ML22013A296

Trp 74 St. Lucie SLRA - Breakout Questions

ML22013A296
Person / Time
Site:	Saint Lucie
Issue date:	12/21/2021
From:	Office of Nuclear Reactor Regulation
To:
Rodriguez-Luccioni H
References
EPID L-2021-SLR-0002, L-2021-SLR-0002
Download: ML22013A296 (6)

Text

St. Lucie SLRA: Breakout Questions SLRA Section 3.5.2.2, Further Evaluation of Aging Management as Recommended by NUREG-2192 TRP: 074, Concrete

Note: Breakout Questions are provided to the applicant and will be incorporated into the publicly -available audit report.

Technical Reviewer George Wang 1 2 /07 /2021 Technical Branch Chief Joseph Colaccino 12/ 20/2021 Breakout Session Date/Time To be filled in by PM

Applicant Staff NRC staff To be filled out by PM during breakout

Question SLRA Section SLRA Background / Issue Discussion Question / Request Outcome of Discussion Number Page (As applicable/needed) 1 3.5.2.2.1.2 3.5 -21 SRP-SLR Section states that 1. Clarify the degradation Subsection CC-3440 of ASME code, threshold temperature limits of Table 3.5.2 - 1 2.5-80 Section III, Division 2, specifies the the ACI standards.

concrete temperature limits for normal operation or any other long-term 2. Clarify the actual general period. (i.e., general area temperature area temperature and local 150 °F and local area temperature area temperature.

200 °F) 3. Explain how the elevated SLRA Section 3.5.2.2.1.2 states temperature (264 oF) in localized hotspots are limited in area containment vessel is and are designed to be maintained adequately managed.

below the degradation threshold temperature limits of the ACI 4. Explain why aging effect for standards. However, it is unclear Table 2 line items (Note I whats the degradation threshold cited): penetrations

temperature limits of the ACI (mechanical), thermal standards used. insulation (type I hot penetrations) is not applicable SLRA AMR item 3.5.1-003 in Table in SLRA Table 3.5.2-1.

3.5-1 states that as described in the UFSAR and consistent with the 5. Clarify whether thermal current renewed licenses, insulation for Type III (semi -

temperatures of containment hot) penetrations is subject to penetrations are below the allowable aging management review.

general and local temperature thresholds for reduction of strength 6. Discuss the plan to u pdate and modulus by design. Hot (Type I) the SLRA as necessary.

penetration assemblies include insulation. This insulation has an insulate (thermal) function for SLR and is addressed in Table 3.5.2-1.

However, SLRA AMR item 3.5.1-048 in Table 3.5-1 states that there have been no instances of elevated temperatures for PSL plant structures other than containment, and PSL Unit 1 UFSAR Section 3.8.2.1.2 states that temperature coincident with design and maximum pressure design pressure is 264 oF, and design pressure and temperature as included in the purchase specification maximum calculated LOCA pressure and temperature are 38.4 psig and 259°F, respectively. PSL Unit 2 UFSAR Section 3.8.2.3.1 also listed temperatures for the design of the containment vessel and penetrations, in which some of them are 264 oF. It appears that there is elevated

temperature in the containment vessel.

SLRA Table 3.5.2-1 cites note I for penetrations (mechanical), thermal insulation (type I hot penetrations),

which aging effect for these components is not applicable.

However, SLRA Section 3.5.2.2.1.2 states that Type I (hot) penetration assemblies are insulated to limit Containment Vessel nozzle thermal stresses that also serve to limit Shield Building concrete temperatures. It appears that thermal insulation (type I hot penetrations) is subject to AMR.

SLRA Type III (semi-hot) penetrations are designed to accommodate moderate thermal movements. Type III penetrations include blowdown, letdown, charging, safety injection, shutdown cooling, RCP bleed-off, and integrated leak rate test (ILRT) lines.

However, the staff could not locate Table 2 AMR line item for thermal insulation (type III semi-hot penetrations).

2 3.5.2.2.2.1.2 3.5-28 SLRA Sections 3.5.2.2.2.1.2 and 1. Clarify whether 3.5.2.2.2.3.2 3.5-31 3.5.2.2.2.3.2 state that the Structures enhancement to the Monitoring AMP has been refined, Structures Monitoring based on industry/fleet information, to program shall be provided on include visual examination for the visual examination for patterned cracking, darkened crack patterned cracking, darkened edges, water ingress and crack edges, water ingress misalignment that would be indicative and misalignment that would

of reaction with aggregates, such as be indicative of reaction with alkali silica reaction (ASR) and alkali aggregates.

carbonate reaction (ACR), and includes opportunistic inspection of 2. Clarify whether pattern inaccessible concrete locations. cracking or crazed concrete However, the staff could not locate cracking were identified on the information of ASR inspection in other buildings besides the procedure ADM-17.32. Turbine Building and Reactor Auxiliary Building that we During our on-site audit, the staff observed during the on-site identified pattern cracking or crazed audit.

concrete cracking on roof slabs of Turbine Building and Reactor 3. Clarify if accessible Auxiliary Building. The staff also concrete areas had exhibit ed reviewed AR 01693560 and AR visual indications of aggregate 01725652, but these OEs have not reactions, as described in the been discussed in SLRA. SRP-SLR sections 3.5.3.2.2.1.2 and SRP-SLR Section 3.5.3.2.2.1.2 and 3.5.2.2.2.3.2, and state if ASR 3.5.3.2.2.3.2 states that a plant-is an applicable aging effect at specific evaluation or program is the site.

required if (1) reactivity tests or petrographic examinations of concrete samples identify reaction with aggregates, or (2) accessible concrete exhibits visual indications of aggregate reactions, such as map or patterned cracking, alkali -silica gel exudations, surface staining, expansion causing structural deformation, relative movement or displacement, or misalignment/distortion of attached components. However, SLRA sections 3.5.2.2.2.1.2 and 3.5.2.2.2.3.2 did not state if

accessible concrete had exhibited visual indications of aggregate reactions, as described in the SRPSLR, and/or stated if ASR is an applicable aging effect at the site.

3 3.5.2.2.2.1.4 3.5-29 SLRA Section 3.5.2.2.2.1.4 states that Clarify whether evaluation on 3.5.2.2.2.3.3 3.5-31 leaching has been observed several all observed leaching is times in the Unit 1 RAB ECCS Room. conducted to conclude that the observed leaching of SLRA Section 3.5.2.2.2.3.3 also calcium hydroxide and states leaching OE for concrete carbonation in accessible components at the intake structure, areas has no impact on the UHS dam and the concrete covered intended function of the dike walls at the intake structure. concrete structure.

SRP-SLR Section 3.5.3.2.2.1.4 guidance states that a plant-specific AMP is not required for the reinforced concrete exposed to flowing water if evaluation determined that the observed leaching of calcium hydroxide and carbonation in accessible areas has no impact on the intended function of the concrete structure. However, the staff could not locate the evaluation for accessing observed leaching of calcium hydroxide and carbonation in accessible areas

4 3.5.2.2.2.2 3.5 -29 SLRA Section 3.5.2.2.2.2 states that 1. Clarify general concrete local hot spots for concrete temperatures and local area penetrations outside containment concrete temperatures in any were not evaluated, and insulation on

process piping with temperatures portion of the concrete above 200 oF is included in the scope Groups 1-5 structures.

of SLR to assist in maintaining local concrete temperatures. The aging 2. Clarify whether tests and/or management of this insulation is calculations are available to provided by the PSL External evaluate the reduction in Surfaces Monitoring of Mechanical strength and modulus Components AMP. It is unclear whats of elasticity and these the elevated temperature and how reductions are applied to the aging effect for insulation on process design calculations when piping with temperatures above 200 concrete temperatures oF is managed. exceed the specified temperature limits.

SPR-SLR Section 3.5.3.2.2.2 3. Clarify Table 2 item for the guidance states a plant-specific evaluation should be performed if any insulation for high-portion of the concrete Groups 1-5 temperature piping (greater structures exceeds specified than 200 oF) managed by the temperature limits ( i.e., general External Surfaces Monitoring temperature greater than 150 °F and of Mechanical Components local area temperature greater than AMP. Explain how this 200 °F). Higher temperatures may be elevated temperature is allowed if tests and/or calculations are adequately managed.

provided to evaluate the reduction in 4. Discuss the plan to update strength and modulus SLRA as necessary.

of elasticity and these reductions are applied to the design calculations.

It appears that SLRA lacks details of OE regarding concrete temperatures and their aging management.