ML19274F846
| ML19274F846 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/16/1979 |
| From: | Ross D NRC - TMI-2 UNRESOLVED SAFETY ISSUES TASK FORCE |
| To: | Richardson ARKANSAS, UNIV. OF, FAYETTEVILLE, AR |
| References | |
| NUDOCS 7908160157 | |
| Download: ML19274F846 (2) | |
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JUL 1 G 1979 Docket No. 50-313 Professor C. B. Richardson Department of Physics 104 Physics Building University of Arkansas Fayetteville, Arkansas 72701
Dear Professor Rich.dson:
The purpose of cnis letter is to supples < :t our recent telephone conversation with respect to your letter to Mr. H. R. Denton, dated June 6,1979. Your letter expressed concern about the design of the drain line from the Arkansas Nuclear One, Unit 1 (ANO-1) reactor building sump to the reactor auxiliary building sump. As you ',ciow, this is a gravity flow line contain-ing two normally closed isolation Valves. The line does not use a pump and requires the manual opening of the' isolation valves to initiate flow from the reactor building to the auxiliary building.
Your belief that a more positive method for precluding an inadvertant transfer of radioactive fluid is needed for safety will be factored into our on-going reviews, as well as your suggestion to utilize a system in which the water is pumped from the reactor building to the auxiliary build-ing, via an outlet at a higher level than the level of water in t!.e reactor.
building sump.
The NRC staff is presently in the process of evaluating Arkansas Power &
L1ght Company's (AP5L) responses to all of the items in IE Bulletins 79-05 (April 1,1979),79-05A (April 5,1979) and 79-058 (April 21,1979). We expect our evaluttien of these matters in late July of this year.
As noted above, we will certainly factor your corrnents and recomendations into our review.
I have added your name to the distribution list for receiving a copy of our Safety Evaluation of AP&L's responses to these Bulletins.
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Professor C. B. Richardson JUL 161979 We appreciate your interest in this matter.
If I can be of further assistance, please contact me.
Sincerely,
&b Denwood F. Ross Director Bulletin & Order Task Force Division of Project Management
oEPARTMENT oF PHYSICS 104 Physics Building Fayetteville, Arkansas 72701 (501) 575-2506 UNIVERSITY OF ARKANSAS College of Arts and Sciences June 6, 1979 Mr. Harold R. Denton Director, Office of Nuclear Reactor Regulation Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Marylapd 20555 s
Dear Mr. Denton; I am a member of a Task Force appointed by the Governor of Arkansas, the Honorable Bill Clinton, to study the accident at Three Mile Island and to consider its consequences to the state because of the operation of Arkansas Nuclear One, Unit One, a reactor of similar design.
The purpose of this letter is to request that special 1
attention and review be given to the response of the licensee, Arkansas Power and Light Company, to item 6 in IE Bulletin 79-05 j
dated April 1,1979:
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" Review your operating modes and procedures for all systems designed to transfer potentially radioactive gases and liquids out of the containment to assure undesired pumping of radioactive liquids and gases will not occur inadvertently."
On April ll, Mr. David C. Trimble, AP&L responded: "The drain line from the ANO-1 Reactor Building Sump to the Reactor Auxiliary Building Sump is a normally closed gravity ficw line which does not use a pump and requires manual operation to transfer liquids." He explains that there are two valves on the line receiving safety-grade power and a Reactor Building Isolation signal.
In a letter of April 16, Mr. Trimble explains that not later than the next fuel outage, these valves will be provided with signals to isolate on icw RCS pressure.
Finally Mr. Trimble states that " procedure modifications will be made to verify termination of any manual draining operation in the avent of an accident."
My concern with this drain design is caused by the feature " gravity flow." The containment building is, of course, the last line of defense against exposure of the public to radiation.
It would seem to me that this defense would be much stronger if the gravity flow line were not present. A drain line with outlet above the level of water in the sump in the worst case and fitted with the two valves with all tne safety features now present and to-be-fitted at ANO-1 g(
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Mr. Harold R. Denton Page 2 June 6,1979 would appear to be much safer. The necessity of lifting the water c.*
of the sump would make it much less likely that a transfer happen inadvertently. Of course, the pump to do this must not. be started au tomatically.
I recuest that the staff give special attention to the design of the sunip drain at ANO-1 with consideration given to changes for improved safety.
Sincerely yours, 0
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C. B. Richardson, Professor CBR/bkd cc: Mr. David C. Trimble, AP&L
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