ML20136E692
| ML20136E692 | |
| Person / Time | |
|---|---|
| Issue date: | 01/10/1984 |
| From: | Mattson R Office of Nuclear Reactor Regulation |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20136E696 | List: |
| References | |
| FOIA-97-104, REF-GTECI-AS, REF-GTECI-B-60, TASK-B-60, TASK-OR TAC-52325, NUDOCS 8401180046 | |
| Download: ML20136E692 (6) | |
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- R. Mattson l T. Spets i D. Eisenhut j Harold R. Denton. Otractor L. Rubenstein M m0RANDUM FOR: Office of Nuclear Reactor Regulation C. Berlinger i
j Roger J. Mattson. Ofrector L. Phillips
/ N: Division of Systems Integration R. Lobel l
CENERIC ISSUE B-60. LOOSE PART5 M l
SUBJECT:
FOR OPERATING REACTORS (TACS 52325) l Integration has The Core Performance Branch of the Division of Systemslicy for ba reviewed the Generic Issue 8-60 to evaluate our pol t ry Guide 1 i
imp 1 mentationsystems monitoring of ReLPMS) (gufor a operating o reactors. h ization to send a l
prepared a briefing package for CRGRnitoring taff review a aut or requesting i program to j
generic report evaluating letter directing conformance of itseachloose parts licensee mo to subm l
the regulatory guide.pending the CRGR decisionbecause:
fit requirement on the generic l
i i Gtnna steam generator tube rupture ffective LPMS will event. procee we have no basis to support a finding that anf accidents 4
I e l I (a) i j result in any significant reduction in the risk o .
i public; d as part of It appears that an LPMS requirement will issuetnot be impose (b) the resolution of the steam generator incentive tube rupture l i to persuade ln i
(c) we believe that there is suffletant econom clicen tarily and some have done so; and to review i for all i
{d) the staff does not have sufficient available operating reactors. onitoring l
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Nevertheless, we continue to believe that a onomic loosebens- par.s mffect A
! program conforming to Regulatory Guide 1,133 damage is e a contribution to reactor safety margins in
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i l . j Roger J. Mattson g n 09 0 ! and reactor downtime. This conviction is supported by recent operating
- experience and it is expected that future events will continue to provide evidence of the value of an effective loose parts monitoring j program.
We have completed our review of Generic Issue B-60 and ou'.' recomendations
- follow
i j (1) The staff should continue to require license applicants to incorporate j an LPMS conforming to Regulatory Guide 1.133 into their plant < design as required by Standard Review Plan Section 4.4. (2) The staff should continue to monitor loose part events and evaluate l their impact on reactor safety. For those events where an effective ! loose parts monitoring program is an important consideration to the j continued safe operation of a reactor or a generte group of reactors. 1 the staff should require infomation concerning the loose parts j monitoring programs for those reactors. ! (3) The staff should encourage licensees to maintain effective loose j part monitoring programs and should provide available technical infomation or perfom technical evaluations when warranted. { (4) The enclosed letter should be sent to all licensees; the letter recommends that licensees review their loose parts monitoring
- programs on a voluntary basis and infoms them of our position.
1 This letter will also complete the action indicated by the Imple-mentation Section D of Regulatory Guide 1.133. Since it does not i impose any requir sents and does not require response by the j licensees, we do not believe that approval by OMB or CRGR is
- needed.
This memorandum completes our action on Generic !ssue 8-60. The Directors of Licensing and safety Technc' gy have already concurred in these reconmendations. If you concur in these recosnendations, we l j request your approval for the Division of Licensing to issue the en-closed letter to all licensees. ,,, vdtrfe Roger J. Maton l Roger J. Mattson, Otrector Division of Systems Integration ]
Enclosure:
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l . . Roger J. Mattson i i l and reactor downtime. This conviction is supported by recent operating experience and it is expected that future events will continue to 3 Provide evidence of the value of an effective loose parts monitoring
- program.
' 1 l We have completed our review of Generic Issue 8-60 and our reconnendations i follow: l (1) The staff should continue to require license applicants to incorporate j sn LPMS conforming to Regulatory Guide 1.133 into their plant design as required by Standard Review Plan Section 4.4. I i (2) The staff should continue to monitor loose part events and evaluate l l their impact on reactor safety. For those events where an effective loose parts monitoring program is an important consideration to the continued safe operation of a reactor or a generic group of reactors. ! the staff should require information concerning the loose parts ! monitoring programs for those reactors. I (3) The staff should encourage licensees to maintain effective loose part monitoring programs and should provide available technical information or perform technical evaluations when warranted. (4) The enclosed letter should be sent to all licensees; the letter recommends that licensees review their loose parts monitoring programs on a voluntary basis and informs them of our position. This letter will also complete the action indicated by the Imple-mentation Section D of Regulatory Guide 1.133. Since it does not impose any requirements and does not require response by the licensees, we do not believe that approval by OMB or CRGR is needed. This memorandum completes our action on Generic issue 8-60. If you concur in these recommendations, we request your approval for the Division of Licensing to issue the enclosed letter to all licensees. Roger J. Mattson, Director Division of Systems Integration
Enclosure:
As stated cc: H. Denton D. Eisenhut T. Spets DSI:CPB
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s I LETTER TO LICENSEES ! 1 \ i Regulatory Guide 1.133 Revision 1 " Loose Part Detection Program for f the Primary System of Light Water-Cooled Reactors " May 1981, in its l[ Implementation Section 0, states: "A letter will be s?nt to the licensee j { i for each operating plant requesting that each licensee complete a review of his loose part detection program and make any appropriate provisions j f , fur equipment and program revisions." The purpose of this letter is to
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l l i j inform each operating reactor licensee of the NRC position resulting from our study of the need for a loose part monitoring system (LPH5) f backfit requirement. Design guidance and review criteria for loose part detection prmrams were oeweloped under NRC Generic Issue B-60, which resulted in publi-cation of Regulatory Guide 1.133. All operating license applications
; under review by the staff after January 1,1978 bave been reviewed for conformance to Regulatory Guide 1.133, which was available in draf t form at that tine. The remaining issue associated with B-50 concerned the backfit implementation of Regulatory Guide 1.133. Revision 1 to oper-ating reactors. This was expected to have primary impact on reactor.
licensed prior to January 1, 1978, when the criteria and licensing commitments to loose part monitoring programs were not well defined. The issue was broadened to include the role of LPMS in the prevention of steam generator tube rupture events when operating experience revealed that detectable loose perts in either the primary or secondary side of steam generators could cause severe demage leading to ruptcre of steam generator tubes. We have completed our review of the B-60 issues and have concluded that LPMS backfit for conformance to Regulatory Guide 1.133 will not be required for safety. The basis for our con-clusion is summarized in the discussion wt ich follows: An effective LPMS provides early indication of loose parts impacts in the reactor coolant system (RCS) and can provide diagnostic information to assist in the e'taluation of safety concerns regarding continued operation with loose parts. Early detection of loose parts can also
*e result in economic benefit by clerting the plant operaters to take
- appropriate actions to reduce the risk of consequential damage to i equiptent and components. There are indications that economic benefits can be derived not only from avoidance of the direct costs associated with equipment repair or replacement, but also by avoidance of replace-ment power costs associated with reactor downtime for repairs. In addition, many licensees having plants with loose parts or with a known design problem which could result in loose parts have cited an effective LPMS for detection of loose parts and reactor system anomalies as a partial justification for continued safe operation.
Based on our generic review of loose parts detection experiences, we are confident that a LPMS which generally conforms to the guidance of
- Regulatory Guide 1.133 with respect to equipment design, calibration and
- use is capable of detecting loose parts as small as four ounces.
Although the Regulatory Guide 1.133 guidelines were intended only for f the detection of loose metalli: parts in the primary side, we are aware that the accelerometer sensors located on the inlet plenum of a steam
- generator can detect loose part impact in either the primary or second-ary side, and that increasing the number of sensc,rs with spatial coverage on the steam generator may provide additional sensitivity for detection of loose parts in the secondary side. We are also aware that the loose parts monitoring programs for many operating reactors are not effective l due to eg'ilpment design, installation or calibration deficiencies or due to ineffective utilization of the system. However, we have concluded that the safety contribution of an LPMS in terms of risk reduction for radiological consequences to the general public is insufficient to justify an LPMS backfit requirement. Although a case can be made for the value of an LPMS in reducing the probability of some serious acci-dents such as steam generator tube rupture, reactor plants are designed to accomodate such accidents without serious radiological consequence to the public. We have also concluded that the potential economic l
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. 3 benefits that can be realized by avoidance of reactor downtime due to loose parts and loose part induced damage is sufficient incentive for an effective loose parts monitoring program to negate the need for a backfit requirement enforced by NRC review. Therefore, we will not require licensees for reactors licensed prior to January 1.1978 to conform to the guidelines of Regulatory Guide 1.133 or to submit their LPMS prograrr for staff review.
We recorrpend that each Itcensee review its loose parts monitoring program for conformance to the guidelines of Regulatory Guide 1.133 and I also consider the location of sensors on steam generators in a manner that will make them effective for detection of loose parts in both the primary and secondary coolant systems. We will continue to require I license appilcants to incorporate an LPMS conforming to Regulatory
', Guide 1.133 into their plant design.
This letter is provided for information purposes only. Actions based on the recommendations provided herein are voluntary and no response to the NRC or review by the NRC is required. N#"' aw.- w .,wasm 4}}