation of the Hydrogen Control System will not adversely affect the safe shutdown of the plant.
(3)
The system will be protected from tornado and external missile hazards.
(4)
The system will not compromise the containment design.
(5)
If the method chosen for hydrogen control is a post-accident inerting system, inadvertent actuation of the system must be safely accommodated during plant operation.
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1G.21-3/1G.21-4