United States Nuclear Regulatory Commission - Protecting People and the Environment

All BWR Applicants for an Operating License and Holders of Operating Licenses for Grand Gulf, Lasalle and Susquehanna (Generic Letter No. 83-24)


                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                           WASHINGTON, D.C.  20555

                                June 29, 1983


ALL BWR APPLICANTS FOR AN OPERATING LICENSE AND HOLDERS OF OPERATING 
LICENSES FOR GRAND GULF, LASALLE AND SUSQUEHANNA 

Gentlemen: 

Subject:  TMI Task Action Plan Item I.G.1, "Special Low Power Testing and 
          Training," Recommendations for BWRs (Generic Letter 83-24) 


The present licensing process is a two-step process for which Task Action 
Plan Item I.G.1, as quoted from NUREG-0694, requires applicants for low 
power operating licenses to: 

     "Define and commit to a special low power testing program 
     approved by NRC to be conducted at power levels no greater 
     than 5 percent for the purposes of providing meaningful 
     technical information beyond that obtained in the normal 
     startup test program and to provide supplemental training." 

Prior to issuance of a full power license, low-power licensees are to: 

     "Supplement operator training by completing the special low-
     power test program.  Tests may be observed by other shifts 
     or repeated on other shifts to provide training to the 
     operators." 

PWRs, beginning with the licensing of Sequoyah 1 in 1980, have complied with
the I.G.1 requirements by conducting special testing and training in natural
circulation and simulated degraded AC power conditions.  The staff has not 
required "follow-on" units to conduct these exercises if they were performed
on the first unit and all licensed operators participated (e.g., Sequoyah 1 
and McGuire 1 conducted a I.G.1 program, but Sequoyah 2 and McGuire 2 did 
not). 

A meaningful I.G.1 program for BWRs comparable to the PWR program has not 
ben defined.  The BWR Owners' Group initial response to TMI Item I.G.1 was 
that it should not apply to BWRs as there are no additional tests analogous 
to the PWR tests which would provide meaningful technical information and 
supplemental operator training.  In a letter from D. B. Waters to D. G. 
Eisenhut dated February 4, 1981, the BWR Owners' Group subsequently proposed 
that BWR applicants meet the I.G.1 requirement by augmenting reactor 
operator participation in the initial test program and by some additional 
preoperational tests.  After review of this response, it was the staff's 
position that, to ensure compliance with I.G.1, the BWR applicants be 
required to do some additional startup testing beyond that called for by 
Regulatory    
.

                                    - 2 -

Guide 1.68 (and in addition to some "new" tests proposed by the BWR Owners' 
Group).  The staff subsequently requested BWR applicants to commit to the 
recommendations of the Owners' Group and, in addition, to perform a 
"Simulated Loss of All A-C Power" (Station Blackout-SBO) test.  The 
objective of the SBO test was to determine the temperature, pressure, and 
level responses and associated time constants of the reactor, drywell, 
containment, and vital spaces in event of a loss of heating, ventilation and 
air conditioning (HVAC) and cooling water, with decay heat being rejected to 
the suppression pool via the safety-relief valves.  Decay heat was to be 
simulated by nuclear heat produced at lower power, or the test could be 
postponed until later in the fuel cycle when sufficient decay heat was 
available. 

The staff has received commitments from each new operating license holder to
conduct the test during the first fuel cycle when decay heat is available. 
However, the Susquehanna licensee, Pennsylvania Power & Light (PP&L), has 
indicated that a simulated loss of all AC power test would subject the 
drywell to a severe temperature and humidity transient having the potential 
of damaging equipment in the drywell.  At least two other BWR licensees have
indicated that they would terminate the test prior to exceeding certain 
temperature limits in the drywell.  Upon further review of the basis for the
requirement, the practicalities and value of such a test, and the proposed 
augmented Owners Group program, we conclude that the SBO test does not 
provide significant new information to justify its performance.  
Furthermore, since one of the original criteria for I.G.1 special tests (as 
stated in the Sequoyah SER) is that the test must not pose a hazard to plant 
equipment, the staff now recommends that the SBO test be deleted from the 
BWR I.G.1 staff position. 

The staff finds that if it can be demonstrated that temperature and/or other
SBO test conditions would adversely impact and pose a hazard to plant 
equipment, the BWR Owner's Group recommendations by themselves would 
constitute compliance with Item I.G.1, since performance of the SBO test 
under less adverse conditions would not provide significant benefit for 
either training or design feedback.  Nor has the staff identified other 
special tests that should be performed at BWR's at this time.  Therefore, 
the staff concludes that, unless the need is identified in the resolution of 
Generic Issue A-44, "Station Blackout", the SBO test should not be required 
at BWR's. 

All applicants for an operating license are required to respond to this 
letter demonstrating the adverse impact the SBO test will have on their 
plant equipment, (i.e., a statement of conclusions and supportive evidence 
that loss of drywell cooling would pose a risk of damage to plant equipment 
in the drywell area) and confirming that the BWR Owner's Group 
recommendations will constitute compliance with Item I.G.1, or NRC 
consideration and documentation in the SER/SSER's.  The remaining two 
holders of operating licenses (i.e., for Grand Gulf and LaSalle) must 
provide a similar response to this letter for NRC consideration in deleting 
the SBO test license condition cited in their operating license. 


                               Darrell G. Eisenhut, Director 
                               Division of Licensing 
                               Office of Nuclear Reactor Regulation
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