ML20245D878
| ML20245D878 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry, Brunswick, 05000000 |
| Issue date: | 08/08/1988 |
| From: | Murley T Office of Nuclear Reactor Regulation |
| To: | Grace D BWR OWNERS GROUP, GENERAL PUBLIC UTILITIES CORP. |
| Shared Package | |
| ML20245D855 | List: |
| References | |
| NUDOCS 8905010209 | |
| Download: ML20245D878 (1) | |
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AUG 0 81988 Mr. Donald N. Grace, Chaiman 8WR Owner's Group J
c/o GPU Nuclear
~1 Upper Pond Road Building E Parsippany, NJ 07054
Dear Mr. Grace:
SU8 JECT:
DIVERSITY REQUIREMENT OF ATWS RULE (10 CFR 50.62) l The purpose of. this letter is to respond to your letter dated June 28, 1988 relating to the Carolina Power & Light Company's appeal of the staff position -
l on Brunswick ARI/RPT system instrument diversity requirement.
Paragaph 3 of the ATWS rule requires each' boiling water reactor to have an ARI system that is diverse (from the reactor trip system) from sensor output to the final actuation device. The staff concludes that the Brunswick ARI design is not in~
conformance with the ATWS rule.
The pressure and level portions of both the reactor trip system and ARI system, while some. functional diversity exists, use identical-components and are not sufficiently diverse.
The diversity required by the ATWS rule is intended to ensure that coninon mode,
failures which disable the electrical portion of the existing reactor trip system will not affect the capability of the ARI system to perfom its design functions.
It is recognized that total component / hardware diversity can be difficult to achieve, however licensees are encouraged to provide a maximum effort to satisfy the diversity requirements. A copy of my response to Carolina Power & Light Company's appeal on this issue is attached for your infomation.
Sincerely, oric...a1 -1.:o !. M1 rhen 1...: 1 c,-
Thomas E. Murley, Director Office of Nuclear Reactor Regulation
Enclosure:
As stated I
cc:
L. W. Eury, CP&L 8905010209 890 59 PDR ADOCK O pg P
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