ML19350C768
| ML19350C768 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/30/1981 |
| From: | Trimble D ARKANSAS POWER & LIGHT CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| 2R-0281-19, 2R-281-19, NUDOCS 8104060676 | |
| Download: ML19350C768 (3) | |
Text
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ARKANSAS POWER & LIGHT COMPANY POST CFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 [501)371-4000 March 30, 1981
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.%' N kid @mt Director of Nuclear Reactor Regulation
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/d ATTN:
Robert A. Clark, Chief Operating Reactors Branch #3
'S v7 Division of Licensing y ( e U. S. Nuclear Regulatory Comm.
Washington, D.C.
20555
SUBJECT:
Arkansas Nuclear One - Unit 2 Docket No. 50-368 License No. NPF-6 Low Temperature Overpressurization (File: 2-1510)
Gentlemen:
In response to your attached telexed questions on the ANO-2 Low Temperature Overpressurization (LTOP) modifications, the following is provided.
QUESTION 1 Bench test with hydroset once per refueling in accordance with ASME Section XI.
QUESTION 2 The representation shown is correct except that an alarm will be generated if any valve is not fully closed above 2700F.
By the same token, if any valve is not fully open below 2600F then an alarm will also be generated.
QUESTION 3 Setpoint of LTOP relief valves is 430 psig.
QUESTION 4_
LTOP offers protection during critical as well as non-critical operation. From ANO-2 Tech Spec Figure 3.4-2, the temperature limits for the alarm logic correspond to the furthermost right hand temperature / pressure curve (f.e., critical operation at low temperatures). Administrative controls are not applicable in any situation below 2600F which w uld disable LTOP except as noted below.
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Mr. Robert A. Clark March 30, 1981 QUESTI0tl 5 Following modifications to the Reactor Coolant System, LTOP may be defeated and replaced by administrative controls in order to perform system hydro.
Very truly yours, obwe.Ll/L David C. Trimble Manager, Licensing DCT:Pf4C:JTE:1p Attachment
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_, _.: X ENCLOSURE 1 i
REQ' JEST FOR ADDIT:0hAL INF0FRATION ON THE ANO 2 LTO?
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O(E' PIP IESSUP.E PROYECTION SYSTEM L~
Ql.
Describe the testing procedcre and testing schedule for trie setpoint relief valves and the isolation valve alarm system.
Q2 There is some disagreement between the description of the temperature D
dependent enable / disable logic for LTOP in the October ll,1977;and the December 1,1980 letters.
From our phone conversations it appears that the as-built LTOP logic is as follows:
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Valves Open - Alarm hf Ei Yalves Closed No Alarm 270 -- -
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Yalves Oper. - No Alarm Valves Closed - Ne Alarm 250 Valves Open - Jto Alarm
. Valves Closed f Alarm Is this correct?
s-Q3.
What is the pressure setpoint for LTOP7 Q4.
Is LTOP supposed to offer protection for non-critical operation only?
In particular, are you deper. dent completely on adm.inistrative control to assure that the reactor is non-critical below 260 Degrees Fahrenheit, so that LTOP'is
.j not a necessary protective function during critical operation?
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Q5.
Are there any codes of operation in which the LTOP alarms will be
.t; administratively defeated?.
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