ML17319B546

Forwards Request for Addl Info Re Hydrogen Control Issues for Ice Condenser Plants.Response Requested by 821015

ML17319B546
Person / Time
Site:	Cook
Issue date:	09/16/1982
From:	Varga S Office of Nuclear Reactor Regulation
To:	Dolan J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
References
NUDOCS 8210040428
Download: ML17319B546 (12)

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$982 Docket Nos.

50-315 and 50-316 ter. John Dolan, Vice President Indiana and Michigan Electric Company Post Office Box 18 Bowling Green Station New York, New York 10004

Dear t1r. Dolan:

DISTRIBUIl Docket File, NRC PDR Local PDR ORB 1 File D. Eisenhut OELD OI8E (1)

R. Cilimberg C. Parrish NSIC ACRS (10)

J.

Heltemes C. Stahle We have identified more items for which additional information is required on hydrogen control issues for ice condenser plants.

We need the information delineated in the enclosure to this letter to support our review.

Please respond to this request by October 15, 1982.

The reporting requirements contained in this letter affect fewer than ten respondents, therefore, OtS clearance is not required under P.l.96-511.

Sincerely, pgfginal s ignore by:

p, A. Varga

Enclosure:

Request f'r Additional Information cc w/enclosure:

See next page Steven A. Varga, Chief Operating Reactors Branch No.

1 Division of Licensing ORB 1

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FlCIAL RECORD COPY USGPO: 1981~9.960

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Mr. John Dolan Indiana and Michigan Electric Company cc:

Mr. Robert M. Jurgensen Chief Nuclear Engineer American Electric Power Service Corporation 2 Br oadway New York, New York 10004 Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.M-Mashington, D. C.

20036 Maude Preston Palenske Memorial Library 500 Market Street St. Joseph, Michigan 49085 M. G. Smith, Jr., Plant Manager Donald C. Cook Nuclear Plant P. 0.

Box 458 Bridgman, Michigan 49106 U. S. Nuclear Regulatory Commission Resident Inspectors Office 7700 Red Arrow Highway Stevensville, Michigan 49127 Milliam J. Scanlon, Esquire 2034 Pauline Boulevard Ann Arbor, Michigan 48103 The Honorable Tom Corcoran United States House of Representatives Mashington, D. C.

20515 James G. Keppler Regional Administrator - Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

ENCLOSURE REQUEST FOR ADDITIONAL INFO$1ATION ON HYDROGEN CONTROL FOR ICE CONDENSER PLANTS A substantial number of laboratory tests were conducted as part of the ICOG/EPRI R 5 D Program for hydrogen Control and Combustion.

Test re-suits were transmitted from the utilities to NRC as they became available; however, for several of the research

programs, only selected test results were reported and organized compilations of all pertinent test information were not provided.

This information,. is required to confirm the adequacy of the test program and assuriytion-made in the containment analyses.

In this regard provide the following:

a)

ACUREX i) a table of droplet size and droplet density estimates for each of the fog/spray tests; ii) a table of estimated flame speed for each test (flame speed should be calculable from thermocouple locations and ignition time data);

and

. iii) pressure and temperature traces similar to those depicted in Figures 4-2 of the December 1981 ACUREX Project Report, but for tests 2.10, 2.11, and 2.12;

. b)

FACTORY MUTUAL results of ignition tests in which a glow plug was used in place of the ignition electrodes; c )

MkITESHELL tables summarizing pre-and post-burn conditions, igniter locations, maximum measured pressure rise, adiabatic pressure

rise, completeness of burn, and estimated flame speed.

These tables should be keyed to and cover all of the tests committed to

.n the test matrix (tables

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4 in Appendix A.l of the fourth quarterly report on the TVA research program; June 16, 1981) plus any additional AECL tests conducted under this program.

Of particular interest to the staff are the results of the 8.5$

H2 test with 30% H20: and top ignition.

Discuss'our plans 'for conducting tests at steam con-centrations above 30%,

as committed to in previous quarterly re-ports; d)

HEDL

, figures depicting concentration gradients for eaoh of the tests.

Figures provided should permit better resolution than those in-eluded in. the pr evious submittal.

2.

The majority of the ICOG/EPRI tests which serve to demonstrate the validity-of the deliberate ignition concept utilized a

GMAC glow plug as the ignitioo W

sour'ce.

TYA currently intends to install 120 Y TAYCO ignitors in the Per-manent Hydrogen Mitigation System instead of the glow plugs.

Although ig-nitor durability tests have been completed by Singleton, additional'testing

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of the 120 V ignitor is requ'ired to show that it is an acceptable replace-ment for the GMAC ignitor.. Specifically, a }

tests should be conducted to ensure that the ignitor will continue to operate as intended in a spray atmosphere typical of that which would be expected in each region of containment where ignitors are to be located; b}

endu'rance tests should be conducted on a suitable sample size to assure

. adequacy and consistency of.ignitor surface temperature and lifetime.

3.

For the 120 V ignitor system, describe the following:

a )

performance characteristics of the ignitors including surface temperature as a function of vol.tage and age;

b) a comparison of surface

area, power density, and other relevant parameters for the original and currently proposed 'igniters; c) igniter mounting provisions d )

proposed preoperational and surveillance testing.

If surveillance testing will be based on comparisons of'measured voltage/current to preoperational

values, specify the range for acceptance; e) power distribution system for the igniters, in particular,

.the lo-cation of the breakers in the system and the number of igniters on a breaker.

4)

Provide details regarding the number and location of permanent igniters in containment.

Discuss the influence of considerations such as volume served per igniter, and preferred flame direction on the design of the permanent system.

5)

Recent tests conducted at HcGill indicate that flame accelerations ac-companied by large pressure increases, and detonations can occur a. hydrogen N

concentrations as low as 13%.

Although remote, the possibility of flame accelerations and local detonations occuring around obstacles and in confined regions of containment cannot be entirely dismissed.

Further analysis of the probability and consequences of these events are thus warranted.

In this re-gard:

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Discuss the chain of events and conditions required to cause flame accelera-tions and detonations in containment, and the probability that such condi-tions might exist.

Identify the locations in containment at which flame accel eration/detonation woul d most

.1 ikely occur.

'b)

Provide quantitative estimates of the extent and magnitude of flame

acceleration in containment and the resulting pressure increase and loads on structures and equipment.

c)

Provide the results of a calculation (pressure versus time curve) for the largest conceivable local detonation which could occur in your con-tainment.

Demonstrate.that the effects of such a detonation could be safetly accommodated by structures and essential equipment.

Also, pro-vide an estimate of the limiting size of a cloud of detonable gas with regard to the structural capability of the containment shell.

6)

The analysis provided to date concerning the survivability of air return fans arid hydrogen skimmer fans neglects any fan overspeed or moto'ring which occurs as a.result of postulated hydrogen combustion in the upper plenum and upper

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compartment..

Describe how the fans will react to the differential pressure associated with hydrogen combustion, and justify the assumptions concerning fan.overspeed.

Describe the effects of combustion, in the lower compartment e.g.,

fan stalling.

7)

With regard to the equipment survivability analysis, the level of conservatism implicit in the temperature forcing functions';developed for the lower contain-ment and the upper plenum is not apparent and quantifiable.

Additional analyses should be conducted to provide a baseline or "best estimate" of equipment re-

sponse, and to ensure that temperature curves assumed in the analyses embody all. uncertainties in the accident sequence and combustion parameters.

Accordingly, provide analyses.of equipment temperature response to:

1) th'e base case transient assumed in the containment analyses, 2) the containment transients resulting from a spectrum of accident scenarios;

,, and 3) the'containment transients resulting under different assumed values for

flame speed and ignition criteria for the worst case accident sequence.

The range of these combustion parameters.

assumed for the equipment surviva-bility analyses should include but not necessarily be limited to the values assumed in the containment sensitivity studies, i.e.,

1 - 12. ft/sec'flame speed and 6 - 10$ hydrogen for igni.tion.

8)

For the survivability.

analysis, it is our understanding that the current thermal model assumes radiation from the flame to the object only during a burn, with convection occurring at all times outside the burn period.

In an actual

burn, radi'ation from the cloud of hot gases following the flame front can. account for a substantial portion of the total heat transfer to the object.

An addi-tional heat flux term or a combined radiation-convection heat transfer coeffi-cient should be used to account, for this radiant heat source.

In 'this regard, clari'fy the treatment of heat transfer following the burn and justify the ap-proach'aken.

9)

HEDL containment mixing tests conducted as part of the ICOG/EPRI R 5 D program indicate that spatial hydrogen concentratio'n gradients of as much as 2 to 7X can be expected to exist within containment at a given time.

If such a gradient were to exist within the volume of ahydrogen cloud in which combustion has just been initiated, the volume-average hydrogen concentration for the 'cloud can conceivably be significantly higher than the hydrogen concentration at the point of ignition.

In light of this, discuss the influence of hydrogen con-centration gradients on the concentration requirement for ignition that is in-put to CLASIX, and justify the ignition concentration value used in the CLASIX containment analyses.

10)

Describe in detail the fog formation study cited in response to question.9 of the July 21, 1981 Request for Information.. )nclude in this description the analytical development of the models for fog formation.,and removal; methods

for solution, assumptions,

and input parameters.'rovide plots of fog concentration and size as a function of time assuming various spray re-moval efficiencies, and mean droplet diameters.

11)

Describe in detail the analyses of fog effects on hydrogen combustion cited in response to q0estion 9 of'the July 21, 1981 Request for In-formation.

Include in this description the analytical development of the combustion kinetics and heat transfer models, and quantitative com-parisons between the theoretical results and data obtained from the Factory

- hutual Tests.

Provide plots of fog droplet size and concentrations re-quired to inert at various hydrogen concentrations under typical post-LOCA; conta inment condi tions.

12)

In the CLASIX spray model it is not clear whether the mass of spray treated in a time increment is assumed to be only that amount. of spray.

mass which is introduced in a single time step,'r the mass of droplet accumulated in the atmosphere over the fall time period.

- Clarify the spray

'ass accounting used in CLASIX and the mass of spray treated in'a single C

time step.

Discuss the significance.of any errors introduced bP the ap-parent assumtion that only one time increment of "spraymass is exposed to the containment atmosphere during a single time step.

'3)

CLASIX spray model analyses provided to date have been limited to the com-

'arison of pressure, temperature, and integrated heat removal for the pur-pose of evaluating the effect of the spray operating in a separate time do-maip.

Additional information is needed, however, to confirm the adequacy of the heat and mass transfer relationships and assu6ptions implicit in the.

CLASIX spray model:, especially in treating a compartment in which hydrogen combustion is taking place.

In this regard:

a) provide a quantitative description of the spray heat and mass transfer under containment conditions typical of a.hydrogen burn.

Include in your response plots of containment temperature, spray heat transfer, spray mass eva'poration, and suspended water mass as a function of time for both the CLASIX spray model and a model in which the spray mass is tracked throughout the fall (and allowed to accumulate in the contain-ment atmosphere).

b)

Provide analyses of spray. mass evaporation and pressure suppressi'on effects for an upper compartment burn.

c )

Justify the drop film coefficient value assumed in the spray model analyses (20 Btu/h ft 'F) and discuss the effect of using a constant value through-out a

burn transient.

14)

Concerning the CLASIX containment response analyses:

a )

Justify the bern time and burn propagation delay times used (reported burn times for Sequoyah and Mc'Guire differ by a factor of 2 to 3);

b)

Justify the radiant heat transfer beam lengths used (a

beam length of 59 ft. for the lower compartment in Sequoyah seems high - 20'o 30 ft.

may be more appropriate);

. c )

The base case and majority of SpD sensitivity studies assume that com-bustion occurs at an8% hydrogen concentration with an 85% completeness of burn.

Available combustion data for hydrogen/dry air mixtures.indicate that lean mixtures of approximately 8i, H2 and below are prevented from reacting completely and adiabatically due to buoyancy, diffusion and heat

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.loss effects.

Only as hydrogen concentration is increased to about 8.5%

will the reaction begin to approach adiabaticity.

Mhile arguments for an 8/ ignition concentration may be valid, provide the results of additional

CLASIX analyses to indicate the effect of an increase in ignition con-centration from 8% to S.5-9%.

d) provide the results of CLASIX analyses for flame speeds of 10 and 100 times the present value; e)

To assess the effect of igniter system failure or ineffectiveness, pro-vide the results of sensitivity studies in which the lower and dead-ended compartments are effectively inerted, and the upper plenum igniters burn with low efficiency or not at all.

Assume combustion in the upper compart-ment at 9-10Ã hydrogen.

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