ML20096H531
| ML20096H531 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 05/20/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20096H528 | List: |
| References | |
| NUDOCS 9205270277 | |
| Download: ML20096H531 (5) | |
Text
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UNITED STATES 3
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.I NUCLEAR REGULATORY COMMISSION
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SATETY EVALUATION BY THE OffiqE OF NUCLEAR REACTOR REiVLATION RELATED TO AMENDHENT NO.180TO FACILITY OPERATING LIWiSE DPR-57 AND AMENDMENT NO.121 TO FACillTY OPLRATihG LICENSE NPF-5 9
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L olN 1. H W n hUCLEAR PLAhl. UNil5 1 A G 2 DOCKET NOS. 50-32LAMD 50-M5 1.0 INTRODVCTION By letter dated October 14, 1991 (Reference 1), Georgia Power Company, et al.
(the licensee), requested amendments to facility Operating License Nos. DPR-57 and NPF-5 for Edwin I. Hatch Nuclear Plant, Units 1 and 2.
The proposed amendments would change the Technical Specifications (TS) and associated Bases related to the removal of the Rod Sequence Control System (RSCS), operation of the Rod Worth Minimizer (RWM), and correct minor administrative items associated with the above changes.
2.0 DISCUSSION The RSCS restricts rod movement to minimize the individual worth of control rods to lessen the consequences of a Rod Drop Accident (RDA).
Control rod movement is restricted through the use of rod select, insert, and withdrawal blocks.
The RSCS is a hardwired (as caposed to a computer controlled),
redundant backup to the RWM.
It is somewhat independent of the RWM in terms of direct inputs and outputs but the two systems are similar and compatible and have the same intent.
The RSCS and RWM are designed to monitor and block when necessary operator control rod selection, withdrawal and insertion actions, and thus assist in preventing significant control rod pattern errors which could lead to a control rod with a high reactivity worth (if dropped).
A significant sattern error is one of several abnormal events all of which must occur to aave an RDA which might exceed fuel energy density limit criteria for the event.
It was designed only for possible mitigation of the RDA and is active only during low power operation (currently generally less than 10 or 20 percent power) when an RDA might be significant, it provides rod blocks on detection of a significent pattern error.
It does not prevent an RDA. A similar pattern control function is also performed by the RWM, a computer controlled system.
All reactors having an RSCS also have an RWM.
9205270277 920520 PDR ADOCK 05000321 P
. In August 1986, the LWR Owner's Group (BWROG) in ccoperation with General Electric proposed an Amendment 17 to GESTAR 11 (References 2 and 3) which would eliminate the requirement for the RSCS and retain the RWM but lower the setpoint for turnoff (during startup) or turnon (during shutdown) from 20 to 10 percent. The NRC staff review concluded that the proposed changes were acceptable, and approved Amendment 17, but imposed several additional requirements which would be necessary to implement the changes.
The staff safety analysis and the additional requirements were provided in an attachment to Reference 4.
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(2) The occasional necessary use of a second operator replacement should be strengthened by a utility review of relevant procedures, related forms and quality control to assure that the second operator provides an effective and truly independent monitoring process.
A discussion of this review should accompany the request for RSCE removal.
(3)
Rod patterns used should be at least equivalent to Banked Positiou Withdrawal Sequence (BPWS) patterns.
3.0 [VAlVAT LOB The licensee has propose'
.nges to several TS and associated Bases related to three categories discussed above.
(Reduction of the RWM setpoint to 10 percent has been previously approved for Hatch 1 and 2.)
These changes are:
A.
Elimination of the RSCS requirea B.
Increased administrative control of RWM operability (intended to result in decreased use of the second operator as a substitute for the RWM).
The licensee has also discussed the procedures for second operator actions, when required, to ensure independent monitoring of the control rod patterns.
BPWS control rod natterns are already required by the 15.
However, this requirement has been reemphasized in several of the IS changes.
C.
Administrative changes deleting unnecessary text and reformatting, and error correctivos.
The NRC staff review and basis for approval of the removal of the RSCS, as proposed by the licensee in sections of the submittal relating to topic A, is provided in Reference 4, The proposed changes f all w'hin the scope of that staff review and approval.
The present staff review
.he proposed TS changes that implement these operational changes conciudes that they are appropriate, clearly stated and are acceptable.
. The licensee has increased the administrative control of the RWM, as required in the staff review of RSCS removal.
The proposed revision to the TS requires the RWH to be operable at the beginning of each startup, with only one exception per year.
This follows the pattern of previously approved RWM TS for BWR 3 operation (discussed in Reference 4) and previous reviews for RSCS removal (e.g., Limerick).
These have been found to provide the. desired improvement in reliability for the system. Also, as required, the TS and procedures for the use of a second operator (when the RWH is inoperable) have seen reviewed by the licensee and have been discussed in the submittal, and appear from the staff review to previde e suitaH e indeendent check on the rcc c;*
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Inc a ng., m re.m.,s are in accord with the staff requirements of Reference 4 and are acceptable, and the proposed changes to the TS and Bases appropriately implement the changes.
Hatch 1 and Hatch 2 TS have different formats, specification numbering and specification language, and therefore details of the changes are different.
However, the content of the changes is similar.
The principal changes are to the RWM and RSCS TS.
Other changes are secondary, and primarily to cecommodate the RSCS removal.
The following TS changes have been proposed and they are all acceptable.
(1) Hatch I and 2:
The Index is changed because of changed or eliminated titles.
(2) Hatch I and 2:
The Bases for Limiting Safety System Settings have references to the RSCS removed.
(3)
Hatch 1:
TS 3.3.B.1 has an administrative error corrected.
(4)
Hatch 2:
TS 3.1.3.6 has references to the RSCS removed.
(5) Hatch 2:
TS 3/4.1.3.7 (Control Rod Position Indication) has requirements for the full-in and full-out indicators removed since they were only required for the RSCS.
(6) Hatch 1:
TS 3/4.3.G.1, arid Hatch 2:
TS 3/4.1.4 (the RWM TS) have the improved requirements for administrative control, discussed above, added to the specification.
(7) Hatch 1:
TS 3/4.3.G.2, and Hatch 2:
TS 3/4.1.4.2 (the RSCS TS) are i
removed.
l (8)
Hatch 1:
TS 3/4.3.G.2 is returned as a TS on Special Test l
Exceptions, and Hatch 2:
TS 3/4.10.2 (Special Test Exception, l
"RSCS") is changed to "RWH" and all reference to the RSCS is i
removed.
The previous RSCS relaxations of requirements for special j
tests are changed to second operator verification requirements.
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. (9) Hatch 1:
Bases 3.3.G and J (References), and Hatch 2:
Bases 3/4.1.4 (and related references) and 3/4.10.2 are changed to correspond to the revised TS.
In conclusion, the NRC staff has reviewed the reports submitted by the licensee for flatch 1 and 2 proposing TS changes relating to the removal of the RSCS. Based on this review, we have concluded that appropriate documentation was submitted and the proposed TS changes satisfy staff positions and requirtments in these areas.
Operation in the modes proposed for Hatch 1 and 2 is acceptable.
4.0 'JA:
- wsRT AT P'i In accordance with the Comission's regulations, the Georgia State official was notified of the proposed issuance of the amendments.
The State official had no coments.
5.0 MYRONMENTAL CONSIDERATION The amendments change requirements with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, end that there is no signifia. ant increase in it.dividual or cumulative occupational radiation exposure. The Comission has previously isst:ed a proposed finding that the amendments involve no significant hazards consideration, and there has been no public coment on such finding (57 FR 13132).
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 LONCLUSION The Comission has concluded, based on the considerations discussed above, i
that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Comission's regulations, and (3) the issuance of the an,endments will not be inimical to the comon defense and security or to the health and safety of the public.
Principal Contributor: Howard J. Richings, NRR, SRXB Date:
May 20, 1992 l
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. REFERENCES I
i 1.
Letter and enclosures from J. T. Beckham, Georgia Power Company, to USNRC, dated October 14, 1991, " Request to Revise Technical Specifications to Eliminate the Rod Sequence Control System."
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2.
Letter and enclosures from T. A. Pickens, BWR Owners' Group to G. Lainas.
NRC, dat<.d Auctst 15,1030, "Amendncnt 17 to GE t ic en:it n 0 t
lH DE-240!I-P- A.
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NEDE-240ll-P-A-9. September 1988, " General Electric Standard Application for Reactor Fuel," (CESTAR II).
4.
Letter from A.-Thadani NRC, to J. Charnley, General Electric, dated December 27, 1987, " Acceptance for Referencing of Licensing Topical Report NEDE-240ll-P-A, Revision 8, Amendment 17."
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