ML20236H015
| ML20236H015 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 10/29/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236H013 | List: |
| References | |
| NUDOCS 8711030391 | |
| Download: ML20236H015 (4) | |
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l ENCLOSURE 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO TECHNICAL SPECIFICATIONS FOR HPCI AND RCIC OPERABILITY BOSTON EDISON COMPANY PILGRIM NUCLEAR POWER STATION DOCKET NO. 50-293
1.0 INTRODUCTION
Ry letter dated June 1,1987 (R. G. Bird, BEco, to V. S. Nuclear Regulatory Commission, with Attachments), the Boston Edison Company submitted revisions to the Technical Specifications (TS) for Pilgrim Station to revise the pressure range over which the high pressure coolant injection (HPCII and reactor core isolation cooling (RCIC) systems are required to be operable.
In support of the proposed change, the licensee submitted a General Electric (GE) report MDE-101-0986 " Evaluation of HPCI and RCIC Operability Requirements at low Vessel Pressure for the Pilgrim Nuclear Power Station" dated September 1986 (Attachment 3 to the base submittal document).
In response to a staff coninent on the original proposal, the licensee submitted in a [[letter::BECO-87-141, Application for Amend to License DPR-35 Revising 870601 Application to Change Tech Specs 3.5.C.1 & 3.5.D.1 to Specify,Quantitatively,Reactor Operating Conditions for Which HPCI & RCIC Required to Be Operable|letter dated September 1,1987]] (BECo 87-141) further information which more precisely defines the Limiting Conditions for Operation (LCO). The second submittal was a minor change for the purpose of clarification. The staff has reviewed the individual portions of the submittal and has prepared the following evaluation.
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2.0 EVALUATION P
2.1 Evaluation of HPCI and RCIC Operability Requirements at Low Reactor Vessel Pressure The present Pilgrim TS Limiting Conditions for Operation (I for the HPCI and RCIC subsystems specify operability requirements for R, ressure greater than 104 psig. The original basis for this pressure value was the ability of
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i the core spray to deliver full rated flow at the point the reactor pressure is I
reduced to 104 psig or'below.
The HPCI or RCIC operability down to that pressure was intended for mitigation of consequences of the small break size
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range of postulated loss of coolant accidents before the core spray flow l
becomes fully effective.
The evaluation provided by GE in MDE-101-0986, l
concludes that the safety analyses for Pilgrim Station take no credit for operation of either the HPCI or RCIC system below 150 psig. The licensee has proposed the Bases for the Core Spray and LPCI subsystem LCO he revised to clarify the assumptions made concerning the pressure requirements of the core spray cooling system to operate under the proposed conditions.
The design bases of both the HPCI and the RCIC systems for the Pilgrim Nuclear Station include coolant injection to the reactor vessel for vessel pressure between 1100 psig and 150 psig. The safety analyses for Pilgrim take no credit for operation of either the HPCI or RCIC systems below 150 psig either directly or indirectly.
Furthermore, none of the beneficial features of either HPCI or RCIC rely on operability below 150 psig. The-previous Bases section of the Pilgrim technical specifications incorrectly state that safety analyses take no credit for core spray flow into the vessel above 104 psig.
Revising this statement avoids incorrect inference regarding HPCI or RCIC operability requirements.
Based on our review of MDE-101-0986 and determination of the continued coverage by the plant safety systems for all break sizes under the proposed change, the staff finds the change from 104 psig to 150 psig acceptable.
The documented safety analysis of GE necessitates an accompanying change in the Bases Section for the subject LCOs.
1 The original proposed change (BEco letter of June 1,1987) in the HPCi/RCIC operability TS was to remove the requirement that HPCI land RCIC be operable
" prior to reactor startup from a Cold Condition" and replace it with required operability when " steam is being produced". This requirement also stipulates I
I that the RPV pressure be greater than 150 psig.
In order to more precisely define the plant condition for the LCO, the licensee presented a follow-up modification (BECo letter of September 1,1987) which replaced the words "when steam is being produced" with the words "and reactor coolant temperature
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is greater than 365 F".
The basis for this modification includes a statement that neither the HPCI or RCIC are needed to be operable during reactor vessel hydrotesting at high reactor vessel pressure and low reactor vessel temperature.
The clarification proposed by BECo -in their letter of September 1,1987 l
reduces the risk of ambiguity in interpreting the Technical Specifications and is, therefore, acceptable.
'2.2 Technical Specification Changes The Pilgrim Technical Specification changes resulting from the accepted proposal are as follows:
I (1) Specification 3.5.C.1, 3.5.C.3, 3.5.D.1 and 3.5.D.3:
The low pressure operability requirement for the HPCI and RCIC systems was changed from 104 psig to 150 psig.
This change is acceptable.
(2) Specifications 3.5.C.1 and 3.5.D.1:
These specifications are revised to clarify that HPCI/RCIC operability is required at reactor vessel pressures greater than 150 psig and reactor coolant temperature greater than 365 F.
This change is acceptable.
(3) Bases Section 3.5.A:
This section is changed to reflect the updated Pilgrim Station accident analysis concerning the core spray system. This change is acceptable.
(4) Bases Sections 3.5.C and 3.5.D:
The licensee has proposed changes to these Bases sections to support the modified LCOs. The staff has reviewed the Bases changes and found them acceptable.
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The page changes identified in the licensee's submittal of June 1, 1987 and supplemental submittal of September 1,1987 contain the acceptable revisions.
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3.0
SUMMARY
As a result of our review, which is described in Section 2.0 of this evaluation, we conclude that the proposed Technical Specification changes to revise the pressure range over which the HPCI and RCIC are required to be operable are acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
S This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff had dPtermined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, the amendment meets the eligibility criteria for categoricalexclusionsetforthin10CFR651.22(c)(9).
Pursuant to 10 CFR 651.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
We have concluded, based on the considerations discussed above, that (1) l there is reasonable assurance that the health and safety of the public will j
not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations,
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and the issuance of this amendment will not be inimical to the common defense j
and security or to the health and safety of the public.
l Principal Contributor:
M. McCoy, SRX8 Dated: October 29, 1987 l
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