ML20041F239
| ML20041F239 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 03/10/1982 |
| From: | Mcgaughy J MISSISSIPPI POWER & LIGHT CO. |
| To: | Tedesco R Office of Nuclear Reactor Regulation |
| References | |
| AECM-82-31, NUDOCS 8203160318 | |
| Download: ML20041F239 (10) | |
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MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi t e m tMdds P. O. B O X 164 0. J AC K S O N, MIS SIS SIP PI 3 9 2 0 5 March 10, 1982,p p9 g
J AMES P. McGAUGHY, JR.
ASSISTANT VICE PRES 4 DENT f
y Mr. Robert L. Tedesco,
~
# D Assistant Director of Licensing q
A1UbN# j Division of Licensing U.S. Nuclear Regulatory Commission
% U;{j$$7 Washington, D.C.
20555 7,{
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<% p q{AN 5
Dear Mr. Tedesco:
4 I,'
SUBJECT:
Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416 and 50-417 File 0260/L-860.0/0756 Hydrogen Control - Potential Impact on License Schedule AECM-82/31 We have received your January 12, 1982 letter regarding the potential imcact on licensing schedule for Unit 1 of the Grand Gulf Nuclear Station (GGNS) due to late responses on hydrogen control.
We believe this matter deserves your further attention.
Furthermore your letter indicates that the cause for the potential schedule slip is late responses on hydrogen control by Mississippi Power
& Light Company (MP&L). We have the following comments which we believe are germane to this issue.
Brief GGNS Chronology On April 9, 1981, MP&L submitted letter AECM-81/139 concerning our evaluation of hydrogen control measures, the selection of igniters, a preliminary and conservative containment response analysis, a preliminary system design, and a preliminary containment ultimate response analysis.
On June 19, 1981, MP&L submitted letter AECM-81/221 which provided substantially more detail than the earlier submittal including four case studies of containn.ent pressure and temperature response using the CLASIX-3 computer code, a summary equipment list and program description regarding equipment survivability and more detailed information on containment ultimate capacity.
On August 18, 1981, MP&L submitted letter AECM-81/298 which provided a list of 36 action items in 10 categories and our schedule of submittals for September, October and December to resolve these issues.
A list of these items, the appropriate schedules and when responses were provided is attached for your use.
This letter also provided further information on the status of hydrogen activities on GGNS.
300; s
8203160318 820310 PDR ADOCK 05000416 I [
A PDR Member Middle South Utilities System
March 10,.1982 AECM-82/31 MICISSIPPI POWER O Ll2HT COMPANY Page 2 On August 31, 1981, MP&L submitted letter'AECM-81/336 which provided substantial additional information on the four cases previously submitted and two additional " bounding" case studies of CLASIX-3 containment response as well as a more detailed description of assumptions and procedural changes being implemented for the integrated base case scenario. This letter also agreed to expedite the submittal of responses to the MP&L developed action items due to informal requests by Nuclear Reactor Regulation (NRR) staff members.
On September 11, 1981, MP&L submitted letter AECM-81/353 in which responses were provided to 19 of the 36 (over 50 percent) MP&L developed action items.
The action item submittal scheduled for October 1981 was not submitted, primarily due to manpower requirements for preparation for ACRS full committee; however, it should be noted that the October submittal was scheduled to include responses to only 6'of the 36 action items (i.e.,
about 15 percent). Of these six items, information was submitted in August which provided three complete responses (items 2.1, 4.1 and 4.4) and one partial item involving substantive information.
Although MP&L had informal discussions on hydrogen with the NRC staff, formal questions, scheduled for November 6,1981, were transmitted by the NRC on October 28, 1981 followed by two additional sets transmitted on November 6, 1981 and November 19, 1981 respectively. Much of the material addressed in the above sets of questions had not been included in the earlier informal discussions.
On December 21, 1981, MP&L submitted letter AECM-81/505 which provided responses to all of the formal NRC questions (although some of the responses referred to material which had not been formally submitted at that_ time). This submittal also completed the responses to the outstanding MP&L action items.
It should be noted that this submittal was four working days late as regards the NRC requested date of December--15, 1981 for question responses, but that the MP&L commitment regarding action items was for submittal by the end of December.
Therefore, the December action items were submitted on schedule.
Also on December 21, 1981, MP&L met formally with members of the NRR staff to discuss the hydrogen control issue on GGNS. The NRC letter of January 12, 1982 indicates that it was learned at that meeting that certain information scheduled for submittal by December 15, 1981 would be delayed until mid-January, 1982. This is not completely accurate, in that, most of the information scheduled by MP&L for submittal in mid-January was on or ahead of schedule, or was supplementary information to responses already' submitted.
Due to NRC concern expressed over schedule at that meeting, the CLASIX-3 Containment Response Sensitivity Analysis nus provided informally to the NRC on December 22, 1981, to expedite your review. Since then, that document has been formally submitted (witht ut modification) by the Hydrogen Control Owners Group (HCOG) on January 15, 1982, and endorsed by MP&L on January 15, 1982 in letter AECM-82/24.
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March 10, 1982 AECM-82/31 MICISSIPPI POWER O LIIHT COMPANY Page 3 In addition, on January 13, 1982 MP&L informally submitted the report on equipment survivability during a Hydrogen Generation Event to further expedite the NRC review. Since then that document was formally submitted (without modification) on January 19, 1982, by letter AECM-82/26. Please note that the action itr a schedule was to provide a status report on equipment survivability in Jecember, 1981. This status report was provided at the December 21, 1981 meeting. The detailed final report was then provided less than one month later, substantially ahead of the schedule which MP&L had earlier discussed informally with the NRC.
On January 21, 1982, MP&L submitted letter AECM-82/32 which provided information on the ability of the GGNS containment to withstand postulated detonations. This supplemented our response to questions submitted on December 21, 1981 and provided the last of the information needed for an interim evaluation.
Hydrogen Control Owners Group We believe that a brief discussion of the HCOG is germane to the GGNS schedule.
During frequent informal meetings with NRR staff, it was made clear that the NRC would prefer to review BWR-6/ Mark III containment hydrogen control on a generic basis rather than several times (once for each applicant).
Indeed, questions on how the issue would be handled generically were directed to LRG-II (of which MP&L is not a member).
In recognition of the efficiency for MP&L of cost sharing on such issues and in response to NRC desires, MP&L was instrumental in the formation of the HCOG to deal with BWR-6/ Mark III containment hydrogen control issues.
Mr. John Richardson of MP&L is Chairman of the HCOG.
Furthermore, with the exception of certain limited studies being conducted by General Electric for the HC00, MP&L has funded in total all HCOG studies and activities to date to prevent administrative delays.
In at least one case (the formal submittal of the CLASIX-3 Containment Response Sensitivity Study), the delay (from December 22, 1981 to January 15, 1982) was to allow review by other HCOG members prior to submittal.
Overdue Information In the second paragraph of your January 12, 1982 letter, a list of overdue information is provided. We believe account should be taken of the following facts with regard to that information:
Overdue Information Remarks CLASIX-3 Sensitivity Studies Scheduled for December submittal. Were provided informally on December 22, 1981, and formally on January 15, 1982, as discussed in the Brief GGNS Chronology above.
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1 March 10, 1982 AECM-82/31-Ml=ISSIPPI POWER O LICHT COMPANY Page 4 Overdue Information Remarks i
Local Detonation Calculations Preliminary information submitted j
December 21, 1981 and the final report was provided on January 21, 1982 as i
discussed in_the Brief GGNS Chronology above.
Containment Mixing The responses to questions 4 and 12 in Sensitivity Studies and Attachment B to letter AECM-81/505 of Test Plan December 21, 1981 discuss containment mixing and related issues including one case of-the CLASIX-3 Containment Response Sensitivity Study submitted informally on December 22, 1981. This substantially completes the analytical work required to close the issue.
In regard to a " test plan" for containment mixing, MP&L has neither committed to nor been required by the NRC to conduct 1
such testing.
W'e recognize the issue and are, in fact, as discussed at the December 21, 1982 meeting with the NRC,.
considering the need for such tests, but no final decision has been made on the i
need for mixing tests.
(See remarks on next item also.)
Combustion Phenomena Testing At the request of the NRC, MP&L retained two respected consultants, Drs. Bernard' Lewis and Bela Karlovitz of Combustion-and Explosives Research, Inc. (COMBEX),
to evaluate ccabustion phenomena as they pertain to Mark III containment geometries, particularly with regard to the potential for transition to detonation. The COMBEX evaluation is I
complete and was used as the basis for response to combustion phenomena questions in the December 21, 1982 submittal. This information was covered by Section 5 of the August 8, 1981 status report, and, as noted above, only a schedule was to be provided in October.
Testing in the area of combustion phenomena was proposed in our response i
l to action item 9.1 in our letter of September 11, 1981, with the provision that COMBEX was being asked to review i
those recommendations and provide comments or concurrence.
In fact, i
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1
March 10, 1982 AECM-82/31 M12GISSIPPI POWER O L12HT CIMPANY Page 5 Overdue Information Remarks COMBEX endorsed those tests with certain comments and modifications. These tests are being delineated in more detail by EPRI/NSAC for the HCOG with the active participation of MP&L. Considerations are underway to include mixing tests in the test program. MP&L has provided a preliminary test program for the combustion phenomena testing in February although we believe that our action item commitment provides sufficient information for an NRC interim report.
The HCOG will be providing a submittal on the test program including mixing tests (if any) in March.
Equipment Survivability On August 18, 1981, MP&L submitted Analysis letter AECM-81/298 which indicated that a status of the Equipment Survivability Program would be reported to the NRC in December of 1981. The program status was reported in letter AECM-81/505, dated December 21, 1981 and the subject report was formally transmitted on January 19, 1982 (AECM-82/26) following an informal submittal on Janua ry 13, 1982.
Conclusion and Additional Remarks Based on the above, we offer the following concluding remarks:
1.
MP&L has provided substantial and detailed information to the NRC in a timely manner. The formal questions addressed to MP&L by the NRC were issued on October 28, 1981 or later and a response was provided on December 21,1981 in 50 days (and still less for the November 6 and November 19, 1981 NRC transmittals) from date of I
receipt.
2.
Although not discussed above, MP&L responded to the original NRC October 30, 1980 letter raising the hydrogen issue with a substantial program and suggested schedule on December 9,1980, in 35 days from date of receipt.
3.
MP&L responded to the NRC letter of February 3, 1981 requesting an expedited schedule with our substantial submittal of April 9, 1981 in 51 days from date of receipt.
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March 10, 1982 AECM-82/31 MIRISSIPPI POWER O LI2HT COMPANY Page 6 4.
With a time delay of 6\\ months from our April 9, 1981 submittal to the first formal NRC questions, MP&L developed its own version of
" appropriate regulatory issues" in the form of the 36 action items described above. Responses to more than half of these were provided in less than 30 days and to the remainder within another 90 days (during a time period when MP&L supported both ACRS subcommittee and full committee meetings).
5.
MP&L aggressively pursued numerous informal telephone calls and brief meetings with NRC staff members to reach agreement on how our program was proceeding in the interest of expediting licensing schedule.
6.
Finally, in accordance with NRC wishes, MP&L was instrumental in forming the HCOG to allow the NRC to more efficiently allocate its limited resources. This was a major effort involving the full and part-time efforts of three professional employees (including managerial and supervisory personnel) for a period of several months. MP&L has nevertheless, with the exception o' a one month delay between formal and informal submittal of a single document maintained a tight schedule for submittals.
Based on the above information, we believe it is clear that MP&L has acted expeditiously in the area of hydrogen control on GGNS and that the NRC should take all steps to expedite its internal review process to allow licensing to proceed without schedule impact as regards your originally scheduled date for issuance of a Supplemental Safety Evaluation Report.
Yourstruly,f k^
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lt@:1Li j
JPM:Im 1
Attachment cc:
Mr. N. L. Stampley (w/a)
Mr. G. B. Taylor (w/a)
Mr. R. B. McGehee (w/a)
Mr. T. B. Conner (w/a)
Mr. Richard C. DeYoung, Director (w/a)
Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 i
AE5Q6 I
ORIGINAL REVISED-RESPONSE PROVIDED SCHEDULE SCHEDULE (AECM-(AECM-LETTER NO.
ACTION ITEM 81/298) 81/336)
DATE NUMBER 1.0-Hydrogen Ignition System (HIS)
Description 1.1 Clarify igniter locations 9/81 9/11/81 9/11/81
- AECM-(centerline) 81/353 1.2 Provide a list of all compartments 9/81, 9/11/81 9/11/81 ** AECM-which have dual igniters 81/353 1.3 Igniter Identification:
9/81 9/11/81 9/11/81 ** AECM '
a) Vendor 81/353 b) Model c) Qualification Program d) Design Criteria 1.4 Discuss design adequacy of assembly 9/81 9/11/81 9/11/81 ** AECM-for pool swell, drywell negative 81/353 pressure transient, etc.
1.5-Discussion of the operation of the 9/81 9/11/81 9/11/81 ** AECM-HIS under moist wetwell environments.
81/353 1.6 Discuss the impingement of break 9/81
'9/11/81
-9/11/81
- AECM-spray (or of SRV discharge) on 81/353 igniters.
1.7 Evaltiate whether the sheet-flow 9/81 9/11/81 9/11/81 **.AECM-into the wetwell impinges on the 81/353 igniters directly.
1.8 Evaluate raising igniter surface 9/81 9/11/81 9/11/81 ** AECM-temperature 81/353 1.9 Evaluation of seven days opera-9/81 9/11/81 9/11/81 **. AECM-bility as a design basis 81/353 1.10 Provide a more detailed description' 9/81 9/11/81 9/11/81 ** AECM-of the HIS and its power supplies:
81/353 2.0 Hydrogen System (HIS) operation.
2.1 Discuss emergency procedures for HIS 10/81
_10/81 8/31/81 ** AECM-initiation prior to water level at 81/336 or below the " Top of Active Fuel" (TAF) and additional guidance to the operator to aid him in responding to situations where there is significant hydrogen' generation.
3.0 Hydrogen Igniter Testing & inspection 3.1 Evaluation of operation of igniter 9/81 9/11/81 9/11/81 ** AECM-during pool swell events and the 81/353 need for testing.
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1, t
ORIGINAL REVISED RESPONSE PROVIDED SCHEDULE SCHEDULE (AECM-(AECM-LETTER No.
ACTION ITEM 81/298) 81/336)
DATE NUMBER 3.2 Define an igniter selection program; 9/81 9/11/81 9/11/81 ** AECM-i.e., how will actual igniters to be 81/353 installed be selected?
3.3 Provide a detailed description of 9/81 9/11/81 9/11/81 ** AECM-the igniter test program'(including) 81/353 seven day operability and immersion testing.)
4.0 Accident Scenarios.
4.1 Provide a list of accident scenarios 10/81 10/81 8/31/81 ** AECM-considered in the design of the 81/336 Grand Gulf HIS.
12/21/81 ** AECM-81/505 4.2 Clarify or confirm ADS availability 10/81 10/81 12/21/81 ** AECM-and actuation:
81/505 a) Discuss emergency procedures b) Discuss TMI-related ADS modification c) Discuss depessurization times of ADS in relation to design scenario 4.3.
Discuss operation of the Containment 10/81 10/81 12/21/81 ** AECM-Spray System (CSS) and how ECCS 81/505 functions are effected by use of CSS.
i 4.4
. Provide a description of the scenario 10/81 10/81 8/31/81 ** AECM-used in the Gcand Gulf analysis, 81/336 including a description of the MARCH analysis.
4.5 Describe the operation of the Com-9/81 9/11/81 9/11/81 ** AECM-bustible Gas Control System (CGCS) revised 81/353 during burns (including a discussion 12/21/81 AECM-of the logic for the purge com-81/505 pressors and the vacuum breakers).
5.0 Hydrogen Behavior Schedule Schedule to be to be provided provided in 10/81 in 10/81 5.1 Discuss mixing in watwell, including 12/21/81 ** AECM-effects of barriers, if any, and local 81/505 releases.
5.2 Discuss the potential for and effects 12/21/81 ** AECM-of transition to detonation.
81/505 1
5.3 Discuss the likelihood and possible 12/21/81 ** AECM-consequences of hydrogen detonation 81/505 in the Grand Gulf containment.
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I ORIGINAL REVISED RESPONSE PROVIDED i-SCllEDULE SCl!EDULE (AECM-(AECM-LETTER
, No.
ACTION ITEM 81/298) 81/336)
DATE NUMBER 5.4 Evaluate hydrogen distribution and 12/21/81 ** AECM-mixing.
81/505 5.5 Provide plots of gas concentrations.
8/31/81 ** AECM-81/336 12/21/81 ** AECM-81/505 6.0 Containment Response.
6.1 Provide additional information on 9/81 9/11/81 9/11/81 ** AECM-containment cross-sectional flow area:
81/353 a) Overall b) Gratings, solid floor 6.2 Rennalyze~ the Drywell Break case 12/81 12/81 12/21/81 AECM-with the' integrated scenario.
81/505 6.3 Conduct sensitivity studies:
12/81 12/81 12/21/81 ** AECM-a) Burn Tarameters, varying:
81/505 1.
Flame Speed 2.
Burn Fraction 3.
Propagation Criteria 4.
Ignition Point b)
Spray Paraneters, varying:
1.
Number of trains 2.
Amount of spray into wetwell c) Heat Sink Parameters, varying:
1.
Convective heat transfer 2.
Beam length d) Convective flow, evaluation:
1.
Flow between Wetwell and Containment e) Gas properties, varying:
1.
Cp during one burn, t.nd 2.
Cv during one burn C9rg3
ORIGINAL REVISED RESPONSE PROVIDED SCHEDULE SCHEDULE (AECM-(AECM-LETTER No.
ACTION ITEM 81/298) 81/336)
DATE NUMBER 6.4 Provide verification of CLASIX-3.
12/81 12/81 12/21/81
6.5 Provide further discussion on the 12/81 12/81 12/21/81 ** AECM-burn parameters.
81/505 6.6 Provide a discussion of how oxygen 12/81 12/81 8/31/81 ** AECM-in the wetwell is replaced.
81/336 6.7 Discuss flame speeds used in the 12/81 12/81 12/21/81 ** AECM-analysis.
81/505 7.0 Containment Ultimate Capacity 7.1 Provide further information on 9/81 9/11/81 l'.'/23 /81 ** AECM-strengthening upper containment 81/414 personnel airlock.
8.0 Equipment Survivability (Note 1) 8.1 Provide a description of the Grand 9/81 9/11/81 9/11/81
- AECM-Gulf equipment survivability program.
81/353 8.2 Provide the status of the equipment 12/81 12/81 12/21/81 ** AECM-survivability program.
81/505 9.0 Testing Program 9.1 Review other testing programs and 9/81 9/11/81 9/11/81 ** AECM-recommend a testing program to 81/353 support Grand Gulf in those areas where currently complete or "in progress" tests are not adequate.
10.0 Other Concerns 10.1 Evaluate the possibility and effects 9/81 9/11/81 9/11/81
- AECM-of secondary fires.
81/353 NOTES:
1.
The Equipment Survivability Report was submitted on January 19, 1982 (AECM-82/26).
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