ML17363A257
| ML17363A257 | |
| Person / Time | |
|---|---|
| Site: | 05200046 |
| Issue date: | 12/29/2017 |
| From: | Korea Hydro & Nuclear Power Co, Ltd |
| To: | Office of New Reactors |
| Shared Package | |
| ML17363A255 | List: |
| References | |
| MKD/NW-17-0381L | |
| Download: ML17363A257 (12) | |
Text
06.02.05-12_Rev.2 - 1 / 3 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.: 541-8724 SRP Section: 06.02.05 - Combustible Gas Control in Containment Application Section: 6.2.5 Date of RAI Issue: 02/21/2017 Question No. 06.02.05-12 This is a follow up question to KHNPs response to RAI 155-8167, Question 6.2.5-4, regarding passive autocatalytic recombiner (PAR) recombination rates.
10 CFR 52.44(c)(1) requires that a standard design certification applicant must ensure a mixed atmosphere in containment during design-basis and significant beyond design basis accidents.
A mixed atmosphere means that the concentration of combustible gases in any part of the containment is below a level that supports combustion or detonation that could cause loss of containment integrity.
APR1400 Design Control Document (DCD) Tier 2, Section 6.2.5 credits the passive autocatalytic recombiners (PAR) with meeting the above criteria.
However, in DCD Tier 1, Table 2.11.4-1, Containment Hydrogen Control System ITAAC, there is insufficient information to determine that the containment hydrogen control system design meets the above criteria. In DCD Tier 2, Table 6.2.5-1, Location of PARs and His, PAR and hydrogen igniters (HI) locations in containment are provided. This information should either be included in Tier 1, Table 2.11.4-1, or a link to Tier 2, Table 6.2.5-1 should be provided in Tier 1, Table 2.11.4-1.
Also, DCD Tier 2, Table 6.2.5-1 describes the PARs as small, middle, large. The actual PAR recombination rates which form the basis of the hydrogen containment analysis should be provided in the DCD.
The response stated that the equation for the recombination rate for the large (FR1-1500) PARs has the two coefficients, A and B. The staff's review indicates that these coefficients, A and B, should be larger. These coefficients were deduced by comparing the recombination rate that is predicted by the formula to the performance specifications published for an AREVA PAR.
06.02.05-12_Rev.2 - 2 / 3 KEPCO/KHNP
KHNPs response to RAI 472-8564, Question 6.2.5-11, confirmed the larger coefficients above were used by KHNP in their analyses. This is in agreement with the coefficients used in staff's MELCOR confirmatory calculation.
In the original RAI 155-8167, question 6.2.5-4, staff also requested the following:
DCD Tier 2, Table 6.2.5-1 describes the PARs as small, middle, large. The actual PAR recombination rates which form the basis of the hydrogen containment analysis should be provided in the DCD, either:
G Into both Tier 2, Table 6.2.5-1 and Tier 1, Table 2.11.4-1, or G Into just Tier 2, Table 6.2.5-1, with a link to Tier 2, Table 6.2.5-1 being provided in Tier 1, Table 2.11.4-1.
Please provide the recombination rates of the three sizes of PARs which establish the capacity of the containment hydrogen control system.
Response - (Rev. 2)
The reference data for hydrogen depletion rates by PAR size are provided in the table below.
They will be added to DCD Tier 2 as Table 6.2.5-3.
Reference data of hydrogen depletion rate by PAR size Condition Hydrogen 4 v/o Hydrogen 8 v/o Size (percent by volume) (percent by volume)
Small 0.9 kg/hr 1.8 kg/hr Medium 1.8 kg/hr 3.6 kg/hr Large 4.0 kg/hr 8.0 kg/hr The hydrogen depletion rates are based on the hydrogen depletion equation from the MAAP manual. The initial condition is of 1.5 bar at 60oC.
In addition, a link to Tier 2, Table 6.2.5-1 in Tier 1, Table 2.11.4-1 (regarding the location of PARs and HIs provided in response to RAI 155-8167, question 6.2.5-4) will be deleted. The PARs and HIs locations will be provided in Tier 1 Table 2.11.4-1 at the qualitative level. The PAR depletion rates will not be provided in Tier 1. The depletion rates are derived from proprietary data and are not appropriate for Tier 1. The hydrogen depletion rates are determined to meet or exceed RG 1.7 criteria of a hydrogen concentration of 10 percent, (by volume), in the containment and IRWST, as discussed in DCD Tier 1 Section 2.11.4.1 and Table 2.11.4-3.
06.02.05-12_Rev.2 - 3 / 3 KEPCO/KHNP
DCD Tier 1 Table 2.11.4-1 will be revised to address the hydrogen depletion rates and location criteria. DCD Tier 1 DCD Table 2.11.4-3 will be revised to address the location and performance criteria. Tier 2 Table 14.3.4-2 will be revised to address the PAR and HI locations.
Impact on DCD DCD Tier 2, Subsections 6.2.5.2.1 and 6.2.8 and Table 14.3.4-2 will be revised and Table 6.2.5-3 will be added as indicated in Attachment 1.
DCD Tier 1, Tables 2.11.4-1 and 2.11.4-3 will be revised as indicated in the Attachment 2.
Impact on PRA There is no impact on the PRA.
Impact on Technical Specifications There is no impact on the Technical Specifications.
Impact on Technical/Topical/Environmental Reports There is no impact on any Technical, Topical, or Environmental Report.
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APR1400 DCD TIER 2 RAI 541-8724 Question 06.02.05-12 RAI 541-8724 Question 06.02.05-12_Rev.1 Table 6.2.1-35 Letdown Heat Exchanger and Valve Subcompartments Vent Path Description............................................................................... 6.2-396
Table 6.2.1-36 Mass and Energy Release Data........................................................ 6.2-398
Table 6.2.1-37 Stored Energy Sources ..................................................................... 6.2-403
Table 6.2.1-38 Primary Side Resistance Factors Used in FLOOD3 Code .............. 6.2-433
Table 6.2.1-39 Blowdown and Reflood Mass and Energy Release for the Minimum Containment Pressure Analysis ...................................... 6.2-434
Table 6.2.2-1 Input Values Used in CSS Evaluation Calculations ........................ 6.2-438
Table 6.2.2-2 Containment Spray System Design Parameters .............................. 6.2-439
Table 6.2.2-3 Containment Spray System Failure Modes and Effects Analysis ........................................................................................... 6.2-441
Table 6.2.2-4 Containment Spray System Display Instrumentation ...................... 6.2-446
Table 6.2.2-5 Mass Mean Diameter ....................................................................... 6.2-447
Table 6.2.4-1 List of Containment Penetrations and System Isolation Positions ........................................................................................... 6.2-448
Table 6.2.5-1 Location of PARs and HIs ............................................................... 6.2-458
Table 6.2.5-2 Hydrogen Monitoring System Failure Modes and Effects Analysis ........................................................................................... 6.2-460
Table 6.3.1-1 Responses of APR1400 to TMI Action Plan ..................................... 6.3-35
Table 6.3.1-2 Responses of APR1400 to Generic Safety Issues.............................. 6.3-36
Table 6.3.1-3 Responses of APR1400 to Generic Letters ....................................... 6.3-37
Table 6.3.2-1 SIS Component Parameters ............................................................... 6.3-38
Table 6.3.2-2 Safety Injection System Failure Modes and Effects Analysis ........... 6.3-41
Table 6.3.2-3 Safety Injection System Head Loss Requirements ............................ 6.3-55
Table 6.3.2-4 Safety Injection System Flow Delivery to RCS (1) ............................ 6.3-56
Table 6.4-1 The Accident Radiation Source Description and Radiation Shielding Design for MCR and TSC ................................................. 6.4-15
Table 6.4-2 MCR and TSC Doses from Design Basis Accidents ......................... 6.4-16
Table 6.4-3 Amounts of Hazardous Chemicals Stored Onsite ............................. 6.4-17
Table 6.5-1 Engineered Safety Features Filter Systems - Component Specification ...................................................................................... 6.5-24
Table 6.2.5-3 Performance Criteria for Depletion Rates of PARs Reference Data of Hydrogen Depletion Rate by PAR Size ix 5HY
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APR1400 DCD TIER 2 RAI 541-8724 Question 06.02.05-12 RAI 541-8724 Question 06.02.05-12_Rev.1 The PARs in the containment and inside the IRWST vent stack, and the HIs in the containment are designed to withstand severe accident conditions. The PARs and HIs provide reasonable assurance that the equipment can perform its identified function during severe accident conditions as described in Section 19.2.
PARs are considered a 15 percent efficiency reduction for iodine vapor and 10 percent efficiency reduction for cable fire. Thus, a total 25 percent efficiency reduction for the PAR was considered for capacity reduction. The HIs include a consideration of the combustion model of the MAAP computer code.
The PARs and HIs are designed to prevent any significant pocketing of hydrogen in order to minimize the potential for localized hydrogen detonation.
The PARs and HIs are able to withstand the effects of their own operations and are designed to provide reasonable assurance that equipment necessary for achieving and maintaining a safe shutdown of the plant and containment integrity are capable of performing their functions during and after their exposure to hydrogen burning.
The PARs and HIs are located throughout the containment open volumes and compartments.
The following location criteria are used:
- a. Flow path requirements
- b. Consideration of enclosed spaces
- c. Equipment performance efficiency
- d. Installation and maintenance
- e. Consideration of dynamic effect For the surveillance test of PARs, a sample of the PAR cartridges or plates is selected and removed from each PAR. Surveillance bench tests are performed on the removed specimens to confirm continued satisfactory performance. The HIs are capable of attaining the surface temperature that is sufficient for igniting hydrogen gases under any environmental conditions including CS actuation. The HI configuration, including possible spray shields, is supported by combustion test data.
The performance criteria for depletion rates of PARs is provided in Table 6.2.5-3.
The reference data of hydrogen depletion rate by PAR size for PAR surveillance test is provided in Table 6.2.5-3. The reference data is based on the hydrogen depletion 6.2-75 43) and the initial condition is of 5HY
equation from MAAP manual (Reference 1.5 bar o
and 60 C.
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APR1400 DCD TIER 2 RAI 541-8724 Question 06.02.05-12
- 39. ASME Section III, Division 1, Article NE 2300, Fracture Toughness Requirements for Material, The American Society of Mechanical Engineers.
- 40. NUREG-0800, Section 6.2.1.2, Subcompartment Analysis, Rev. 3, U.S. Nuclear Regulatory Commission, March 2007.
- 41. NRC RG 1.141, Containment Isolation Provisions for Fluid Systems.
- 42. APR1400-E-P-NR-14003-P(Proprietary)&NP(Non-Proprietary) Severe Accident Analysis Report, Rev. 1 KHNP, February 2017.
- 43. FAI/12-0005, "MAAP 4.0.8 Transmittal Document," Electric Power Research Institute, February 2012.
6.2-93 5HY
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APR1400 DCD TIER 2 RAI 541-8724 Question 06.02.05-12_Rev.1 Table 6.2.5-2 (6 of 6)
Symptoms and Local Inherent Potential Effect Including Method of Compensating Remarks and Name/Valve No. Failure Mode Plant Condition Dependent Failure Detection Provision Other Effects
- 6. Channel B a) Fails to open Detection of hydrogen in x No safety-related Valve Isolation is x Normally containment on demand containment building impact on plant information: achieved by closed monitor discharge x Isolation is achieved x Valve position redundant x Fail closed to containment by redundant valve indication in containment CM-010 MCR isolation valve (CM-009) b) Fails to x Loss of electrical power x No safety-related H2 monitoring close on x Receipt of high impact on plant line is formed in demand containment pressure x H2 monitoring line is the closed loop signal formed in the closed x Receipt of low loop pressurizer pressure signal add Table 6.2.5-3 in next page 6.2-465 5HY
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RAI 541-8724 Question 06.02.05-12 RAI 541-8724 Question 06.02.05-12_Rev.1 Reference Data for Hydrogen Depletion Rate by PAR Size
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APR1400 DCD TIER 2 RAI 541-8724 Question 06.02.05-12_Rev.1 Table 14.3.4-2 (7 of 7)
Tier 1 Tier 2 Item # Reference Design Features Reference 2-47 2.11.4 The containment hydrogen control system (CHCS) is non- 6.2.5 Design safety-related system. The CHCS is used to maintain 19.1.3 hydrogen gas concentration in containment at a level that Description 19.2.3 precludes an uncontrolled hydrogen and oxygen ITAAC #3 recombination within containment following beyond-design-basis accidents.
The CHCS consists of the passive autocatalytic recombiners (PARs) and hydrogen igniters (HIs). The PARs and HIs are designed to control and allow adiabatic controlled burning of hydrogen at fairly low concentration in containment and in-containment refueling water storage tank (IRWST) from exceeding 10 volume percent during a degraded core accident with 100 percent fuel clad metal-water reaction.
2-48 2.11.4 The CHCS provides PARs complemented by HIs to control 6.2.5 ITAAC #3 the containment hydrogen concentration for beyond-design- 19.1.3 basis accidents.
19.2.3 2-49 2.11.4 At least 30 PARs and 8 hydrogen igniters are provided 6.2.5 ITAAC #3.a inside containment. 19.2.3 2-50 3.2 The UHS provides the capability to reject the heat under 9.2.5
- a. normal and accident conditions (safe shutdown or post- 19.1.3 accident) assuming a single active failure concurrent with a loss of offsite power.
2-53 2.11.4 A report exists and concludes that the hydrogen depletion 6.2.5 ITAAC #3.b rates for each installed PAR and HI will maintain containment 19.2.3 hydrogen concentration of less than or equal to 10 percent by volume.
14.3-44 5HY
RAI 541-8724 - Question 06.02.05-12_Rev.2 Attachment 2 (1/3)
APR1400 DCD TIER 1 RAI 541-8724 Question 06.02.05-12 RAI 541-8724 Question 06.02.05-12_Rev.1 Table 2.11.4-1 Replaced with A in next page.
Containment Hydrogen Control System Components List ASME Class Display/ Display/ Active Loss of Component Section III Seismic 1E/Harsh Control at Control at Control Safety Motive Power Name Item No. Location(1) Class Category Envir. Qual. MCR RSR Signal Function Position Passive HR01A/01B ~ Containment - I -/- -/- -/- - No -
Autocatalytic HR15A/15B Recombiner Hydrogen HI01 ~ HI08 Containment - I No/- Yes/Yes Yes/Yes - No -
Igniter Containment CM-TE-031A Containment - I Yes/Yes Yes/No Yes/No - No -
Temperature Element (1) Location of PARs and His are provided in DCD Tier 2, Table 6.2.5-1 (2) Dash (-) indicates not applicable.
Deleted 2.11-59 5HY
RAI 541-8724 - Question 06.02.05-12_Rev.2 Attachment 2 (2/3)
APR1400 DCD TIER 1 RAI 541-8724 Question 06.02.05-12_Rev.1 Table 2.11.4-1 A
Containment Hydrogen Control System Components List ASME Class Display/ Display/ Active Loss of Component General Seismic Control Item No. Section III 1E/Harsh Control at Control at Safety Motive Power Name Location Category Signal Class Envir. Qual. MCR RSR Function Position HR01A/01B ~ Containment HR04A/04B Dome Area HR05A/05B ~ Steam Generator Large PAR HR06A/06B Compartment HR07A/07B ~ Upper HR08A/08B Compartment HR09A/09B ~
Inside IRWST HR10A/10B Medium PAR HR11A/11B ~ Lower
- I -/- -/- -/- - No -
HR13A/13B Compartment Reactor Detector Tube HR14A/14B Compartment, Cavity Region Small PAR Regenerative heat exchanger and HR15A/15B Pressurizer compartment Cavity access HI01 area Regenerative heat HI02 Hydrogen exchanger Room
- I No/- Yes/Yes Yes/Yes - No -
Igniter Pressurizer HI03~HI04 Compartment Steam Generator HI05~HI08 Compartment Containment Temperature CM-TE-031A Containment - I Yes/Yes Yes/No Yes/No - No -
Element (1) Dash (-) indicates not applicable.
RAI 541-8724 - Question 06.02.05-12_Rev.2 Attachment 2 (3/3)
APR1400 DCD TIER 1 RAI 541-8724 Question 06.02.05-12_Rev.1 RAI 541-8724 Question 06.02.05-12_Rev.2 Table 2.11.4-3 (1 of 2)
Containment Hydrogen Control System ITAAC Design Commitment Inspections, Tests, Analyses Acceptance Criteria
- 1. The functional arrangement 1. Inspection of the as-built 1. The as-built CHCS conforms of the CHCS is as described CHCS will be conducted. with the functional in the Design Description of arrangement as described in Subsection 2.11.4.1 and in the Design Description of Table 2.11.4-1 and as shown Subsection 2.11.4.1 and in in Figure 2.11.4-1.
and their general location,as Table 2.11.4-1 and as shown described in Table 2.11.4-1, in Figure 2.11.4-1.
- 2. The seismic Category I 2. Inspections will be 2. The as-built seismic components identified in performed to verify that the Category I components Table 2.11.4-1 withstand as-built seismic Category I identified in Table 2.11.4-1 seismic design basis loads components are located in are located in a seismic without loss of safety the seismic Category I Category I structure.
function. structure.
- 3. The CHCS provides PARs 3.a Inspection for the number of 3.a At least thirty PARs and complemented by HIs to PARs and hydrogen igniters eight hydrogen igniters are control the containment will be performed. provided inside containment.
hydrogen concentration for 3.b Operability testing will be 3.b A report exists and beyond design basis performed on the PARs and concludes that the PAR accidents.
hydrogen igniters. depletion rate for each installed PAR is equal to or greater than that of A report exists and concludes that the hydrogen depletion predetermined PAR rates for each installed PAR and HI will maintain hydrogen depletion capacity.
containment hydrogen concentration of less than or equal to For hydrogen igniters, the surface temperature exceeds 10 percent by volume. 1,700 °F
- 4. The electrical power for HIs 4. Tests will be performed on 4. The as-built HIs listed in is supplied from the Class the as-built HIs. Table 2.11.4-1 are powered 1E division. On loss of from class 1E division, the offsite power and failure of emergency diesel generator, the emergency diesel the AAC generator, and DC generator to start or run, the battery.
HIs have the alternate power supply from the alternate alternating current (AAC) generator. Also, HIs are powered by battery back-up.
5.a Controls exist in the MCR to 5.a Tests will be performed 5.a Controls in the as-built MCR start and stop the HIs using the controls in the start and stop the hydrogen identified in Table 2.11.4-1. MCR. igniters listed in Table 2.11.4-1.
the installed PARs and HIs will maintain containment hydrogen concentration, both locally and globally, of less than or equal to 10 percent by volume, or avoids DDT or detonation in order to maintain containment integrity.
2.11-61 5HY