ML20008F978
| ML20008F978 | |
| Person / Time | |
|---|---|
| Site: | Allens Creek File:Houston Lighting and Power Company icon.png |
| Issue date: | 05/11/1981 |
| From: | Jun Lee Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20008F949 | List: |
| References | |
| NUDOCS 8105120429 | |
| Download: ML20008F978 (7) | |
Text
i 05/11/81 g
. lied STATES 0F A!; ERICA s
f:U: LEG TEGULATOTY C0;;;;ISSION BEFORE THE AT0".IC SAFETY /SD LICE!!SI?:G ECARD In the Matter of
)
)
HOUSTON LIGHTING A';D PO'.?ER
)
Docket No. 50-466 C0!;PANY
)
)
(Allens Creek 1:uclear Generating
)
Station, Unit No.1)
)
NRC STAFF TESTIMONY OF JAY Y. LEE REGARDING CHARC0AL AD50RBER FIRES (TexPirg Contention 30) and (McCorkle Contention 17)
Q.1.
Please state your name and position with the NRC.
A.1.
My name is Jay Y. Lee.
I am a senior nuclear engineer with the U. S.
Nuclear Regulatory Commission assigned to the Effluent Treatment Systems Branch, Division of Systems Integration, Office of Nuclear Reactor Regulation.
Q.2.
Have you prepared a statement of professional qualifications?
A.2.
Yes. A copy of this statement is attached to this testimony.
Q.3.
What issues are you addressing in this testimony?
A.3.
I am addressing TexPirg Contention 30 and McCorkle Contention 17.
TexPirg Contention 30 states, " Applicant's decision not to use water sprays to maintain the charcoal adsorber material below ignition tem-perature is an unwise shortcut on the safety of petitioner's member's 8105120Q
t health and economic interests.
A fire in these filters folic. ing a DBA would result in release of radioactive iodine and other dangerous sub-stances. No reason is given for removing a system recommended by a Regulatory Guide, nor is there likely to be any way to enter tre con-tainment building and spray these filters following a Design Basis Accident or unexpected accident. Other accidents do occur, such as Browns Ferry,1975, and the retention of this system offers protec-tion against fire, a conceivable situation around a power plant because of high temperatures in various places of the operation continually or randomly".
McCorkle Contention 17, which is related to TexPirg Contention 30, states, "Also, the filter adsorber may start a fire by' auto-ignition, yet there is no water spray to prevent such auto-ignition as required by NRC Regulatory Guide 1.52".
Q.4.
In what systems at AC'4GS does the applicant utilize chcrcoal adsorbers?
Explain briefly the main function of those systems that utilize charcoal adsorbers.
A.4.
The charcoal adsorbers will be utilized in the Off-Gas Processing System, the ECCS Area Filtered Exhaust System ( AFES), the Standby Gas Treatment System (SGTS), and the Control Room Emergency Filtration System (CREFS) at ACNGS. The Off-Gas Processing System processes air and non-condensible gases drawn from the main condenser by a steam air ejector.
The system utilizes four (4) charcoal adsorber tanks operating at a r-
4
-?-
y constant temperature of 40 F cooled by a glycol ps cooler. This system is not an Engineered-Safety 4 esture (ESF) At:aosphere Cleanup system and therefore, Regulatory Guide 1.52 is not applicable. The system meets, however, the IJRC Effluent Treatrent Syste's Branch Tech-nical Position 11-1, Rev.1, criteria for seismic design and quality group classification.
On the other hand, the ECCS-AFES, the SGTS, and the CREFS are classified as ESF Atmosphere Cleanup Systems ai, ' 3re designed to control the re-leases of radioactive materials in gaseous effluents following a design basis accident (DBA). These systems therefore, must conform to Regula-tory Guide 1.52 or an acceptable alternative.
Q.5.
Will the charcoal adsorbers in these ESF Atmosphere Cleanup Systems be in conformance with Regulatory Guide 1.52?
A.5.
Yes. These ESF Atmosphere Cleanup Systems, including the charcoal adsorbers, will be designed in accordance with the guidelines of Regulatory Guide 1.52.
Q.6.
What method does the applicant propose to cool the charcoal adsorbers following a DBA? Explain why the method proposed by the applicant would prevent the release of iodine into the environment in the case of a fire in the charcoal adsorber.
A.6.
The applicant proposed a system design which includes provisions for preventing adsorber fire by ensuring continued cooling of charcoal adsorbers in the ESF Atmosphere Cleanup Systems by low-flow air bleed.
This is accomplished by providing cross connections bet > e'en redundant air bleed fans and the'ESF filter trains.
1 c-This cccling rethod proposed by the cpolicant is n t designed to ex-tinguish a fire but to prevent temperature rise in the charcoal adsorters due to radioactivity-induced decay heat. Therefore, the probability of combustion occuring in a charcoal adsorber is very renate.
Subsequent to the NRC safety evaluation on these systems, the applicant proposed to add a manually initiated water spray system (non-safety class) to the ESF Atmosphere Cleanup System charcoal adsorbers even though the proposed low-flow air bleed system conforms to Regulatory Guide 1.52 without this additional water spray system.
Q.7.
What is the normal operating temperature of the charcoal adsorbers?
A.7.
The normal operating temperature of the charcal adsorbers in the ESF Atmospheric Cleanup Systems is expected to be ambient temperature (77 F to 130 F). The normal operating temperature of the charcoal adsorbers in the Off-Gas Processing System is maintained at 40 F by a glycol gas cooler.
Q.8.
How does the applicant propose to monitor temperature rise in the charcoal adsorbers?
1.8.
Charcoal adsorber temperature with redundant sensors will be indicated and recorded in the control room for the ESF Atmosphere Cleanup System.'
Also, temperature indicators will be provided locally at the inlet of the ESF chdecoal adsorbers.
-5 Q.9.
What is the ig.iition tenperature of charcoal?
A.9.
The potassium iodide impregnated carbons with a minim;. ignition temperature of 350 C (688 F) will be utilized at ACNGS.
0.10.
1: hat temperatures can be expected during the type of accident that can cause the maximum temperatures in the charcoal?
A.10.
The maximum temperature of influent air to the E5F Atmosphere Cleanup Systems resulting from a postulated design basis accident is estimated to be 180 F (Table 1 of Regulatory Guide 1.52).
Q.11. How do you compare the applicant's proposed low-flow air bleed cooling system to a water spray system that are utilized for some other nuclear power plants?
A.11.
Both methods are acceptable to the NRC staff as described in Regulatory Guide 1.52.
In my opinion however, a low-flow air bleed cooling system is the preferred method over a water spray system since the air cooling system is designed to prevent a fire in the charcoal beds while the water spray system is designed to extinguish a fire mitigating its ef fect. Water spray systems also can inadvertently actuate and possibly degrade the charcoal to the point that it needs replacement.
Q.12.
Is there any relevancy between the Browns Ferry charcoal adsorber temperature excursion incident in 1977 and the auto-ignition of char- -
coal adsorbers due to radioactivity, induced decay heat?
A.12.
No. The Browns Ferry incident was caused by combustible mixture of hydrogen and oxygen downstream from the recombiners in the Off-Gas
O 1
[.
Processing System and sustained ccu'austian in t0:2 cf t :. c' a rcor.1 adsorbers. None of ESF Atmosphere Cleanup Systers were af fectai cnd the event was not' caused by radioactivity-induced d2 cay heat.
Q.13. Assuming that the low-flow air bleed ccoling system is effective at preventing auto-ignition of the charcoal. is it reasonable to postulate another ignition source such as that er.perienced at Breuns Ferry?
A.13.
There are no postulational ignition sources in the ESF Atrasphere Cleanup Systems. We can not postulate any other likely ige.ition sources in the Off-Gas Processing System other than that experienced at Browns Ferry.
Q.14. Were there any radioactive effluents released as a result of the Browns Ferry incident?
f A.14.
No. There was no notable increase in stack gas radioactivity at any time during or following the incident.
a 4
Jay Y. Lee Effluent Treataant Systens Bran:h Division of Systems Integratien Of fice of 'Juclear Reactor Regulation
!!y name is Jay Y. Lee.
I am a senior nuclear engineer in the Effluent Treat-cant Systems Branch in the Of fice of Nuclear Reactor Regulation.
In this position I am responsible for technical review, analyses, and evaluations of reactor plant systems and equipment for fission product renoval and treatment of radioactive wcstes, as to the adcquacy of provisions in reeting the applic-able regulations.
Froa April 1979 to March 1981, I was detailed and subsequently assigned to the TMI Technical Support of the TMI Program Office at the Three :lile Island
!!uclear Station and at the NRC Bethesda Office. In this position I performed technical reviews, analyses, and evaluations of the recovery operations for TMI-2, the restart programs for TMI-1, and the TMI-2 Reactor Containment Building entrance program.
I received a Bachelor of Science degree in Cheniical Engineering from the University of Minnesota in 1962 and a Master of Science degree in Nuclear Engineering from the Catholic University of America.
My professional experience totals approximately 18 years of design, construc-tion, start-up, operation, and licensing of central station n/ clear power plants.
From 1962 to 1966 I was employed as the plant chemical engineer by Northern States Power Company at Pathfinder Atomic Power Plant (decommissioned).
In this position, I was responsible for operation and maintenance of radwaste treatment systems and for the implementation of the occupational health and effluent and environmental monitoring programs.
From 1966 to 1969, I was a nuclear systems engineer with Bechtel Corporation at San Francisco.
In this position, I was responsible for technical review of the design and construction of reactor plant systems of central station nuclear power plants.
From 1969 to 1974, I was employed as the senior chemical engineer by Sacramento Municipal Utility District at Rancho Seco Nuclear Generating Station.
In this position, I was responsible for design reviews, construction and start-up operation of the radwaste treatment systems and the plant secondary system.
In 1974, I accepted the position of senior nuclear engineer with the United States Nuclear Regulatory Commission.
,