ML17179A540
| ML17179A540 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Davis Besse  |
| Issue date: | 10/27/1992 |
| From: | Miller H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Zwolinski J Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17179A539 | List: |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 NUDOCS 9211030101 | |
| Download: ML17179A540 (3) | |
Text
,.
MEMORANDUM FOR:
FROM:
SUBJECT:
OCi 2 7 1992 John A. Zwolinski, Assistant Director for Region III Reactors Division of Reactor Projects - IIl/IV/V Office of Nuclear Reactor Regulation (NRR)
Hubert J. Miller, Director Division of Reactor Safety, Region III REQUEST FOR TECHNICAL ASSISTANCE INTERPRETATION AND RESOLUTION OF
- REGULATORY GUIDE (RG) 1.97 AT DAVIS-BESSE, DOCKET NUMBER 50-346 (AUS # *92-0635)
ENCLOSURE 1 D~termi ne. if the licensee complies with RG 1. 97, Revision 3 for steam generator pressure instrumentation, the reclassification of a Category 1, Type A variable, and the method of control room instrument identification.
Three unresolved items remain open.
Unresolved item 346/88038-02{DRSl:
Interpret and resolve redundancy issue concerning RG 1.97, Table 1, paragraph 2.
The licensee's interpretation of RG. 1.97 was that redundancy was only required for steam generator level instrument channels and not for steam generator pressure.
Steam generator pressure transmitters, PT-SP12Bl and PT-SP12A2, for steam generators 1-1 and 1-2, respectively, were identified (RG 1.97 submittal dated June 28, 1984), as Category 1, Type A, with no other steam generator pressure instruments identified that meet Category 1 requirements.
The licensee stated that steam generator 1-1 and steam generator 1-2 outlet pressure indications are redundant to each other and that only one steam generator is required to establish and maintain the plant in a safe shutdown condition under most accident scenarios.
The licensee's position concerning this issue is documented in their letter (serial number 1738) dated March 19, 1990.
Discussions with the licensee and NRR/SICB indicated that ambiguities exist within RG.1.97, such that, what is stated (apparently as in this case) is not necessarily what is actually intended.
For example, the last sentence in paragraph 2 states, "... Within each redundant division of a safety system, redundant monitoring channels are not needed except for steam generator level instrumentation in two-loop plants." This appears to be in contradiction to a previous statement in the paragraph, which states, "This may be accomplished by providing additional independent channels of information of the same variable (addition of an identical channel).... "
The Region's position is that redundant Category 1 instrumentation is required for steam generator 9211030101 921027 PDR ADOCK 05000237 P
J. A. Zwolinski 2
OCT 2 7 1992 pressure instrumentation. However, based upon the licensee' position and discussions with NRR/SICB, further review and analysis by NRR is required.
Unresolved item 346/88038-04CDRSl:
Evaluate and determine acceptance of the*
licensee's request, letter (serial number 1879) dated March 15, 1991, to downgrade the control room normal ventilation system (CRNVS) isolation status variable to Category 2, Type D.
This variable was initially designated by the
. licensee and approved in the SER as a Category 1, Type A variable. Subsequent regional inspections determined that this variaQle had pressure switches which did not meet the Category 1, Type A requirements.
RG 1.97 classifies this parameter as a Category 2, Type D variable.
The licensee committed to reevaluate the designation and determine if proper isolation of the circuit was maintained.
The licensee addressed this concern and concluded that reclassification of this variable as Category 2, Type D, is warranted.
Unresolved i~em 346/88038-08CDRSl:
Determine the adequacy of the licen~ee's method of implementing RG 1.97, Table 1, paragraph 8, which addresses equipment identification. For a number of Category land 2 variables, *in cas.es where only RG 1.97 qualified indicators are installed in an instrumentation channel, no special or unique identification of th~ RG 1.97 instrumentation is provided.
Paragraph 8 states, "Types A, 8, and C instruments designated as Categories 1 and 2 sh6uld be specifically identified with a common.designator on the.control panels so that.the operator can easily discern that they are intended for use under acciderit conditions." The licensee justified this method to minimize control board clutter.* The Region believes that this method meets the intent of RG 1.97, however, during subsequent discussions with Mr. Barry Marcus of NRR/SICB and the licensee during the regional inspection it was determined that this method required further review by NRR.
Direct ~ny questions concerning this subject to-either George Hausman at (708) 790-552l or Frank Jablonski at (708) 790-5555.
We consider this to be.a Priority 2 item with a completion date of January 16, 1993.
- Attachments:
- 1. Centerion Energy Letter S/N 1738 dated March 19, 1990
- 2. Centerion Energy Letter S/N 1879 dated March 15, 1991 See Attached Distribution-Riii Riii Hubert -J. Miller, Director Division of Reactor Saf_ety Riii Riii
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Riii Jab~nski 10/ i~/92 ts'::
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J. A. Zwolinski cc w/attachments:
J. B. Hopkins, NRR A. G. Hansen, NRR B. S. Marcus, NRR S. F. Newberry, NRR DCD/DCB{RIDS) 3